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Sample records for modeling individual effects

  1. Nonlinear mixed-effects modeling: individualization and prediction.

    Science.gov (United States)

    Olofsen, Erik; Dinges, David F; Van Dongen, Hans P A

    2004-03-01

    The development of biomathematical models for the prediction of fatigue and performance relies on statistical techniques to analyze experimental data and model simulations. Statistical models of empirical data have adjustable parameters with a priori unknown values. Interindividual variability in estimates of those values requires a form of smoothing. This traditionally consists of averaging observations across subjects, or fitting a model to the data of individual subjects first and subsequently averaging the parameter estimates. However, the standard errors of the parameter estimates are assessed inaccurately by such averaging methods. The reason is that intra- and inter-individual variabilities are intertwined. They can be separated by mixed-effects modeling in which model predictions are not only determined by fixed effects (usually constant parameters or functions of time) but also by random effects, describing the sampling of subject-specific parameter values from probability distributions. By estimating the parameters of the distributions of the random effects, mixed-effects models can describe experimental observations involving multiple subjects properly (i.e., yielding correct estimates of the standard errors) and parsimoniously (i.e., estimating no more parameters than necessary). Using a Bayesian approach, mixed-effects models can be "individualized" as observations are acquired that capture the unique characteristics of the individual at hand. Mixed-effects models, therefore, have unique advantages in research on human neurobehavioral functions, which frequently show large inter-individual differences. To illustrate this we analyzed laboratory neurobehavioral performance data acquired during sleep deprivation, using a nonlinear mixed-effects model. The results serve to demonstrate the usefulness of mixed-effects modeling for data-driven development of individualized predictive models of fatigue and performance.

  2. Multilevel Modeling of Individual and Group Level Mediated Effects.

    Science.gov (United States)

    Krull, J L; MacKinnon, D P

    2001-04-01

    This article combines procedures for single-level mediational analysis with multilevel modeling techniques in order to appropriately test mediational effects in clustered data. A simulation study compared the performance of these multilevel mediational models with that of single-level mediational models in clustered data with individual- or group-level initial independent variables, individual- or group-level mediators, and individual level outcomes. The standard errors of mediated effects from the multilevel solution were generally accurate, while those from the single-level procedure were downwardly biased, often by 20% or more. The multilevel advantage was greatest in those situations involving group-level variables, larger group sizes, and higher intraclass correlations in mediator and outcome variables. Multilevel mediational modeling methods were also applied to data from a preventive intervention designed to reduce intentions to use steroids among players on high school football teams. This example illustrates differences between single-level and multilevel mediational modeling in real-world clustered data and shows how the multilevel technique may lead to more accurate results.

  3. Estimation of Nonlinear Dynamic Panel Data Models with Individual Effects

    Directory of Open Access Journals (Sweden)

    Yi Hu

    2014-01-01

    Full Text Available This paper suggests a generalized method of moments (GMM based estimation for dynamic panel data models with individual specific fixed effects and threshold effects simultaneously. We extend Hansen’s (Hansen, 1999 original setup to models including endogenous regressors, specifically, lagged dependent variables. To address the problem of endogeneity of these nonlinear dynamic panel data models, we prove that the orthogonality conditions proposed by Arellano and Bond (1991 are valid. The threshold and slope parameters are estimated by GMM, and asymptotic distribution of the slope parameters is derived. Finite sample performance of the estimation is investigated through Monte Carlo simulations. It shows that the threshold and slope parameter can be estimated accurately and also the finite sample distribution of slope parameters is well approximated by the asymptotic distribution.

  4. Effects of uncertainty in model predictions of individual tree volume on large area volume estimates

    Science.gov (United States)

    Ronald E. McRoberts; James A. Westfall

    2014-01-01

    Forest inventory estimates of tree volume for large areas are typically calculated by adding model predictions of volumes for individual trees. However, the uncertainty in the model predictions is generally ignored with the result that the precision of the large area volume estimates is overestimated. The primary study objective was to estimate the effects of model...

  5. A Nonlinear Mixed Effects Model for the Prediction of Natural Gas Consumption by Individual Customers

    Czech Academy of Sciences Publication Activity Database

    Brabec, Marek; Konár, Ondřej; Pelikán, Emil; Malý, Marek

    2008-01-01

    Roč. 24, č. 4 (2008), s. 659-678 ISSN 0169-2070 R&D Projects: GA AV ČR 1ET400300513 Institutional research plan: CEZ:AV0Z10300504 Keywords : individual gas consumption * nonlinear mixed effects model * ARIMAX * ARX * generalized linear mixed model * conditional modeling Subject RIV: JE - Non-nuclear Energetics, Energy Consumption ; Use Impact factor: 1.685, year: 2008

  6. Oslo traffic study - part 2: quantifying effects of traffic measures using individual exposure modeling

    International Nuclear Information System (INIS)

    Clench-Aas, J.; Bartonova, A.; Klaeboe, R.; Kolbenstvedt, M.

    2000-01-01

    In quantifying the benefits of air pollution reduction measures, it is desirable to compare the size of the benefits with the effects of other individual confounding factors such as smoking or passive smoking. The effect of pollution is rarely very large and in order to quantify it, exposure estimating procedures must be as accurate as possible. Dispersion models, run for hourly time intervals and controlled by measurements, are therefore used to provide estimates for specific receptor points. Results of three consecutive cross-sectional investigations in an area of Oslo characterized by heavy traffic are presented. The study was designed to provide repeated information on the effects of traffic diversion measures on the self-reporting of symptoms of reduced health of 1100 adults living in Oslo. The principal source of air pollution in Oslo is vehicular traffic. The primary pollutants of interest are nitrogen dioxide (NO 2 ) and respirable particles (PM 2.5 and PM 10 ). The mean hourly concentration of exposure was estimated at each participant's home by means of a time-dependent finite dispersion model combined with subgrid models to describe the source contribution to the grid concentrations. The study controlled the confounding factors. Using the symptom fatigue, the study illustrates that by controlling the changes in population composition, estimated exposure-effect relationships for health symptoms allow the effect of the studied traffic measures on the population to be evaluated. Since the method is based on individual estimates of exposure to different pollutants, it allows standardizing the exposure to compare effects of different pollutants. The study offers a methodology that is useful in evaluating the benefits of measures by both being able to quantify and compare the effects of different compounds and effects on different population sub-groups. (author)

  7. Modelling the effects of environmental and individual variability when measuring the costs of first reproduction

    Directory of Open Access Journals (Sweden)

    Barbraud, C.

    2004-06-01

    Full Text Available How do animals balance their investment in young against their own chances to survive and reproduce in the future? This life–history trade–off, referred to as the cost of reproduction (Williams, 1966, holds a central place in life–history theory (Roff, 1992; Stearns, 1992; McNamara & Houston, 1996. Because individuals can only acquire a limited amount of energy, reproduction and survival as well as current and future reproduction are considered as functions competing for the same resources. In this framework, individuals may optimise life–history decisions. If the reproductive effort in one year leads to a loss in future reproductive output through decreased adult survival or reduced fecundity, then the optimal effort in the current season is less than the effort that would maximize the number of offspring produced in that season (Charnov & Krebs, 1974. There are at least two kinds of factors likely to confound the measurement of the costs of reproduction in the wild. First, there could be differences in the amount of energy individuals acquire and allocate to various functions. This phenotypic heterogeneity can mask or exacerbate individual allocation patterns when trends are averaged across a population (Vaupel & Yashin, 1985; McDonald et al., 1996; Cam & Monnat, 2000. Second, there could be variations in resource availability affecting energy acquisition and allocation. Theoretical models examining the optimal phenotypic balance between reproduction and survival under variable breeding conditions have investigated the influence of environmental stochasticity on the cost of reproduction in birds (Erikstad et al., 1998; Orzack & Tuljapurkar, 2001. However, there is little empirical evidence supporting these theoretical models. Here, we present analysis of the influence of experience, but also of the differential effects of environmental and individual variation on survival and future breeding probability. We address the question of the

  8. Modelling the propagation of effects of chronic exposure to ionising radiation from individuals to populations

    Energy Technology Data Exchange (ETDEWEB)

    Alonzo, F. [Laboratory of Environmental Modelling, DEI/SECRE/LME, Institute of Radioprotection and Nuclear Safety (IRSN), Cadarache, Building 159, BP3, 13115 St-Paul-lez-Durance Cedex (France); Laboratory of Radioecology and Ecotoxicology, DEI/SECRE/LRE, Institute of Radioprotection and Nuclear Safety (IRSN), Cadarache Building 186, BP3, 13115 St-Paul-lez-Durance Cedex (France)], E-mail: frederic.alonzo@irsn.fr; Hertel-Aas, T. [Department of Plant and Environmental Sciences, P.O. Box 5003, Norwegian University of Life Sciences, 1432 Aas (Norway); Gilek, M. [School of Life Sciences, Soedertoern University College, 14189 Huddinge (Sweden); Gilbin, R. [Laboratory of Radioecology and Ecotoxicology, DEI/SECRE/LRE, Institute of Radioprotection and Nuclear Safety (IRSN), Cadarache Building 186, BP3, 13115 St-Paul-lez-Durance Cedex (France); Oughton, D.H. [Department of Plant and Environmental Sciences, P.O. Box 5003, Norwegian University of Life Sciences, 1432 Aas (Norway); Garnier-Laplace, J. [Laboratory of Radioecology and Ecotoxicology, DEI/SECRE/LRE, Institute of Radioprotection and Nuclear Safety (IRSN), Cadarache Building 186, BP3, 13115 St-Paul-lez-Durance Cedex (France)

    2008-09-15

    This study evaluated the potential effect of ionising radiation on population growth using simple population models and parameter values derived from chronic exposure experiments in two invertebrate species with contrasting life-history strategies. In the earthworm Eisenia fetida, models predicted increasing delay in population growth with increasing gamma dose rate (up to 0.6 generation times at 11 mGy h{sup -1}). Population extinction was predicted at 43 mGy h{sup -1}. In the microcrustacean Daphnia magna, models predicted increasing delay in population growth with increasing alpha dose rate (up to 0.8 generation times at 15.0 mGy h{sup -1}), only after two successive generations were exposed. The study examined population effects of changes in different individual endpoints (including survival, number of offspring produced and time to first reproduction). Models showed that the two species did not respond equally to equivalent levels of change, the fast growing daphnids being more susceptible to reduction in fecundity or delay in reproduction than the slow growing earthworms. This suggested that susceptibility of a population to ionising radiation cannot be considered independent of the species' life history.

  9. Developing a new individualized 3-node model for evaluating the effects of personal factors on thermal sensation.

    Science.gov (United States)

    Davoodi, Farzin; Hasanzadeh, Hasan; Alireza Zolfaghari, Seyed; Maerefat, Mehdi

    2017-10-01

    Individual differences, such as weight, height, gender, age, and Basal Metabolic Rate (BMR), between human subjects can significantly affect body thermoregulatory mechanisms. Therefore, application of common population-based thermal comfort models cannot provide accurate results for an individual's thermal sensation. Based on the standard thermal models, including those of Fanger and Gagge, individual parameters are not considered in the evaluation of thermal sensations. Thus, these simplified standard models have some limitations under varied individual conditions. In this study, a new individualized thermal comfort model is presented on the basis of a simplified 3-node model. This model was developed by regarding the effects of individual characteristics, such as age, gender, Body Mass Index (BMI), and BMR on the thermal sensations of the bare and clothed parts of the body. A good agreement was found in the current model, which was verified based on the experimental data. In conclusion, the results indicated that the mean error in the prediction of skin temperature decreased from 1.2°C to 0.4°C when using the new individual model instead of a non-individualized 3-node model. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Generic linear mixed-effects individual-tree biomass models for ...

    African Journals Online (AJOL)

    Quantification of forest biomass is important for practical forestry and for scientific purposes. It is fundamental to develop generic individual-tree biomass models suitable for large-scale forest biomass estimation. However, compatibility of forest biomass estimates at different scales may become a problem. We developed ...

  11. Population modeling using harpacticoid copepods : Bridging the gap between individual-level effects and protection goals of environmental risk assessment

    OpenAIRE

    Lundström Belleza, Elin

    2014-01-01

    To protect the environment from contaminants, environmental risk assessment (ERA) evaluates the risk of adverse effects to populations, communities and ecosystems. Environmental management decisions rely on ERAs, which commonly are based on a few endpoints at the individual organism level. To bridge the gap between what is measured and what is intended for protection, individual-level effects can be integrated in population models, and translated to the population level. The general aim of th...

  12. Application of an Individual-Based Transmission Hazard Model for Estimation of Influenza Vaccine Effectiveness in a Household Cohort.

    Science.gov (United States)

    Petrie, Joshua G; Eisenberg, Marisa C; Ng, Sophia; Malosh, Ryan E; Lee, Kyu Han; Ohmit, Suzanne E; Monto, Arnold S

    2017-12-15

    Household cohort studies are an important design for the study of respiratory virus transmission. Inferences from these studies can be improved through the use of mechanistic models to account for household structure and risk as an alternative to traditional regression models. We adapted a previously described individual-based transmission hazard (TH) model and assessed its utility for analyzing data from a household cohort maintained in part for study of influenza vaccine effectiveness (VE). Households with ≥4 individuals, including ≥2 children hazards (PH) models. For each individual, TH models estimated hazards of infection from the community and each infected household contact. Influenza A(H3N2) infection was laboratory-confirmed in 58 (4%) subjects. VE estimates from both models were similarly low overall (Cox PH: 20%, 95% confidence interval: -57, 59; TH: 27%, 95% credible interval: -23, 58) and highest for children Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  13. Nonlinear mixed-effects (NLME diameter growth models for individual China-Fir (Cunninghamia lanceolata trees in Southeast China.

    Directory of Open Access Journals (Sweden)

    Hao Xu

    Full Text Available An individual-tree diameter growth model was developed for Cunninghamia lanceolata in Fujian province, southeast China. Data were obtained from 72 plantation-grown China-fir trees in 24 single-species plots. Ordinary non-linear least squares regression was used to choose the best base model from among 5 theoretical growth equations; selection criteria were the smallest absolute mean residual and root mean square error and the largest adjusted coefficient of determination. To account for autocorrelation in the repeated-measures data, we developed one-level and nested two-level nonlinear mixed-effects (NLME models, constructed on the selected base model; the NLME models incorporated random effects of the tree and plot. The best random-effects combinations for the NLME models were identified by Akaike's information criterion, Bayesian information criterion and -2 logarithm likelihood. Heteroscedasticity was reduced with two residual variance functions, a power function and an exponential function. The autocorrelation was addressed with three residual autocorrelation structures: a first-order autoregressive structure [AR(1], a combination of first-order autoregressive and moving average structures [ARMA(1,1] and a compound symmetry structure (CS. The one-level (tree NLME model performed best. Independent validation data were used to test the performance of the models and to demonstrate the advantage of calibrating the NLME models.

  14. Modeling Individual Differences in Within-Person Variation of Negative and Positive Affect in a Mixed Effects Location Scale Model Using BUGS/JAGS

    Science.gov (United States)

    Rast, Philippe; Hofer, Scott M.; Sparks, Catharine

    2012-01-01

    A mixed effects location scale model was used to model and explain individual differences in within-person variability of negative and positive affect across 7 days (N=178) within a measurement burst design. The data come from undergraduate university students and are pooled from a study that was repeated at two consecutive years. Individual…

  15. Multistate models for clustered duration data - An application to workplace effects on individual sickness absenteeism

    NARCIS (Netherlands)

    Lindeboom, Maarten; Kerkhofs, Marcel

    2000-01-01

    Sickness absenteeism figures show a relatively large amount of variation across firms and organizations, indicating substantial within-firm correlations between absenteeism records of individual workers. To study the role of firm-specific circumstances and workforce composition, we specify

  16. Performance of the marginal structural cox model for estimating individual and joined effects of treatments given in combination.

    Science.gov (United States)

    Lusivika-Nzinga, Clovis; Selinger-Leneman, Hana; Grabar, Sophie; Costagliola, Dominique; Carrat, Fabrice

    2017-12-04

    The Marginal Structural Cox Model (Cox-MSM), an alternative approach to handle time-dependent confounder, was introduced for survival analysis and applied to estimate the joint causal effect of two time-dependent nonrandomized treatments on survival among HIV-positive subjects. Nevertheless, Cox-MSM performance in the case of multiple treatments has not been fully explored under different degree of time-dependent confounding for treatments or in case of interaction between treatments. We aimed to evaluate and compare the performance of the marginal structural Cox model (Cox-MSM) to the standard Cox model in estimating the treatment effect in the case of multiple treatments under different scenarios of time-dependent confounding and when an interaction between treatment effects is present. We specified a Cox-MSM with two treatments including an interaction term for situations where an adverse event might be caused by two treatments taken simultaneously but not by each treatment taken alone. We simulated longitudinal data with two treatments and a time-dependent confounder affected by one or the two treatments. To fit the Cox-MSM, we used the inverse probability weighting method. We illustrated the method to evaluate the specific effect of protease inhibitors combined (or not) to other antiretroviral medications on the anal cancer risk in HIV-infected individuals, with CD4 cell count as time-dependent confounder. Overall, Cox-MSM performed better than the standard Cox model. Furthermore, we showed that estimates were unbiased when an interaction term was included in the model. Cox-MSM may be used for accurately estimating causal individual and joined treatment effects from a combination therapy in presence of time-dependent confounding provided that an interaction term is estimated.

  17. Effects of landscape composition and configuration on migrating songbirds: inference from and individual-based model

    Science.gov (United States)

    Emily Cohen; Scott Pearson; Frank Moore

    2014-01-01

    The behavior of long-distance migrants during stopover is constrained by the need to quickly and safely replenish energetic reserves. Replenishing fuel stores at stopover sites requires adjusting to unfamiliar landscapes with little to no information about the distribution of resources. Despite their critical importance to the success of songbird migration, the effects...

  18. Modelling the effect of climate change on recovery of acidified freshwaters. Relative sensitivity of individual processes in the MAGIC model

    Energy Technology Data Exchange (ETDEWEB)

    Wright, R.F. [Norwegian Institute for Water Research, Box 173, N-0411 Oslo (Norway); Aherne, J. [Environmental and Resources Studies Programme, Trent University, Peterborough, Ontario (Canada); Bishop, K.; Erlandsson, M. [Department of Environmental Assessment, Swedish Agricultural University, Box 7070, SE75007 Uppsala (Sweden); Camarero, L. [Centre d' Estudis Avancats de Blanes-CSIC, Acces Cala St. Francecs, 14, E-17300 Blanes (Spain); Cosby, B.J. [Department of Environmental Sciences, University of Virginia, Charlottesville, VA 22904-4123 (United States); Evans, C.D. [Centre for Ecology and Hydrology, Deiniol Road, Bangor, Gwynedd, LL57 2UP (United Kingdom); Forsius, M. [Finnish Environment Institute, Box140, FIN-00251 Helsinki (Finland); Hardekopf, D.W. [Institute for Environmental Studies, Charles University, Benatska 2, CZ-12801 Prague 2 (Czech Republic); Helliwell, R. [Macaulay Institute, Craigiebuckler, Aberdeen, AB15 8QH (United Kingdom); Hruska, J. [Czech Geological Survey, Klarov 3 CZ-11821 Prague (Czech Republic); Jenkins, A. [Centre for Ecology and Hydrology, Wallingford, OX 10 8BB (United Kingdom); Kopacek, J. [Hydrobiological Institute, AS CR and Faculty of Biological Sciences, USB, Na Sadkach 7, CZ-370 05 Ceske Budejovice (Czech Republic); Moldan, F. [Swedish Environmental Research Institute, Box 5302, SE-40014 Gothenburg (Sweden); Posch, M. [Netherlands Environmental Assessment Agency, PO Box 303, NL-3720 AH Bilthoven (Netherlands); Rogora, M. [CNR Institute for Ecosystem Study, Section of Hydrobiology and Ecology of Inland Waters, L. go Tonolli, I-28922 Verbania Pallanza (Italy)

    2006-07-15

    The MAGIC model was used to evaluate the relative sensitivity of several possible climate-induced effects on the recovery of soil and surface water from acidification. A common protocol was used at 14 intensively studied sites in Europe and eastern North America. The results show that several of the factors are of only minor importance (increase in pCO{sub 2} in soil air and runoff, for example), several are important at only a few sites (seasalts at near-coastal sites, for example) and several are important at nearly all sites (increased concentrations of organic acids in soil solution and runoff, for example). In addition changes in forest growth and decomposition of soil organic matter are important at forested sites and sites at risk of nitrogen saturation. The trials suggest that in future modelling of recovery from acidification should take into account possible concurrent climate changes and focus specially on the climate-induced changes in organic acids and nitrogen retention. (author)

  19. Individual and school level effects of perceived harm, perceived availability, and community size on marijuana use among 12th-grade students: a random effects model.

    Science.gov (United States)

    Swaim, Randall C

    2003-06-01

    A hierarchical linear model was used to estimate the individual and school level effects for marijuana use among a national sample of 12th-grade students. School effects were small in comparison to individual level effects, accounting for 2.9% of the variance in marijuana use. At the individual level, perceived harm, perceived availability, and their interaction were significant predictors, each of which varied randomly across schools. Among two school-level predictors, the normative environment for perceived harm was not significant, but normative perceived availability predicted level of marijuana use. The effect of perceived availability on marijuana use was stronger in larger, compared to smaller communities. Results are discussed in light of the use of random regression methods for identifying school-specific patterns of risk and protection for prevention planning.

  20. A Randomized Clinical Trial Investigating the Effect of a Healthcare Access Model for Individuals with Severe Psychiatric Disabilities.

    Science.gov (United States)

    Rogers, E Sally; Maru, Mihoko; Kash-MacDonald, Megan; Archer-Williams, Mariah; Hashemi, Lobat; Boardman, Judith

    2016-08-01

    We conducted a randomized trial to examine a model for integrating primary care into a community mental health setting. Two hundred individuals were recruited and randomly assigned to receive primary care delivered by a nurse practitioner (n = 94) or services-as-usual (n = 106), assessed on health and mental health outcomes, and followed for 12 months. Intent-to-Treat and exposure analyses were conducted and suggest that participants who engaged with the nurse practitioner experienced gains in perceptions of primary care quality. Health benefits accrued for individuals having receiving nurse practitioner services in a mental health setting to address primary care needs.

  1. Mathematical models of behavior of individual animals.

    Science.gov (United States)

    Tsibulsky, Vladimir L; Norman, Andrew B

    2007-01-01

    This review is focused on mathematical modeling of behaviors of a whole organism with special emphasis on models with a clearly scientific approach to the problem that helps to understand the mechanisms underlying behavior. The aim is to provide an overview of old and contemporary mathematical models without complex mathematical details. Only deterministic and stochastic, but not statistical models are reviewed. All mathematical models of behavior can be divided into two main classes. First, models that are based on the principle of teleological determinism assume that subjects choose the behavior that will lead them to a better payoff in the future. Examples are game theories and operant behavior models both of which are based on the matching law. The second class of models are based on the principle of causal determinism, which assume that subjects do not choose from a set of possibilities but rather are compelled to perform a predetermined behavior in response to specific stimuli. Examples are perception and discrimination models, drug effects models and individual-based population models. A brief overview of the utility of each mathematical model is provided for each section.

  2. The effect of education based on individual empowerment model on the quality of life in the menopause women in Zarandieh

    Directory of Open Access Journals (Sweden)

    mahmood Karimy

    2014-09-01

    Conclusion: The findings support the educational program designed based on empowerment model effects on quality of life, design and performance of similar educational program is recommended to promote the quality of life in menopausal women.

  3. Don't Think, Just Feel the Music: Individuals with Strong Pavlovian-to-Instrumental Transfer Effects Rely Less on Model-based Reinforcement Learning.

    Science.gov (United States)

    Sebold, Miriam; Schad, Daniel J; Nebe, Stephan; Garbusow, Maria; Jünger, Elisabeth; Kroemer, Nils B; Kathmann, Norbert; Zimmermann, Ulrich S; Smolka, Michael N; Rapp, Michael A; Heinz, Andreas; Huys, Quentin J M

    2016-07-01

    Behavioral choice can be characterized along two axes. One axis distinguishes reflexive, model-free systems that slowly accumulate values through experience and a model-based system that uses knowledge to reason prospectively. The second axis distinguishes Pavlovian valuation of stimuli from instrumental valuation of actions or stimulus-action pairs. This results in four values and many possible interactions between them, with important consequences for accounts of individual variation. We here explored whether individual variation along one axis was related to individual variation along the other. Specifically, we asked whether individuals' balance between model-based and model-free learning was related to their tendency to show Pavlovian interferences with instrumental decisions. In two independent samples with a total of 243 participants, Pavlovian-instrumental transfer effects were negatively correlated with the strength of model-based reasoning in a two-step task. This suggests a potential common underlying substrate predisposing individuals to both have strong Pavlovian interference and be less model-based and provides a framework within which to interpret the observation of both effects in addiction.

  4. A minimal limit-cycle model to profile movement patterns of individuals during agility drill performance: Effects of skill level.

    Science.gov (United States)

    Mehdizadeh, Sina; Arshi, Ahmed Reza; Davids, Keith

    2015-06-01

    Identification of control strategies during agility performance is significant in understanding movement behavior. This study aimed at providing a fundamental mathematical model for describing the motion of participants during an agility drill and to determine whether skill level constrained model components. Motion patterns of two groups of skilled and unskilled participants (n=8 in each) during performance of a forward/backward agility drill modeled as limit-cycles. Participant movements were recorded by motion capture of a reflective marker attached to the sacrum of each individual. Graphical and regression analyses of movement kinematics in Hooke's plane, phase plane and velocity profile were performed to determine components of the models. Results showed that the models of both skilled and unskilled groups had terms from Duffing stiffness as well as Van der Pol damping oscillators. Data also indicated that the proposed models captured on average 97% of the variance for both skilled and unskilled groups. Findings from this study revealed the movement patterning associated with skilled and unskilled performance in a typical forward/backward agility drill which might be helpful for trainers and physiotherapists in enhancing agility. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. A smoothed maximum score estimator for the binary choice panel data model with individual fixed effects and applications to labour force participation

    NARCIS (Netherlands)

    Charlier, G.W.P.

    1994-01-01

    In a binary choice panel data model with individual effects and two time periods, Manski proposed the maximum score estimator, based on a discontinuous objective function, and proved its consistency under weak distributional assumptions. However, the rate of convergence of this estimator is low (N)

  6. Individual tree diameter increment model for managed even-aged stands of ponderosa pine throughout the western United States using a multilevel linear mixed effects model

    Science.gov (United States)

    Fabian C.C. Uzoh; William W. Oliver

    2008-01-01

    A diameter increment model is developed and evaluated for individual trees of ponderosa pine throughout the species range in the United States using a multilevel linear mixed model. Stochastic variability is broken down among period, locale, plot, tree and within-tree components. Covariates acting at tree and stand level, as breast height diameter, density, site index...

  7. Modeling individual and collective opinion in online social networks: drivers of choice behavior and effects of marketing interventions

    NARCIS (Netherlands)

    Koster, S.E.; Langley, D.J.

    2013-01-01

    We investigate factors influencing choice behavior in online social networks. We use twitter data from a Dutch television talent show. In study one, we implement a nested conditional logit model with latent classes. We find heterogeneous effects. For two latent classes, cognitive factors most

  8. Multilevel mixed effects parametric survival models using adaptive Gauss-Hermite quadrature with application to recurrent events and individual participant data meta-analysis.

    Science.gov (United States)

    Crowther, Michael J; Look, Maxime P; Riley, Richard D

    2014-09-28

    Multilevel mixed effects survival models are used in the analysis of clustered survival data, such as repeated events, multicenter clinical trials, and individual participant data (IPD) meta-analyses, to investigate heterogeneity in baseline risk and covariate effects. In this paper, we extend parametric frailty models including the exponential, Weibull and Gompertz proportional hazards (PH) models and the log logistic, log normal, and generalized gamma accelerated failure time models to allow any number of normally distributed random effects. Furthermore, we extend the flexible parametric survival model of Royston and Parmar, modeled on the log-cumulative hazard scale using restricted cubic splines, to include random effects while also allowing for non-PH (time-dependent effects). Maximum likelihood is used to estimate the models utilizing adaptive or nonadaptive Gauss-Hermite quadrature. The methods are evaluated through simulation studies representing clinically plausible scenarios of a multicenter trial and IPD meta-analysis, showing good performance of the estimation method. The flexible parametric mixed effects model is illustrated using a dataset of patients with kidney disease and repeated times to infection and an IPD meta-analysis of prognostic factor studies in patients with breast cancer. User-friendly Stata software is provided to implement the methods. Copyright © 2014 John Wiley & Sons, Ltd.

  9. Individual tree height increment model for managed even-aged stands of ponderosa pine throughout the western United States using linear mixed effects models

    Science.gov (United States)

    Fabian Uzoh; William W. Oliver

    2006-01-01

    A height increment model is developed and evaluated for individual trees of ponderosa pine throughout the species range in western United States. The data set used in this study came from long-term permanent research plots in even-aged, pure stands both planted and of natural origin. The data base consists of six levels-of-growing stock studies supplemented by initial...

  10. Error propagation models to examine the effects of geocoding quality on spatial analysis of individual-level datasets.

    Science.gov (United States)

    Zandbergen, P A; Hart, T C; Lenzer, K E; Camponovo, M E

    2012-04-01

    The quality of geocoding has received substantial attention in recent years. A synthesis of published studies shows that the positional errors of street geocoding are somewhat unique relative to those of other types of spatial data: (1) the magnitude of error varies strongly across urban-rural gradients; (2) the direction of error is not uniform, but strongly associated with the properties of local street segments; (3) the distribution of errors does not follow a normal distribution, but is highly skewed and characterized by a substantial number of very large error values; and (4) the magnitude of error is spatially autocorrelated and is related to properties of the reference data. This makes it difficult to employ analytic approaches or Monte Carlo simulations for error propagation modeling because these rely on generalized statistical characteristics. The current paper describes an alternative empirical approach to error propagation modeling for geocoded data and illustrates its implementation using three different case-studies of geocoded individual-level datasets. The first case-study consists of determining the land cover categories associated with geocoded addresses using a point-in-raster overlay. The second case-study consists of a local hotspot characterization using kernel density analysis of geocoded addresses. The third case-study consists of a spatial data aggregation using enumeration areas of varying spatial resolution. For each case-study a high quality reference scenario based on address points forms the basis for the analysis, which is then compared to the result of various street geocoding techniques. Results show that the unique nature of the positional error of street geocoding introduces substantial noise in the result of spatial analysis, including a substantial amount of bias for some analysis scenarios. This confirms findings from earlier studies, but expands these to a wider range of analytical techniques. Copyright © 2012 Elsevier Ltd

  11. Effectiveness of Gross Model-Based Emotion Regulation Strategies Training on Anger Reduction in Drug-Dependent Individuals and its Sustainability in Follow-up.

    Science.gov (United States)

    Massah, Omid; Sohrabi, Faramarz; A'azami, Yousef; Doostian, Younes; Farhoudian, Ali; Daneshmand, Reza

    2016-03-01

    Emotion plays an important role in adapting to life changes and stressful events. Difficulty regulating emotions is one of the problems drug abusers often face, and teaching these individuals to express and manage their emotions can be effective on improving their difficult circumstances. The present study aimed to determine the effectiveness of the Gross model-based emotion regulation strategies training on anger reduction in drug-dependent individuals. The present study had a quasi-experimental design wherein pretest-posttest evaluations were applied using a control group. The population under study included addicts attending Marivan's methadone maintenance therapy centers in 2012 - 2013. Convenience sampling was used to select 30 substance-dependent individuals undergoing maintenance treatment who were then randomly assigned to the experiment and control groups. The experiment group received its training in eight two-hour sessions. Data were analyzed using analysis of co-variance and paired t-test. There was significant reduction in anger symptoms of drug-dependent individuals after gross model based emotion regulation training (ERT) (P emotion regulation strategies training. Based on the results of this study, we may conclude that the gross model based emotion regulation strategies training can be applied alongside other therapies to treat drug abusers undergoing rehabilitation.

  12. Assessing the effect of quantitative and qualitative predictors on gastric cancer individuals survival using hierarchical artificial neural network models.

    Science.gov (United States)

    Amiri, Zohreh; Mohammad, Kazem; Mahmoudi, Mahmood; Parsaeian, Mahbubeh; Zeraati, Hojjat

    2013-01-01

    ). Probabilities of survival were calculated using three neural network models with 3, 5, and 7 nodes in the hidden layer, and it has been observed that none of the predictions was significantly different from results with the Kaplan-Meier method and they appeared more comparable towards the last months (fifth year). However, we observed better accuracy using the neural network with 5 nodes in the hidden layer. Using the Cox proportional hazards and a neural network with 3 nodes in the hidden layer, we found enhanced accuracy with the neural network model. Neural networks can provide more accurate predictions for survival probabilities compared to the Cox proportional hazards mode, especially now that advances in computer sciences have eliminated limitations associated with complex computations. It is not recommended in order to adding too many hidden layer nodes because sample size related effects can reduce the accuracy. We recommend increasing the number of nodes to a point that increased accuracy continues (decrease in mean standard error), however increasing nodes should cease when a change in this trend is observed.

  13. Crosslinking with transglutaminase does not change metabolic effects of sodium caseinate in model beverage in healthy young individuals

    Directory of Open Access Journals (Sweden)

    Juvonen Kristiina R

    2012-06-01

    Full Text Available Abstract Background Postprandial metabolic and appetitive responses of proteins are dependent on protein source and processing technique prior to ingestion. Studies on the postprandial effects of enzymatic crosslinking of milk proteins are sparse. Our aim was to study the effect of transglutaminase (TG-induced crosslinking of sodium caseinate on postprandial metabolic and appetite responses. Whey protein was included as reference protein. Methods Thirteen healthy individuals (23.3 ± 1.1 y, BMI 21.7 ± 0.4 kg/m2 participated in a single-blind crossover design experiment in which the subjects consumed three different isovolumic (500 g pourable beverages containing either sodium caseinate (Cas, 29 g, TG-treated sodium caseinate (Cas-TG, 29 g or whey protein (Wh, 30 g in a randomized order. Blood samples were collected at baseline and for 4 h postprandially for the determination of plasma glucose, insulin and amino acid (AA concentrations. Gastric emptying (GE was measured using the 13 C-breath test method. Appetite was assessed using visual analogue scales. Results All examined postprandial responses were comparable with Cas and Cas-TG. The protein type used in the beverages was reflected as differences in plasma AA concentrations between Wh and Cas, but there were no differences in plasma glucose or insulin responses. A tendency for faster GE rate after Wh was detected. Appetite ratings or subsequent energy intake did not differ among the protein beverages. Conclusions Our results indicate that the metabolic responses of enzymatically crosslinked and native sodium caseinate in a liquid matrix are comparable, suggesting similar digestion and absorption rates and first pass metabolism despite the structural modification of Cas-TG.

  14. Bivalves: From individual to population modelling

    NARCIS (Netherlands)

    Saraiva, S.; van der Meer, J.; Kooijman, S.A.L.M.

    2014-01-01

    An individual based population model for bivalves was designed, built and tested in a 0D approach, to simulate the population dynamics of a mussel bed located in an intertidal area. The processes at the individual level were simulated following the dynamic energy budget theory, whereas initial egg

  15. Individual Hearing Loss: Characterization, Modelling, Compensation Strategies

    DEFF Research Database (Denmark)

    Santurette, Sébastien; Dau, Torsten; Christensen-Dalsgaard, Jakob

    2016-01-01

    It is well-established that hearing loss does not only lead to a reduction of hearing sensitivity. Large individual differences are typically observed among listeners with hearing impairment in a wide range of suprathreshold auditory measures. In many cases, audiometric thresholds cannot fully...... account for such individual differences, which make it challenging to find adequate compensation strategies in hearing devices. How to characterize, model, and compensate for individual hearing loss were the main topics of the fifth International Symposium on Auditory and Audiological Research (ISAAR...

  16. Individual model evaluation and probabilistic weighting of models

    International Nuclear Information System (INIS)

    Atwood, C.L.

    1994-01-01

    This note stresses the importance of trying to assess the accuracy of each model individually. Putting a Bayesian probability distribution on a population of models faces conceptual and practical complications, and apparently can come only after the work of evaluating the individual models. Moreover, the primary issue is open-quotes How good is this modelclose quotes? Therefore, the individual evaluations are first in both chronology and importance. They are not easy, but some ideas are given here on how to perform them

  17. Legacy effects of wildfire on stream thermal regimes and rainbow trout ecology: an integrated analysis of observation and individual-based models

    Science.gov (United States)

    Rosenberger, Amanda E.; Dunham, Jason B.; Neuswanger, Jason R.; Railsback, Steven F.

    2015-01-01

    Management of aquatic resources in fire-prone areas requires understanding of fish species’ responses to wildfire and of the intermediate- and long-term consequences of these disturbances. We examined Rainbow Trout populations in 9 headwater streams 10 y after a major wildfire: 3 with no history of severe wildfire in the watershed (unburned), 3 in severely burned watersheds (burned), and 3 in severely burned watersheds subjected to immediate events that scoured the stream channel and eliminated streamside vegetation (burned and reorganized). Results of a previous study of this system suggested the primary lasting effects of this wildfire history on headwater stream habitat were differences in canopy cover and solar radiation, which led to higher summer stream temperatures. Nevertheless, trout were present throughout streams in burned watersheds. Older age classes were least abundant in streams draining watersheds with a burned and reorganized history, and individuals >1 y old were most abundant in streams draining watersheds with an unburned history. Burned history corresponded with fast growth, low lipid content, and early maturity of Rainbow Trout. We used an individual-based model of Rainbow Trout growth and demographic patterns to determine if temperature interactions with bioenergetics and competition among individuals could lead to observed phenotypic and ecological differences among populations in the absence of other plausible mechanisms. Modeling suggested that moderate warming associated with wildfire and channel disturbance history leads to faster individual growth, which exacerbates competition for limited food, leading to decreases in population densities. The inferred mechanisms from this modeling exercise suggest the transferability of ecological patterns to a variety of temperature-warming scenarios.

  18. Real-time individualization of the unified model of performance.

    Science.gov (United States)

    Liu, Jianbo; Ramakrishnan, Sridhar; Laxminarayan, Srinivas; Balkin, Thomas J; Reifman, Jaques

    2017-12-01

    Existing mathematical models for predicting neurobehavioural performance are not suited for mobile computing platforms because they cannot adapt model parameters automatically in real time to reflect individual differences in the effects of sleep loss. We used an extended Kalman filter to develop a computationally efficient algorithm that continually adapts the parameters of the recently developed Unified Model of Performance (UMP) to an individual. The algorithm accomplishes this in real time as new performance data for the individual become available. We assessed the algorithm's performance by simulating real-time model individualization for 18 subjects subjected to 64 h of total sleep deprivation (TSD) and 7 days of chronic sleep restriction (CSR) with 3 h of time in bed per night, using psychomotor vigilance task (PVT) data collected every 2 h during wakefulness. This UMP individualization process produced parameter estimates that progressively approached the solution produced by a post-hoc fitting of model parameters using all data. The minimum number of PVT measurements needed to individualize the model parameters depended upon the type of sleep-loss challenge, with ~30 required for TSD and ~70 for CSR. However, model individualization depended upon the overall duration of data collection, yielding increasingly accurate model parameters with greater number of days. Interestingly, reducing the PVT sampling frequency by a factor of two did not notably hamper model individualization. The proposed algorithm facilitates real-time learning of an individual's trait-like responses to sleep loss and enables the development of individualized performance prediction models for use in a mobile computing platform. © 2017 European Sleep Research Society.

  19. Collaborative Model for Acceleration of Individualized Therapy of Colon Cancer

    Science.gov (United States)

    2015-12-01

    Award Number: W81XWH-11-1-0527 TITLE: Collaborative Model for Acceleration of Individualized Therapy of Colon Cancer PRINCIPAL INVESTIGATOR: Aik...AND SUBTITLE 5a. CONTRACT NUMBER Collaborative Model for Acceleration of Individualized Therapy of Colon Cancer 5b. GRANT NUMBER W81XWH-11-1-0527 5c...neck, lung, breast and colon malignancies, among others. In this preclinical study we assessed the antitumor effects of the novel Plk inhibitor, TAK

  20. Modelling individual temperature profiles from an isolated perfused bovine tongue

    NARCIS (Netherlands)

    Raaymakers, B. W.; Crezee, J.; Lagendijk, J. J.

    2000-01-01

    To predict the temperature distribution during hyperthermia treatments a thermal model that accounts for the thermal effect of blood flow is mandatory. The DIscrete VAsculature (DIVA) thermal model developed at our department is able to do so; geometrically described vessels are handled individually

  1. Effects of departing individuals on collective behaviors

    Science.gov (United States)

    Nishiyama, Yuta; Okuda, Shoma; Migita, Masao; Murakami, Hisashi; Tomaru, Takenori

    2017-07-01

    Utilizing living organisms' abilities is an effective approach to realize flexible and unconventional computing. One possible bio-inspired computer might be developed from animal collective research by clarifying collective behaviors. Therefore, it is important to reveal how collective animal behaviors emerge. In many studies, individuals departing from the other individualsare generally ignored. Is it not possible that such departing individuals contribute to the organization of such collectives? To investigate the effects of individuals departing from a collective against collective behaviors, we observed and analyzed the behaviors of 40 soldier crabs in four types of experimental arenas. The recorded behaviors demonstrate a temporally changing pattern and the existence of departing individuals. We analyzed the relationship between global activity and cohesion levels and verified the features of departing individuals. The results imply that departing individuals contribute to collective behaviors.

  2. Individualized Positron Emission Tomography–Based Isotoxic Accelerated Radiation Therapy Is Cost-Effective Compared With Conventional Radiation Therapy: A Model-Based Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Bongers, Mathilda L., E-mail: ml.bongers@vumc.nl [Department of Epidemiology and Biostatistics, VU University Medical Center, Amsterdam (Netherlands); Coupé, Veerle M.H. [Department of Epidemiology and Biostatistics, VU University Medical Center, Amsterdam (Netherlands); De Ruysscher, Dirk [Radiation Oncology University Hospitals Leuven/KU Leuven, Leuven (Belgium); Department of Radiation Oncology, GROW Research Institute, Maastricht University Medical Center, Maastricht (Netherlands); Oberije, Cary; Lambin, Philippe [Department of Radiation Oncology, GROW Research Institute, Maastricht University Medical Center, Maastricht (Netherlands); Uyl-de Groot, Cornelia A. [Department of Epidemiology and Biostatistics, VU University Medical Center, Amsterdam (Netherlands); Institute for Medical Technology Assessment, Erasmus University Rotterdam, Rotterdam (Netherlands)

    2015-03-15

    Purpose: To evaluate long-term health effects, costs, and cost-effectiveness of positron emission tomography (PET)-based isotoxic accelerated radiation therapy treatment (PET-ART) compared with conventional fixed-dose CT-based radiation therapy treatment (CRT) in non-small cell lung cancer (NSCLC). Methods and Materials: Our analysis uses a validated decision model, based on data of 200 NSCLC patients with inoperable stage I-IIIB. Clinical outcomes, resource use, costs, and utilities were obtained from the Maastro Clinic and the literature. Primary model outcomes were the difference in life-years (LYs), quality-adjusted life-years (QALYs), costs, and the incremental cost-effectiveness and cost/utility ratio (ICER and ICUR) of PET-ART versus CRT. Model outcomes were obtained from averaging the predictions for 50,000 simulated patients. A probabilistic sensitivity analysis and scenario analyses were carried out. Results: The average incremental costs per patient of PET-ART were €569 (95% confidence interval [CI] €−5327-€6936) for 0.42 incremental LYs (95% CI 0.19-0.61) and 0.33 QALYs gained (95% CI 0.13-0.49). The base-case scenario resulted in an ICER of €1360 per LY gained and an ICUR of €1744 per QALY gained. The probabilistic analysis gave a 36% probability that PET-ART improves health outcomes at reduced costs and a 64% probability that PET-ART is more effective at slightly higher costs. Conclusion: On the basis of the available data, individualized PET-ART for NSCLC seems to be cost-effective compared with CRT.

  3. Estimating police effectiveness with individual victimisation data

    NARCIS (Netherlands)

    Vollaard, B.; Koning, P.

    2005-01-01

    In this paper, we present evidence on the effect of greater numbers of police personnel on victimisation of crime and experience of nuisance. We make use of individual data from a Dutch victimisation survey unique in its size, duration and scope. By using individual victimisation data we provide

  4. A model approach to evaluate the effect of temperature and food concentration on individual life-history and population dynamics of Daphnia

    NARCIS (Netherlands)

    Rinke, K.; Vijverberg, J.

    2005-01-01

    We present a model framework for the simulation of growth and reproduction of Daphnia at varying conditions of food concentration and temperature. The core of our framework consists of an individual level model that simulates allocation of assimilated carbon into somatic growth, maintenance costs,

  5. A general method for assessing the effects of uncertainty in individual-tree volume model predictions on large-area volume estimates with a subtropical forest illustration

    Science.gov (United States)

    Ronald E. McRoberts; Paolo Moser; Laio Zimermann Oliveira; Alexander C. Vibrans

    2015-01-01

    Forest inventory estimates of tree volume for large areas are typically calculated by adding the model predictions of volumes for individual trees at the plot level, calculating the mean over plots, and expressing the result on a per unit area basis. The uncertainty in the model predictions is generally ignored, with the result that the precision of the large-area...

  6. Trajectories and models of individual growth

    Directory of Open Access Journals (Sweden)

    Arseniy Karkach

    2006-11-01

    Full Text Available It has long been recognized that the patterns of growth play an important role in the evolution of age trajectories of fertility and mortality (Williams, 1957. Life history studies would benefit from a better understanding of strategies and mechanisms of growth, but still no comparative research on individual growth strategies has been conducted. Growth patterns and methods have been shaped by evolution and a great variety of them are observed. Two distinct patterns - determinate and indeterminate growth - are of a special interest for these studies since they present qualitatively different outcomes of evolution. We attempt to draw together studies covering growth in plant and animal species across a wide range of phyla focusing primarily on the noted qualitative features. We also review mathematical descriptions of growth, namely empirical growth curves and growth models, and discuss the directions of future research.

  7. Modeling the effects of positive and negative mood on the ability to resist eating in obese and non-obese individuals.

    Science.gov (United States)

    Udo, Tomoko; Grilo, Carlos M; Brownell, Kelly D; Weinberger, Andrea H; Dileone, Ralph J; McKee, Sherry A

    2013-01-01

    This pilot study adapted a well-established drug self-administration paradigm to examine the effects of mood induction on the ability to resist high-calorie foods and subsequent food consumption differently in 15 obese individuals (40.0% women, BMI: 35.1±3.70) and 15 non-obese individuals (46.7% women, BMI: 23.0±1.96). Participants completed two laboratory sessions (positive vs. negative mood conditions) consisting of 3-hour food deprivation, followed by mood induction, and a 3-hour ad-lib eating period, where they were asked to choose between favorite high-calorie snacks and monetary reinforcement. Obese individuals were less able to resist eating and increased high-calorie food consumption during the positive mood condition than the negative condition. Non-obese individuals were less able to resist eating during the negative mood condition than the positive condition, but their total consumption was not affected by the mood conditions. In obese individuals, food craving was associated with less ability to resist eating and greater calorie consumption during the negative mood condition. This is the first study to experimentally demonstrate that mood state may increase vulnerability to food consumption by reducing the ability to resist eating. The ability to resist eating may be a novel dimension of eating behaviors that has a significant contribution to understanding mood-eating relationships. Copyright © 2012. Published by Elsevier Ltd.

  8. Modeling the Effects of Positive and Negative Mood on the Ability to Resist Eating in Obese and Non-obese Individuals

    Science.gov (United States)

    Udo, Tomoko; Grilo, Carlos M.; Brownell, Kelly D.; Weinberger, Andrea H.; DiLeone, Ralph J.; McKee, Sherry A.

    2013-01-01

    This pilot study adapted a well-established drug self-administration paradigm to examine the effects of mood induction on the ability to resist high-calorie foods and subsequent food consumption differently in 15 obese individuals (40.0% women, BMI: 35.1±3.70) and 15 non-obese individuals (46.7% women, BMI: 23.0±1.96). Participants completed two laboratory sessions (positive vs. negative mood conditions) consisting of 3-hour food deprivation, followed by mood induction, and a 3-hour ad-lib eating period, where they were asked to choose between favorite high-calorie snacks and monetary reinforcement. Obese individuals were less able to resist eating and increased high-calorie food consumption during the positive mood condition than the negative condition. Non-obese individuals were less able to resist eating during the negative mood condition than the positive condition, but their total consumption was not affected by the mood conditions. In obese individuals, food craving was associated with less ability to resist eating and greater calorie consumption during the negative mood condition. This is the first study to experimentally demonstrate that mood state may increase vulnerability to food consumption by reducing the ability to resist eating. The ability to resist eating may be a novel dimension of eating behaviors that has a significant contribution to understanding mood-eating relationships. PMID:23265400

  9. Integrating Individual-Based Indices of Contaminant Effects

    Directory of Open Access Journals (Sweden)

    Christopher L. Rowe

    2001-01-01

    Full Text Available Habitat contamination can alter numerous biological processes in individual organisms. Examining multiple individual-level responses in an integrative fashion is necessary to understand how individual health or fitness reflects environmental contamination. Here we provide an example of such an integrated perspective based upon recent studies of an amphibian (the bullfrog, Rana catesbeiana that experiences several, disparate changes when larval development occurs in a trace element�contaminated habitat. First, we present an overview of studies focused on specific responses of individuals collected from, or transplanted into, a habitat contaminated by coal combustion residues (CCR. These studies have reported morphological, behavioral, and physiological modifications to individuals chronically interacting with sediments in the CCR-contaminated site. Morphological abnormalities in the oral and tail regions in contaminant-exposed individuals influenced other properties such as grazing, growth, and swimming performance. Behavioral changes in swimming activities and responses to stimuli appear to influence predation risk in the contaminant-exposed population. Significant changes in bioenergetics in the contaminated habitat, evident as abnormally high energetic expenditures for survival (maintenance costs, may ultimately influence production pathways (growth, energy storage in individuals. We then present a conceptual model to examine how interactions among the affected systems (morphological, behavioral, physiological may ultimately bring about more severe effects than would be predicted if the responses were considered in isolation. A complex interplay among simultaneously occurring biological changes emerges in which multiple, sublethal effects ultimately can translate into reductions in larval or juvenile survival, and thus reduced recruitment of juveniles into the population. In systems where individuals are exposed to low concentrations of

  10. A system model of the effects of exercise on plasma Interleukin-6 dynamics in healthy individuals: Role of skeletal muscle and adipose tissue.

    Directory of Open Access Journals (Sweden)

    Micaela Morettini

    Full Text Available Interleukin-6 (IL-6 has been recently shown to play a central role in glucose homeostasis, since it stimulates the production and secretion of Glucagon-like Peptide-1 (GLP-1 from intestinal L-cells and pancreas, leading to an enhanced insulin response. In resting conditions, IL-6 is mainly produced by the adipose tissue whereas, during exercise, skeletal muscle contractions stimulate a marked IL-6 secretion as well. Available mathematical models describing the effects of exercise on glucose homeostasis, however, do not account for this IL-6 contribution. This study aimed at developing and validating a system model of exercise's effects on plasma IL-6 dynamics in healthy humans, combining the contributions of both adipose tissue and skeletal muscle. A two-compartment description was adopted to model plasma IL-6 changes in response to oxygen uptake's variation during an exercise bout. The free parameters of the model were estimated by means of a cross-validation procedure performed on four different datasets. A low coefficient of variation (<10% was found for each parameter and the physiologically meaningful parameters were all consistent with literature data. Moreover, plasma IL-6 dynamics during exercise and post-exercise were consistent with literature data from exercise protocols differing in intensity, duration and modality. The model successfully emulated the physiological effects of exercise on plasma IL-6 levels and provided a reliable description of the role of skeletal muscle and adipose tissue on the dynamics of plasma IL-6. The system model here proposed is suitable to simulate IL-6 response to different exercise modalities. Its future integration with existing models of GLP-1-induced insulin secretion might provide a more reliable description of exercise's effects on glucose homeostasis and hence support the definition of more tailored interventions for the treatment of type 2 diabetes.

  11. A system model of the effects of exercise on plasma Interleukin-6 dynamics in healthy individuals: Role of skeletal muscle and adipose tissue.

    Science.gov (United States)

    Morettini, Micaela; Palumbo, Maria Concetta; Sacchetti, Massimo; Castiglione, Filippo; Mazzà, Claudia

    2017-01-01

    Interleukin-6 (IL-6) has been recently shown to play a central role in glucose homeostasis, since it stimulates the production and secretion of Glucagon-like Peptide-1 (GLP-1) from intestinal L-cells and pancreas, leading to an enhanced insulin response. In resting conditions, IL-6 is mainly produced by the adipose tissue whereas, during exercise, skeletal muscle contractions stimulate a marked IL-6 secretion as well. Available mathematical models describing the effects of exercise on glucose homeostasis, however, do not account for this IL-6 contribution. This study aimed at developing and validating a system model of exercise's effects on plasma IL-6 dynamics in healthy humans, combining the contributions of both adipose tissue and skeletal muscle. A two-compartment description was adopted to model plasma IL-6 changes in response to oxygen uptake's variation during an exercise bout. The free parameters of the model were estimated by means of a cross-validation procedure performed on four different datasets. A low coefficient of variation (dynamics during exercise and post-exercise were consistent with literature data from exercise protocols differing in intensity, duration and modality. The model successfully emulated the physiological effects of exercise on plasma IL-6 levels and provided a reliable description of the role of skeletal muscle and adipose tissue on the dynamics of plasma IL-6. The system model here proposed is suitable to simulate IL-6 response to different exercise modalities. Its future integration with existing models of GLP-1-induced insulin secretion might provide a more reliable description of exercise's effects on glucose homeostasis and hence support the definition of more tailored interventions for the treatment of type 2 diabetes.

  12. The effects of individual housing on mice and rats

    DEFF Research Database (Denmark)

    Krohn, Thomas Cæcius; Sørensen, Dorte Bratbo; Ottesen, Jan Lund

    2006-01-01

    and auditory contact, and thus not totally isolated. During the fifties and sixties several studies claimed to show physiological and behavioural differences between individually and group housed rats and mice. The so-called ‘Isolation Syndrome’ characterised by changes in corticosterone levels, metabolism......, growth, and behaviour was introduced, rather as a model for psychoneurosis than through any concern for animal welfare. Today, it is often stated as common knowledge in laboratory animal science textbooks that individual housing as well as isolation of rats and mice has an effect on physiology...... and behaviour. It is, however, unclear whether this effect actually impairs animal welfare. The aim of this paper is to analyse studies on individual housing of mice and rats to evaluate whether there is documented proof that individual housing affects welfare, and, alternatively whether it is possible to house...

  13. A flexible mixed-effect negative binomial regression model for detecting unusual increases in MRI lesion counts in individual multiple sclerosis patients.

    Science.gov (United States)

    Kondo, Yumi; Zhao, Yinshan; Petkau, John

    2015-06-15

    We develop a new modeling approach to enhance a recently proposed method to detect increases of contrast-enhancing lesions (CELs) on repeated magnetic resonance imaging, which have been used as an indicator for potential adverse events in multiple sclerosis clinical trials. The method signals patients with unusual increases in CEL activity by estimating the probability of observing CEL counts as large as those observed on a patient's recent scans conditional on the patient's CEL counts on previous scans. This conditional probability index (CPI), computed based on a mixed-effect negative binomial regression model, can vary substantially depending on the choice of distribution for the patient-specific random effects. Therefore, we relax this parametric assumption to model the random effects with an infinite mixture of beta distributions, using the Dirichlet process, which effectively allows any form of distribution. To our knowledge, no previous literature considers a mixed-effect regression for longitudinal count variables where the random effect is modeled with a Dirichlet process mixture. As our inference is in the Bayesian framework, we adopt a meta-analytic approach to develop an informative prior based on previous clinical trials. This is particularly helpful at the early stages of trials when less data are available. Our enhanced method is illustrated with CEL data from 10 previous multiple sclerosis clinical trials. Our simulation study shows that our procedure estimates the CPI more accurately than parametric alternatives when the patient-specific random effect distribution is misspecified and that an informative prior improves the accuracy of the CPI estimates. Copyright © 2015 John Wiley & Sons, Ltd.

  14. Stochastic wind turbine modeling for individual pitch control

    DEFF Research Database (Denmark)

    Thomsen, Sven Creutz; Niemann, Hans Henrik; Poulsen, Niels Kjølstad

    2009-01-01

    and a simplified description of the aerodynamics with sufficient detail to design model-based individual pitch controllers. Combined with a simplified model of the wind turbine, we exemplify how to use the model elements to systematically design an individual pitch controller. The design is investigated...

  15. Individualized Biomathematical Modeling of Fatigue and Performance

    Science.gov (United States)

    2008-05-29

    waking period are omitted in order to avoid confounds from sleep inertia. Gray bars indicate scheduled sleep periods . (b) Performance predictions...i.e., total sleep deprivation; black). Light gray areas indicate nocturnal sleep periods . In this illustration, the bifurcation point is set to...confounds from sleep inertia. Gray bars indicate scheduled sleep periods . (b) Corresponding performance predictions according to the new model

  16. Seasonal patterns in growth, blood consumption, and effects on hosts by parasitic-phase sea lampreys in the Great Lakes: an individual-based model approach

    Science.gov (United States)

    Madenjian, Charles P.; Cochran, Philip A.; Bergstedt, Roger A.

    2003-01-01

    An individual-based model (IBM) was developed for sea lamprey (Petromyzon marinus) populations in the Laurentian Great Lakes. The IBM was then calibrated to observed growth, by season, for sea lampreys in northern Lake Huron under two different water temperature regimes: a regime experienced by Seneca-strain lake trout (Salvelinus namaycush) and a regime experienced by Marquettestrain lake trout. Modeling results indicated that seasonal blood consumption under the Seneca regime was very similar to that under the Marquette regime. Simulated mortality of lake trout directly due to blood removal by sea lampreys occurred at nearly twice the rate during August and September under the Marquette regime than under the Seneca regime. However, cumulative sea lamprey-induced mortality on lake trout over the entire duration of the sea lamprey's parasitic phase was only 7% higher for the Marquette regime compared with the Seneca regime. Thus, these modeling results indicated that the strain composition of the host (lake trout) population was not important in determining total number of lake trout deaths or total blood consumption attributable to the sea lamprey population, given the sea lamprey growth pattern. Regardless of water temperature regime, both blood consumption rate by sea lampreys and rate of sea lamprey-induced mortality on lake trout peaked in late October. Elevated blood consumption in late October appeared to be unrelated to changes in water temperature. The IBM approach should prove useful in optimizing control of sea lampreys in the Laurentian Great Lakes.

  17. Individual-based model for radiation risk assessment

    Science.gov (United States)

    Smirnova, O.

    A mathematical model is developed which enables one to predict the life span probability for mammals exposed to radiation. It relates statistical biometric functions with statistical and dynamic characteristics of an organism's critical system. To calculate the dynamics of the latter, the respective mathematical model is used too. This approach is applied to describe the effects of low level chronic irradiation on mice when the hematopoietic system (namely, thrombocytopoiesis) is the critical one. For identification of the joint model, experimental data on hematopoiesis in nonirradiated and irradiated mice, as well as on mortality dynamics of those in the absence of radiation are utilized. The life span probability and life span shortening predicted by the model agree with corresponding experimental data. Modeling results show the significance of ac- counting the variability of the individual radiosensitivity of critical system cells when estimating the radiation risk. These findings are corroborated by clinical data on persons involved in the elimination of the Chernobyl catastrophe after- effects. All this makes it feasible to use the model for radiation risk assessments for cosmonauts and astronauts on long-term missions such as a voyage to Mars or a lunar colony. In this case the model coefficients have to be determined by making use of the available data for humans. Scenarios for the dynamics of dose accumulation during space flights should also be taken into account.

  18. A model of involvement in work-related learning and development activity: the effects of individual, situational, motivational, and age variables.

    Science.gov (United States)

    Maurer, Todd J; Weiss, Elizabeth M; Barbeite, Francisco G

    2003-08-01

    Eight hundred employees from across the U.S. work force participated in a detailed 13-month longitudinal study of involvement in learning and development activities. A new model was posited and tested in which the hypothesized sequence was as follows: worker age --> individual and situational antecedents --> perceived benefits of participation and self-efficacy for development --> attitudes toward development --> intentions to participate --> participation. The results depict a person who is oriented toward employee development as having participated in development activities before, perceiving themselves as possessing qualities needed for learning, having social support for development at work and outside of work, being job involved, having insight into his or her career, and believing in the need for development, in his or her ability to develop skills and to receive intrinsic benefits from participating. Given the aging work force, a detailed treatment of age differences in development is presented. Implications for new ideas in practice and future research are discussed.

  19. Mental Models, Magical Thinking, And Individual Differences

    Directory of Open Access Journals (Sweden)

    Phil Turner

    2009-01-01

    Full Text Available Broadly, there are two mutually exclusive accounts of how people (non-specialist users reason about and conceptualize interactive technology. The first is based on classical cognitive psychology and is characterized by the term mental model. The second, drawing on concepts from social cognition, observes that people often anthropomorphize technology. We argue that people are able to exhibit both of these quite different styles of cognition, which Baron-Cohen has described as systemizing and empathizing. The former is associated with the drive to analyze, explore, and construct a system, whereas the latter is the ability to spontaneously tune into another’s thoughts and feelings. The propensity to systemize might give rise to a mental model, while the empathizing tendency might tend to anthropomorphize technology. We present an empirical study that lends support for the above position.

  20. Modeling individual animal histories with multistate capture–recapture models

    Science.gov (United States)

    Lebreton, Jean-Dominique; Nichols, James D.; Barker, Richard J.; Pradel, Roger; Spendelow, Jeffrey A.

    2009-01-01

    Many fields of science begin with a phase of exploration and description, followed by investigations of the processes that account for observed patterns. The science of ecology is no exception, and recent decades have seen a focus on understanding key processes underlying the dynamics of ecological systems. In population ecology, emphasis has shifted from the state variable of population size to the demographic processes responsible for changes in this state variable: birth, death, immigration, and emigration. In evolutionary ecology, some of these same demographic processes, rates of birth and death, are also the determinants of fitness. In animal population ecology, the estimation of state variables and their associated vital rates is especially problematic because of the difficulties in sampling such populations and detecting individual animals. Indeed, early capture–recapture models were developed for the purpose of estimating population size, given the reality that all animals are not caught or detected at any sampling occasion. More recently, capture–recapture models for open populations were developed to draw inferences about survival in the face of these same sampling problems. The focus of this paper is on multi‐state mark–recapture models (MSMR), which first appeared in the 1970s but have undergone substantial development in the last 15 years. These models were developed to deal explicitly with biological variation, in that animals in different “states” (classes defined by location, physiology, behavior, reproductive status, etc.) may have different probabilities of survival and detection. Animal transitions between states are also stochastic and themselves of interest. These general models have proven to be extremely useful and provide a way of thinking about a remarkably wide range of important ecological processes. These methods are now at a stage of refinement and sophistication where they can readily be used by biologists to tackle a wide

  1. LINKAGES: An Individual-based Forest Ecosystem Biogeochemistry Model

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This model product contains the source codes for version 1 of the individual-based forest ecosystem biogeochemistry model LINKAGES and two subsequent...

  2. LINKAGES: An Individual-based Forest Ecosystem Biogeochemistry Model

    Data.gov (United States)

    National Aeronautics and Space Administration — This model product contains the source codes for version 1 of the individual-based forest ecosystem biogeochemistry model LINKAGES and two subsequent versions as...

  3. Individual-based modeling of ecological and evolutionary processes

    NARCIS (Netherlands)

    DeAngelis, D.L.; Mooij, W.M.

    2005-01-01

    Individual-based models (IBMs) allow the explicit inclusion of individual variation in greater detail than do classical differential and difference equation models. Inclusion of such variation is important for continued progress in ecological and evolutionary theory. We provide a conceptual basis

  4. Investigating the effect of recruitment variability on length-based recruitment indices for antarctic krill using an individual-based population dynamics model.

    Directory of Open Access Journals (Sweden)

    Stéphane Thanassekos

    Full Text Available Antarctic krill (Euphausia superba; herein krill is monitored as part of an on-going fisheries observer program that collects length-frequency data. A krill feedback management programme is currently being developed, and as part of this development, the utility of data-derived indices describing population level processes is being assessed. To date, however, little work has been carried out on the selection of optimum recruitment indices and it has not been possible to assess the performance of length-based recruitment indices across a range of recruitment variability. Neither has there been an assessment of uncertainty in the relationship between an index and the actual level of recruitment. Thus, until now, it has not been possible to take into account recruitment index uncertainty in krill stock management or when investigating relationships between recruitment and environmental drivers. Using length-frequency samples from a simulated population - where recruitment is known - the performance of six potential length-based recruitment indices is assessed, by exploring the index-to-recruitment relationship under increasing levels of recruitment variability (from ±10% to ±100% around a mean annual recruitment. The annual minimum of the proportion of individuals smaller than 40 mm (F40 min, % was selected because it had the most robust index-to-recruitment relationship across differing levels of recruitment variability. The relationship was curvilinear and best described by a power law. Model uncertainty was described using the 95% prediction intervals, which were used to calculate coverage probabilities and assess model performance. Despite being the optimum recruitment index, the performance of F40 min degraded under high (>50% recruitment variability. Due to the persistence of cohorts in the population over several years, the inclusion of F40 min values from preceding years in the relationship used to estimate recruitment in a given year

  5. Modeling Systematicity and Individuality in Nonlinear Second Language Development: The Case of English Grammatical Morphemes

    Science.gov (United States)

    Murakami, Akira

    2016-01-01

    This article introduces two sophisticated statistical modeling techniques that allow researchers to analyze systematicity, individual variation, and nonlinearity in second language (L2) development. Generalized linear mixed-effects models can be used to quantify individual variation and examine systematic effects simultaneously, and generalized…

  6. Individual Differences in Animal Stress Models: Considering Resilience, Vulnerability, and the Amygdala in Mediating the Effects of Stress and Conditioned Fear on Sleep.

    Science.gov (United States)

    Wellman, Laurie L; Fitzpatrick, Mairen E; Hallum, Olga Y; Sutton, Amy M; Williams, Brook L; Sanford, Larry D

    2016-06-01

    To examine the REM sleep response to stress and fearful memories as a potential marker of stress resilience and vulnerability and to assess the role of the basolateral amygdala (BLA) in mediating the effects of fear memory on sleep. Outbred Wistar rats were surgically implanted with electrodes for recording EEG and EMG and with bilateral guide cannulae directed at the BLA. Data loggers were placed intraperitoneally to record core body temperature. After recovery from surgery, the rats received shock training (ST: 20 footshocks, 0.8 mA, 0.5-s duration, 60-s interstimulus interval) and afterwards received microinjections of the GABAA agonist muscimol (MUS; 1.0 μM) to inactivate BLA or microinjections of vehicle (VEH) alone. Subsequently, the rats were separated into 4 groups (VEH-vulnerable (VEH-Vul; n = 14), VEH-resilient (VEH-Res; n = 13), MUS-vulnerable (MUS-Vul; n = 8), and MUS-resilient (MUS-Res; n = 11) based on whether or not REM was decreased, compared to baseline, during the first 4 h following ST. We then compared sleep, freezing, and the stress response (stress-induced hyperthermia, SIH) across groups to determine the effects of ST and fearful context re-exposure alone (CTX). REM was significantly reduced on the ST day in both VEH-Vul and MUS-Vul rats; however, post-ST MUS blocked the reduction in REM on the CTX day in the MUS-Vul group. The VEH-Res and MUS-Res rats showed similar levels of REM on both ST and CTX days. The effects of post-ST inactivation of BLA on freezing and SIH were minimal. Outbred Wistar rats can show significant individual differences in the effects of stress on REM that are mediated by BLA. These differences in REM can be independent of behavioral fear and the peripheral stress response, and may be an important biomarker of stress resilience and vulnerability. © 2016 Associated Professional Sleep Societies, LLC.

  7. Individualism in plant populations: using stochastic differential equations to model individual neighbourhood-dependent plant growth.

    Science.gov (United States)

    Lv, Qiming; Schneider, Manuel K; Pitchford, Jonathan W

    2008-08-01

    We study individual plant growth and size hierarchy formation in an experimental population of Arabidopsis thaliana, within an integrated analysis that explicitly accounts for size-dependent growth, size- and space-dependent competition, and environmental stochasticity. It is shown that a Gompertz-type stochastic differential equation (SDE) model, involving asymmetric competition kernels and a stochastic term which decreases with the logarithm of plant weight, efficiently describes individual plant growth, competition, and variability in the studied population. The model is evaluated within a Bayesian framework and compared to its deterministic counterpart, and to several simplified stochastic models, using distributional validation. We show that stochasticity is an important determinant of size hierarchy and that SDE models outperform the deterministic model if and only if structural components of competition (asymmetry; size- and space-dependence) are accounted for. Implications of these results are discussed in the context of plant ecology and in more general modelling situations.

  8. A paradox in individual-based models of populations

    NARCIS (Netherlands)

    Van der Meer, J.

    2016-01-01

    The standard dynamic energy budget model is widely used to describe the physiology of individual animals. It assumes thatassimilation rate scales with body surface area, whereas maintenance rate scales with body volume. When the model is usedas the building block of a population model, only limited

  9. A paradox in individual-based models of populations

    NARCIS (Netherlands)

    van der Meer, J.

    2016-01-01

    The standard dynamic energy budget model is widely used to describe the physiology of individual animals. It assumes that assimilation rate scales with body surface area, whereas maintenance rate scales with body volume. When the model is used as the building block of a population model, only

  10. ASSESSING INDIVIDUAL PERFORMANCE ON INFORMATION TECHNOLOGY ADOPTION: A NEW MODEL

    OpenAIRE

    Diah Hari Suryaningrum

    2012-01-01

    This paper aims to propose a new model in assessing individual performance on information technology adoption. The new model to assess individual performance was derived from two different theories: decomposed theory of planned behavior and task-technology fit theory. Although many researchers have tried to expand these theories, some of their efforts might lack of theoretical assumptions. To overcome this problem and enhance the coherence of the integration, I used a theory from social scien...

  11. A Network-Individual-Resource Model for HIV Prevention

    Science.gov (United States)

    Johnson, Blair T.; Redding, Colleen A.; DiClemente, Ralph J.; Mustanski, Brian S.; Dodge, Brian M.; Sheeran, Paschal; Warren, Michelle R.; Zimmerman, Rick S.; Fisher, William A.; Conner, Mark T.; Carey, Michael P.; Fisher, Jeffrey D.; Stall, Ronald D.; Fishbein, Martin

    2014-01-01

    HIV is transmitted through dyadic exchanges of individuals linked in transitory or permanent networks of varying sizes. To optimize prevention efficacy, a complementary theoretical perspective that bridges key individual level elements with important network elements can be a foundation for developing and implementing HIV interventions with outcomes that are more sustainable over time and have greater dissemination potential. Toward that end, we introduce a Network-Individual-Resource (NIR) model for HIV prevention that recognizes how exchanges of resources between individuals and their networks underlies and sustains HIV-risk behaviors. Individual behavior change for HIV prevention, then, may be dependent on increasing the supportiveness of that individual's relevant networks for such change. Among other implications, an NIR model predicts that the success of prevention efforts depends on whether the prevention efforts (1) prompt behavior changes that can be sustained by the resources the individual or their networks possess; (2) meet individual and network needs and are consistent with the individual's current situation/developmental stage; (3) are trusted and valued; and (4) target high HIV-prevalence networks. PMID:20862606

  12. A paradox in individual-based models of populations

    OpenAIRE

    Van der Meer, J.

    2016-01-01

    The standard dynamic energy budget model is widely used to describe the physiology of individual animals. It assumes that assimilation rate scales with body surface area, whereas maintenance rate scales with body volume. When the model is used as the building block of a population model, only limited dynamical behaviour, the so-called juvenile-driven cycles, emerges. The reason is that in the model juveniles are competitively superior over adults, because juveniles have a higher surface area-...

  13. Individual based and mean-field modeling of direct aggregation

    KAUST Repository

    Burger, Martin

    2013-10-01

    We introduce two models of biological aggregation, based on randomly moving particles with individual stochasticity depending on the perceived average population density in their neighborhood. In the firstorder model the location of each individual is subject to a density-dependent random walk, while in the second-order model the density-dependent random walk acts on the velocity variable, together with a density-dependent damping term. The main novelty of our models is that we do not assume any explicit aggregative force acting on the individuals; instead, aggregation is obtained exclusively by reducing the individual stochasticity in response to higher perceived density. We formally derive the corresponding mean-field limits, leading to nonlocal degenerate diffusions. Then, we carry out the mathematical analysis of the first-order model, in particular, we prove the existence of weak solutions and show that it allows for measure-valued steady states. We also perform linear stability analysis and identify conditions for pattern formation. Moreover, we discuss the role of the nonlocality for well-posedness of the first-order model. Finally, we present results of numerical simulations for both the first- and second-order model on the individual-based and continuum levels of description. 2012 Elsevier B.V. All rights reserved.

  14. Hybrid Modelling of Individual Movement and Collective Behaviour

    KAUST Repository

    Franz, Benjamin

    2013-01-01

    Mathematical models of dispersal in biological systems are often written in terms of partial differential equations (PDEs) which describe the time evolution of population-level variables (concentrations, densities). A more detailed modelling approach is given by individual-based (agent-based) models which describe the behaviour of each organism. In recent years, an intermediate modelling methodology - hybrid modelling - has been applied to a number of biological systems. These hybrid models couple an individual-based description of cells/animals with a PDE-model of their environment. In this chapter, we overview hybrid models in the literature with the focus on the mathematical challenges of this modelling approach. The detailed analysis is presented using the example of chemotaxis, where cells move according to extracellular chemicals that can be altered by the cells themselves. In this case, individual-based models of cells are coupled with PDEs for extracellular chemical signals. Travelling waves in these hybrid models are investigated. In particular, we show that in contrary to the PDEs, hybrid chemotaxis models only develop a transient travelling wave. © 2013 Springer-Verlag Berlin Heidelberg.

  15. Modeling Gameplay Enjoyment, Goal Orientations, and Individual Characteristics

    Science.gov (United States)

    Quick, John M.; Atkinson, Robert K.

    2014-01-01

    The purpose of this study was to investigate the relationships between gameplay enjoyment, gaming goal orientations, and individual characteristics. A total of 301 participants were surveyed and the data were analyzed using structural equation modeling. This led to an expanded Gameplay Enjoyment Model (GEM) with 41 game design features that…

  16. Effects of Film Modeling on the Reduction of Anxiety-Related Behaviors in Individuals Varying in Level of Previous Experience in the Stress Situation.

    Science.gov (United States)

    Melamed, Barbara G.; And Others

    1978-01-01

    Evaluated influence of film preparation on children undergoing dental sessions with respect to peer modeling v demonstration of procedures and amount of information. Children exposed to peer-model videotaped presentations immediately preceding their restorative treatment exhibited fewer disruptive behaviors and less apprehension than those…

  17. Individual-based modeling of ecological and evolutionary processes

    Science.gov (United States)

    DeAngelis, Donald L.; Mooij, Wolf M.

    2005-01-01

    Individual-based models (IBMs) allow the explicit inclusion of individual variation in greater detail than do classical differential-equation and difference-equation models. Inclusion of such variation is important for continued progress in ecological and evolutionary theory. We provide a conceptual basis for IBMs by describing five major types of individual variation in IBMs: spatial, ontogenetic, phenotypic, cognitive, and genetic. IBMs are now used in almost all subfields of ecology and evolutionary biology. We map those subfields and look more closely at selected key papers on fish recruitment, forest dynamics, sympatric speciation, metapopulation dynamics, maintenance of diversity, and species conservation. Theorists are currently divided on whether IBMs represent only a practical tool for extending classical theory to more complex situations, or whether individual-based theory represents a radically new research program. We feel that the tension between these two poles of thinking can be a source of creativity in ecology and evolutionary theory.

  18. Comparing observed and modelled growth of larval herring (Clupea harengusz: Testing individual-based model parameterisations

    Directory of Open Access Journals (Sweden)

    Helena M. Hauss

    2009-10-01

    Full Text Available Experiments that directly test larval fish individual-based model (IBM growth predictions are uncommon since it is difficult to simultaneously measure all relevant metabolic and behavioural attributes. We compared observed and modelled somatic growth of larval herring (Clupea harengus in short-term (50 degree-day laboratory trials conducted at 7 and 13°C in which larvae were either unfed or fed ad libitum on different prey sizes (~100 to 550 µm copepods, Acartia tonsa. The larval specific growth rate (SGR, % DW d-1 was generally overestimated by the model, especially for larvae foraging on large prey items. Model parameterisations were adjusted to explore the effect of 1 temporal variability in foraging of individuals, and 2 reduced assimilation efficiency due to rapid gut evacuation at high feeding rates. With these adjustments, the model described larval growth well across temperatures, prey sizes, and larval sizes. Although the experiments performed verified the growth model, variability in growth and foraging behaviour among larvae shows that it is necessary to measure both the physiology and feeding behaviour of the same individual. This is a challenge for experimentalists but will ultimately yield the most valuable data to adequately model environmental impacts on the survival and growth of marine fish early life stages.

  19. Individual SWCNT based ionic field effect transistor

    Science.gov (United States)

    Pang, Pei; He, Jin; Park, Jae Hyun; Krstic, Predrag; Lindsay, Stuart

    2011-03-01

    Here we report that the ionic current through a single-walled carbon nanotube (SWCNT) can be effectively gated by a perpendicular electrical field from a top gate electrode, working as ionic field effect transistor. Both our experiment and simulation confirms that the electroosmotic current (EOF) is the main component in the ionic current through the SWCNT and is responsible for the gating effect. We also studied the gating efficiency as a function of solution concentration and pH and demonstrated that the device can work effectively in the physiological relevant condition. This work opens the door to use CNT based nanofluidics for ion and molecule manipulation. This work was supported by the DNA Sequencing Technology Program of the National Human Genome Research Institute (1RC2HG005625-01, 1R21HG004770-01), Arizona Technology Enterprises and the Biodesign Institute.

  20. Group level effects of social versus individual learning.

    Science.gov (United States)

    Jost, Jürgen; Li, Wei

    2013-06-01

    We study the effects of learning by imitating others within the framework of an iterated game in which the members of two complementary populations interact via random pairing at each round. This allows us to compare both the fitness of different strategies within a population and the performance of populations in which members have access to different types of strategies. Previous studies reveal some emergent dynamics at the population level, when players learn individually. We here investigate a different mechanism in which players can choose between two different learning strategies, individual or social. Imitating behavior can spread within a mixed population, with the frequency of imitators varying over generation time. When compared to a pure population with solely individual learners, a mixed population with both individual and social learners can do better, independently of the precise learning scheme employed. We can then search for the best imitating strategy. Imitating the neighbor with the highest payoff turns out to be consistently superior. This is in agreement with findings in experimental and model studies that have been carried out in different settings.

  1. An Opinion Interactive Model Based on Individual Persuasiveness.

    Science.gov (United States)

    Zhou, Xin; Chen, Bin; Liu, Liang; Ma, Liang; Qiu, Xiaogang

    2015-01-01

    In order to study the formation process of group opinion in real life, we put forward a new opinion interactive model based on Deffuant model and its improved models in this paper because current models of opinion dynamics lack considering individual persuasiveness. Our model has following advantages: firstly persuasiveness is added to individual's attributes reflecting the importance of persuasiveness, which means that all the individuals are different from others; secondly probability is introduced in the course of interaction which simulates the uncertainty of interaction. In Monte Carlo simulation experiments, sensitivity analysis including the influence of randomness, initial persuasiveness distribution, and number of individuals is studied at first; what comes next is that the range of common opinion based on the initial persuasiveness distribution can be predicted. Simulation experiment results show that when the initial values of agents are fixed, no matter how many times independently replicated experiments, the common opinion will converge at a certain point; however the number of iterations will not always be the same; the range of common opinion can be predicted when initial distribution of opinion and persuasiveness are given. As a result, this model can reflect and interpret some phenomena of opinion interaction in realistic society.

  2. Effects of individual popularity on information spreading in complex networks

    Science.gov (United States)

    Gao, Lei; Li, Ruiqi; Shu, Panpan; Wang, Wei; Gao, Hui; Cai, Shimin

    2018-01-01

    In real world, human activities often exhibit preferential selection mechanism based on the popularity of individuals. However, this mechanism is seldom taken into account by previous studies about spreading dynamics on networks. Thus in this work, an information spreading model is proposed by considering the preferential selection based on individuals' current popularity, which is defined as the number of individuals' cumulative contacts with informed neighbors. A mean-field theory is developed to analyze the spreading model. Through systematically studying the information spreading dynamics on uncorrelated configuration networks as well as real-world networks, we find that the popularity preference has great impacts on the information spreading. On the one hand, the information spreading is facilitated, i.e., a larger final prevalence of information and a smaller outbreak threshold, if nodes with low popularity are preferentially selected. In this situation, the effective contacts between informed nodes and susceptible nodes are increased, and nodes almost have uniform probabilities of obtaining the information. On the other hand, if nodes with high popularity are preferentially selected, the final prevalence of information is reduced, the outbreak threshold is increased, and even the information cannot outbreak. In addition, the heterogeneity of the degree distribution and the structure of real-world networks do not qualitatively affect the results. Our research can provide some theoretical supports for the promotion of spreading such as information, health related behaviors, and new products, etc.

  3. A cortical edge-integration model of object-based lightness computation that explains effects of spatial context and individual differences.

    Science.gov (United States)

    Rudd, Michael E

    2014-01-01

    Previous work has demonstrated that perceived surface reflectance (lightness) can be modeled in simple contexts in a quantitatively exact way by assuming that the visual system first extracts information about local, directed steps in log luminance, then spatially integrates these steps along paths through the image to compute lightness (Rudd and Zemach, 2004, 2005, 2007). This method of computing lightness is called edge integration. Recent evidence (Rudd, 2013) suggests that human vision employs a default strategy to integrate luminance steps only along paths from a common background region to the targets whose lightness is computed. This implies a role for gestalt grouping in edge-based lightness computation. Rudd (2010) further showed the perceptual weights applied to edges in lightness computation can be influenced by the observer's interpretation of luminance steps as resulting from either spatial variation in surface reflectance or illumination. This implies a role for top-down factors in any edge-based model of lightness (Rudd and Zemach, 2005). Here, I show how the separate influences of grouping and attention on lightness can be modeled in tandem by a cortical mechanism that first employs top-down signals to spatially select regions of interest for lightness computation. An object-based network computation, involving neurons that code for border-ownership, then automatically sets the neural gains applied to edge signals surviving the earlier spatial selection stage. Only the borders that survive both processing stages are spatially integrated to compute lightness. The model assumptions are consistent with those of the cortical lightness model presented earlier by Rudd (2010, 2013), and with neurophysiological data indicating extraction of local edge information in V1, network computations to establish figure-ground relations and border ownership in V2, and edge integration to encode lightness and darkness signals in V4.

  4. A Cortical Edge-integration Model of Object-Based Lightness Computation that Explains Effects of Spatial Context and Individual Differences

    Directory of Open Access Journals (Sweden)

    Michael E Rudd

    2014-08-01

    Full Text Available Previous work demonstrated that perceived surface reflectance (lightness can be modeled in simple contexts in a quantitatively exact way by assuming that the visual system first extracts information about local, directed steps in log luminance, then spatial integrates these steps along paths through the image to compute lightness (Rudd & Zemach, 2004, 2005, 2007. This method of computing lightness is called edge integration. Recent evidence (Rudd, 2013 suggests that the human vision employs a default strategy to integrate luminance steps only along paths from a common background region to the targets whose lightness is computed. This implies a role for gestalt grouping in edge-based lightness computation. Rudd (2010 further showed the perceptual weights applied to edges in lightness computation can be influenced by the observer’s interpretation of luminance steps as resulting from either spatial variation in surface reflectance or illumination. This implies a role for top-down factors in any edge-based model of lightness (Rudd & Zemach, 2005. Here, I show how the separate influences of grouping and attention on lightness can be together modeled by a cortical mechanism that first employs top-down signals to spatially select regions of interest for lightness computation. An object-based network computation, involving neurons that code for border-ownership, then automatically sets the neural gains applied to edge signals surviving the earlier spatial selection stage. Only the borders that survive both processing stages are spatially integrated to compute lightness. The model assumptions are consistent with those of the cortical lightness model presented earlier by Rudd (2010, 2013, and with neurophysiological data indicating extraction of local edge information in V1, network computations to establish figure-ground relations and border ownership in V2, and edge integration to encode lightness and darkness signals in V4.

  5. A cortical edge-integration model of object-based lightness computation that explains effects of spatial context and individual differences

    Science.gov (United States)

    Rudd, Michael E.

    2014-01-01

    Previous work has demonstrated that perceived surface reflectance (lightness) can be modeled in simple contexts in a quantitatively exact way by assuming that the visual system first extracts information about local, directed steps in log luminance, then spatially integrates these steps along paths through the image to compute lightness (Rudd and Zemach, 2004, 2005, 2007). This method of computing lightness is called edge integration. Recent evidence (Rudd, 2013) suggests that human vision employs a default strategy to integrate luminance steps only along paths from a common background region to the targets whose lightness is computed. This implies a role for gestalt grouping in edge-based lightness computation. Rudd (2010) further showed the perceptual weights applied to edges in lightness computation can be influenced by the observer's interpretation of luminance steps as resulting from either spatial variation in surface reflectance or illumination. This implies a role for top-down factors in any edge-based model of lightness (Rudd and Zemach, 2005). Here, I show how the separate influences of grouping and attention on lightness can be modeled in tandem by a cortical mechanism that first employs top-down signals to spatially select regions of interest for lightness computation. An object-based network computation, involving neurons that code for border-ownership, then automatically sets the neural gains applied to edge signals surviving the earlier spatial selection stage. Only the borders that survive both processing stages are spatially integrated to compute lightness. The model assumptions are consistent with those of the cortical lightness model presented earlier by Rudd (2010, 2013), and with neurophysiological data indicating extraction of local edge information in V1, network computations to establish figure-ground relations and border ownership in V2, and edge integration to encode lightness and darkness signals in V4. PMID:25202253

  6. Individual attitudes toward corruption: do social effects matter?

    OpenAIRE

    Roberta Gatti; Stefano Paternostro; Jamele Rigolini

    2003-01-01

    Using individual-level data for 35 countries, the authors investigate the microeconomic determinants of attitudes toward corruption. They find women, employed, less wealthy, and older individuals to be more averse to corruption. The authors also provide evidence that social effects play an important role in determining individual attitudes toward corruption, as these are robustly and signi...

  7. A Note on the Use of Mixture Models for Individual Prediction.

    Science.gov (United States)

    Cole, Veronica T; Bauer, Daniel J

    Mixture models capture heterogeneity in data by decomposing the population into latent subgroups, each of which is governed by its own subgroup-specific set of parameters. Despite the flexibility and widespread use of these models, most applications have focused solely on making inferences for whole or sub-populations, rather than individual cases. The current article presents a general framework for computing marginal and conditional predicted values for individuals using mixture model results. These predicted values can be used to characterize covariate effects, examine the fit of the model for specific individuals, or forecast future observations from previous ones. Two empirical examples are provided to demonstrate the usefulness of individual predicted values in applications of mixture models. The first example examines the relative timing of initiation of substance use using a multiple event process survival mixture model whereas the second example evaluates changes in depressive symptoms over adolescence using a growth mixture model.

  8. Modelling community, family, and individual determinants of childhood dental caries

    NARCIS (Netherlands)

    Duijster, D.; Loveren, C. van; Dusseldorp, E.; Verrips, G.H.W.

    2014-01-01

    This cross-sectional study empirically tested a theoretical model of pathways and inter-relationships among community, family, and individual determinants of childhood dental caries in a sample of 630, 6-year-old children from the Netherlands. Children's decayed, missing, and filled teeth (dmft)

  9. An Integrative Model of Individual Predisposition and Contextual ...

    African Journals Online (AJOL)

    Specifically, our integrative model makes connection between individuals' personality factor of openness and the contextual factors. The contextual factors reflect human capital of education and experience, motivational resources representing self-efficacy and initiative and networking behaviour influencing opportunity ...

  10. Individual loss reserving with the Multivariate Skew Normal model

    NARCIS (Netherlands)

    Pigeon, M.; Antonio, K.; Denuit, M.

    2011-01-01

    In general insurance, the evaluation of future cash ows and solvency capital has become increasingly important. To assist in this process, the present paper proposes an individual discrete-time loss re- serving model describing the occurrence, the reporting delay, the timeto the first payment, and

  11. Individual based model of slug population and spatial dynamics

    NARCIS (Netherlands)

    Choi, Y.H.; Bohan, D.A.; Potting, R.P.J.; Semenov, M.A.; Glen, D.M.

    2006-01-01

    The slug, Deroceras reticulatum, is one of the most important pests of agricultural and horticultural crops in UK and Europe. In this paper, a spatially explicit individual based model (IbM) is developed to study the dynamics of a population of D. reticulatum. The IbM establishes a virtual field

  12. Knowledge Growth: Applied Models of General and Individual Knowledge Evolution

    Science.gov (United States)

    Silkina, Galina Iu.; Bakanova, Svetlana A.

    2016-01-01

    The article considers the mathematical models of the growth and accumulation of scientific and applied knowledge since it is seen as the main potential and key competence of modern companies. The problem is examined on two levels--the growth and evolution of objective knowledge and knowledge evolution of a particular individual. Both processes are…

  13. QED effects on individual atomic orbital energies

    Science.gov (United States)

    Kozioł, Karol; Aucar, Gustavo A.

    2018-04-01

    Several issues, concerning QED corrections, that are important in precise atomic calculations are presented. The leading QED corrections, self-energy and vacuum polarization, to the orbital energy for selected atoms with 30 ≤ Z ≤ 118 have been calculated. The sum of QED and Breit contributions to the orbital energy is analyzed. It has been found that for ns subshells the Breit and QED contributions are of comparative size, but for np and nd subshells the Breit contribution takes a major part of the QED+Breit sum. It has also, been found that the Breit to leading QED contributions ratio for ns subshells is almost independent of Z. The Z-dependence of QED and Breit+QED contributions per subshell is shown. The fitting coefficients may be used to estimate QED effects on inner molecular orbitals. We present results of our calculations for QED contributions to orbital energy of valence ns-subshell for group 1 and 11 atoms and discuss about the reliability of these numbers by comparing them with experimental first ionization potential data.

  14. Effects of individualized assignments on biology achievement

    Science.gov (United States)

    Kremer, Philip L.

    A pretest-posttest, randomized, two groups, experimental, factorial design compared effects of detailed and nondetailed assignments on biology achievement over seven and a half months. Detailed assignments (favoring field independence and induction) employed block diagrams and stepwise directions. Nondetailed assignments (favoring field dependence and deduction) virtually lacked these. The accessible population was 101 tenth grade preparatory school male students. The 95 students enrolled in first year biology constituted the sample. Two by three ANOVA was done on residualized posttest score means of the students. Totally, the detailed students achieved significantly higher than the nondetailed students. This significantly higher achievement was only true of detailed students in the middle thirds of the deviation intelligence quotient (DIQ) range and of the grade point average (G.P.A.) range after the breakdown into upper, middle, and lower thirds of intellectual capability (ability and achievement). The upper third detailed DIQ grouping indirectly achieved higher than its peers, whereas the lower detailed DIQ third achieved lower than its peers. Thus, high capability students apparently benefit from flow and block diagrams, inductions, field independence, and high structure, whereas low capability students may be hindered by these.

  15. An Individual-based Probabilistic Model for Fish Stock Simulation

    Directory of Open Access Journals (Sweden)

    Federico Buti

    2010-08-01

    Full Text Available We define an individual-based probabilistic model of a sole (Solea solea behaviour. The individual model is given in terms of an Extended Probabilistic Discrete Timed Automaton (EPDTA, a new formalism that is introduced in the paper and that is shown to be interpretable as a Markov decision process. A given EPDTA model can be probabilistically model-checked by giving a suitable translation into syntax accepted by existing model-checkers. In order to simulate the dynamics of a given population of soles in different environmental scenarios, an agent-based simulation environment is defined in which each agent implements the behaviour of the given EPDTA model. By varying the probabilities and the characteristic functions embedded in the EPDTA model it is possible to represent different scenarios and to tune the model itself by comparing the results of the simulations with real data about the sole stock in the North Adriatic sea, available from the recent project SoleMon. The simulator is presented and made available for its adaptation to other species.

  16. A paradox in individual-based models of populations.

    Science.gov (United States)

    van der Meer, Jaap

    2016-01-01

    The standard dynamic energy budget model is widely used to describe the physiology of individual animals. It assumes that assimilation rate scales with body surface area, whereas maintenance rate scales with body volume. When the model is used as the building block of a population model, only limited dynamical behaviour, the so-called juvenile-driven cycles, emerges. The reason is that in the model juveniles are competitively superior over adults, because juveniles have a higher surface area-to-volume ratio. Maintenance requirements for adults are therefore relatively large, and a reduced assimilation rate as a result of lowered food levels will easily become insufficient. Here, an alternative dynamic energy budget model is introduced that gives rise to adult-driven cycles, which may be closer to what is often observed in reality. However, this comes at the price of a rather odd description of the individual, in that maintenance scales with body area and assimilation rate with body volume, resulting in unbounded exponential body growth. I make a plea to solve the paradox and come up with reliable descriptions at both the individual and the population level.

  17. Modelling biological invasions: Individual to population scales at interfaces

    KAUST Repository

    Belmonte-Beitia, J.

    2013-10-01

    Extracting the population level behaviour of biological systems from that of the individual is critical in understanding dynamics across multiple scales and thus has been the subject of numerous investigations. Here, the influence of spatial heterogeneity in such contexts is explored for interfaces with a separation of the length scales characterising the individual and the interface, a situation that can arise in applications involving cellular modelling. As an illustrative example, we consider cell movement between white and grey matter in the brain which may be relevant in considering the invasive dynamics of glioma. We show that while one can safely neglect intrinsic noise, at least when considering glioma cell invasion, profound differences in population behaviours emerge in the presence of interfaces with only subtle alterations in the dynamics at the individual level. Transport driven by local cell sensing generates predictions of cell accumulations along interfaces where cell motility changes. This behaviour is not predicted with the commonly used Fickian diffusion transport model, but can be extracted from preliminary observations of specific cell lines in recent, novel, cryo-imaging. Consequently, these findings suggest a need to consider the impact of individual behaviour, spatial heterogeneity and especially interfaces in experimental and modelling frameworks of cellular dynamics, for instance in the characterisation of glioma cell motility. © 2013 Elsevier Ltd.

  18. IBSEM: An Individual-Based Atlantic Salmon Population Model.

    Directory of Open Access Journals (Sweden)

    Marco Castellani

    Full Text Available Ecology and genetics can influence the fate of individuals and populations in multiple ways. However, to date, few studies consider them when modelling the evolutionary trajectory of populations faced with admixture with non-local populations. For the Atlantic salmon, a model incorporating these elements is urgently needed because many populations are challenged with gene-flow from non-local and domesticated conspecifics. We developed an Individual-Based Salmon Eco-genetic Model (IBSEM to simulate the demographic and population genetic change of an Atlantic salmon population through its entire life-cycle. Processes such as growth, mortality, and maturation are simulated through stochastic procedures, which take into account environmental variables as well as the genotype of the individuals. IBSEM is based upon detailed empirical data from salmon biology, and parameterized to reproduce the environmental conditions and the characteristics of a wild population inhabiting a Norwegian river. Simulations demonstrated that the model consistently and reliably reproduces the characteristics of the population. Moreover, in absence of farmed escapees, the modelled populations reach an evolutionary equilibrium that is similar to our definition of a 'wild' genotype. We assessed the sensitivity of the model in the face of assumptions made on the fitness differences between farm and wild salmon, and evaluated the role of straying as a buffering mechanism against the intrusion of farm genes into wild populations. These results demonstrate that IBSEM is able to capture the evolutionary forces shaping the life history of wild salmon and is therefore able to model the response of populations under environmental and genetic stressors.

  19. Improved Mental Acuity Forecasting with an Individualized Quantitative Sleep Model

    Directory of Open Access Journals (Sweden)

    Brent D. Winslow

    2017-04-01

    Full Text Available Sleep impairment significantly alters human brain structure and cognitive function, but available evidence suggests that adults in developed nations are sleeping less. A growing body of research has sought to use sleep to forecast cognitive performance by modeling the relationship between the two, but has generally focused on vigilance rather than other cognitive constructs affected by sleep, such as reaction time, executive function, and working memory. Previous modeling efforts have also utilized subjective, self-reported sleep durations and were restricted to laboratory environments. In the current effort, we addressed these limitations by employing wearable systems and mobile applications to gather objective sleep information, assess multi-construct cognitive performance, and model/predict changes to mental acuity. Thirty participants were recruited for participation in the study, which lasted 1 week. Using the Fitbit Charge HR and a mobile version of the automated neuropsychological assessment metric called CogGauge, we gathered a series of features and utilized the unified model of performance to predict mental acuity based on sleep records. Our results suggest that individuals poorly rate their sleep duration, supporting the need for objective sleep metrics to model circadian changes to mental acuity. Participant compliance in using the wearable throughout the week and responding to the CogGauge assessments was 80%. Specific biases were identified in temporal metrics across mobile devices and operating systems and were excluded from the mental acuity metric development. Individualized prediction of mental acuity consistently outperformed group modeling. This effort indicates the feasibility of creating an individualized, mobile assessment and prediction of mental acuity, compatible with the majority of current mobile devices.

  20. Improved Mental Acuity Forecasting with an Individualized Quantitative Sleep Model.

    Science.gov (United States)

    Winslow, Brent D; Nguyen, Nam; Venta, Kimberly E

    2017-01-01

    Sleep impairment significantly alters human brain structure and cognitive function, but available evidence suggests that adults in developed nations are sleeping less. A growing body of research has sought to use sleep to forecast cognitive performance by modeling the relationship between the two, but has generally focused on vigilance rather than other cognitive constructs affected by sleep, such as reaction time, executive function, and working memory. Previous modeling efforts have also utilized subjective, self-reported sleep durations and were restricted to laboratory environments. In the current effort, we addressed these limitations by employing wearable systems and mobile applications to gather objective sleep information, assess multi-construct cognitive performance, and model/predict changes to mental acuity. Thirty participants were recruited for participation in the study, which lasted 1 week. Using the Fitbit Charge HR and a mobile version of the automated neuropsychological assessment metric called CogGauge, we gathered a series of features and utilized the unified model of performance to predict mental acuity based on sleep records. Our results suggest that individuals poorly rate their sleep duration, supporting the need for objective sleep metrics to model circadian changes to mental acuity. Participant compliance in using the wearable throughout the week and responding to the CogGauge assessments was 80%. Specific biases were identified in temporal metrics across mobile devices and operating systems and were excluded from the mental acuity metric development. Individualized prediction of mental acuity consistently outperformed group modeling. This effort indicates the feasibility of creating an individualized, mobile assessment and prediction of mental acuity, compatible with the majority of current mobile devices.

  1. DEVELOPMENT OF INDIVIDUAL TREE GROWTH MODELS BASED ON DIFFERENTIAL EQUATIONS

    Directory of Open Access Journals (Sweden)

    Breno Rodrigues Mendes

    2006-09-01

    Full Text Available This study generate individual tree non-linear models from differential equation and evaluated the adjustment quality to express the basal area growth. The data base is from continuous forest inventory of clonal Eucalyptus spp. plantations, given by Aracruz Cellulose Company, located in the Brazilian costal region, Bahia and Espirito Santo states. The model precision was verified by ratio likelihood test, by mean square error (MSE and by graphical residual analysis. The results showed that the complete model with 3 parameters, developed from the original model with one regressor, was superior to the other models, due to the inclusion of stand based variables, such as: clone, total height (HT, dominant height (HD, quadratic diameter (Dg, Basal Area (G, site index (IS and Density (N, generating a new model, called Complete Model III. The improvement of the precision was highly significant when compared to another models. Consequently, this model provides information with a high degree of precision and accuracy for the forest companies planning.

  2. INDIVIDUAL-BASED MODELS: POWERFUL OR POWER STRUGGLE?

    Science.gov (United States)

    Willem, L; Stijven, S; Hens, N; Vladislavleva, E; Broeckhove, J; Beutels, P

    2015-01-01

    Individual-based models (IBMs) offer endless possibilities to explore various research questions but come with high model complexity and computational burden. Large-scale IBMs have become feasible but the novel hardware architectures require adapted software. The increased model complexity also requires systematic exploration to gain thorough system understanding. We elaborate on the development of IBMs for vaccine-preventable infectious diseases and model exploration with active learning. Investment in IBM simulator code can lead to significant runtime reductions. We found large performance differences due to data locality. Sorting the population once, reduced simulation time by a factor two. Storing person attributes separately instead of using person objects also seemed more efficient. Next, we improved model performance up to 70% by structuring potential contacts based on health status before processing disease transmission. The active learning approach we present is based on iterative surrogate modelling and model-guided experimentation. Symbolic regression is used for nonlinear response surface modelling with automatic feature selection. We illustrate our approach using an IBM for influenza vaccination. After optimizing the parameter spade, we observed an inverse relationship between vaccination coverage and the clinical attack rate reinforced by herd immunity. These insights can be used to focus and optimise research activities, and to reduce both dimensionality and decision uncertainty.

  3. COSYMA: Health effects models

    International Nuclear Information System (INIS)

    Ehrhardt, J.

    1995-02-01

    As one of the main objectives of the MARIA project (''Methods for Assessing the Radiological Impact of Accidents'') initiated by the Commission of the European Communities the program package COSYMA (''COde SYstem from MARIA'') for assessing the radiological and economic off-site consequences of accidental releases of radioactive material to the atmosphere has been jointly developed by the Kernforschungszentrum Karlsruhe (KfK), FRG, and the National Radiological Protection Board (NRPB), UK. COSYMA includes models and data for assessing a broad spectrum of accident consequences, and they are implemented in independent modules. The subject of this report are those modules, which incorporate models and data for assessing individual and collective risks for deterministic and stochastic health effects. It describes the models implemented, the mathematical algorithms and the required data. Examples are given and explained for the input and output part of the modules. (orig.)

  4. Worked Example Effects in Individual and Group Work Settings

    Science.gov (United States)

    Retnowati, Endah; Ayres, Paul; Sweller, John

    2010-01-01

    This study compared the effects of worked example and problem-solving approaches in individual or group work settings on learning to solve geometry problems. One hundred and one seventh graders from Indonesia were randomly allocated to four experimental groups using a 2 (problem-solving vs. worked examples) x 2 (individual vs. group study) design.…

  5. Effect of Dominant Individual on Budget Implementation in Nigeria: A ...

    African Journals Online (AJOL)

    This paper examines the effect of dominant individuals on budget implementations in Nigeria. The methodology used in the study is content analysis method. The literature and empirical review reveal that the activities of dominant individuals ranges from manipulation of budget items before and after approval of annual ...

  6. Assessing Instructional Modalities: Individualized Treatment Effects for Personalized Learning

    Science.gov (United States)

    Beemer, Joshua; Spoon, Kelly; Fan, Juanjuan; Stronach, Jeanne; Frazee, James P.; Bohonak, Andrew J.; Levine, Richard A.

    2018-01-01

    Estimating the efficacy of different instructional modalities, techniques, and interventions is challenging because teaching style covaries with instructor, and the typical student only takes a course once. We introduce the individualized treatment effect (ITE) from analyses of personalized medicine as a means to quantify individual student…

  7. Comparing the effects of different individualized music interventions for elderly individuals with severe dementia

    OpenAIRE

    Sakamoto, Mayumi; Ando, Hiroshi; Tsutou, Akimitsu

    2013-01-01

    Background: Individuals with dementia often experience poor quality of life (QOL) due to behavioral and psychological symptoms of dementia (BPSD). Music therapy can reduce BPSD, but most studies have focused on patients with mild to moderate dementia. We hypothesized that music intervention would have beneficial effects compared with a no-music control condition, and that interactive music intervention would have stronger effects than passive music intervention. Methods: Thirty-nine individua...

  8. Are Androgynous Individuals More Effective Persons and Parents?

    Science.gov (United States)

    Baumrind, Diana

    1982-01-01

    Using extensive, multifaceted observational and interview data from the Family Socialization and Developmental Competence Project (FSP), this paper examines the claims that androgynes, by comparison with sex-typed individuals, are more effective persons and parents. (Author/RH)

  9. Individual brain structure and modelling predict seizure propagation.

    Science.gov (United States)

    Proix, Timothée; Bartolomei, Fabrice; Guye, Maxime; Jirsa, Viktor K

    2017-03-01

    See Lytton (doi:10.1093/awx018) for a scientific commentary on this article.Neural network oscillations are a fundamental mechanism for cognition, perception and consciousness. Consequently, perturbations of network activity play an important role in the pathophysiology of brain disorders. When structural information from non-invasive brain imaging is merged with mathematical modelling, then generative brain network models constitute personalized in silico platforms for the exploration of causal mechanisms of brain function and clinical hypothesis testing. We here demonstrate with the example of drug-resistant epilepsy that patient-specific virtual brain models derived from diffusion magnetic resonance imaging have sufficient predictive power to improve diagnosis and surgery outcome. In partial epilepsy, seizures originate in a local network, the so-called epileptogenic zone, before recruiting other close or distant brain regions. We create personalized large-scale brain networks for 15 patients and simulate the individual seizure propagation patterns. Model validation is performed against the presurgical stereotactic electroencephalography data and the standard-of-care clinical evaluation. We demonstrate that the individual brain models account for the patient seizure propagation patterns, explain the variability in postsurgical success, but do not reliably augment with the use of patient-specific connectivity. Our results show that connectome-based brain network models have the capacity to explain changes in the organization of brain activity as observed in some brain disorders, thus opening up avenues towards discovery of novel clinical interventions. © The Author (2017). Published by Oxford University Press on behalf of the Guarantors of Brain.

  10. Individual-based modeling of fish: Linking to physical models and water quality.

    Energy Technology Data Exchange (ETDEWEB)

    Rose, K.A.

    1997-08-01

    The individual-based modeling approach for the simulating fish population and community dynamics is gaining popularity. Individual-based modeling has been used in many other fields, such as forest succession and astronomy. The popularity of the individual-based approach is partly a result of the lack of success of the more aggregate modeling approaches traditionally used for simulating fish population and community dynamics. Also, recent recognition that it is often the atypical individual that survives has fostered interest in the individual-based approach. Two general types of individual-based models are distribution and configuration. Distribution models follow the probability distributions of individual characteristics, such as length and age. Configuration models explicitly simulate each individual; the sum over individuals being the population. DeAngelis et al (1992) showed that, when distribution and configuration models were formulated from the same common pool of information, both approaches generated similar predictions. The distribution approach was more compact and general, while the configuration approach was more flexible. Simple biological changes, such as making growth rate dependent on previous days growth rates, were easy to implement in the configuration version but prevented simple analytical solution of the distribution version.

  11. Does individualism bring happiness? Negative effects of individualism on interpersonal relationships and happiness

    Directory of Open Access Journals (Sweden)

    Yuji eOgihara

    2014-03-01

    Full Text Available We examined the negative effects of individualism in an East Asian culture. Although individualistic systems decrease interpersonal relationships through competition, individualistic values have prevailed in European American cultures. One reason is because individuals could overcome negativity by actively constructing interpersonal relationships. In contrast, people in East Asian cultures do not have such strategies to overcome the negative impact of individualistic systems, leading to decreased well-being. To test this hypothesis, we investigated the relationship between individualistic values, number of close friends, and subjective well-being (SWB. Study 1 indicated that individualistic values were negatively related with the number of close friends and SWB for Japanese college students but not for American college students. Moreover, Study 2 showed that even in an individualistic workplace in Japan, individualistic values were negatively related with the number of close friends and SWB. We discuss how cultural change toward increasing individualism might affect interpersonal relationships and well-being.

  12. Analytical models approximating individual processes: a validation method.

    Science.gov (United States)

    Favier, C; Degallier, N; Menkès, C E

    2010-12-01

    Upscaling population models from fine to coarse resolutions, in space, time and/or level of description, allows the derivation of fast and tractable models based on a thorough knowledge of individual processes. The validity of such approximations is generally tested only on a limited range of parameter sets. A more general validation test, over a range of parameters, is proposed; this would estimate the error induced by the approximation, using the original model's stochastic variability as a reference. This method is illustrated by three examples taken from the field of epidemics transmitted by vectors that bite in a temporally cyclical pattern, that illustrate the use of the method: to estimate if an approximation over- or under-fits the original model; to invalidate an approximation; to rank possible approximations for their qualities. As a result, the application of the validation method to this field emphasizes the need to account for the vectors' biology in epidemic prediction models and to validate these against finer scale models. Copyright © 2010 Elsevier Inc. All rights reserved.

  13. Modeling Feedbacks Between Individual Human Decisions and Hydrology Using Interconnected Physical and Social Models

    Science.gov (United States)

    Murphy, J.; Lammers, R. B.; Proussevitch, A. A.; Ozik, J.; Altaweel, M.; Collier, N. T.; Alessa, L.; Kliskey, A. D.

    2014-12-01

    The global hydrological cycle intersects with human decision making at multiple scales, from dams and irrigation works to the taps in individuals' homes. Residential water consumers are commonly encouraged to conserve; these messages are heard against a background of individual values and conceptions about water quality, uses, and availability. The degree to which these values impact the larger-hydrological dynamics, the way that changes in those values have impacts on the hydrological cycle through time, and the feedbacks by which water availability and quality in turn shape those values, are not well explored. To investigate this domain we employ a global-scale water balance model (WBM) coupled with a social-science-grounded agent-based model (ABM). The integration of a hydrological model with an agent-based model allows us to explore driving factors in the dynamics in coupled human-natural systems. From the perspective of the physical hydrologist, the ABM offers a richer means of incorporating the human decisions that drive the hydrological system; from the view of the social scientist, a physically-based hydrological model allows the decisions of the agents to play out against constraints faithful to the real world. We apply the interconnected models to a study of Tucson, Arizona, USA, and its role in the larger Colorado River system. Our core concept is Technology-Induced Environmental Distancing (TIED), which posits that layers of technology can insulate consumers from direct knowledge of a resource. In Tucson, multiple infrastructure and institutional layers have arguably increased the conceptual distance between individuals and their water supply, offering a test case of the TIED framework. Our coupled simulation allows us to show how the larger system transforms a resource with high temporal and spatial variability into a consumer constant, and the effects of this transformation on the regional system. We use this to explore how pricing, messaging, and

  14. Individual acceptance of the biogas innovation: A structural equation model

    International Nuclear Information System (INIS)

    Emmann, Carsten H.; Arens, Ludwig; Theuvsen, Ludwig

    2013-01-01

    The rapid spread of biogas production in Germany has resulted in an increased public debate over this new business branch. Today the production of biogas is much more controversially debated than several years ago. At the same time it could be proven that even among farmers themselves the acceptance of biogas production in some regions is somewhat dampened due to accompanying “collateral damages”. Therefore, the goal of this paper is to identify relevant influencing factors that determine the acceptance of the innovation “biogas” among farmers by applying a causal analysis. Initial results among the five investigated determinants show that not only an individual attitude toward biogas but also the farmers' personal innovativeness strongly and significantly influences an individual's acceptance of the innovation “biogas”. -- Highlights: •Strong expansion of biogas production based on renewable resources in Germany since 2004. •Low acceptance of biogas production in some regions. •Identification of influencing factors that determine the individual acceptance of the biogas innovation among German farmers. •Compared to existing studies, personal innovativeness was taken into account in the causal model. •Results are important for the further expansion of biogas production in Germany as well as in other countries

  15. Modeling structured population dynamics using data from unmarked individuals

    Science.gov (United States)

    Grant, Evan H. Campbell; Zipkin, Elise; Thorson, James T.; See, Kevin; Lynch, Heather J.; Kanno, Yoichiro; Chandler, Richard; Letcher, Benjamin H.; Royle, J. Andrew

    2014-01-01

    The study of population dynamics requires unbiased, precise estimates of abundance and vital rates that account for the demographic structure inherent in all wildlife and plant populations. Traditionally, these estimates have only been available through approaches that rely on intensive mark–recapture data. We extended recently developed N-mixture models to demonstrate how demographic parameters and abundance can be estimated for structured populations using only stage-structured count data. Our modeling framework can be used to make reliable inferences on abundance as well as recruitment, immigration, stage-specific survival, and detection rates during sampling. We present a range of simulations to illustrate the data requirements, including the number of years and locations necessary for accurate and precise parameter estimates. We apply our modeling framework to a population of northern dusky salamanders (Desmognathus fuscus) in the mid-Atlantic region (USA) and find that the population is unexpectedly declining. Our approach represents a valuable advance in the estimation of population dynamics using multistate data from unmarked individuals and should additionally be useful in the development of integrated models that combine data from intensive (e.g., mark–recapture) and extensive (e.g., counts) data sources.

  16. Fraud, individuals, and networks: A biopsychosocial model of scientific frauds.

    Science.gov (United States)

    Leistedt, Samuel J; Linkowski, Paul

    2016-03-01

    The problem of fraud, especially scientific fraud, is global and its identification risk is still in its infancy. Based on an in-depth analysis of several financial and scientific fraud trials, the authors propose a new and integrative model of scientific fraud. This model identifies two major levels for committing fraud: (i) at the personal skills level (micro-level) and (ii) at the network skills level (macro-level). Interacting continuously with each other, they form a dynamic, efficient, and integrative system: an integrative model of fraud. The micro-level refers to three factors: (i) personality organization, (ii) social competence, and (iii) the so-called triangle of fraud. The macro-level refers essentially to social network organization and social engineering. Then, the key to understanding and mostly controlling fraud is to consider both the individual and the environment in which they operate. Based on our model, several steps at the micro- and macro-levels can be proposed. Copyright © 2016 The Chartered Society of Forensic Sciences. Published by Elsevier Ireland Ltd. All rights reserved.

  17. Beyond Individual Differences: Exploring School Effects on SAT Scores

    Science.gov (United States)

    Everson, Howard T.; Millsap, Roger E.

    2004-01-01

    This article explores the complex, hierarchical relation among school characteristics, individual differences in academic achievement, extracurricular activities, and socioeconomic background on performance on the verbal and mathematics Scholastic Aptitude Test (SAT). Using multilevel structural equation models (SEMs) with latent means, we…

  18. Individual-based modelling of population growth and diffusion in discrete time.

    Directory of Open Access Journals (Sweden)

    Natalie Tkachenko

    Full Text Available Individual-based models (IBMs of human populations capture spatio-temporal dynamics using rules that govern the birth, behavior, and death of individuals. We explore a stochastic IBM of logistic growth-diffusion with constant time steps and independent, simultaneous actions of birth, death, and movement that approaches the Fisher-Kolmogorov model in the continuum limit. This model is well-suited to parallelization on high-performance computers. We explore its emergent properties with analytical approximations and numerical simulations in parameter ranges relevant to human population dynamics and ecology, and reproduce continuous-time results in the limit of small transition probabilities. Our model prediction indicates that the population density and dispersal speed are affected by fluctuations in the number of individuals. The discrete-time model displays novel properties owing to the binomial character of the fluctuations: in certain regimes of the growth model, a decrease in time step size drives the system away from the continuum limit. These effects are especially important at local population sizes of <50 individuals, which largely correspond to group sizes of hunter-gatherers. As an application scenario, we model the late Pleistocene dispersal of Homo sapiens into the Americas, and discuss the agreement of model-based estimates of first-arrival dates with archaeological dates in dependence of IBM model parameter settings.

  19. Using decision models to enhance investigations of individual differences in cognitive neuroscience

    Directory of Open Access Journals (Sweden)

    Corey N White

    2016-02-01

    Full Text Available There is great interest in relating individual differences in cognitive processing to activation of neural systems. The general process involves relating measures of task performance like reaction times or accuracy to brain activity to identify individual differences in neural processing. One limitation of this approach is that measures like reaction times can be affected by multiple components of processing. For instance, some individuals might have higher accuracy in a memory task because they respond more cautiously, not because they have better memory. Computational models of decision making, like the drift-diffusion model and the linear ballistic accumulator model, provide a potential solution to this problem. They can be fitted to data from individual participants to disentangle the effects of the different processes driving behavior. In this sense the models can provide cleaner measures of the processes of interest, and enhance our understanding of how neural activity varies across individuals or populations. The advantages of this model-based approach to investigating individual differences in neural activity are discussed with recent examples of how this method can improve our understanding of the brain-behavior relationship.

  20. Dosha brain-types: A neural model of individual differences.

    Science.gov (United States)

    Travis, Frederick T; Wallace, Robert Keith

    2015-01-01

    This paper explores brain patterns associated with the three categories of regulatory principles of the body, mind, and behavior in Ayurveda, called Vata, Pitta, and Kapha dosha. A growing body of research has reported patterns of blood chemistry, genetic expression, physiological states, and chronic diseases associated with each dosha type. Since metabolic and growth factors are controlled by the nervous system, each dosha type should be associated with patterns of functioning of six major areas of the nervous system: The prefrontal cortex, the reticular activating system, the autonomic nervous system, the enteric nervous system, the limbic system, and the hypothalamus. For instance, the prefrontal cortex, which includes the anterior cingulate, ventral medial, and the dorsal lateral cortices, would exhibit a high range of functioning in the Vata brain-type leading to the possibility of being easily overstimulated. The Vata brain-type performs activity quickly. Learns quickly and forgets quickly. Their fast mind gives them an edge in creative problem solving. The Pitta brain-type reacts strongly to all challenges leading to purposeful and resolute actions. They never give up and are very dynamic and goal oriented. The Kapha brain-type is slow and steady leading to methodical thinking and action. They prefer routine and needs stimulation to get going. A model of dosha brain-types could provide a physiological foundation to understand individual differences. This model could help individualize treatment modalities to address different mental and physical dysfunctions. It also could explain differences in behavior seen in clinical as well as in normal populations.

  1. Dosha brain-types: A neural model of individual differences

    Directory of Open Access Journals (Sweden)

    Frederick T Travis

    2015-01-01

    Full Text Available This paper explores brain patterns associated with the three categories of regulatory principles of the body, mind, and behavior in Ayurveda, called Vata, Pitta, and Kapha dosha. A growing body of research has reported patterns of blood chemistry, genetic expression, physiological states, and chronic diseases associated with each dosha type. Since metabolic and growth factors are controlled by the nervous system, each dosha type should be associated with patterns of functioning of six major areas of the nervous system: The prefrontal cortex, the reticular activating system, the autonomic nervous system, the enteric nervous system, the limbic system, and the hypothalamus. For instance, the prefrontal cortex, which includes the anterior cingulate, ventral medial, and the dorsal lateral cortices, would exhibit a high range of functioning in the Vata brain-type leading to the possibility of being easily overstimulated. The Vata brain-type performs activity quickly. Learns quickly and forgets quickly. Their fast mind gives them an edge in creative problem solving. The Pitta brain-type reacts strongly to all challenges leading to purposeful and resolute actions. They never give up and are very dynamic and goal oriented. The Kapha brain-type is slow and steady leading to methodical thinking and action. They prefer routine and needs stimulation to get going. A model of dosha brain-types could provide a physiological foundation to understand individual differences. This model could help individualize treatment modalities to address different mental and physical dysfunctions. It also could explain differences in behavior seen in clinical as well as in normal populations.

  2. Effect of Surfactants on the Growth of Individual Cloud Droplets

    Science.gov (United States)

    Frossard, A. A.; Li, W.; Gerard, V.; Noziere, B.; Cohen, R. C.

    2016-12-01

    Accurately predicting cloud droplet growth and lifetime remains a large uncertainty in estimates of Earth's changing energy budget. Current findings suggest that surface-active organic compounds and other surfactants in cloud droplets can affect the rate and magnitude of water condensation onto and evaporation from droplets affecting a myriad of cloud properties. This idea represents a significant change from prior thinking that focused solely on solubility as the chemical influence on water uptake to droplets. Recent observations show that surfactants extracted from atmospheric aerosol particles can considerably reduce the surface tension of water, making them important factors in cloud droplet growth that were until recently considered to be negligible. Using the surfactant Igepal CA-630, which has properties similar to that of surfactants extracted from atmospheric aerosol samples, model cloud droplets were created in the laboratory. The evaporation and condensation of the individual droplets were investigated using an aerosol optical trap with Raman spectroscopy. With a change in relative humidity (RH) from 70% to 80%, droplets containing both Igepal and NaCl had much larger changes in droplet radii than droplets containing NaCl only, demonstrating a significant effect of surface tension depression on evaporation and condensation. Given an increase in RH in the atmosphere, this could lead to droplets containing surfactants growing larger than those without surfactants and a substantial change in CCN activity.

  3. Structure and sensitivity analysis of individual-based predator–prey models

    International Nuclear Information System (INIS)

    Imron, Muhammad Ali; Gergs, Andre; Berger, Uta

    2012-01-01

    The expensive computational cost of sensitivity analyses has hampered the use of these techniques for analysing individual-based models in ecology. A relatively cheap computational cost, referred to as the Morris method, was chosen to assess the relative effects of all parameters on the model’s outputs and to gain insights into predator–prey systems. Structure and results of the sensitivity analysis of the Sumatran tiger model – the Panthera Population Persistence (PPP) and the Notonecta foraging model (NFM) – were compared. Both models are based on a general predation cycle and designed to understand the mechanisms behind the predator–prey interaction being considered. However, the models differ significantly in their complexity and the details of the processes involved. In the sensitivity analysis, parameters that directly contribute to the number of prey items killed were found to be most influential. These were the growth rate of prey and the hunting radius of tigers in the PPP model as well as attack rate parameters and encounter distance of backswimmers in the NFM model. Analysis of distances in both of the models revealed further similarities in the sensitivity of the two individual-based models. The findings highlight the applicability and importance of sensitivity analyses in general, and screening design methods in particular, during early development of ecological individual-based models. Comparison of model structures and sensitivity analyses provides a first step for the derivation of general rules in the design of predator–prey models for both practical conservation and conceptual understanding. - Highlights: ► Structure of predation processes is similar in tiger and backswimmer model. ► The two individual-based models (IBM) differ in space formulations. ► In both models foraging distance is among the sensitive parameters. ► Morris method is applicable for the sensitivity analysis even of complex IBMs.

  4. Using a Structural Equation Model to Examine Factors Affecting Married Individuals' Sexual Embarrassment

    Science.gov (United States)

    Celik, Eyup; Arici, Neslihan

    2014-01-01

    This study aimed to predict the effects of levels of sexual awareness, sexual courage, and sexual self-disclosure on sexual embarrassment. Data was collected from 336 married individuals, who have students in the Sultangazi District of Istanbul. According to the structural equation model (SEM), sexual self-disclosure, directly, and sexual courage…

  5. An Integrated, Multidimensional Treatment Model for Individuals Living with HIV, Mental Illness, and Substance Abuse

    Science.gov (United States)

    Bouis, Stephanie; Reif, Susan; Whetten, Kathryn; Scovil, Janet; Murray, Andrea; Swartz, Marvin

    2007-01-01

    The challenge of providing effective treatment services for the growing population of HIV-positive individuals who are also dually diagnosed with substance use and mental disorders has only recently been recognized as an important public health concern affecting both HIV treatment and prevention. This article describes a treatment model that was…

  6. The effect of caffeine supplementation on trained individuals ...

    African Journals Online (AJOL)

    The effect of caffeine supplementation on trained individuals subjected to maximal treadmill test. Viviane Martins Mana Salicio, Carlos Alexandre Fett, Marcos Adriano Salicio, Camila Fernanda Costa Cunha Moraes Brandão, Luiz Fabrizio Stoppiglia, Waléria Christiane Rezende Fett, Clovis Botelho ...

  7. Effect of direction on loudness in individual binaural synthesis

    DEFF Research Database (Denmark)

    Sivonen, Ville Pekka; Minnaar, Pauli; Ellermeier, Wolfgang

    2005-01-01

    The effect of sound incidence angle on loudness is investigated in this study using binaural synthesis. Individual head-related transfer functions (HRTFs) and headphone equalization are used to present narrow-band noises from different directions to listeners. Their task is to match the loudness...

  8. Effect of individualized diabetes education for type 2 diabetes ...

    African Journals Online (AJOL)

    Background: To evaluate the effect of individualized education for patients with type 2 diabetes mellitus (T2DM). Methods: A total of 280 patients (158 males, mean age 63 ± 10 years) with T2DM were randomly divided into study and control group. Eysenck Personality questionnaire was used to assess the personality of the ...

  9. Effect of individualized diabetes education for type 2 diabetes mellitus

    African Journals Online (AJOL)

    Background: To evaluate the effect of individualized education for patients with type 2 diabetes mellitus (T2DM). Methods: A total of 280 ..... tabase Syst Rev 2008; 16:CD006424. 9.Hans Jürgen Eysenck , Sybil B. G. Eysenck. Manual of the Eysenck Personality Questionnaire. London: Hodder and Stoughton, 1975. 10.

  10. THE INFLUENCE OF DISPOSITION EFFECT IN INDIVIDUAL INVESTMENT DECISIONS

    OpenAIRE

    Ribeiro, Mariana Almeida; Carvalho Junior, Cesar Valentim de Oliveira; Rocha, Joséilton Silveira

    2015-01-01

    We investigated the occurrence of the disposition effect in individual investment decisions, to identify if the presentation of analysts recommendations and accounting informations reduces this effect and improves the results of negotiations on the financial market. Krishnan and Booker (2002) indicate that the presence of the analysts recommendation reduces the error provision for situations in which the gains of operations, but not for losses. When additional information is presented the err...

  11. Individualized Risk Model for Venous Thromboembolism After Total Joint Arthroplasty.

    Science.gov (United States)

    Parvizi, Javad; Huang, Ronald; Rezapoor, Maryam; Bagheri, Behrad; Maltenfort, Mitchell G

    2016-09-01

    Venous thromboembolism (VTE) after total joint arthroplasty (TJA) is a potentially fatal complication. Currently, a standard protocol for postoperative VTE prophylaxis is used that makes little distinction between patients at varying risks of VTE. We sought to develop a simple scoring system identifying patients at higher risk for VTE in whom more potent anticoagulation may need to be administered. Utilizing the National Inpatient Sample data, 1,721,806 patients undergoing TJA were identified, among whom 15,775 (0.9%) developed VTE after index arthroplasty. Among the cohort, all known potential risk factors for VTE were assessed. An initial logistic regression model using potential predictors for VTE was performed. Predictors with little contribution or poor predictive power were pruned from the data, and the model was refit. After pruning of variables that had little to no contribution to VTE risk, using the logistic regression, all independent predictors of VTE after TJA were identified in the data. Relative weights for each factor were determined. Hypercoagulability, metastatic cancer, stroke, sepsis, and chronic obstructive pulmonary disease had some of the highest points. Patients with any of these conditions had risk for postoperative VTE that exceeded the 3% rate. Based on the model, an iOS (iPhone operating system) application was developed (VTEstimator) that could be used to assign patients into low or high risk for VTE after TJA. We believe individualization of VTE prophylaxis after TJA can improve the efficacy of preventing VTE while minimizing untoward risks associated with the administration of anticoagulation. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Explorations in combining cognitive models of individuals and system dynamics models of groups.

    Energy Technology Data Exchange (ETDEWEB)

    Backus, George A.

    2008-07-01

    This report documents a demonstration model of interacting insurgent leadership, military leadership, government leadership, and societal dynamics under a variety of interventions. The primary focus of the work is the portrayal of a token societal model that responds to leadership activities. The model also includes a linkage between leadership and society that implicitly represents the leadership subordinates as they directly interact with the population. The societal model is meant to demonstrate the efficacy and viability of using System Dynamics (SD) methods to simulate populations and that these can then connect to cognitive models depicting individuals. SD models typically focus on average behavior and thus have limited applicability to describe small groups or individuals. On the other hand, cognitive models readily describe individual behavior but can become cumbersome when used to describe populations. Realistic security situations are invariably a mix of individual and population dynamics. Therefore, the ability to tie SD models to cognitive models provides a critical capability that would be otherwise be unavailable.

  13. Competition of Dynamic Self-Confidence and Inhomogeneous Individual Influence in Voter Models

    Directory of Open Access Journals (Sweden)

    Fei Xiong

    2013-12-01

    Full Text Available In social systems, agents often have different ability to persuade neighbors to adopt their opinions. In this paper, we aim to investigate how the location and heterogeneity of influencers in social networks can improve convergence. We propose a voter model with dynamic self-conviction and heterogeneous individual influence which is related to the underlying network topology. An agent may keep its current opinion according to personal conviction, or otherwise, it may preferentially choose the opinion of the neighbor that has a great influence. Individual conviction evolves during the dynamic process, and can be strengthened by social recognition. Simulations indicate our model has three nontrivial results. First, the conservation of average magnetization in the voter model is broken under the effect of individual conviction and influence, and the system evolves to an ordered state in which one opinion is dominant, but total consensus is prevented by extremists. Furthermore, individual influence has a subtle action on opinion evolution. The heterogeneity of individual influence accelerates the relaxation process, but, with the action of dynamic conviction, more heterogeneous influence does not mean the average magnetization will be more ordered. In addition, when competing with agents’ conviction, more heterogeneous individual influence plays a more significant role in agents’ decisions. These results are helpful for understanding some aspects of collective phenomena that occur on online social media.

  14. Effects of tongue pressing effortful swallow in older healthy individuals.

    Science.gov (United States)

    Park, Taeok; Kim, Youngsun

    2016-01-01

    The risk of swallowing disorders is increased for older individuals due to weak tongue and pharyngeal muscle strength. This study was appraised the value of a preventative approach by developing the tongue pressing effortful swallow (TPES) applied using a home-based and self-administered procedure. The TPES was developed by combining two swallowing exercises: tongue strengthening exercise and the effortful swallow. The purpose of this study was to examine the effects of the TPES on maximum tongue pressure and peak amplitude of submental muscle activity in older individuals. 27 older individuals (mean 73 years) performed a 4-week TPES. The exercise program was adapted to a home-based and self-administered procedure. The maximum tongue pressure was measured by the Iowa Oral Performance Instrument and peak amplitude of submental muscle activity by surface electromyography (sEMG). Statistical comparisons were made by a matched pairs t-test (ptongue pressure, but the peak amplitude of the submental sEMG did not differ between before and after exercises. The TPES had a positive impact in older individuals. The TPES, a combining exercise, was possible because two exercises had common physiological events. The TPES was a more innovative and efficient approach than the tongue strengthening exercise alone. In addition, older individuals were able to perform the swallowing exercise at home and by themselves with little assistance. Future research needs to refine the TPES and apply it to patients with dysphagia. Published by Elsevier Ireland Ltd.

  15. Impact of different individual GNSS receiver antenna calibration models on geodetic positioning

    Science.gov (United States)

    Baire, Q.; Pottiaux, E.; Bruyninx, C.; Defraigne, P.; Aerts, W.; Legrand, J.; Bergeot, N.; Chevalier, J. M.

    2012-04-01

    Since April 2011, the igs08.atx antenna calibration model is used in the routine IGS (International GNSS Service) data analysis. The model includes mean robot calibrations to correct for the offset and phase center variations of the GNSS receiver antennas. These so-called "type" calibrations are means of the individual calibrations available for a specific antenna/radome combination. The GNSS data analysis performed within the EUREF Permanent Network (EPN) aims at being as consistent as possible with the IGS analysis. This also applies to the receiver antenna calibrations. However, when available, individual antenna calibrations are used within the EPN analysis instead of the "type" calibration. When these individual calibrations are unavailable, then the EPN analysis falls back to (type) calibrations identical as the ones used within the IGS (igs08.atx). The aim of this study is to evaluate the significance of the offset caused by using different receiver antenna calibration models on the station position. Using the PPP (Precise Point Positioning) technique, we first investigate the differences in positioning obtained when switching between individual antenna calibrations and type calibrations. We analyze the observations of the 43 EPN stations equipped with receiver antenna individually calibrated over the period covering from 2003 to 2010 and we show that these differences can reach up to 4 mm in horizontal and 10 mm in vertical. Secondly, we study the accuracy of the individual calibrations models and we evaluate the effect of different sets of individual calibrations on the positioning. For that purpose, we use the data from 6 GNSS stations equipped with an antenna which has been individually calibrated at two calibration facilities recognized by the IGS: GEO++ and Bonn institute.

  16. The Effects of Individual Disengagement on Insurgency Campaigns

    Science.gov (United States)

    2010-12-01

    Embeddedness and Job Search Behaviors Influence Quitting,” Academy of Management Journal, 52, no. 3 (2009): 545. 50 Terence R. Mitchell, Brooks C...Holtom, Thomas W. Lee, Chris J. Sablynski, and Miriam Erez, “Why People Stay: Using Job Embeddedness to Predict Voluntary Turnover,” Academy of...support.58 This consequence has longer-term effects for the individual as new friendship ties take a significant amount of time to develop . D

  17. Beyond modeling abstractions: Learning nouns over developmental time in atypical populations and individuals

    Directory of Open Access Journals (Sweden)

    Clare eSims

    2013-11-01

    Full Text Available Connectionist models that capture developmental change over time have much to offer in the field of language development research. Several models in the literature have made good contact with developmental data, effectively captured behavioral tasks, and accurately represented linguistic input available to young children. However, fewer models of language development have truly captured the process of developmental change over time. In this review paper, we discuss several prominent connectionist models of early word learning, focusing on semantic development, as well as our recent work modeling the emergence of word learning biases in different populations. We also discuss the potential of these kinds of models to capture children’s language development at the individual level. We argue that a modeling approach that truly captures change over time has the potential to inform theory, guide research, and lead to innovations in early language intervention.

  18. Priming and Habituation for Faces: Individual Differences and Inversion Effects

    Science.gov (United States)

    Rieth, Cory A.; Huber, David E.

    2010-01-01

    Immediate repetition priming for faces was examined across a range of prime durations in a threshold identification task. Similar to word repetition priming results, short duration face primes produced positive priming whereas long duration face primes eliminated or reversed this effect. A habituation model of such priming effects predicted that…

  19. Can plasticity make spatial structure irrelevant in individual-tree models?

    Directory of Open Access Journals (Sweden)

    Oscar García

    2014-08-01

    Full Text Available Background Distance-dependent individual-tree models have commonly been found to add little predictive power to that of distance-independent ones. One possible reason is plasticity, the ability of trees to lean and to alter crown and root development to better occupy available growing space. Being able to redeploy foliage (and roots into canopy gaps and less contested areas can diminish the importance of stem ground locations. Methods Plasticity was simulated for 3 intensively measured forest stands, to see to what extent and under what conditions the allocation of resources (e.g., light to the individual trees depended on their ground coordinates. The data came from 50 × 60 m stem-mapped plots in natural monospecific stands of jack pine, trembling aspen and black spruce from central Canada. Explicit perfect-plasticity equations were derived for tessellation-type models. Results Qualitatively similar simulation results were obtained under a variety of modelling assumptions. The effects of plasticity varied somewhat with stand uniformity and with assumed plasticity limits and other factors. Stand-level implications for canopy depth, distribution modelling and total productivity were examined. Conclusions Generally, under what seem like conservative maximum plasticity constraints, spatial structure accounted for less than 10% of the variance in resource allocation. The perfect-plasticity equations approximated well the simulation results from tessellation models, but not those from models with less extreme competition asymmetry. Whole-stand perfect plasticity approximations seem an attractive alternative to individual-tree models.

  20. Is group pelvic floor retraining as effective as individual treatment?

    Science.gov (United States)

    Jones, H J S; Gosselink, M P; Fourie, S; Lindsey, I

    2015-06-01

    Traditionally, pelvic floor retraining for faecal incontinence or obstructed defaecation has been delivered to patients through individual sessions with a specialist pelvic floor nurse, a resource-intensive practice. This study aimed to assess whether a similar outcome can be achieved by delivering retraining to patients in small groups, allowing considerable savings in the use of resources. Data were collected prospectively in a pelvic floor database. Patients received pelvic floor retraining either individually or in a small group setting and completed baseline and follow-up questionnaires. Two hundred and fifteen patients were treated, 119 individually and 96 in a small group setting. Scores before and after treatment for the two settings were compared for the Gastrointestinal Quality of Life Index, the Fecal Incontinence Severity Index and the Patient Assessment of Constipation Symptoms. Additionally patients receiving group treatment completed a short questionnaire on their experience. The median change in Gastrointestinal Quality of Life Index score was 5 (range -62 to 73) for individual treatment and 4 (range -41 to 47) for group treatment, both showing statistically significant improvement. However, there was no significant difference between the settings. Similar results were obtained with the Fecal Incontinence Severity Index and Patient Assessment of Constipation Symptoms scores for the faecal incontinence and obstructed defaecation subgroups respectively. The majority of patients experienced symptomatic improvement following pelvic floor retraining and there was no significant difference in the resulting improvement according to treatment setting. As treatment costs are considerably less in a group setting, group pelvic floor retraining is more cost-effective than individual treatment. Colorectal Disease © 2014 The Association of Coloproctology of Great Britain and Ireland.

  1. THE WORLD-MODELLING POTENCY OF THE INDIVIDUAL METAPHOR

    Directory of Open Access Journals (Sweden)

    Pavlova, M.S.

    2016-03-01

    Full Text Available This article analyzes individual metaphors as a fundamental component of the artistic worldview. The research discusses the correlation between the individual metaphor and interdiscourse markedness that allows identifying some peculiarities of cultural identity of the English-language literary text. The central place belongs to the propositions connected with the ways of reality conceptualization in the minds of the English-speaking mentality, which are necessary for correct interpretation of the cultural-specific information.

  2. From Genes to Ecosystems in Microbiology: Modeling Approaches and the Importance of Individuality

    Directory of Open Access Journals (Sweden)

    Jan-Ulrich Kreft

    2017-11-01

    Full Text Available Models are important tools in microbial ecology. They can be used to advance understanding by helping to interpret observations and test hypotheses, and to predict the effects of ecosystem management actions or a different climate. Over the past decades, biological knowledge and ecosystem observations have advanced to the molecular and in particular gene level. However, microbial ecology models have changed less and a current challenge is to make them utilize the knowledge and observations at the genetic level. We review published models that explicitly consider genes and make predictions at the population or ecosystem level. The models can be grouped into three general approaches, i.e., metabolic flux, gene-centric and agent-based. We describe and contrast these approaches by applying them to a hypothetical ecosystem and discuss their strengths and weaknesses. An important distinguishing feature is how variation between individual cells (individuality is handled. In microbial ecosystems, individual heterogeneity is generated by a number of mechanisms including stochastic interactions of molecules (e.g., gene expression, stochastic and deterministic cell division asymmetry, small-scale environmental heterogeneity, and differential transport in a heterogeneous environment. This heterogeneity can then be amplified and transferred to other cell properties by several mechanisms, including nutrient uptake, metabolism and growth, cell cycle asynchronicity and the effects of age and damage. For example, stochastic gene expression may lead to heterogeneity in nutrient uptake enzyme levels, which in turn results in heterogeneity in intracellular nutrient levels. Individuality can have important ecological consequences, including division of labor, bet hedging, aging and sub-optimality. Understanding the importance of individuality and the mechanism(s underlying it for the specific microbial system and question investigated is essential for selecting the

  3. An individual-based modelling approach to estimate landscape connectivity for bighorn sheep (Ovis canadensis

    Directory of Open Access Journals (Sweden)

    Corrie H. Allen

    2016-05-01

    Full Text Available Background. Preserving connectivity, or the ability of a landscape to support species movement, is among the most commonly recommended strategies to reduce the negative effects of climate change and human land use development on species. Connectivity analyses have traditionally used a corridor-based approach and rely heavily on least cost path modeling and circuit theory to delineate corridors. Individual-based models are gaining popularity as a potentially more ecologically realistic method of estimating landscape connectivity. However, this remains a relatively unexplored approach. We sought to explore the utility of a simple, individual-based model as a land-use management support tool in identifying and implementing landscape connectivity. Methods. We created an individual-based model of bighorn sheep (Ovis canadensis that simulates a bighorn sheep traversing a landscape by following simple movement rules. The model was calibrated for bighorn sheep in the Okanagan Valley, British Columbia, Canada, a region containing isolated herds that are vital to conservation of the species in its northern range. Simulations were run to determine baseline connectivity between subpopulations in the study area. We then applied the model to explore two land management scenarios on simulated connectivity: restoring natural fire regimes and identifying appropriate sites for interventions that would increase road permeability for bighorn sheep. Results. This model suggests there are no continuous areas of good habitat between current subpopulations of sheep in the study area; however, a series of stepping-stones or circuitous routes could facilitate movement between subpopulations and into currently unoccupied, yet suitable, bighorn habitat. Restoring natural fire regimes or mimicking fire with prescribed burns and tree removal could considerably increase bighorn connectivity in this area. Moreover, several key road crossing sites that could benefit from

  4. Continuous time modelling with individually varying time intervals for oscillating and non-oscillating processes.

    Science.gov (United States)

    Voelkle, Manuel C; Oud, Johan H L

    2013-02-01

    When designing longitudinal studies, researchers often aim at equal intervals. In practice, however, this goal is hardly ever met, with different time intervals between assessment waves and different time intervals between individuals being more the rule than the exception. One of the reasons for the introduction of continuous time models by means of structural equation modelling has been to deal with irregularly spaced assessment waves (e.g., Oud & Delsing, 2010). In the present paper we extend the approach to individually varying time intervals for oscillating and non-oscillating processes. In addition, we show not only that equal intervals are unnecessary but also that it can be advantageous to use unequal sampling intervals, in particular when the sampling rate is low. Two examples are provided to support our arguments. In the first example we compare a continuous time model of a bivariate coupled process with varying time intervals to a standard discrete time model to illustrate the importance of accounting for the exact time intervals. In the second example the effect of different sampling intervals on estimating a damped linear oscillator is investigated by means of a Monte Carlo simulation. We conclude that it is important to account for individually varying time intervals, and encourage researchers to conceive of longitudinal studies with different time intervals within and between individuals as an opportunity rather than a problem. © 2012 The British Psychological Society.

  5. A global model of stress in parents of individuals with autism spectrum disorders (ASD

    Directory of Open Access Journals (Sweden)

    Pilar Pozo

    2014-01-01

    Full Text Available This research sought to analyse stress among mothers and fathers of individuals with autism spectrum disorders (ASD to determine the relevant variables for its explanation and the possible gender differences. To examine parents' stress, we propose a multidimensional model based on the Double ABCX theoretical model. We argue that the result of stress depends on the following four interrelated factors: the characteristics of the individual with ASD (the severity of the disorder and behaviour problems, the social supports, the parents' perception of the situation (evaluated by sense of coherence and the coping strategies. Fiftynine sets of parents (59 mothers and 59 fathers of individuals diagnosed with ASD participated in the study. The data were analysed using a path analysis through the LISREL 8.80 program. We obtained two empirical models of stress: one model for mothers and one for fathers. In both models, the severity of the disorder and the behaviour problems had a direct and positive effect on stress. The sense of coherence (SOC and active avoidance coping strategies had a mediating role in models. Social support was relevant only for mothers. Finally, the results offer some guidelines for professionals working with families.

  6. An individual-based model simulating goat response variability and long-term herd performance.

    Science.gov (United States)

    Puillet, L; Martin, O; Sauvant, D; Tichit, M

    2010-12-01

    Finding ways of increasing the efficiency of production systems is a key issue of sustainability. System efficiency is based on long-term individual efficiency, which is highly variable and management driven. To study the effects of management on herd and individual efficiency, we developed the model simulation of goat herd management (SIGHMA). This dynamic model is individual-based and represents the interactions between technical operations (relative to replacement, reproduction and feeding) and individual biological processes (performance dynamics based on energy partitioning and production potential). It simulates outputs at both herd and goat levels over 20 years. A farmer's production project (i.e. a targeted milk production pattern) is represented by configuring the herd into female groups reflecting the organisation of kidding periods. Each group is managed by discrete events applying decision rules to simulate the carrying out of technical operations. The animal level is represented by a set of individual goat models. Each model simulates a goat's biological dynamics through its productive life. It integrates the variability of biological responses driven by genetic scaling parameters (milk production potential and mature body weight), by the regulations of energy partitioning among physiological functions and by responses to diet energy defined by the feeding strategy. A sensitivity analysis shows that herd efficiency was mainly affected by feeding management and to a lesser extent by the herd production potential. The same effects were observed on herd milk feed costs with an even lower difference between production potential and feeding management. SIGHMA was used in a virtual experiment to observe the effects of feeding strategies on herd and individual performances. We found that overfeeding led to a herd production increase and a feed cost decrease. However, this apparent increase in efficiency at the herd level (as feed cost decreased) was related

  7. Grasping Kinematics from the Perspective of the Individual Digits: A Modelling Study

    Science.gov (United States)

    Verheij, Rebekka; Brenner, Eli; Smeets, Jeroen B. J.

    2012-01-01

    Grasping is a prototype of human motor coordination. Nevertheless, it is not known what determines the typical movement patterns of grasping. One way to approach this issue is by building models. We developed a model based on the movements of the individual digits. In our model the following objectives were taken into account for each digit: move smoothly to the preselected goal position on the object without hitting other surfaces, arrive at about the same time as the other digit and never move too far from the other digit. These objectives were implemented by regarding the tips of the digits as point masses with a spring between them, each attracted to its goal position and repelled from objects' surfaces. Their movements were damped. Using a single set of parameters, our model can reproduce a wider variety of experimental findings than any previous model of grasping. Apart from reproducing known effects (even the angles under which digits approach trapezoidal objects' surfaces, which no other model can explain), our model predicted that the increase in maximum grip aperture with object size should be greater for blocks than for cylinders. A survey of the literature shows that this is indeed how humans behave. The model can also adequately predict how single digit pointing movements are made. This supports the idea that grasping kinematics follow from the movements of the individual digits. PMID:22412997

  8. Building aggregate timber supply models from individual harvest choice

    Science.gov (United States)

    Maksym Polyakov; David N. Wear; Robert Huggett

    2009-01-01

    Timber supply has traditionally been modelled using aggregate data. In this paper, we build aggregate supply models for four roundwood products for the US state of North Carolina from a stand-level harvest choice model applied to detailed forest inventory. The simulated elasticities of pulpwood supply are much lower than reported by previous studies. Cross price...

  9. Impulsive vaccination and dispersal on dynamics of an SIR epidemic model with restricting infected individuals boarding transports

    Science.gov (United States)

    Jiao, Jianjun; Cai, Shaohong; Li, Limei

    2016-05-01

    To understand the effect of impulsive vaccination and restricting infected individuals boarding transports on disease spread, we establish an SIR model with impulsive vaccination, impulsive dispersal and restricting infected individuals boarding transports. This SIR epidemic model for two regions, which are connected by transportation of non-infected individuals, portrays the evolvement of diseases. We prove that all solutions of the investigated system are uniformly ultimately bounded. We also prove that there exists globally asymptotically stable infection-free boundary periodic solution. The condition for permanence is discussed. It is concluded that the approach of impulsive vaccination and restricting infected individuals boarding transports provides reliable tactic basis for preventing disease spread.

  10. An individual-based growth and competition model for coastal redwood forest restoration

    Science.gov (United States)

    van Mantgem, Phillip J.; Das, Adrian J.

    2014-01-01

    Thinning treatments to accelerate coastal redwood forest stand development are in wide application, but managers have yet to identify prescriptions that might best promote Sequoia sempervirens (Lamb. ex D. Don) Endl. (redwood) growth. The creation of successful thinning prescriptions would be aided by identifying the underlying mechanisms governing how individual tree growth responds to competitive environments in coastal redwood forests. We created a spatially explicit individual-based model of tree competition and growth parameterized using surveys of upland redwood forests at Redwood National Park, California. We modeled competition for overstory trees (stems ≥ 20 cm stem diameter at breast height, 1.37 m (dbh)) as growth reductions arising from sizes, distances, and species identity of competitor trees. Our model explained up to half of the variation in individual tree growth, suggesting that neighborhood crowding is an important determinant of growth in this forest type. We used our model to simulate the effects of novel thinning prescriptions (e.g., 40% stand basal area removal) for redwood forest restoration, concluding that these treatments could lead to substantial growth releases, particularly for S. sempervirens. The results of this study, along with continued improvements to our model, will help to determine spacing and species composition that best encourage growth.

  11. Effects of Web-Based Collaborative Writing on Individual L2 Writing Development

    Science.gov (United States)

    Bikowski, Dawn; Vithanage, Ramyadarshanie

    2016-01-01

    This study investigated the effect of repeated in-class web-based collaborative writing tasks on second language writers' (L2) individual writing scores. A pre-test post-test research model was used in addition to participant surveys, class observations, and teacher interviews. Participants included 59 L2 writers in a writing class at a large U.S.…

  12. The Combined Use of Video Modeling and Social Stories in Teaching Social Skills for Individuals with Intellectual Disability

    Science.gov (United States)

    Gül, Seray Olçay

    2016-01-01

    There are many studies in the literature in which individuals with intellectual disabilities exhibit social skills deficits and which show the need for teaching these skills systematically. This study aims to investigate the effects of an intervention package of consisting computer-presented video modeling and Social Stories on individuals with…

  13. Photovoltaic effect in individual asymmetrically contacted lead sulfide nanosheets

    Science.gov (United States)

    Dogan, Sedat; Bielewicz, Thomas; Lebedeva, Vera; Klinke, Christian

    2015-03-01

    Solution-processable, two-dimensional semiconductors are promising optoelectronic materials which could find application in low-cost solar cells. Lead sulfide nanocrystals raised attention since the effective band gap can be adapted over a wide range by electronic confinement and observed multi-exciton generation promises higher efficiencies. We report on the influence of the contact metal work function on the properties of transistors based on individual two-dimensional lead sulfide nanosheets. Using palladium we observed mobilities of up to 31 cm2 V-1 s-1. Furthermore, we demonstrate that asymmetrically contacted nanosheets show photovoltaic effect and that the nanosheets' height has a decisive impact on the device performance. Nanosheets with a thickness of 5.4 nm contacted with platinum and titanium show a power conversion efficiency of up to 0.94% (EQE 75.70%). The results underline the high hopes put on such materials.Solution-processable, two-dimensional semiconductors are promising optoelectronic materials which could find application in low-cost solar cells. Lead sulfide nanocrystals raised attention since the effective band gap can be adapted over a wide range by electronic confinement and observed multi-exciton generation promises higher efficiencies. We report on the influence of the contact metal work function on the properties of transistors based on individual two-dimensional lead sulfide nanosheets. Using palladium we observed mobilities of up to 31 cm2 V-1 s-1. Furthermore, we demonstrate that asymmetrically contacted nanosheets show photovoltaic effect and that the nanosheets' height has a decisive impact on the device performance. Nanosheets with a thickness of 5.4 nm contacted with platinum and titanium show a power conversion efficiency of up to 0.94% (EQE 75.70%). The results underline the high hopes put on such materials. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr06957a

  14. A mechanistic spatio-temporal framework for modelling individual-to-individual transmission-With an application to the 2014-2015 West Africa Ebola outbreak.

    Directory of Open Access Journals (Sweden)

    Max S Y Lau

    2017-10-01

    Full Text Available In recent years there has been growing availability of individual-level spatio-temporal disease data, particularly due to the use of modern communicating devices with GPS tracking functionality. These detailed data have been proven useful for inferring disease transmission to a more refined level than previously. However, there remains a lack of statistically sound frameworks to model the underlying transmission dynamic in a mechanistic manner. Such a development is particularly crucial for enabling a general epidemic predictive framework at the individual level. In this paper we propose a new statistical framework for mechanistically modelling individual-to-individual disease transmission in a landscape with heterogeneous population density. Our methodology is first tested using simulated datasets, validating our inferential machinery. The methodology is subsequently applied to data that describes a regional Ebola outbreak in Western Africa (2014-2015. Our results show that the methods are able to obtain estimates of key epidemiological parameters that are broadly consistent with the literature, while revealing a significantly shorter distance of transmission. More importantly, in contrast to existing approaches, we are able to perform a more general model prediction that takes into account the susceptible population. Finally, our results show that, given reasonable scenarios, the framework can be an effective surrogate for susceptible-explicit individual models which are often computationally challenging.

  15. A watershed model of individual differences in fluid intelligence.

    Science.gov (United States)

    Kievit, Rogier A; Davis, Simon W; Griffiths, John; Correia, Marta M; Cam-Can; Henson, Richard N

    2016-10-01

    Fluid intelligence is a crucial cognitive ability that predicts key life outcomes across the lifespan. Strong empirical links exist between fluid intelligence and processing speed on the one hand, and white matter integrity and processing speed on the other. We propose a watershed model that integrates these three explanatory levels in a principled manner in a single statistical model, with processing speed and white matter figuring as intermediate endophenotypes. We fit this model in a large (N=555) adult lifespan cohort from the Cambridge Centre for Ageing and Neuroscience (Cam-CAN) using multiple measures of processing speed, white matter health and fluid intelligence. The model fit the data well, outperforming competing models and providing evidence for a many-to-one mapping between white matter integrity, processing speed and fluid intelligence. The model can be naturally extended to integrate other cognitive domains, endophenotypes and genotypes. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  16. Departure time choice: Modelling individual preferences, intention and constraints

    DEFF Research Database (Denmark)

    Thorhauge, Mikkel

    to change their departure time rather than changing their transport mode to avoid congestion (Hendrickson and Planke, 1984; SACTRA, 1994; Kroes et al., 1996; Hess et al., 2007a). Hence, understanding the departure time choice from an individual perspective is important to develop policies aimed to address...... working hours) as the penalty of late arrival is very likely to be higher for individuals with constraints on arrival time. However, flexibility is not only a matter of fixed arrival time. Activities can be mandatory or discretionary (Yamamoto and Kitamura, 1999), performed alone or jointly with family...... departure time. Parallel with the micro-economic theory, the psychology literature has evidenced that individuals’ behaviours are driven by underlying latent constructs, such as attitude, norms and perceptions. In the past decades, more attention has been given to incorporate and understand underlying...

  17. An individual-based model of rabbit viral haemorrhagic disease on European wild rabbits (Oryctolagus cuniculus)

    Science.gov (United States)

    Fa, John E.; Sharples, Colin M.; Bell, Diana J.; DeAngelis, Donald L.

    2001-01-01

    We developed an individual-based model of Rabbit Viral Hemorrhagic Disease (RVHD) for European wild rabbits (Oryctolagus cuniculus L.), representing up to 1000 rabbits in four hectares. Model output for productivity and recruitment matched published values. The disease was density-dependent and virulence affected outcome. Strains that caused death after several days produced greater overall mortality than strains in which rabbits either died or recovered very quickly. Disease effect also depended on time of year. We also elaborated a larger scale model representing 25 km2 and 100,000+ rabbits, split into a number of grid-squares. This was a more traditional model that did not represent individual rabbits, but employed a system of dynamic equations for each grid-square. Disease spread depended on probability of transmission between neighboring grid-squares. Potential recovery from a major population crash caused by the disease relied on disease virulence and frequency of recurrence. The model's dependence on probability of disease transmission between grid-squares suggests the way that the model represents the spatial distribution of the population affects simulation. Although data on RVHD in Europe are lacking, our models provide a basis for describing the disease in realistic detail and for assessing influence of various social and spatial factors on spread.

  18. Job crafting: Towards a new model of individual job redesign

    Directory of Open Access Journals (Sweden)

    Maria Tims

    2010-12-01

    Research purpose: The purpose of the study was to fit job crafting in job design theory. Motivation for the study: The study was an attempt to shed more light on the types of proactive behaviours of individual employees at work. Moreover, we explored the concept of job crafting and its antecedents and consequences. Research design, approach and method: A literature study was conducted in which the focus was first on proactive behaviour of the employee and then on job crafting. Main findings: Job crafting can be seen as a specific form of proactive behaviour in which the employee initiates changes in the level of job demands and job resources. Job crafting may be facilitated by job and individual characteristics and may enable employees to fit their jobs to their personal knowledge, skills and abilities on the one hand and to their preferences and needs on the other hand. Practical/managerial implications: Job crafting may be a good way for employees to improve their work motivation and other positive work outcomes. Employees could be encouraged to exert more influence on their job characteristics. Contribution/value-add: This article describes a relatively new perspective on active job redesign by the individual, called job crafting, which has important implications for job design theories.

  19. [Relationship between two models of personality in old individuals].

    Science.gov (United States)

    Calvet, Benjamin; Bricaud, Magali; Clément, Jean-Pierre

    2014-12-01

    The relationships between the seven dimensions of the Cloninger psychobiological model and the five factors of the Costa and McCrae model were examined in 54 elderly subjects from the French general population. The dimensions of temperament (novelty seeking, harm avoidance, reward dependence) and character (determination, cooperation, transcendence) from the Cloninger's model were measured by the temperament and character inventory whereas the five factors of Costa and McCrae model (neuroticism, extraversion, openness to experience, agreeableness and conscientiousness) were evaluated using the NEO PI-R. Multiple regression analyses show that some dimensions of the temperament and character inventory predict some dimensions of the Big five and vice versa. Therefore we suggest that the Big five model could be related to brain monoaminergic activities.

  20. Individually dosed omalizumab: an effective treatment for severe peanut allergy.

    Science.gov (United States)

    Brandström, J; Vetander, M; Lilja, G; Johansson, S G O; Sundqvist, A-C; Kalm, F; Nilsson, C; Nopp, A

    2017-04-01

    Treatment with omalizumab has shown a positive effect on food allergies, but no dosages are established. Basophil allergen threshold sensitivity (CD-sens) can be used to objectively measure omalizumab treatment efficacy and correlates with the outcome of double-blind placebo-controlled food challenge to peanut. To evaluate whether individualized omalizumab treatment monitored by CD-sens could be an effective intervention for suppression of allergic reactions to peanut. Severely peanut allergic adolescents (n = 23) were treated with omalizumab for 8 weeks, and CD-sens was analysed before and after. Based on whether CD-sens was suppressed after 8 weeks, the patients either were subject to a peanut challenge or received eight more weeks with increased dose of omalizumab, followed by peanut challenge or another 8-week cycle of omalizumab. IgE and IgE-antibodies to peanut and its components were analysed before treatment. After individualized omalizumab treatment (8-24 weeks), all patients continued with an open peanut challenge with no (n = 18) or mild (n = 5) objective allergic symptoms. Patients (n = 15) needing an elevated omalizumab dose (ED) to suppress CD-sens had significantly higher CD-sens values at baseline 1.49 (0.44-20.5) compared to those (n = 8) who managed with normal dose (ND) 0.32 (0.24-5.5) (P omalizumab, monitored by CD-sens, is an effective and safe treatment for severe peanut allergy. The ratio of IgE-ab to storage protein Ara h 2/IgE as well as CD-sens to peanut may predict the need of a higher omalizumab dose. Clinical trials numbers: EudraCT; 2012-005625-78, ClinicalTrials.gov; NCT02402231. © 2016 John Wiley & Sons Ltd.

  1. Individual class evaluation and effective teaching characteristics in integrated curricula.

    Science.gov (United States)

    Hwang, Jung Eun; Kim, Na Jin; Song, Meiying; Cui, Yinji; Kim, Eun Ju; Park, In Ae; Lee, Hye In; Gong, Hye Jin; Kim, Su Young

    2017-12-12

    In an integrated curriculum, multiple instructors take part in a course in the form of team teaching. Accordingly, medical schools strive to manage each course run by numerous instructors. As part of the curriculum management, course evaluation is conducted, but a single, retrospective course evaluation does not comprehensively capture student perception of classes by different instructors. This study aimed to demonstrate the need for individual class evaluation, and further to identify teaching characteristics that instructors need to keep in mind when preparing classes. From 2014 to 2015, students at one medical school left comments on evaluation forms after each class. Courses were also assessed after each course. Their comments were categorized by connotation (positive or negative) and by subject. Within each subject category, test scores were compared between positively and negatively mentioned classes. The Mann-Whitney U test was performed to test group differences in scores. The same method was applied to the course evaluation data. Test results for course evaluation showed group difference only in the practice/participation category. However, test results for individual class evaluation showed group differences in six categories: difficulty, main points, attitude, media/contents, interest, and materials. That is, the test scores of classes positively mentioned in six domains were significantly higher than those of negatively mentioned classes. It was proved that individual class evaluation is needed to manage multi-instructor courses in integrated curricula of medical schools. Based on the students' extensive feedback, we identified teaching characteristics statistically related to academic achievement. School authorities can utilize these findings to encourage instructors to develop effective teaching characteristics in class preparation.

  2. Targeted screening of individuals at high risk for pancreatic cancer: results of a simulation model.

    Science.gov (United States)

    Pandharipande, Pari V; Heberle, Curtis; Dowling, Emily C; Kong, Chung Yin; Tramontano, Angela; Perzan, Katherine E; Brugge, William; Hur, Chin

    2015-04-01

    To identify when, from the standpoint of relative risk, magnetic resonance (MR) imaging-based screening may be effective in patients with a known or suspected genetic predisposition to pancreatic cancer. The authors developed a Markov model of pancreatic ductal adenocarcinoma (PDAC). The model was calibrated to National Cancer Institute Surveillance, Epidemiology, and End Results registry data and informed by the literature. A hypothetical screening strategy was evaluated in which all population individuals underwent one-time MR imaging screening at age 50 years. Screening outcomes for individuals with an average risk for PDAC ("base case") were compared with those for individuals at an increased risk to assess for differential benefits in populations with a known or suspected genetic predisposition. Effects of varying key inputs, including MR imaging performance, surgical mortality, and screening age, were evaluated with a sensitivity analysis. RESULTS In the base case, screening resulted in a small number of cancer deaths averted (39 of 100 000 men, 38 of 100 000 women) and a net decrease in life expectancy (-3 days for men, -4 days for women), which was driven by unnecessary pancreatic surgeries associated with false-positive results. Life expectancy gains were achieved if an individual's risk for PDAC exceeded 2.4 (men) or 2.7 (women) times that of the general population. When relative risk increased further, for example to 30 times that of the general population, averted cancer deaths and life expectancy gains increased substantially (1219 of 100 000 men, life expectancy gain: 65 days; 1204 of 100 000 women, life expectancy gain: 71 days). In addition, results were sensitive to MR imaging specificity and the surgical mortality rate. Although PDAC screening with MR imaging for the entire population is not effective, individuals with even modestly increased risk may benefit. © RSNA, 2014 Online supplemental material is available for this article.

  3. Sensitivity analysis of an individual-based model for simulation of influenza epidemics.

    Directory of Open Access Journals (Sweden)

    Elaine O Nsoesie

    Full Text Available Individual-based epidemiology models are increasingly used in the study of influenza epidemics. Several studies on influenza dynamics and evaluation of intervention measures have used the same incubation and infectious period distribution parameters based on the natural history of influenza. A sensitivity analysis evaluating the influence of slight changes to these parameters (in addition to the transmissibility would be useful for future studies and real-time modeling during an influenza pandemic.In this study, we examined individual and joint effects of parameters and ranked parameters based on their influence on the dynamics of simulated epidemics. We also compared the sensitivity of the model across synthetic social networks for Montgomery County in Virginia and New York City (and surrounding metropolitan regions with demographic and rural-urban differences. In addition, we studied the effects of changing the mean infectious period on age-specific epidemics. The research was performed from a public health standpoint using three relevant measures: time to peak, peak infected proportion and total attack rate. We also used statistical methods in the design and analysis of the experiments. The results showed that: (i minute changes in the transmissibility and mean infectious period significantly influenced the attack rate; (ii the mean of the incubation period distribution appeared to be sufficient for determining its effects on the dynamics of epidemics; (iii the infectious period distribution had the strongest influence on the structure of the epidemic curves; (iv the sensitivity of the individual-based model was consistent across social networks investigated in this study and (v age-specific epidemics were sensitive to changes in the mean infectious period irrespective of the susceptibility of the other age groups. These findings suggest that small changes in some of the disease model parameters can significantly influence the uncertainty

  4. Individual discriminative face recognition models based on subsets of features

    DEFF Research Database (Denmark)

    Clemmensen, Line Katrine Harder; Gomez, David Delgado; Ersbøll, Bjarne Kjær

    2007-01-01

    The accuracy of data classification methods depends considerably on the data representation and on the selected features. In this work, the elastic net model selection is used to identify meaningful and important features in face recognition. Modelling the characteristics which distinguish one...... selection techniques such as forward selection or lasso regression become inadequate. In the experimental section, the performance of the elastic net model is compared with geometrical and color based algorithms widely used in face recognition such as Procrustes nearest neighbor, Eigenfaces, or Fisher...

  5. Individualized Human CAD Models: Anthropmetric Morphing and Body Tissue Layering

    Science.gov (United States)

    2014-07-31

    Part Flow Chart of the Interaction among VBA Macros, Excel® Spreadsheet, and SolidWorks Front View of the Male and Female Soldier CAD Model...yellow highlighting. The spreadsheet is linked to the CAD model by macros created with the Visual Basic for Application ( VBA ) editor in Microsoft Excel...basically three working parts to the anthropometric morphing that are all interconnected ( VBA macros, Excel spreadsheet, and SolidWorks). The flow

  6. Individual and population level effects of partner notification for Chlamydia trachomatis.

    Directory of Open Access Journals (Sweden)

    Christian L Althaus

    Full Text Available Partner notification (PN or contact tracing is an important aspect of treating bacterial sexually transmitted infections (STIs, such as Chlamydia trachomatis. It facilitates the identification of new infected cases that can be treated through individual case management. PN also acts indirectly by limiting onward transmission in the general population. However, the impact of PN, both at the level of individuals and the population, remains unclear. Since it is difficult to study the effects of PN empirically, mathematical and computational models are useful tools for investigating its potential as a public health intervention. To this end, we developed an individual-based modeling framework called Rstisim. It allows the implementation of different models of STI transmission with various levels of complexity and the reconstruction of the complete dynamic sexual partnership network over any time period. A key feature of this framework is that we can trace an individual's partnership history in detail and investigate the outcome of different PN strategies for C. trachomatis. For individual case management, the results suggest that notifying three or more partners from the preceding 18 months yields substantial numbers of new cases. In contrast, the successful treatment of current partners is most important for preventing re-infection of index cases and reducing further transmission of C. trachomatis at the population level. The findings of this study demonstrate the difference between individual and population level outcomes of public health interventions for STIs.

  7. Effects of Environmental Stress on Individual Decision Making

    Science.gov (United States)

    1987-12-15

    Strategies. The "Ways of Coping Inventory" ( Folkman & Lazarus , 1980) (see Appendix E) was used to measure coping strategies that subjects used while...334. Fisher, S. A distraction effect of noise bursts. ~erception, 1972, l• 233-236. Folkman , S. & Lazarus , R.S. An analysis of coping in a mirldle...sufficient for pituitary-adrenal activation. 2 3 The psychological stress model advanced by Lazarus (1966) views psychological variables as instrumental in

  8. Variation in Primary Cesarean Delivery Rates by Individual Physician within a Single Hospital Laborist Model

    Science.gov (United States)

    METZ, Torri D.; ALLSHOUSE, Amanda A.; GILBERT, Sara A Babcock; DOYLE, Reina; TONG, Angie; CAREY, J. Christopher

    2016-01-01

    Background Laborist practice models are associated with lower cesarean delivery rates than individual private practice models in several studies; however, this effect is not uniform. Further exploration of laborist models may help us better understand the observed reduction in cesarean delivery rates in some hospitals with implementation of a laborist model. Objective Our objective was to evaluate the degree of variation in primary cesarean delivery rates by individual laborists within a single institution employing a laborist model. In addition, we sought to evaluate whether differences in cesarean delivery rates resulted in different maternal or short-term neonatal outcomes. Study Design At this teaching institution, one laborist (either a generalist or maternal-fetal medicine attending physician) is directly responsible for labor and delivery management during each shift. No patients are followed in a private practice model nor are physicians incentivized to perform deliveries. We retrospectively identified all laborists who delivered nulliparous, term women with cephalic singletons at this institution from 2007-14. Overall and individual primary cesarean delivery rates were reported as percentages with exact Pearson 95% CI. Laborists were grouped by tertile as having low, medium or high cesarean delivery rates. Characteristics of the women delivered, indications for cesarean delivery, and short-term neonatal outcomes were compared between these groups. A binomial regression model of cesarean delivery was estimated, where the relative rates of each laborist compared to the lowest-unadjusted laborist rate were calculated; a second model was estimated to adjust for patient-level maternal characteristics. Results Twenty laborists delivered 2,224 nulliparous, term women with cephalic singletons. The overall cesarean delivery rate was 24.1% (95% CI 21.4-26.8). In an unadjusted binomial model, the overall effect of individual laborist was significant (pcesarean

  9. Illstrative probabilistic biosphere model for Yucca Mountain individual risk calculations

    International Nuclear Information System (INIS)

    Wilems, R.E.

    1994-01-01

    The proposed EPA Standards for the disposal of spent fuel, high-level and transuranic radioactive waste prescribe future biosphere--one in which no sustained human activity occurs inside the controlled zone, yet sustained use of groundwater occurs just outside the controlled zone boundary. Performance assessments have generally assumed a person at this location extracts all his water needs directly from the projected contaminated plume for all of his life. Dose to this maximally-exposed individual is too conservative a measure of performance for a nuclear waste repository and does not reflect the isolation characteristics of a site. A better measure is individual risk in which uncertainties in biosphere characteristics for the longer periods of performance, for a site like Yucca Mountain only those characteristics associated with well water scenarios need be prescribed. Such a prescription of the biosphere is appropriate because the goal of the regulations is to provide indicators of future performance so the regulators can make a responsible decision regarding reasonable assurance of public health and safety

  10. Individual discriminative face recognition models based on subsets of features

    DEFF Research Database (Denmark)

    Clemmensen, Line Katrine Harder; Gomez, David Delgado; Ersbøll, Bjarne Kjær

    2007-01-01

    of the face recognition problem. The elastic net model is able to select a subset of features with low computational effort compared to other state-of-the-art feature selection methods. Furthermore, the fact that the number of features usually is larger than the number of images in the data base makes feature......The accuracy of data classification methods depends considerably on the data representation and on the selected features. In this work, the elastic net model selection is used to identify meaningful and important features in face recognition. Modelling the characteristics which distinguish one...... person from another using only subsets of features will both decrease the computational cost and increase the generalization capacity of the face recognition algorithm. Moreover, identifying which are the features that better discriminate between persons will also provide a deeper understanding...

  11. Developing population models with data from marked individuals

    Science.gov (United States)

    Hae Yeong Ryu,; Kevin T. Shoemaker,; Eva Kneip,; Anna Pidgeon,; Patricia Heglund,; Brooke Bateman,; Thogmartin, Wayne E.; Reşit Akçakaya,

    2016-01-01

    Population viability analysis (PVA) is a powerful tool for biodiversity assessments, but its use has been limited because of the requirements for fully specified population models such as demographic structure, density-dependence, environmental stochasticity, and specification of uncertainties. Developing a fully specified population model from commonly available data sources – notably, mark–recapture studies – remains complicated due to lack of practical methods for estimating fecundity, true survival (as opposed to apparent survival), natural temporal variability in both survival and fecundity, density-dependence in the demographic parameters, and uncertainty in model parameters. We present a general method that estimates all the key parameters required to specify a stochastic, matrix-based population model, constructed using a long-term mark–recapture dataset. Unlike standard mark–recapture analyses, our approach provides estimates of true survival rates and fecundities, their respective natural temporal variabilities, and density-dependence functions, making it possible to construct a population model for long-term projection of population dynamics. Furthermore, our method includes a formal quantification of parameter uncertainty for global (multivariate) sensitivity analysis. We apply this approach to 9 bird species and demonstrate the feasibility of using data from the Monitoring Avian Productivity and Survivorship (MAPS) program. Bias-correction factors for raw estimates of survival and fecundity derived from mark–recapture data (apparent survival and juvenile:adult ratio, respectively) were non-negligible, and corrected parameters were generally more biologically reasonable than their uncorrected counterparts. Our method allows the development of fully specified stochastic population models using a single, widely available data source, substantially reducing the barriers that have until now limited the widespread application of PVA. This method

  12. Conceptual Models of the Individual Public Service Provider

    DEFF Research Database (Denmark)

    Andersen, Lotte Bøgh; Bhatti, Yosef; Petersen, Ole Helby

    Individual public service providers’ motivation can be conceptualized as either extrinsic, autonomous or prosocial, and the question is how we can best theoretically understand this complexity without losing too much coherence and parsimony. Drawing on Allison’s approach (1969), three perspectives...... are used to gain insight on the motivation of public service providers; namely principal-agent theory, self-determination theory and public service motivation theory. We situate the theoretical discussions in the context of public service providers being transferred to private organizations...... as a consequence of outsourcing by the public sector. Although this empirical setting is interesting in itself, here it serves primarily as grist for a wider discussion on strategies for applying multiple theoretical approaches and crafting a theoretical synthesis. The key contribution of the paper is thus...

  13. An individual-level selection model for the apparent altruism ...

    Indian Academy of Sciences (India)

    Amotz Zahavi

    2018-02-16

    Feb 16, 2018 ... remain solitary when the rest have completed aggregation. Their response to starvation (apparently) is not to become part of an aggregate, but instead to take a chance on a fresh source of food appearing quickly. Modelling shows that given the right environmental conditions, this can work. (Tarnita et al.

  14. Modeling the Role of Networks and Individual Differences in Inter-Group Violence.

    Science.gov (United States)

    Isakov, Alexander; Holcomb, Amelia; Glowacki, Luke; Christakis, Nicholas A

    2016-01-01

    There is significant heterogeneity within and between populations in their propensity to engage in conflict. Most research has neglected the role of within-group effects in social networks in contributing to between-group violence and focused instead on the precursors and consequences of violence, or on the role of between-group ties. Here, we explore the role of individual variation and of network structure within a population in promoting and inhibiting group violence towards other populations. Motivated by ethnographic observations of collective behavior in a small-scale society, we describe a model with differentiated roles for individuals embedded within friendship networks. Using a simple model based on voting-like dynamics, we explore several strategies for influencing group-level behavior. When we consider changing population level attitude changes and introducing control nodes separately, we find that a particularly effective control strategy relies on exploiting network degree. We also suggest refinements to our model such as tracking fine-grained information spread dynamics that can lead to further enrichment in using evolutionary game theory models for sociological phenomena.

  15. Modeling the Role of Networks and Individual Differences in Inter-Group Violence.

    Directory of Open Access Journals (Sweden)

    Alexander Isakov

    Full Text Available There is significant heterogeneity within and between populations in their propensity to engage in conflict. Most research has neglected the role of within-group effects in social networks in contributing to between-group violence and focused instead on the precursors and consequences of violence, or on the role of between-group ties. Here, we explore the role of individual variation and of network structure within a population in promoting and inhibiting group violence towards other populations. Motivated by ethnographic observations of collective behavior in a small-scale society, we describe a model with differentiated roles for individuals embedded within friendship networks. Using a simple model based on voting-like dynamics, we explore several strategies for influencing group-level behavior. When we consider changing population level attitude changes and introducing control nodes separately, we find that a particularly effective control strategy relies on exploiting network degree. We also suggest refinements to our model such as tracking fine-grained information spread dynamics that can lead to further enrichment in using evolutionary game theory models for sociological phenomena.

  16. A finite-element reciprocity solution for EEG forward modeling with realistic individual head models.

    Science.gov (United States)

    Ziegler, Erik; Chellappa, Sarah L; Gaggioni, Giulia; Ly, Julien Q M; Vandewalle, Gilles; André, Elodie; Geuzaine, Christophe; Phillips, Christophe

    2014-12-01

    We present a finite element modeling (FEM) implementation for solving the forward problem in electroencephalography (EEG). The solution is based on Helmholtz's principle of reciprocity which allows for dramatically reduced computational time when constructing the leadfield matrix. The approach was validated using a 4-shell spherical model and shown to perform comparably with two current state-of-the-art alternatives (OpenMEEG for boundary element modeling and SimBio for finite element modeling). We applied the method to real human brain MRI data and created a model with five tissue types: white matter, gray matter, cerebrospinal fluid, skull, and scalp. By calculating conductivity tensors from diffusion-weighted MR images, we also demonstrate one of the main benefits of FEM: the ability to include anisotropic conductivities within the head model. Root-mean square deviation between the standard leadfield and the leadfield including white-matter anisotropy showed that ignoring the directional conductivity of white matter fiber tracts leads to orientation-specific errors in the forward model. Realistic head models are necessary for precise source localization in individuals. Our approach is fast, accurate, open-source and freely available online. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Mindfulness Training among Individuals with Parkinson's Disease: Neurobehavioral Effects

    Science.gov (United States)

    Pickut, Barbara; Hirsch, Mark A.; Van Hecke, Wim; Mariën, Peter; Parizel, Paul M.; Crosiers, David; Cras, Patrick

    2015-01-01

    Objective. To investigate possible neurobehavioral changes secondary to a mindfulness based intervention (MBI) training for individuals living with Parkinson's disease (PD). Background. In the context of complementary medicine, MBIs are increasingly being used for stress reduction and in patient populations coping with chronic illness. The use of alternative and complementary medicine may be higher in patients with chronic conditions such as PD. However, behavioral effects of mindfulness training in PD have not yet been reported in the literature and this points to an unmet need and warrants further examination. Methods. A total of 27 out of 30 PD patients completed a randomized controlled longitudinal trial. Questionnaires and the UPDRS I–IV were obtained at baseline and 8-week follow-up. Results. Significant changes after the MBI were found including a 5.5 point decrease on the UPDRS motor score, an increase of 0.79 points on Parkinson's disease questionnaire (PDQ-39) pain item, and a 3.15 point increase in the Five Facet Mindfulness Questionnaire observe facet. Conclusions. To the best of our knowledge, this is the first quantitative analysis of neurobehavioral effects of MBI in PD. PMID:26101690

  18. Ecological impacts of umbrella effects of radiation on the individual members

    International Nuclear Information System (INIS)

    Doi, Masahiro; Kawaguchi, Isao

    2007-01-01

    In order to study the interactions in a model aquatic microcosm, an individual-based computer simulation model was developed. The microcosm consists of Euglena gracilis as an autotroph algae, Tetrahymena thermophila as a heterotroph protozoa and Escherichia coli as a saprotroph bacteria. There exists a strong interaction between Tetrahymena and E. coli as the first is the predator of the second. Ecological toxicity tests were conducted to test the population level impacts of the biological effects of radiation and toxicants on the lethality and mobility factors that influence directly or indirectly growth and reproduction. Radiological effects on lethality of E. coli individuals were translated to the reduction of the equilibrium population of Tetrahymena. A synergistic effect at the community level was also observed by the simulation of a combined exposure of radiation and a toxicant which reduced the feeding efficiency of Tetrahymena

  19. Individualized prediction of perineural invasion in colorectal cancer: development and validation of a radiomics prediction model.

    Science.gov (United States)

    Huang, Yanqi; He, Lan; Dong, Di; Yang, Caiyun; Liang, Cuishan; Chen, Xin; Ma, Zelan; Huang, Xiaomei; Yao, Su; Liang, Changhong; Tian, Jie; Liu, Zaiyi

    2018-02-01

    To develop and validate a radiomics prediction model for individualized prediction of perineural invasion (PNI) in colorectal cancer (CRC). After computed tomography (CT) radiomics features extraction, a radiomics signature was constructed in derivation cohort (346 CRC patients). A prediction model was developed to integrate the radiomics signature and clinical candidate predictors [age, sex, tumor location, and carcinoembryonic antigen (CEA) level]. Apparent prediction performance was assessed. After internal validation, independent temporal validation (separate from the cohort used to build the model) was then conducted in 217 CRC patients. The final model was converted to an easy-to-use nomogram. The developed radiomics nomogram that integrated the radiomics signature and CEA level showed good calibration and discrimination performance [Harrell's concordance index (c-index): 0.817; 95% confidence interval (95% CI): 0.811-0.823]. Application of the nomogram in validation cohort gave a comparable calibration and discrimination (c-index: 0.803; 95% CI: 0.794-0.812). Integrating the radiomics signature and CEA level into a radiomics prediction model enables easy and effective risk assessment of PNI in CRC. This stratification of patients according to their PNI status may provide a basis for individualized auxiliary treatment.

  20. Process Mining for Individualized Behavior Modeling Using Wireless Tracking in Nursing Homes

    Directory of Open Access Journals (Sweden)

    Vicente Traver

    2013-11-01

    Full Text Available The analysis of human behavior patterns is increasingly used for several research fields. The individualized modeling of behavior using classical techniques requires too much time and resources to be effective. A possible solution would be the use of pattern recognition techniques to automatically infer models to allow experts to understand individual behavior. However, traditional pattern recognition algorithms infer models that are not readily understood by human experts. This limits the capacity to benefit from the inferred models. Process mining technologies can infer models as workflows, specifically designed to be understood by experts, enabling them to detect specific behavior patterns in users. In this paper, the eMotiva process mining algorithms are presented. These algorithms filter, infer and visualize workflows. The workflows are inferred from the samples produced by an indoor location system that stores the location of a resident in a nursing home. The visualization tool is able to compare and highlight behavior patterns in order to facilitate expert understanding of human behavior. This tool was tested with nine real users that were monitored for a 25-week period. The results achieved suggest that the behavior of users is continuously evolving and changing and that this change can be measured, allowing for behavioral change detection.

  1. Process Mining for Individualized Behavior Modeling Using Wireless Tracking in Nursing Homes

    Science.gov (United States)

    Fernández-Llatas, Carlos; Benedi, José-Miguel; García-Gómez, Juan M.; Traver, Vicente

    2013-01-01

    The analysis of human behavior patterns is increasingly used for several research fields. The individualized modeling of behavior using classical techniques requires too much time and resources to be effective. A possible solution would be the use of pattern recognition techniques to automatically infer models to allow experts to understand individual behavior. However, traditional pattern recognition algorithms infer models that are not readily understood by human experts. This limits the capacity to benefit from the inferred models. Process mining technologies can infer models as workflows, specifically designed to be understood by experts, enabling them to detect specific behavior patterns in users. In this paper, the eMotiva process mining algorithms are presented. These algorithms filter, infer and visualize workflows. The workflows are inferred from the samples produced by an indoor location system that stores the location of a resident in a nursing home. The visualization tool is able to compare and highlight behavior patterns in order to facilitate expert understanding of human behavior. This tool was tested with nine real users that were monitored for a 25-week period. The results achieved suggest that the behavior of users is continuously evolving and changing and that this change can be measured, allowing for behavioral change detection. PMID:24225907

  2. Modeling auditory perception of individual hearing-impaired listeners

    DEFF Research Database (Denmark)

    Jepsen, Morten Løve; Dau, Torsten

    showed that, in most cases, the reduced or absent cochlear compression, associated with outer hair-cell loss, quantitatively accounts for broadened auditory filters, while a combination of reduced compression and reduced inner hair-cell function accounts for decreased sensitivity and slower recovery from...... selectivity. Three groups of listeners were considered: (a) normal hearing listeners; (b) listeners with a mild-to-moderate sensorineural hearing loss; and (c) listeners with a severe sensorineural hearing loss. A fixed set of model parameters were derived for each hearing-impaired listener. The simulations...

  3. Magnetic field modeling with a set of individual localized coils.

    Science.gov (United States)

    Juchem, Christoph; Nixon, Terence W; McIntyre, Scott; Rothman, Douglas L; de Graaf, Robin A

    2010-06-01

    A set of generic, circular individual coils is shown to be capable of generating highly complex magnetic field distributions in a flexible fashion. Arbitrarily oriented linear field gradients can be generated in three-dimensional as well as sliced volumes at amplitudes that allow imaging applications. The multi-coil approach permits the simultaneous generation of linear MRI encoding fields and complex shim fields by the same setup, thereby reducing system complexity. The choice of the sensitive volume over which the magnetic fields are optimized remains temporally and spatially variable at all times. The restriction of the field synthesis to experimentally relevant, smaller volumes such as single slices directly translates into improved efficiency, i.e. higher magnetic field amplitudes and/or reduced coil currents. For applications like arterial spin labeling, signal spoiling and diffusion weighting, perfect linearity of the gradient fields is not required and reduced demands on accuracy can also be readily translated into improved efficiency. The first experimental realization was achieved for mouse head MRI with 24 coils that were mounted on the surface of a cylindrical former. Oblique linear field gradients of 20 kHz/cm (47 mT/m) were generated with a maximum current of 1.4A which allowed radial imaging of a mouse head. The potential of the new approach for generating arbitrary magnetic field shapes is demonstrated by synthesizing the more complex, higher order spherical harmonic magnetic field distributions X2-Y2, Z2 and Z2X. The new multi-coil approach provides the framework for the integration of conventional imaging and shim coils into a single multi-coil system in which shape, strength, accuracy and spatial coverage of the magnetic field can be specifically optimized for the application at hand. (c) 2010 Elsevier Inc. All rights reserved.

  4. CLRP: Individual evaluation of model performance for scenario S

    International Nuclear Information System (INIS)

    Krajewski, P.

    1996-01-01

    The model CLRP was created in 1989 as a part of research project ''Long-Lived Post-Chernobyl Radioactivity and Radiation Protection Criteria for Risk Reduction'' performed in cooperation with US Environmental Protection Agency. The aim of this project was to examine the fate of long-lived radionuclides in the terrestrial ecosystem. Concentrations of Cs-137 and Cs-134 in the particular components of terrestrial ecosystem e.g. soil, vegetation, animal tissues and animal products are calculated as a function of time following deposition from the atmosphere. Based on this data the whole body contents of radionuclide as a function of time is calculated and dose to a specific organ for the radionuclide may be estimated as an integral of the resultant dose rate over a sufficient period. In addition, the model allows estimation of inhalation dose from time integrated air concentration and external dose from total deposition using simple conversion factors. The program is designed to allow the simulation of many different radiological situations (chronic or acute releases) and dose affecting countermeasures. Figs, tabs

  5. Model-Based Individualized Treatment of Chemotherapeutics: Bayesian Population Modeling and Dose Optimization.

    Directory of Open Access Journals (Sweden)

    Devaraj Jayachandran

    Full Text Available 6-Mercaptopurine (6-MP is one of the key drugs in the treatment of many pediatric cancers, auto immune diseases and inflammatory bowel disease. 6-MP is a prodrug, converted to an active metabolite 6-thioguanine nucleotide (6-TGN through enzymatic reaction involving thiopurine methyltransferase (TPMT. Pharmacogenomic variation observed in the TPMT enzyme produces a significant variation in drug response among the patient population. Despite 6-MP's widespread use and observed variation in treatment response, efforts at quantitative optimization of dose regimens for individual patients are limited. In addition, research efforts devoted on pharmacogenomics to predict clinical responses are proving far from ideal. In this work, we present a Bayesian population modeling approach to develop a pharmacological model for 6-MP metabolism in humans. In the face of scarcity of data in clinical settings, a global sensitivity analysis based model reduction approach is used to minimize the parameter space. For accurate estimation of sensitive parameters, robust optimal experimental design based on D-optimality criteria was exploited. With the patient-specific model, a model predictive control algorithm is used to optimize the dose scheduling with the objective of maintaining the 6-TGN concentration within its therapeutic window. More importantly, for the first time, we show how the incorporation of information from different levels of biological chain-of response (i.e. gene expression-enzyme phenotype-drug phenotype plays a critical role in determining the uncertainty in predicting therapeutic target. The model and the control approach can be utilized in the clinical setting to individualize 6-MP dosing based on the patient's ability to metabolize the drug instead of the traditional standard-dose-for-all approach.

  6. Comparison of individual-based modeling and population approaches for prediction of foodborne pathogens growth.

    Science.gov (United States)

    Augustin, Jean-Christophe; Ferrier, Rachel; Hezard, Bernard; Lintz, Adrienne; Stahl, Valérie

    2015-02-01

    Individual-based modeling (IBM) approach combined with the microenvironment modeling of vacuum-packed cold-smoked salmon was more effective to describe the variability of the growth of a few Listeria monocytogenes cells contaminating irradiated salmon slices than the traditional population models. The IBM approach was particularly relevant to predict the absence of growth in 25% (5 among 20) of artificially contaminated cold-smoked salmon samples stored at 8 °C. These results confirmed similar observations obtained with smear soft cheese (Ferrier et al., 2013). These two different food models were used to compare the IBM/microscale and population/macroscale modeling approaches in more global exposure and risk assessment frameworks taking into account the variability and/or the uncertainty of the factors influencing the growth of L. monocytogenes. We observed that the traditional population models significantly overestimate exposure and risk estimates in comparison to IBM approach when contamination of foods occurs with a low number of cells (population model were characterized by a great uncertainty. The overestimation was mainly linked to the ability of IBM to predict no growth situations rather than the consideration of microscale environment. On the other hand, when the aim of quantitative risk assessment studies is only to assess the relative impact of changes in control measures affecting the growth of foodborne bacteria, the two modeling approach gave similar results and the simplest population approach was suitable. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. THE EFFECTS OF AUTOMATIC ENROLLMENT SYSTEM ON INDIVIDUAL PENSION SECTOR

    OpenAIRE

    AKIN, Faruk

    2018-01-01

    When compared to its worldwide applications, the Individual Pension System hasshown a significant growth since its launch year of 2003. Among the funds collectedwithin the Individual Pension System, lets the realization of several importantgoals such as the increasing the country's savings volume, providing a long-termfund inflow to the markets and increasing the welfare levels of the participantsduring their retirement period. Starting with January 1st , 2017, Individual PensionSystem w...

  8. The modelled benefits of individualizing radiotherapy patients' dose using cellular radiosensitivity assays with inherent variability

    International Nuclear Information System (INIS)

    Mackay, R.I.; Hendry, J.H.

    1999-01-01

    Objective: To model the increases in local tumour control that may be achieved, without increasing normal tissue complications, by prescribing a patient's dose based on cellular radiosensitivity measured using an assay possessing inherent variability.Method: Patient populations with varying radiosensitivity were simulated, based on measured distributions among cancer patients of the surviving fraction of their fibroblasts given a dose of 2 Gy in vitro (SF 2 ). The dose-response curve for complications in the population was assessed using a formula relating SF 2 to normal tissue complication probability (NTCP), by summing the data for the individuals. This curve was similar to clinically-derived dose-response curves. The effect of individualizing the patients' doses was explored, based on individual radiosensitivities measured by SF 2 , so that every patient had the same low (5%) value of NTCP.Results: It was found that a significant gain (up to around 30%) in tumour control probability (TCP) was predicted for the population when the doses were individualized using a predictive assay result strongly correlated with NTCP. A greater gain in TCP was predicted when each of the individuals were assumed to have a higher sensitivity and the distribution of radiosensitivity in the population was widened to compensate. The gain in TCP was less (around 20%) when considering less-sensitive patients and a narrower distribution of radiosensitivities. The effect of assay variability and other factors that could affect the predictive power of the assay was simulated. Assay variability and an imperfect correlation between in vitro cell survival and tissue complications, rapidly increased the NTCP for the population when treated with individualized doses. However the individualized doses could be reduced so that NTCP declined to an acceptable level, but in this case the TCP for the population also declined. For example, when the assay variability was half the true variability in SF

  9. Integrating ecological insight derived from individual-based simulations and physiologically structured population models

    NARCIS (Netherlands)

    Nisbet, R.M.; Martin, B.T.; de Roos, A.M.

    2016-01-01

    Two contrasting approaches are widely used to derive population dynamics as an emergent property deriving from the physiology and behavior of individual organisms. "Individual-based models" (IBMs) are computer simulations where the "state" (e.g., age, size) of each individual in a population is fol-

  10. Effects of resistance training in individuals with knee osteoarthritis

    Directory of Open Access Journals (Sweden)

    Grazielle Cordeiro Aguiar

    Full Text Available Abstract Introduction: Osteoarthritis (OA, the most common form of arthritis, is considered the main cause of pain and disability in the elderly. Objective: To evaluate the effect of systematic muscle strength training on functional performance and quality of life in individuals with knee OA. Methods: Subjects with knee OA (n = 27, 46 - 76 years completed the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC, Medical Outcomes Short-Form 36-item Health Survey (SF-36, and visual analog scale (VAS questionnaires, musculoskeletal assessments, and 10-repetition maximum and timed 10-meter walk tests both before and after training. The training consisted of an exercise resistance program and stretches for 12 weeks (three sessions of 80 each per week. Results: Twenty-two subjects completed the training. Reduced overall scores and WOMAC physical function indicated improved functional performance (p < 0.001 as well as increased gait speed (p < 0.001. The perception of pain decreased after training, as evidenced by the VAS, WOMAC pain domain, and SF-36 scores (p < 0.001. Quality of life improvements occurred primarily in the areas of pain, functional capacity, and SF-36 physical aspects. No change in body mass index was noted (p = 0.93. Conclusion: Our results indicate that the combination of resistance training for the quadriceps, gluteus, and abdominal muscles could be a viable alternative to improving functionality and quality of life in patients with knee OA. However, more studies are necessary to confirm our findings.

  11. Real beards and real networks: a spin-glass model for interacting individuals

    Science.gov (United States)

    O'Neale, Dion

    ''I want to be different, just like all the other different people'' sang the band King Missile. Whether they are the Beatniks of the 1950s, the punks of the 1970s, or the hipsters of today, non-conformists often tend to look the same, seemingly at odds with their goal of non-conformity. The spin-glass model, originally developed to describe the interaction of magnetic spins, and since applied to situations as diverse as the electrical activity of networks of neurons, to trades on a financial market, has recently been used in social science to study populations of interacting individuals comprised of a mix of both conformists and anti-conformists - or hipsters. Including delay effects for the interactions between individuals has been shown to give a system with non-trivial dynamics with a phase transition from stable behaviour to periodic switching between two states (let's call them bushy bearded and clean shaven). Analytic solutions to such a model are possible, but only for particular assumptions about the interaction and delay matrices. In this work we will show what happens when the interactions in the model are based on real-world networks with ''small-world'' effects and clustering.

  12. Traveling waves for a model of individual clustering with logistic growth rate

    Science.gov (United States)

    Ibrahim, H.; Nasreddine, E.

    2017-08-01

    We consider a traveling wave problem for a one-dimensional model of individual clustering or aggregation. This model, originally formulated by Grindrod [J. Math. Biol. 26(6), 651-660 (1988)], describes the mechanism of individual dispersion when individuals are able to utilize information about their local environment. Specifically, it assumes that each individual disperses randomly with probability δ and disperses deterministically so as to improve his reproductive rate with probability 1 -δ . In this paper, we prove the existence of a traveling wave solution when the probability of random dispersion exceeds a critical value δ* uniquely determined by the biased individual velocity.

  13. Dyadic Effects of Individual and Friend on Physical Activity in College Students.

    Science.gov (United States)

    Kim, Gwang Suk; Lee, Chung Yul; Kim, In Sook; Lee, Tae Hwa; Cho, Eunhee; Lee, Hyeonkyeong; McCreary, Linda L; Kim, Su Hee

    2015-01-01

    Physical activity (PA) tends to decline throughout the college years, and close friends' influence is known to be an important factor in maintaining PA. This study examined the actor effect and partner effect between an individual and his/her friend regarding the influence of self-efficacy and social support on PA among Korean college students. Cross-sectional survey data from 108 pairs of individual students and friends were analyzed. The survey questionnaire measured PA, self-efficacy toward exercise, social support for PA, anxiety and depression, community environments, and perceived health status. Structural equation modeling with path analysis was conducted to test Actor-Partner Interdependence Model (APIM) explaining close relationships on PA. One-sided partner effect that friends' perceived friend support was directly related to individual's PA (β = 0.20, p college-aged young adults that promotes friend support for PA as well as individual self-efficacy toward PA, to engage young adults in establishing lifelong health-promoting PA. © 2015 Wiley Periodicals, Inc.

  14. Coupling of an individual-based model of anchovy with lower trophic level and hydrodynamic models

    Science.gov (United States)

    Wang, Yuheng; Wei, Hao; Kishi, Michio J.

    2013-03-01

    Anchovy ( Engraulis japonicus), a small pelagic fish and food of other economic fishes, is a key species in the Yellow Sea ecosystem. Understanding the mechanisms of its recruitment and biomass variation is important for the prediction and management of fishery resources. Coupled with a hydrodynamic model (POM) and a lower trophic level ecosystem model (NEMURO), an individual-based model of anchovy is developed to study the influence of physical environment on anchovy's biomass variation. Seasonal variations of circulation, water temperature and mix-layer depth from POM are used as external forcing for NEMURO and the anchovy model. Biomasses of large zooplankton and predatory zooplankton which anchovy feeds on are output from NEMURO and are controlled by the consumption of anchovy on them. Survival fitness theory related to temperature and food is used to determine the swimming action of anchovy in the model. The simulation results agree well with observations and elucidate the influence of temperature in over-wintering migration and food in feeding migration.

  15. The Rape Prevention and Education (RPE) Theory Model of Community Change: Connecting Individual and Social Change

    Science.gov (United States)

    Cox, Pamela J.; Lang, Karen S.; Townsend, Stephanie M.; Campbell, Rebecca

    2010-01-01

    Social work practice has long focused on the connections between an individual and the social environment that affect the individual's social functioning. The Rape Prevention and Education (RPE) Program's theory model, Creating Safer Communities: The Rape Prevention and Education Model of Community Change, provides family social workers with a…

  16. Maximum likelihood estimators for extended growth curve model with orthogonal between-individual design matrices

    NARCIS (Netherlands)

    Klein, Daniel; Zezula, Ivan

    The extended growth curve model is discussed in this paper. There are two versions of the model studied in the literature, which differ in the way how the column spaces of the design matrices are nested. The nesting is applied either to the between-individual or to the within-individual design

  17. Modeling the Individual Within the Group: an Interdisciplinary Approach to Collaborative Knowledge Construction

    OpenAIRE

    Lund, Kristine

    2016-01-01

    Constructing knowledge with others is fundamental for all human activity, and many disciplines have sought to understand how the individual, other people, and the context, all influence collaborative knowledge construction, be it individual or group knowledge. The goal of this Habilitation à Diriger des Recherches is to present an analytical model of the relations of the individual to the group in situations of collaborative knowledge construction. The model is inspired by the work of Levinso...

  18. Health behavior models for informing digital technology interventions for individuals with mental illness.

    Science.gov (United States)

    Naslund, John A; Aschbrenner, Kelly A; Kim, Sunny Jung; McHugo, Gregory J; Unützer, Jürgen; Bartels, Stephen J; Marsch, Lisa A

    2017-09-01

    Theoretical models offer valuable insights for designing effective and sustainable behavioral health interventions, yet the application of theory for informing digital technology interventions for people with mental illness has received limited attention. We offer a perspective on the importance of applying behavior theories and models to developing digital technology interventions for addressing mental and physical health concerns among people with mental illness. In this commentary, we summarize prominent theories of human behavior, highlight key theoretical constructs, and identify opportunities to inform digital health interventions for people with mental illness. We consider limitations with existing theories and models, and examine recent theoretical advances that can specifically guide development of digital technology interventions. Established behavioral frameworks including health belief model, theory of planned behavior, transtheoretical model, and social cognitive theory consist of important and overlapping constructs that can inform digital health interventions for people with mental illness. As digital technologies continue to evolve and enable longitudinal data collection, real-time behavior monitoring, and adaptive features tailored to users' changing needs over time, there are new opportunities to broaden our understanding of health behaviors and mechanisms of behavior change. Recent advances include dynamic models of behavior, persuasive system design, the behavioral intervention technology model, and behavioral models for just-in-time adaptive interventions. Behavior theories offer advantages for guiding use of digital technologies. Future researchers must explore how theoretical models can effectively advance efforts to develop, evaluate, and disseminate digital health interventions targeting individuals with mental illness. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  19. Effects of Computer Course on Computer Self-Efficacy, Computer Attitudes and Achievements of Young Individuals in Siirt, Turkey

    Science.gov (United States)

    Çelik, Halil Coskun

    2015-01-01

    The purpose of this study is to investigate the effects of computer courses on young individuals' computer self-efficacy, attitudes and achievement. The study group of this research included 60 unemployed young individuals (18-25 ages) in total; 30 in the experimental group and 30 in the control group. An experimental research model with pretest…

  20. Starting a sport in the Netherlands : A life-course analysis of the effects of individual, parental and partner characteristics

    NARCIS (Netherlands)

    Kraaykamp, Gerbert; Oldenkamp, Marloes; Breedveld, Koen

    In this article we investigate the effects of parental, individual and partner characteristics on the starting of a sport. Employing event history models we analyze 72,491 person-years of 2276 individuals from the Family Survey Dutch Population 1998 and 2003. Our results show that growing up in a

  1. Starting a sport in the Netherlands: A life-course analysis of the effects of individual, parental and partner characteristics

    NARCIS (Netherlands)

    Kraaykamp, G.L.M.; Oldenkamp, M.; Breedveld, K.

    2013-01-01

    In this article we investigate the effects of parental, individual and partner characteristics on the starting of a sport. Employing event history models we analyze 72,491 person-years of 2276 individuals from the Family Survey Dutch Population 1998 and 2003. Our results show that growing up in a

  2. Parameter Scaling for Epidemic Size in a Spatial Epidemic Model with Mobile Individuals.

    Directory of Open Access Journals (Sweden)

    Chiyori T Urabe

    Full Text Available In recent years, serious infectious diseases tend to transcend national borders and widely spread in a global scale. The incidence and prevalence of epidemics are highly influenced not only by pathogen-dependent disease characteristics such as the force of infection, the latent period, and the infectious period, but also by human mobility and contact patterns. However, the effect of heterogeneous mobility of individuals on epidemic outcomes is not fully understood. Here, we aim to elucidate how spatial mobility of individuals contributes to the final epidemic size in a spatial susceptible-exposed-infectious-recovered (SEIR model with mobile individuals in a square lattice. After illustrating the interplay between the mobility parameters and the other parameters on the spatial epidemic spreading, we propose an index as a function of system parameters, which largely governs the final epidemic size. The main contribution of this study is to show that the proposed index is useful for estimating how parameter scaling affects the final epidemic size. To demonstrate the effectiveness of the proposed index, we show that there is a positive correlation between the proposed index computed with the real data of human airline travels and the actual number of positive incident cases of influenza B in the entire world, implying that the growing incidence of influenza B is attributed to increased human mobility.

  3. The effect of individual and neighborhood socioeconomic status on gastric cancer survival.

    Directory of Open Access Journals (Sweden)

    Chin-Chia Wu

    Full Text Available PURPOSE: Gastric cancer is a leading cause of death, particularly in the developing world. The literature reports individual socioeconomic status (SES or neighborhood SES as related to survival, but the effect of both has not been studied. This study investigated the effect of individual and neighborhood SES simultaneously on mortality in gastric cancer patients in Taiwan. MATERIALS AND METHODS: A study was conducted of 3,396 patients diagnosed with gastric cancer between 2002 and 2006. Each patient was followed for five years or until death. Individual SES was defined by income-related insurance premium (low, moderate, and high. Neighborhood SES was based on household income dichotomized into advantaged and disadvantaged areas. Multilevel logistic regression model was used to compare survival rates by SES group after adjusting for possible confounding factors. RESULTS: In patients younger than 65 years, 5-year overall survival rates were lowest for those with low individual SES. After adjusting for patient characteristics (age, gender, Charlson Comorbidity Index Score, gastric cancer patients with high individual SES had 68% risk reduction of mortality (adjusted odds ratio [OR] of mortality, 0.32; 95% confidence interval [CI], 0.17-0.61. Patients aged 65 and above had no statistically significant difference in mortality rates by individual SES group. Different neighborhood SES did not statistically differ in the survival rates. CONCLUSION: Gastric cancer patients aged less than 65 years old with low individual SES have higher risk of mortality, even under an universal healthcare system. Public health strategies, education and welfare policies should seek to correct the inequality in gastric cancer survival, especially in those with lower individual SES.

  4. Modeling information technology effectiveness

    OpenAIRE

    Aleksander Lotko

    2005-01-01

    Numerous cases of systems not bringing expected results cause that investments in information technology are treated more and more carefully and are not privileged amongst others. This gives rise to the need for applying costs–effect calculations. Modeling IT effectiveness is a procedure which helps to bring system complexity under control. By using proper measures it is possible to perform an objective investment appraisal for projects under consideration. In the paper, a framework of method...

  5. [Effects of situational and individual variables on critical thinking expression].

    Science.gov (United States)

    Tanaka, Yuko; Kusumi, Takashi

    2016-04-01

    The present study examined when people decide to choose an expression that is based on critical thinking, and how situational and individual variables affect such a decision process. Given a conversation scenario including overgeneralization with two friends, participants decided whether to follow the conversation by a critical-thinking expression or not. The authors controlled purpose and topic as situational variables, and measured critical-thinking ability, critical-thinking disposition, and self-monitoring as individual variables. We conducted an experiment in which the situational variables were counterbalanced in a within-subject design with 60 university students. The results of logistic regression analysis showed differences within individuals in the decision process whether to choose a critical-thinking expression, and that some situational factors and some subscales of the individual measurements were related to the differences.

  6. [Digital modeling for the individual mandibular 3D mesh scaffold based on 3D printing technology].

    Science.gov (United States)

    Yan, Rongzeng; Luo, Danmei; Qin, Xiaoyu; Li, Runxin; Rong, Qiguo; Hu, Min

    2016-05-01

    To investigate an ideal modeling method of designing 3D mesh scaffold substitutes based on tissue engineering to restore mandibular bone defects. By analyzing the theoretical model from titanium scaffolds fabricated by 3D printing, the feasibility and effectiveness of the proposed methodology were verified. Based on the CT scanned data of a subject, the Mimics 15.0 and Geomagic studio 12.0 reverse engineering software were adopted to generate surface model of mandibular bone and the defect area was separated from the 3D model of bone. Then prosthesis was designed via mirror algorithm, in which outer shape was used as the external shape of scaffold. Unigraphics software NX 8.5 was applied on Boolean calculation of subtraction between prosthesis and regular microstructure structure and ANSYS 14.0 software was used to design the inner construction of 3D mesh scaffolds. The topological structure and the geometrical parameters of 3D mesh titanium scaffolds were adjusted according to the aim of optimized structure and maximal strength with minimal weight. The 3D mesh scaffolds solid model through two kinds of computer-aided methods was input into 3D printing equipment to fabricate titanium scaffolds. Individual scaffolds were designed successfully by two modeling methods. The finite element optimization made 10% decrease of the stress peak and volume decrease of 43%, and the porosity increased to 76.32%. This modeling method was validated by 3D printing titanium scaffold to be feasible and effective. 3D printing technology combined with finite element topology optimization to obtain the ideal mandibular 3D mesh scaffold is feasible and effective.

  7. DISPLACE: a dynamic, individual-based model for spatial fishing planning and effort displacement: Integrating underlying fish population models

    DEFF Research Database (Denmark)

    Bastardie, Francois; Nielsen, J. Rasmus; Miethe, Tanja

    or to the alteration of individual fishing patterns. We demonstrate that integrating the spatial activity of vessels and local fish stock abundance dynamics allow for interactions and more realistic predictions of fishermen behaviour, revenues and stock abundance......We previously developed a spatially explicit, individual-based model (IBM) evaluating the bio-economic efficiency of fishing vessel movements between regions according to the catching and targeting of different species based on the most recent high resolution spatial fishery data. The main purpose...... was to test the effects of alternative fishing effort allocation scenarios related to fuel consumption, energy efficiency (value per litre of fuel), sustainable fish stock harvesting, and profitability of the fisheries. The assumption here was constant underlying resource availability. Now, an advanced...

  8. State and Trait Effects on Individual Differences in Children's Mathematical Development

    Science.gov (United States)

    Bailey, Drew H.; Watts, Tyler W.; Littlefield, Andrew K.; Geary, David C.

    2015-01-01

    Substantial longitudinal relations between children's early mathematics achievement and their much later mathematics achievement are firmly established. These findings are seemingly at odds with studies showing that early educational interventions have diminishing effects on children's mathematics achievement across time. We hypothesized that individual differences in children's later mathematical knowledge are more an indicator of stable, underlying characteristics related to mathematics learning throughout development than of direct effects of early mathematical competency on later mathematical competency. We tested this hypothesis in two longitudinal data sets, by simultaneously modeling effects of latent traits (stable characteristics that influence learning across time) and states (e.g., prior knowledge) on children's mathematics achievement over time. Latent trait effects on children's mathematical development were substantially larger than state effects. Approximately 60% of the variance in trait mathematics achievement was accounted for by commonly used control variables, such as working memory, but residual trait effects remained larger than state effects. Implications for research and practice are discussed. PMID:25231900

  9. Individual decision-making in the causal pathway to addiction: contributions and limitations of rodent models.

    Science.gov (United States)

    Ahmed, Serge H

    2018-01-01

    The causal pathway from vulnerability to drug use and addiction involves a complex interaction between genetic, environmental, and behavioral factors. An individual can intervene on this causal pathway by two major types of individual decision. There is the inaugural, momentous decision to use a drug for the first time. This decision is influenced by both prior knowledge on the drug and its expected effects, and also by prior self-knowledge on one's own vulnerability. After an individual has used a drug for the first time, there is the decision to repeat drug use. This decision is influenced by the same factors that were involved in the inaugural decision to initiate drug use, except for one crucial difference. The first drug use has now acted on the individual, changing its brain acutely and also potentially persistently in a way that could bias subsequent decision-making in favor of repeated drug use. The goal of this review article is to assess the contributions and limitations of rodent models (i.e., rats, mice) to understand how prior drug use can influence decision-making in a way that favors future drug use. Overall, research on rodents shows that prior drug use can increase impulsive, risky and/or potentially harmful decision-making. However, this does not apparently translate into more drug use when rodents have the choice between a drug and a competing, nondrug option, except when the expected value of the latter is considerably decreased. The delayed drug reward hypothesis is developed to resolve and explain this apparent discrepancy. This novel hypothesis makes several unique predictions, some of them counterintuitive, and suggests that extrapolation of rodent research to humans should not only take into account differences in drug choice situations but also inherent species-specific differences in individual decision-making. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. INDIVIDUAL DIFFERENCES IN WORKING MEMORY PERFORMANCE: «OVERLOAD» EFFECT

    Directory of Open Access Journals (Sweden)

    Yuri G. Pavlov

    2015-01-01

    Full Text Available The aim of this research is to study the relationship betweenfrontal midline theta rhythm changes and individual differences in working memory performance.Methods. The methods involve behavioural testing on the basis of the program for a presentation of stimulus and registration of answers «PsyTask»; method of EEG (electroencephalography; a technique of measurement of efficiency of working memory; the comparative analysis. Software packages EEGLab for Matlab and Fieldtrip are applied while data processing.Results. After the behavioral test all subjects were separated into 2 groups according to their performance: with «highly productive» and «low productive» memory. Specially prepared author’s complete set of the tasks which complexity varied from average to ultrahigh level was offered to participants of experiment –students and employees of the Ural Federal University and Ural Legal Institute of the Ministry of Internal Affairs. Working memory tasks included sets of verbal stimuli for memorizing in strict order without any mental manipulation and sets of similar stimuli for memorizing in alphabetical order (with manipulations. Measured characteristics of theta-rhythm of EEG during information deduction in memory were compared of two groups’ representatives. The obtained data has shown rather uniform and similar dynamics of decrease in quantity of right answers in process of increasing tasks’ complexity. However, changes of a thetarhythm in different groups had sharply expressed distinctions. «Highly productive» examinees have systematic expansion of a theta-rhythm in the central assignments with stabilisation on the most difficult tasks; «low productive» – while tasks performance of average complexity, a sharp falling of theta-rhythm activity is observed after achievement of its maximum activation.Scientific novelty. The working memory «overload» effect and its EEG correlates are demonstrated on a big sample of

  11. The anchor integration model: A descriptive model of anchoring effects.

    Science.gov (United States)

    Turner, Brandon M; Schley, Dan R

    2016-11-01

    Few experimental effects in the psychology of judgment and decision making have been studied as meticulously as the anchoring effect. Although the existing literature provides considerable insight into the psychological processes underlying anchoring effects, extant theories up to this point have only generated qualitative predictions. While these theories have been productive in advancing our understanding of the underlying anchoring process, they leave much to be desired in the interpretation of specific anchoring effects. In this article, we introduce the Anchor Integration Model (AIM) as a descriptive tool for the measurement and quantification of anchoring effects. We develop two versions the model: one suitable for assessing between-participant anchoring effects, and another for assessing individual differences in anchoring effects. We then fit each model to data from two experiments, and demonstrate the model's utility in describing anchoring effects. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Effects of hippotherapy on posture in individuals with Down Syndrome

    Directory of Open Access Journals (Sweden)

    Ana Paula Espindula

    Full Text Available Abstract Introduction: Individuals with Down syndrome (DS have alterations that affect the musculoskeletal system, causing abnormal patterns, and alter the morphological anatomical and mechanical axes that provide intrinsic stability to the skeleton, and can trigger misalignments and orthopedic disorders in adulthood. Objective: The objective of student to evaluate posture and postural alignment before and after the hippotherapyin individuals with DS. Methods: Posture of five individuals with DS was evaluated by the software SAPO before and after 27 sessions the hippotherapy. Data were subjected to qualitative descriptive analysis using cluster and statistical analysis with the aid of the software Sigma Stat 2.0, considering differences as statistically significant at p-value < 5%. Results: Improvements were achieved for the alignment of shoulder, head, hip, and lower limbs, in addition to decrease in kyphosis and head protrusion. Conclusion: Patients with DS demonstrated satisfactory changes in motor behavior reflected in improved static posture after treatment with hippotherapy.

  13. Individual variations in numerically modeled human muscle and temporomandibular joint forces during static biting.

    Science.gov (United States)

    Iwasaki, Laura R; Thornton, Benjamin R; McCall, Willard D; Nickel, Jeffrey C

    2004-01-01

    To test the effects of occlusal force (OF) angle on the variations in predicted muscle and temporomandibular joint (TMJ) forces during unilateral molar bites. The craniomandibular (CM) geometries of 21 individuals were determined from lateral and posteroanterior cephalometric radiographs. These geometries were used in a numerical model based on minimization of muscle effort. This model was previously validated for this subject group through the use of jaw tracking and electromyographic data. The model predicted muscle and TMJ forces associated with static OFs on the right mandibular first molar. OF angle was varied from vertical to 40 degrees in the buccal and lingual directions, in increments of 10 degrees. Intra- and intersubject variations in predicted muscle and TMJ forces for unilateral molar biting were dependent on OF angle and CM geometry. Nonvertical OFs were associated with either large anterior temporalis muscle forces (> 100% of applied OF in 3 subjects) or large inferior lateral pterygoid muscle forces (> 90% of applied OF in 3 subjects). On average, vertically and buccally directed OFs were associated with higher mean contralateral TMJ forces (60% of applied OF, SD 12%). Two subjects had large ipsilateral or contralateral TMJ forces (> 90% of applied OF). In a group of healthy subjects, depending on the individual CM geometry, large muscle and/or TMJ forces were predicted to be associated with specific unilateral molar OF angles. Propensities to increased muscle or joint forces may be predisposing factors in the development of myofascial pain or intracapsular disease. The results may explain, in part, the variation in location of symptoms in individuals who first present with temporomandibular disorders.

  14. An Individual-Based Diploid Model Predicts Limited Conditions Under Which Stochastic Gene Expression Becomes Advantageous

    KAUST Repository

    Matsumoto, Tomotaka

    2015-11-24

    Recent studies suggest the existence of a stochasticity in gene expression (SGE) in many organisms, and its non-negligible effect on their phenotype and fitness. To date, however, how SGE affects the key parameters of population genetics are not well understood. SGE can increase the phenotypic variation and act as a load for individuals, if they are at the adaptive optimum in a stable environment. On the other hand, part of the phenotypic variation caused by SGE might become advantageous if individuals at the adaptive optimum become genetically less-adaptive, for example due to an environmental change. Furthermore, SGE of unimportant genes might have little or no fitness consequences. Thus, SGE can be advantageous, disadvantageous, or selectively neutral depending on its context. In addition, there might be a genetic basis that regulates magnitude of SGE, which is often referred to as “modifier genes,” but little is known about the conditions under which such an SGE-modifier gene evolves. In the present study, we conducted individual-based computer simulations to examine these conditions in a diploid model. In the simulations, we considered a single locus that determines organismal fitness for simplicity, and that SGE on the locus creates fitness variation in a stochastic manner. We also considered another locus that modifies the magnitude of SGE. Our results suggested that SGE was always deleterious in stable environments and increased the fixation probability of deleterious mutations in this model. Even under frequently changing environmental conditions, only very strong natural selection made SGE adaptive. These results suggest that the evolution of SGE-modifier genes requires strict balance among the strength of natural selection, magnitude of SGE, and frequency of environmental changes. However, the degree of dominance affected the condition under which SGE becomes advantageous, indicating a better opportunity for the evolution of SGE in different genetic

  15. Contrasting Expectations of Individuals and Collectivists: Achieving Effective Group Interaction.

    Science.gov (United States)

    Waltman, John L.; Bush-Bacelis, Jean L.

    1995-01-01

    Techniques for training students of international business to understand collectivism and individualism, both as they affect classroom interaction and as they may affect intercultural relations in business, are presented. Tools are offered for adapting group projects given to individualists in individualist cultures to help them develop a…

  16. The Effect of Shared versus Individual Reflection on Team Outcomes

    Science.gov (United States)

    Domke-Damonte, Darla J.; Keels, J. Kay

    2015-01-01

    In this study, teams in a strategic management classroom were given one of two versions of an assignment related to the development of a team contract: independent individual reflections on desired team behaviors versus team-level reflections on desired behavioral norms. Results of a multivariate analysis of covariance, controlling for gender and…

  17. Individual learning effects on knowledge transfer in international joint ventures

    DEFF Research Database (Denmark)

    Dao, Li Thuy; Napier, Nancy

    2016-01-01

    This paper examines micro (individual-level) aspects of knowledge transfer and learning in international joint ventures in an emerging economy context. Learning by expatriate and local managers appears far more complex, mutually dependent, and significant to the knowledge transfer process than su...

  18. Individual Difference Effects in Human-Computer Interaction

    Science.gov (United States)

    1991-10-01

    DAVID DOS - a modified version of DOS 3.3.) 4.1.2.1.2 REMOTE DATABASE This option allows the experinenter to communicate with a remote database...Gardner, R.W., Holzman , P.S., Klein, G.S., Lintnn, H.B., and Spence, D.P., "Cognitive Control: A Study of Individual Consistencies in Cognitive

  19. Population modelling to compare chronic external radiotoxicity between individual and population endpoints in four taxonomic groups

    International Nuclear Information System (INIS)

    Alonzo, Frédéric; Hertel-Aas, Turid; Real, Almudena; Lance, Emilie; Garcia-Sanchez, Laurent; Bradshaw, Clare; Vives i Batlle, Jordi; Oughton, Deborah H.; Garnier-Laplace, Jacqueline

    2016-01-01

    In this study, we modelled population responses to chronic external gamma radiation in 12 laboratory species (including aquatic and soil invertebrates, fish and terrestrial mammals). Our aim was to compare radiosensitivity between individual and population endpoints and to examine how internationally proposed benchmarks for environmental radioprotection protected species against various risks at the population level. To do so, we used population matrix models, combining life history and chronic radiotoxicity data (derived from laboratory experiments and described in the literature and the FREDERICA database) to simulate changes in population endpoints (net reproductive rate R 0 , asymptotic population growth rate λ, equilibrium population size N eq ) for a range of dose rates. Elasticity analyses of models showed that population responses differed depending on the affected individual endpoint (juvenile or adult survival, delay in maturity or reduction in fecundity), the considered population endpoint (R 0 , λ or N eq ) and the life history of the studied species. Among population endpoints, net reproductive rate R 0 showed the lowest EDR 10 (effective dose rate inducing 10% effect) in all species, with values ranging from 26 μGy h −1 in the mouse Mus musculus to 38,000 μGy h −1 in the fish Oryzias latipes. For several species, EDR 10 for population endpoints were lower than the lowest EDR 10 for individual endpoints. Various population level risks, differing in severity for the population, were investigated. Population extinction (predicted when radiation effects caused population growth rate λ to decrease below 1, indicating that no population growth in the long term) was predicted for dose rates ranging from 2700 μGy h −1 in fish to 12,000 μGy h −1 in soil invertebrates. A milder risk, that population growth rate λ will be reduced by 10% of the reduction causing extinction, was predicted for dose rates ranging from 24 μGy h −1 in

  20. Analysis of individual cell trajectories in lattice-gas cellular automaton models for migrating cell populations.

    Science.gov (United States)

    Mente, Carsten; Voss-Böhme, Anja; Deutsch, Andreas

    2015-04-01

    Collective dynamics of migrating cell populations drive key processes in tissue formation and maintenance under normal and diseased conditions. Collective cell behavior at the tissue level is typically characterized by considering cell density patterns such as clusters and moving cell fronts. However, there are also important observables of collective dynamics related to individual cell behavior. In particular, individual cell trajectories are footprints of emergent behavior in populations of migrating cells. Lattice-gas cellular automata (LGCA) have proven successful to model and analyze collective behavior arising from interactions of migrating cells. There are well-established methods to analyze cell density patterns in LGCA models. Although LGCA dynamics are defined by cell-based rules, individual cells are not distinguished. Therefore, individual cell trajectories cannot be analyzed in LGCA so far. Here, we extend the classical LGCA framework to allow labeling and tracking of individual cells. We consider cell number conserving LGCA models of migrating cell populations where cell interactions are regulated by local cell density and derive stochastic differential equations approximating individual cell trajectories in LGCA. This result allows the prediction of complex individual cell trajectories emerging in LGCA models and is a basis for model-experiment comparisons at the individual cell level.

  1. Training effectiveness evaluation model

    International Nuclear Information System (INIS)

    Penrose, J.B.

    1993-01-01

    NAESCO's Training Effectiveness Evaluation Model (TEEM) integrates existing evaluation procedures with new procedures. The new procedures are designed to measure training impact on organizational productivity. TEEM seeks to enhance organizational productivity through proactive training focused on operation results. These results can be identified and measured by establishing and tracking performance indicators. Relating training to organizational productivity is not easy. TEEM is a team process. It offers strategies to assess more effectively organizational costs and benefits of training. TEEM is one organization's attempt to refine, manage and extend its training evaluation program

  2. Ecotoxicological effects extrapolation models

    Energy Technology Data Exchange (ETDEWEB)

    Suter, G.W. II

    1996-09-01

    One of the central problems of ecological risk assessment is modeling the relationship between test endpoints (numerical summaries of the results of toxicity tests) and assessment endpoints (formal expressions of the properties of the environment that are to be protected). For example, one may wish to estimate the reduction in species richness of fishes in a stream reach exposed to an effluent and have only a fathead minnow 96 hr LC50 as an effects metric. The problem is to extrapolate from what is known (the fathead minnow LC50) to what matters to the decision maker, the loss of fish species. Models used for this purpose may be termed Effects Extrapolation Models (EEMs) or Activity-Activity Relationships (AARs), by analogy to Structure-Activity Relationships (SARs). These models have been previously reviewed in Ch. 7 and 9 of and by an OECD workshop. This paper updates those reviews and attempts to further clarify the issues involved in the development and use of EEMs. Although there is some overlap, this paper does not repeat those reviews and the reader is referred to the previous reviews for a more complete historical perspective, and for treatment of additional extrapolation issues.

  3. The effects of peroral glycerol on plasma osmolarity in diabetic patients and healthy individuals

    DEFF Research Database (Denmark)

    Thornit, Dorte Nellemann; Sander, Birgit; la Cour, Morten

    2009-01-01

    Glycerol is used as a peroral treatment of increased intraocular and intracranial pressure due to its osmotic effect despite the potential increase in blood pressure and blood glucose. We examined the effects of peroral glycerol in diabetic patients and healthy individuals on blood pressure......, capillary glucose, and plasma osmolarity. On two separate days, 15 diabetic patients ingested glycerol in doses of 855 and 1710 mg/kg body weight in a randomised, unmasked sequence. Five healthy individuals ingested a dose of 1710 mg/kg body weight. Mean arterial blood pressure (MAP), capillary glucose (CG......, non-significant increase occurred in blood pressure. Maximal DeltaCG was approximately 1 mM irrespective of the dose and presence of diabetes (p > 0.1). The pOSM response was analysed with a kinetic model and found independent of the presence of diabetes (p = 0.6). The maximal fitted DeltapOSM was 12...

  4. Career Planning: Towards a More Inclusive Model for Women and Diverse Individuals

    Science.gov (United States)

    Banks, Claretha H.

    2006-01-01

    Since the 1953 introduction of Super's model of career development, many publications regarding career development and career planning have been developed. However, career planning models for women and diverse individuals are not prevalent. This paper contains a literature review of various well-known models that have few specific applications for…

  5. Predicting Longitudinal Change in Language Production and Comprehension in Individuals with Down Syndrome: Hierarchical Linear Modeling.

    Science.gov (United States)

    Chapman, Robin S.; Hesketh, Linda J.; Kistler, Doris J.

    2002-01-01

    Longitudinal change in syntax comprehension and production skill, measured over six years, was modeled in 31 individuals (ages 5-20) with Down syndrome. The best fitting Hierarchical Linear Modeling model of comprehension uses age and visual and auditory short-term memory as predictors of initial status, and age for growth trajectory. (Contains…

  6. A Linear Variable-[theta] Model for Measuring Individual Differences in Response Precision

    Science.gov (United States)

    Ferrando, Pere J.

    2011-01-01

    Models for measuring individual response precision have been proposed for binary and graded responses. However, more continuous formats are quite common in personality measurement and are usually analyzed with the linear factor analysis model. This study extends the general Gaussian person-fluctuation model to the continuous-response case and…

  7. The Onion Model: Myth or Reality in the Field of Individual Differences Psychology?

    Science.gov (United States)

    Cools, Eva; Bellens, Kim

    2012-01-01

    To bring order in concepts related to individual learner differences, Curry (1983) designed the three-layered onion model. As this model provides an interesting way to distinguish related concepts--such as cognitive styles and approaches to studying--on the basis of their stability in learning situations, ample studies build further on this model.…

  8. Individual and combined in vitro (anti)androgenic effects of certain food additives and cosmetic preservatives.

    Science.gov (United States)

    Pop, Anca; Drugan, Tudor; Gutleb, Arno C; Lupu, Diana; Cherfan, Julien; Loghin, Felicia; Kiss, Béla

    2016-04-01

    The individual and combined (binary mixtures) (anti)androgenic effect of butylparaben (BuPB), butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and propyl gallate (PG) was evaluated using the MDA-kb2 cell line. Exposing these cells to AR agonists results in the expression of the reporter gene (encoding for luciferase) and luminescence can be measured in order to monitor the activity of the reporter protein. In case of the evaluation of the anti-androgenic effect, the individual test compounds or binary mixtures were tested in the presence of a fixed concentration of a strong AR agonist (1000 pM 5-alpha-dihydrotestosterone; DHT). Cell viability was assessed using a resazurin based assay. For PG, this is the first report in the literature concerning its (anti)androgenic activity. In case of both individual and mixture testing none of the compounds or binary combinations showed androgenic activity. When tested in the presence of DHT, BuPB, BHA and BHT proved to be weak anti-androgens and this was confirmed during the evaluation of binary mixtures (BuPB+BHA, BuPB+BHT and BHA+BHT). Besides performing the in vitro testing of the binary combinations, two mathematical models (dose addition and response addition) were evaluated in terms of accuracy of prediction of the anti-androgenic effect of the selected binary mixtures. The dose addition model guaranteed a good correlation between the experimental and predicted data. However, no estimation was possible in case of mixtures containing PG, due to the lack of effect of the compound in case of the individual testing. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Additive gamma frailty models with applications to competing risks in related individuals

    DEFF Research Database (Denmark)

    Eriksson, Frank; Scheike, Thomas

    2015-01-01

    Epidemiological studies of related individuals are often complicated by the fact that follow-up on the event type of interest is incomplete due to the occurrence of other events. We suggest a class of frailty models with cause-specific hazards for correlated competing events in related individual...

  10. Analysis of habitat-selection rules using an individual-based model

    Science.gov (United States)

    Steven F. Railsback; Bret C. Harvey

    2002-01-01

    Abstract - Despite their promise for simulating natural complexity,individual-based models (IBMs) are rarely used for ecological research or resource management. Few IBMs have been shown to reproduce realistic patterns of behavior by individual organisms.To test our IBM of stream salmonids and draw conclusions about foraging theory,we analyzed the IBM ’s ability to...

  11. Micro-macro multilevel latent class models with multiple discrete individual-level variables

    NARCIS (Netherlands)

    Bennink, M.; Croon, M.A.; Kroon, B.; Vermunt, J.K.

    2016-01-01

    An existing micro-macro method for a single individual-level variable is extended to the multivariate situation by presenting two multilevel latent class models in which multiple discrete individual-level variables are used to explain a group-level outcome. As in the univariate case, the

  12. Evaluation of an e-PBL model to promote individual reasoning.

    Science.gov (United States)

    Kim, Kyong-Jee; Kee, Changwon

    2013-01-01

    Medical educators should promote the development of student clinical reasoning toward independence in clinical settings. The objective of this study was to evaluate an online problem-based learning (e-PBL) model designed to promote student individual reasoning in supplement to traditional PBL. Twelve e-PBL modules were added to the fully problem-based curriculum for Year 2 at Sungkyunkwan University School of Medicine (SKKUSOM). In this e-PBL, students worked on the problems individually in an online setting, followed by face-to-face discussions in a colloquium. The cases were presented using interactive multimedia to enhance the authenticity of the case and stimulate student interest in learning. A formative evaluation study was conducted to determine student satisfaction with e-PBL and its effectiveness as perceived by the students using both quantitative and qualitative methods. A cohort of Year 2 students at SKKUSOM (n = 38) took part in this study. Students perceived e-PBL significantly more positively after they had taken a module in terms of its ability to foster problem-solving skills and its ability to allow them to learn in ways suited to individual learning styles. Additionally, student survey and interview revealed that a vast majority of students were satisfied with the overall learning process in e-PBL and perceived it positively in fostering knowledge acquisition and clinical reasoning. Moreover, students found the cases realistic and engaging. The results show the potential of e-PBL to enhance traditional PBL by promoting the development of individual reasoning in a flexible online-learning environment and offering cases in an interactive multimedia format, which warrants further investigation into its impact on student learning outcomes.

  13. Linking sub-individual and supra-individual effects in Daphnia magna exposed to sub-lethal concentration of chlorpyrifos.

    Science.gov (United States)

    Ferrario, Claudia; Parolini, Marco; De Felice, Beatrice; Villa, Sara; Finizio, Antonio

    2018-04-01

    The main objective of the present study was to investigate possible links between sub-individual and supra-individual levels (i.e. population level) biomarkers in D. magna exposed to sublethal concentrations of the insecticide chlorpyrifos (CPF). To achieve the aim, 8-day old individuals were exposed for 96 h to two environmentally relevant concentrations of CPF (50 and 250 ng/L). Sub-individual level effects were investigated by measuring the activity of antioxidant (SOD, CAT, and GPx) and detoxifying (GST) enzymes, as well as by measuring the acetylcholinesterase (AChE) inhibition. In addition, the effects at supra-individual level were assessed by using a video-tracking system and analyzing changes in swimming capabilities (i.e. percentage of activity time, distance moved, and velocity). Our data have shown that daphnids exposed to both CPF concentrations were in a condition of stress which was highlighted by changes in both sub- and supra-individual biomarkers. Moreover, our results highlighted that the lowest tested CPF concentration did not modulate the antioxidant and detoxifying enzymes, whereas, an inhibition of AChE and a decrease of some parameters related to swimming behaviour (distance moved and velocity) were noted. On the contrary, significant changes in all the sub-individual biomarkers were measured at the highest tested concentration. In addition, organisms recovered the movement capability (distance moved) and also activate a mechanism of avoidance (increased swimming velocity). On the other hand, a reduction in the percent of active time was measured and this was attributed to the energy spent by organisms to activate antioxidant and detoxifying enzymes and the mechanism of avoidance. Based on these results, our study suggests the existence of a link between sub- and supra-individual levels, as the activation or non-activation in the antioxidant and detoxifying enzymes activities can led to different modifications of the swimming behaviour

  14. Predicting Individual Physiological Responses During Marksmanship Field Training Using an Updated SCENARIO-J Model

    National Research Council Canada - National Science Library

    Yokota, Miyo

    2004-01-01

    ...)) for individual variation and a metabolic rate (M) correction during downhill movements. This study evaluated the updated version of the model incorporating these new features, using a dataset collected during U.S. Marine Corps (USMC...

  15. Teachers’ individual action theories about competence-based education: the value of the cognitive apprenticeship model

    OpenAIRE

    Seezink, Audrey; Poell, Rob; Kirschner, Paul A.

    2009-01-01

    Seezink, A., Poell, R. F., & Kirschner, P. A. (2009). Teachers' individual action theories about competence-based education: The value of the cognitive apprenticeship model. Journal of Vocational Education & Training, 61, 203-215.

  16. Analyzing repeated measures data on individuals nested within groups: accounting for dynamic group effects.

    Science.gov (United States)

    Bauer, Daniel J; Gottfredson, Nisha C; Dean, Danielle; Zucker, Robert A

    2013-03-01

    Researchers commonly collect repeated measures on individuals nested within groups such as students within schools, patients within treatment groups, or siblings within families. Often, it is most appropriate to conceptualize such groups as dynamic entities, potentially undergoing stochastic structural and/or functional changes over time. For instance, as a student progresses through school, more senior students matriculate while more junior students enroll, administrators and teachers may turn over, and curricular changes may be introduced. What it means to be a student within that school may thus differ from 1 year to the next. This article demonstrates how to use multilevel linear models to recover time-varying group effects when analyzing repeated measures data on individuals nested within groups that evolve over time. Two examples are provided. The 1st example examines school effects on the science achievement trajectories of students, allowing for changes in school effects over time. The 2nd example concerns dynamic family effects on individual trajectories of externalizing behavior and depression. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  17. Extrapolating toxic effects on individuals to the population level: the role of dynamic energy budgets.

    Science.gov (United States)

    Jager, Tjalling; Klok, Chris

    2010-11-12

    The interest of environmental management is in the long-term health of populations and ecosystems. However, toxicity is usually assessed in short-term experiments with individuals. Modelling based on dynamic energy budget (DEB) theory aids the extraction of mechanistic information from the data, which in turn supports educated extrapolation to the population level. To illustrate the use of DEB models in this extrapolation, we analyse a dataset for life cycle toxicity of copper in the earthworm Dendrobaena octaedra. We compare four approaches for the analysis of the toxicity data: no model, a simple DEB model without reserves and maturation (the Kooijman-Metz formulation), a more complex one with static reserves and simplified maturation (as used in the DEBtox software) and a full-scale DEB model (DEB3) with explicit calculation of reserves and maturation. For the population prediction, we compare two simple demographic approaches (discrete time matrix model and continuous time Euler-Lotka equation). In our case, the difference between DEB approaches and population models turned out to be small. However, differences between DEB models increased when extrapolating to more field-relevant conditions. The DEB3 model allows for a completely consistent assessment of toxic effects and therefore greater confidence in extrapolating, but poses greater demands on the available data.

  18. Chinese Basic Pension Substitution Rate: A Monte Carlo Demonstration of the Individual Account Model

    OpenAIRE

    Dong, Bei; Zhang, Ling; Lu, Xuan

    2008-01-01

    At the end of 2005, the State Council of China passed ”The Decision on adjusting the Individual Account of Basic Pension System”, which adjusted the individual account in the 1997 basic pension system. In this essay, we will analyze the adjustment above, and use Life Annuity Actuarial Theory to establish the basic pension substitution rate model. Monte Carlo simulation is also used to prove the rationality of the model. Some suggestions are put forward associated with the substitution rate ac...

  19. Calculation of Individual Tree Water Use in a Bornean Tropical Rain Forest Using Individual-Based Dynamic Vegetation Model SEIB-DGVM

    Science.gov (United States)

    Nakai, T.; Kumagai, T.; Saito, T.; Matsumoto, K.; Kume, T.; Nakagawa, M.; Sato, H.

    2015-12-01

    Bornean tropical rain forests are among the moistest biomes of the world with abundant rainfall throughout the year, and considered to be vulnerable to a change in the rainfall regime; e.g., high tree mortality was reported in such forests induced by a severe drought associated with the ENSO event in 1997-1998. In order to assess the effect (risk) of future climate change on eco-hydrology in such tropical rain forests, it is important to understand the water use of trees individually, because the vulnerability or mortality of trees against climate change can depend on the size of trees. Therefore, we refined the Spatially Explicit Individual-Based Dynamic Global Vegetation Model (SEIB-DGVM) so that the transpiration and its control by stomata are calculated for each individual tree. By using this model, we simulated the transpiration of each tree and its DBH-size dependency, and successfully reproduced the measured data of sap flow of trees and eddy covariance flux data obtained in a Bornean lowland tropical rain forest in Lambir Hills National Park, Sarawak, Malaysia.

  20. Effect of genetic architecture on the prediction accuracy of quantitative traits in samples of unrelated individuals.

    Science.gov (United States)

    Morgante, Fabio; Huang, Wen; Maltecca, Christian; Mackay, Trudy F C

    2018-02-10

    Predicting complex phenotypes from genomic data is a fundamental aim of animal and plant breeding, where we wish to predict genetic merits of selection candidates; and of human genetics, where we wish to predict disease risk. While genomic prediction models work well with populations of related individuals and high linkage disequilibrium (LD) (e.g., livestock), comparable models perform poorly for populations of unrelated individuals and low LD (e.g., humans). We hypothesized that low prediction accuracies in the latter situation may occur when the genetics architecture of the trait departs from the infinitesimal and additive architecture assumed by most prediction models. We used simulated data for 10,000 lines based on sequence data from a population of unrelated, inbred Drosophila melanogaster lines to evaluate this hypothesis. We show that, even in very simplified scenarios meant as a stress test of the commonly used Genomic Best Linear Unbiased Predictor (G-BLUP) method, using all common variants yields low prediction accuracy regardless of the trait genetic architecture. However, prediction accuracy increases when predictions are informed by the genetic architecture inferred from mapping the top variants affecting main effects and interactions in the training data, provided there is sufficient power for mapping. When the true genetic architecture is largely or partially due to epistatic interactions, the additive model may not perform well, while models that account explicitly for interactions generally increase prediction accuracy. Our results indicate that accounting for genetic architecture can improve prediction accuracy for quantitative traits.

  1. Assessing the Effects of Individual Augmentation (IA) on Active Component Navy Enlisted and Officer Retention

    National Research Council Canada - National Science Library

    Fricker, Jr., Ronald D; Buttrey, Samuel E

    2008-01-01

    .... Retention rates were compared in three different ways: aggregate comparisons, comparisons by individual demographic categories, and comparisons based on standard statistical modeling techniques (logistic regression...

  2. Effect of individual finger skin temperature on vibrotactile perception threshold

    Directory of Open Access Journals (Sweden)

    Barbara Harazin

    2013-12-01

    Full Text Available Objectives: In healthy people, the vibrotactile perception threshold (VPT at fingertips depends on a given measurement method and on individual characteristics such as age, gender and finger skin temperature. The aim of the study was to compare the VPT values in 2 groups of healthy subjects with different finger skin temperature. Materials and Methods: The study group comprised 56 males and 76 females, who formed pairs matched with respect to age, gender and body mass index (BMI but differing in terms of finger skin temperature at pre-launch testing. The finger skin temperature of less than 29°C indicated the subjects with "cold hands" and that of more than 29°C, the subjects with "warm hands". The measuring system made use of P8 pallesthesiometer (EMSON-MAT, Poland and the measurement procedure was in compliance with the ISO 13091-1:2001 standard. VPT measurements were performed for the index, middle and ring fingers of both hands at the frequencies of 4 Hz, 25 Hz, 31.5 Hz, 63 Hz, 125 Hz and 250 Hz. Results: The findings of the study revealed that the mean VPTs among the subjects with "cold hands" were significantly higher than the corresponding values among the subjects with "warm hands". Conclusions: The type of individual peripheral thermoregulation should be considered when assessing the VPT and determining its reference values.

  3. Effect of eliminating chronic diseases among elderly individuals

    Directory of Open Access Journals (Sweden)

    Alessandro Goncalves Campolina

    2013-06-01

    Full Text Available OBJECTIVE: To determine whether the elimination of certain chronic diseases is capable of leading to the compression of morbidity among elderly individuals. METHODS: A population-based, cross-sectional study was carried out with official data for the city of Sao Paulo, Southeastern Brazil in 2000 and data from the SABE (Health, Wellbeing and Ageing study. Sullivan's method was used to calculate disability-free life expectancy. Cause-deleted life tables were used to calculate the probabilities of death and disabilities with the elimination of health conditions. RESULTS: The largest gains in disability-free life expectancy, with the elimination of chronic illness, occurred in the female gender. Among individuals of a more advanced age, gains in disability-free life expectancy occurred as result of a relative compression of morbidity. Among men aged 75 years, all conditions studied, except heart disease and systemic arterial pressure, led to an absolute expansion of morbidity and, at the same time, to a relative compression of morbidity upon being eliminated. CONCLUSIONS: The elimination of chronic diseases in the elderly could lead to the compression of morbidity in elderly men and women.

  4. Individualizing Services, Individualizing Responsibility

    DEFF Research Database (Denmark)

    Garsten, Christina; Hollertz, Katarina; Jacobsson, Kerstin

    possibilities for individual voice, autonomy and self-determination in the local delivery of activation policy? What barriers do specific organisational models and practices imply for clients to choose, determine and access tailor-made programmes and services? What policy technologies are at work in governing......-oriented, and the normative demands placed on individuals appear increasingly totalizing, concerning the whole individual rather than the job-related aspects only. The paper is based on 23 in-depth interviews with individual clients as well as individual caseworkers and other professionals engaged in client-related work...

  5. Fit of different functions to the individual deviations in random regression test day models for milk yield in dairy cattle

    Directory of Open Access Journals (Sweden)

    L.R. Schaeffer

    2010-04-01

    Full Text Available The shape of individual deviations of milk yield for dairy cattle from the fixed part of a random regression test day model (RRTDM was investigated. Data were 53,217 TD records for milk yield of 6,229 first lactation Canadian Holsteins in Ontario. Data were fitted with a model that included the fixed effects of herd-testdate, DIM interval nested within age and season of calving. Residuals of the model were then fitted with the following functions: Ali and Schaeffer 5 parameter model, fourth-order Legendre Polynomials, and cubic spline with three, four or five knots. Result confirm the great variability of shape that can be found when individual lactation are modeled. Cubic splines gave better fitting pe4rformances although together with a marked tendency to yield aberrant estimates at the edge of the lactation trajectory.

  6. Discontinuous growth modeling of adaptation to sleep setting changes: individual differences and age.

    Science.gov (United States)

    Bliese, Paul D; McGurk, Dennis; Thomas, Jeffrey L; Balkin, Thomas J; Wesensten, Nancy

    2007-05-01

    Biomedical devices allow investigators to collect long-term repeated measures data to study adaptation. We examined 26 d of actigraph sleep data and tested for individual differences in sleep patterns prior to, during, and after a transition of sleeping in garrison to sleeping in a field exercise setting. In addition, we examined whether the individual difference variable of participant age (a continuous variable ranging from 19-29 yr) was related to sleep patterns. Actigraph data was obtained from 77 cadets participating in a month-long military training program. At day 17, participants transitioned from sleeping in garrison to sleeping in a field exercise setting. A discontinuous growth model tested for individual differences in 1) overall sleep time, 2) garrison sleep slope, 3) the transition, and 4) the sleep slope during the field exercise setting. Individuals varied significantly in their overall sleep time, pattern of sleep in garrison, and the degree to which sleep decreased at the transition. The decline in sleep at the transition was related to participant age such that increases in age were associated with larger declines in sleep minutes. Individuals display significant variability in sleep patterns that can be detected using discontinuous growth models. The individual difference variable of participant age explains some of this variability. Much of the variability, however, remains unexplained. Future work will benefit from using discontinuous growth models to identify and model individual difference variables such as age when examining response patterns and transitions in data collected in applied field settings.

  7. Towards Linking 3D SAR and Lidar Models with a Spatially Explicit Individual Based Forest Model

    Science.gov (United States)

    Osmanoglu, B.; Ranson, J.; Sun, G.; Armstrong, A. H.; Fischer, R.; Huth, A.

    2017-12-01

    In this study, we present a parameterization of the FORMIND individual-based gap model (IBGM)for old growth Atlantic lowland rainforest in La Selva, Costa Rica for the purpose of informing multisensor remote sensing techniques for above ground biomass techniques. The model was successfully parameterized and calibrated for the study site; results show that the simulated forest reproduces the structural complexity of Costa Rican rainforest based on comparisons with CARBONO inventory plot data. Though the simulated stem numbers (378) slightly underestimated the plot data (418), particularly for canopy dominant intermediate shade tolerant trees and shade tolerant understory trees, overall there was a 9.7% difference. Aboveground biomass (kg/ha) showed a 0.1% difference between the simulated forest and inventory plot dataset. The Costa Rica FORMIND simulation was then used to parameterize a spatially explicit (3D) SAR and lidar backscatter models. The simulated forest stands were used to generate a Look Up Table as a tractable means to estimate aboveground forest biomass for these complex forests. Various combinations of lidar and radar variables were evaluated in the LUT inversion. To test the capability of future data for estimation of forest height and biomass, we considered data of 1) L- (or P-) band polarimetric data (backscattering coefficients of HH, HV and VV); 2) L-band dual-pol repeat-pass InSAR data (HH/HV backscattering coefficients and coherences, height of scattering phase center at HH and HV using DEM or surface height from lidar data as reference); 3) P-band polarimetric InSAR data (canopy height from inversion of PolInSAR data or use the coherences and height of scattering phase center at HH, HV and VV); 4) various height indices from waveform lidar data); and 5) surface and canopy top height from photon-counting lidar data. The methods for parameterizing the remote sensing models with the IBGM and developing Look Up Tables will be discussed. Results

  8. Reading through the Life Span: Individual Differences in Psycholinguistic Effects

    Science.gov (United States)

    Davies, Rob A. I.; Arnell, Ruth; Birchenough, Julia M. H.; Grimmond, Debbie; Houlson, Sam

    2017-01-01

    The effects of psycholinguistic variables are critical to the evaluation of theories about the cognitive reading system. However, reading research has tended to focus on the impact of key variables on average performance. We report the first investigation examining variation in psycholinguistic effects across the life span, from childhood into old…

  9. Effect of fragrance use on discrimination of individual body odor

    Science.gov (United States)

    Allen, Caroline; Havlíček, Jan; Roberts, S. Craig

    2015-01-01

    Previous research suggests that artificial fragrances may be chosen to complement or enhance an individual’s body odor, rather than simply masking it, and that this may create an odor blend with an emergent quality that is perceptually distinguishable from body odor or fragrance alone. From this, it can be predicted that a new emergent odor might be more easily identified than an individual’s body odor in isolation. We used a triangle test paradigm to assess whether fragrance affects people’s ability to distinguish between individual odors. Six male and six female donors provided axillary odor samples in three conditions (without fragrance, wearing their own fragrance, and wearing an assigned fragrance). In total, 296 female and 131 male participants selected the odd one from three odor samples (two from one donor, one from another; both of the same sex). We found that participants could discriminate between the odors at above chance levels in all three odor conditions. Olfactory identification ability (measured using Sniffin’ Sticks) positively predicted discrimination performance, and sex differences in performance were also observed, with female raters being correct more often than men. Success rates were also higher for odors of male donors. Additionally, while performance was above chance in all conditions, individual odor discrimination varied across the three conditions. Discrimination rate was significantly higher in the “no fragrance” condition than either of the fragranced conditions. Importantly, however, discrimination rate was also significantly higher in the “own fragrance” condition than the “assigned fragrance” condition, suggesting that naturally occurring variance in body odor is more preserved when blended with fragrances that people choose for themselves, compared with other fragrances. Our data are consistent with the idea that fragrance choices are influenced by fragrance interactions with an individual’s own body odor

  10. Effect of fragrance use on discrimination of individual body odor

    Directory of Open Access Journals (Sweden)

    Caroline eAllen

    2015-08-01

    Full Text Available Previous research suggests that artificial fragrances may be chosen to complement or enhance an individual’s body odor, rather than simply masking it, and that this may create an odor blend with an emergent quality that is perceptually distinguishable from body odor or fragrance alone. From this, it can be predicted that a new emergent odor might be more easily identified than an individual’s body odor in isolation. We used a triangle test paradigm to assess whether fragrance affects people’s ability to distinguish between individual odors. Six male and six female donors provided axillary odor samples in three conditions (without fragrance, wearing their own fragrance, and wearing an assigned fragrance. In total, 296 female and 131 male participants selected the odd one out from three odor samples (two from one donor, one from another; both of the same sex. We found that participants could discriminate between the odors at above chance levels in all three odour conditions. Olfactory identification ability (measured using Sniffin’ Sticks positively predicted discrimination performance, and sex differences in performance were also observed, with female raters being correct more often than men. Success rates were also higher for odors of male donors. Additionally, while performance was above chance in all conditions, individual odor discrimination varied across the three conditions. Discrimination rate was significantly higher in the ‘no fragrance’ condition than either of the fragranced conditions. Importantly, however, discrimination rate was also significantly higher in the ‘own fragrance’ condition than the ‘assigned fragrance’ condition, suggesting that naturally occurring variance in body odor is more preserved when blended with fragrances that people choose for themselves, compared with other fragrances. Our data are consistent with the idea that fragrance choices are influenced by fragrance interactions with an

  11. Developing an agent-based model on how different individuals solve complex problems

    Directory of Open Access Journals (Sweden)

    Ipek Bozkurt

    2015-01-01

    Full Text Available Purpose: Research that focuses on the emotional, mental, behavioral and cognitive capabilities of individuals has been abundant within disciplines such as psychology, sociology, and anthropology, among others. However, when facing complex problems, a new perspective to understand individuals is necessary. The main purpose of this paper is to develop an agent-based model and simulation to gain understanding on the decision-making and problem-solving abilities of individuals. Design/Methodology/approach: The micro-level analysis modeling and simulation paradigm Agent-Based Modeling Through the use of Agent-Based Modeling, insight is gained on how different individuals with different profiles deal with complex problems. Using previous literature from different bodies of knowledge, established theories and certain assumptions as input parameters, a model is built and executed through a computer simulation. Findings: The results indicate that individuals with certain profiles have better capabilities to deal with complex problems. Moderate profiles could solve the entire complex problem, whereas profiles within extreme conditions could not. This indicates that having a strong predisposition is not the ideal way when approaching complex problems, and there should always be a component from the other perspective. The probability that an individual may use these capabilities provided by the opposite predisposition provides to be a useful option. Originality/value: The originality of the present research stems from how individuals are profiled, and the model and simulation that is built to understand how they solve complex problems. The development of the agent-based model adds value to the existing body of knowledge within both social sciences, and modeling and simulation.

  12. Stochastic Individual-Based Modeling of Bacterial Growth and Division Using Flow Cytometry

    Directory of Open Access Journals (Sweden)

    Míriam R. García

    2018-01-01

    Full Text Available A realistic description of the variability in bacterial growth and division is critical to produce reliable predictions of safety risks along the food chain. Individual-based modeling of bacteria provides the theoretical framework to deal with this variability, but it requires information about the individual behavior of bacteria inside populations. In this work, we overcome this problem by estimating the individual behavior of bacteria from population statistics obtained with flow cytometry. For this objective, a stochastic individual-based modeling framework is defined based on standard assumptions during division and exponential growth. The unknown single-cell parameters required for running the individual-based modeling simulations, such as cell size growth rate, are estimated from the flow cytometry data. Instead of using directly the individual-based model, we make use of a modified Fokker-Plank equation. This only equation simulates the population statistics in function of the unknown single-cell parameters. We test the validity of the approach by modeling the growth and division of Pediococcus acidilactici within the exponential phase. Estimations reveal the statistics of cell growth and division using only data from flow cytometry at a given time. From the relationship between the mother and daughter volumes, we also predict that P. acidilactici divide into two successive parallel planes.

  13. Effects of individualized word retrieval in kindergarten vocabulary intervention

    NARCIS (Netherlands)

    Damhuis, C.M.P.; Segers, P.C.J.; Scheltinga, F.; Verhoeven, L.T.W.

    2016-01-01

    We examined the effects of adaptive word retrieval intervention on a classroom vocabulary program on children's vocabulary acquisition in kindergarten. In the experimental condition, word retrieval was provided in a classroom vocabulary program, combining implicit and explicit vocabulary

  14. An individual-based, spatial foraging model for cadmium accumulation in diving ducks

    Energy Technology Data Exchange (ETDEWEB)

    Lovvorn, J.R.; Gillingham, M.P. [Univ. of Wyoming, Laramie, WY (United States). Dept. of Zoology and Physiology

    1994-12-31

    Contaminant studies of migratory birds include two main approaches: (1) collecting wild birds and analyzing their tissues, and (2) toxicity assays with captive birds. The first approach has shortcomings for these highly mobile animals--one seldom knows their length of stay in the area, and sites are often in urban environments where shooting is problematic. The second approach with captive birds ignores changes in food intake with varying activity and weather experienced by wild birds, and greater toxic consequences under multiple environmental stresses. Neither of these approaches alone can predict maximum allowable contaminant levels in foods that preclude toxic effects under different field conditions, or what body burdens accumulate during varying lengths of stay and affect the birds` biology at other places and times. To allow such predictions, the authors developed an individual-based model for intake of benthic foods by diving ducks for varying weather, water depth, food dispersion, and nutrient content of food. Food-intake estimates are combined with laboratory data on contaminant uptake as a function of food consumption and contaminant content. As an example, the authors estimate cadmium uptake by canvas back ducks foraging on below ground tubers of the submerged plant Vallisneria americans. They then show how their model can be used to include avian benthiovores in aquatic food web models for ecological risk assessment.

  15. The combined effect of individual and neighborhood socioeconomic status on cancer survival rates.

    Directory of Open Access Journals (Sweden)

    Chun-Ming Chang

    Full Text Available BACKGROUND: This population-based study investigated the relationship between individual and neighborhood socioeconomic status (SES and mortality rates for major cancers in Taiwan. METHODS: A population-based follow-up study was conducted with 20,488 cancer patients diagnosed in 2002. Each patient was traced to death or for 5 years. The individual income-related insurance payment amount was used as a proxy measure of individual SES for patients. Neighborhood SES was defined by income, and neighborhoods were grouped as living in advantaged or disadvantaged areas. The Cox proportional hazards model was used to compare the death-free survival rates between the different SES groups after adjusting for possible confounding and risk factors. RESULTS: After adjusting for patient characteristics (age, gender, Charlson Comorbidity Index Score, urbanization, and area of residence, tumor extent, treatment modalities (operation and adjuvant therapy, and hospital characteristics (ownership and teaching level, colorectal cancer, and head and neck cancer patients under 65 years old with low individual SES in disadvantaged neighborhoods conferred a 1.5 to 2-fold higher risk of mortality, compared with patients with high individual SES in advantaged neighborhoods. A cross-level interaction effect was found in lung cancer and breast cancer. Lung cancer and breast cancer patients less than 65 years old with low SES in advantaged neighborhoods carried the highest risk of mortality. Prostate cancer patients aged 65 and above with low SES in disadvantaged neighborhoods incurred the highest risk of mortality. There was no association between SES and mortality for cervical cancer and pancreatic cancer. CONCLUSIONS: Our findings indicate that cancer patients with low individual SES have the highest risk of mortality even under a universal health-care system. Public health strategies and welfare policies must continue to focus on this vulnerable group.

  16. Effect of acute and chronic job demands on effective individual teamwork behaviour in medical emergencies.

    Science.gov (United States)

    Gevers, Josette; van Erven, Pierre; de Jonge, Jan; Maas, Maaike; de Jong, Jos

    2010-07-01

    This paper is a report of a study conducted to determine the combined effect of acute and chronic job demands on acute job strains experienced during medical emergencies, and its consequences for individual teamwork behaviour. Medical emergency personnel have to cope with high job demands, which may cause considerable work stress (i.e. job strains), particularly when both acute and chronic job demands are experienced to be high. This may interfere with effective individual teamwork behaviour. A cross-sectional survey study was conducted in 2008, involving 48 members (doctors and nurses) of medical emergency teams working in the emergency department of a Dutch general hospital. Data were analyzed by means of hierarchical regression analyses. High acute job demands impeded effective teamwork behaviour, but only when they resulted in acute job strain. Acute emotional demands were more likely to result in acute job strain when chronic emotional job demands were also experienced as high. Although acute cognitive and physical strains were also detrimental, effective teamwork behaviour was particularly impeded by acute emotional strain. Acute job strains impair effective individual teamwork behaviour during medical emergencies, and there is urgent need to prevent or reduce a build-up of job strain from high acute and chronic demands, particularly of the emotional kind.

  17. Driving-forces model on individual behavior in scenarios considering moving threat agents

    Science.gov (United States)

    Li, Shuying; Zhuang, Jun; Shen, Shifei; Wang, Jia

    2017-09-01

    The individual behavior model is a contributory factor to improve the accuracy of agent-based simulation in different scenarios. However, few studies have considered moving threat agents, which often occur in terrorist attacks caused by attackers with close-range weapons (e.g., sword, stick). At the same time, many existing behavior models lack validation from cases or experiments. This paper builds a new individual behavior model based on seven behavioral hypotheses. The driving-forces model is an extension of the classical social force model considering scenarios including moving threat agents. An experiment was conducted to validate the key components of the model. Then the model is compared with an advanced Elliptical Specification II social force model, by calculating the fitting errors between the simulated and experimental trajectories, and being applied to simulate a specific circumstance. Our results show that the driving-forces model reduced the fitting error by an average of 33.9% and the standard deviation by an average of 44.5%, which indicates the accuracy and stability of the model in the studied situation. The new driving-forces model could be used to simulate individual behavior when analyzing the risk of specific scenarios using agent-based simulation methods, such as risk analysis of close-range terrorist attacks in public places.

  18. The Effect of Individual Factors, Socioeconomic and Social Participation on Individual Happiness: A Cross-Sectional Study.

    Science.gov (United States)

    Azizi, Maryam; Mohamadian, Fathola; Ghajarieah, Mozhgan; Direkvand-Moghadam, Ashraf

    2017-06-01

    Happiness and exhilaration are the most essential demands of human innate psychological needs that affect both physical and mental health. The present study aimed to investigate the effect of individual factors, socioeconomic and social participation on individual happiness. In this study, we evaluated 15 to 54-year-old individuals to find the effects of individual factors, socioeconomic and social partnership (formal or informal) on human happiness. A random sampling method was used in the present study. The Oxford Happiness Questionnaire (OHQ) was used. Data analysis was performed using descriptive statistics including; frequency, percentage, Mean±SD. Correlation coefficient, one way ANOVA and logistic regression were also used as analytical statistics. There was a significant relationship between gender (p=0.001, r=0.144), marital status (p=0.001, r=0.174), happy parents (p=0.001, r=0.194), educational grade (p=0.001, r=0.189), employment status (p=0.001, r=0.180), income (p=0.001, r=0.264), car ownership (p=0.001, r=0.173), informal social participation (p=0.001, r=0.3) and formal social participation (p=0.001, r=0.231) with happiness. However, the relationship between home ownership (p=0.346, r=-0.015), and happiness was not significant. It seems that good and cordial relations with others, including family, relatives and friends (informal social participation) are the main sources and the most important factors of life satisfaction and human happiness. Higher income can increase happiness by enhancing the possibility to access the needs, desires, problems solving, enhancing the social support and self esteem and opportunities to perform one's favourite activities.

  19. Probabilistic Inference: Task Dependency and Individual Differences of Probability Weighting Revealed by Hierarchical Bayesian Modeling.

    Science.gov (United States)

    Boos, Moritz; Seer, Caroline; Lange, Florian; Kopp, Bruno

    2016-01-01

    Cognitive determinants of probabilistic inference were examined using hierarchical Bayesian modeling techniques. A classic urn-ball paradigm served as experimental strategy, involving a factorial two (prior probabilities) by two (likelihoods) design. Five computational models of cognitive processes were compared with the observed behavior. Parameter-free Bayesian posterior probabilities and parameter-free base rate neglect provided inadequate models of probabilistic inference. The introduction of distorted subjective probabilities yielded more robust and generalizable results. A general class of (inverted) S-shaped probability weighting functions had been proposed; however, the possibility of large differences in probability distortions not only across experimental conditions, but also across individuals, seems critical for the model's success. It also seems advantageous to consider individual differences in parameters of probability weighting as being sampled from weakly informative prior distributions of individual parameter values. Thus, the results from hierarchical Bayesian modeling converge with previous results in revealing that probability weighting parameters show considerable task dependency and individual differences. Methodologically, this work exemplifies the usefulness of hierarchical Bayesian modeling techniques for cognitive psychology. Theoretically, human probabilistic inference might be best described as the application of individualized strategic policies for Bayesian belief revision.

  20. Validation of simplified centre of mass models during gait in individuals with chronic stroke.

    Science.gov (United States)

    Huntley, Andrew H; Schinkel-Ivy, Alison; Aqui, Anthony; Mansfield, Avril

    2017-10-01

    The feasibility of using a multiple segment (full-body) kinematic model in clinical gait assessment is difficult when considering obstacles such as time and cost constraints. While simplified gait models have been explored in healthy individuals, no such work to date has been conducted in a stroke population. The aim of this study was to quantify the errors of simplified kinematic models for chronic stroke gait assessment. Sixteen individuals with chronic stroke (>6months), outfitted with full body kinematic markers, performed a series of gait trials. Three centre of mass models were computed: (i) 13-segment whole-body model, (ii) 3 segment head-trunk-pelvis model, and (iii) 1 segment pelvis model. Root mean squared error differences were compared between models, along with correlations to measures of stroke severity. Error differences revealed that, while both models were similar in the mediolateral direction, the head-trunk-pelvis model had less error in the anteroposterior direction and the pelvis model had less error in the vertical direction. There was some evidence that the head-trunk-pelvis model error is influenced in the mediolateral direction for individuals with more severe strokes, as a few significant correlations were observed between the head-trunk-pelvis model and measures of stroke severity. These findings demonstrate the utility and robustness of the pelvis model for clinical gait assessment in individuals with chronic stroke. Low error in the mediolateral and vertical directions is especially important when considering potential stability analyses during gait for this population, as lateral stability has been previously linked to fall risk. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Taking individual scaling differences into account by analyzing profile data with the Mixed Assessor Model

    DEFF Research Database (Denmark)

    Brockhoff, Per Bruun; Schlich, Pascal; Skovgaard, Ib

    2015-01-01

    Scale range differences between individual assessors will often constitute a non-trivial part of the assessor-by-product interaction in sensory profile data (Brockhoff, 2003, 1998; Brockhoff and Skovgaard, 1994). We suggest a new mixed model ANOVA analysis approach, the Mixed Assessor Model (MAM...

  2. An individual-based model of Zebrafish population dynamics accounting for energy dynamics

    DEFF Research Database (Denmark)

    Beaudouin, Remy; Goussen, Benoit; Piccini, Benjamin

    2015-01-01

    Developing population dynamics models for zebrafish is crucial in order to extrapolate from toxicity data measured at the organism level to biological levels relevant to support and enhance ecological risk assessment. To achieve this, a dynamic energy budget for individual zebrafish (DEB model) w...

  3. Influence of Erroneous Patient Records on Population Pharmacokinetic Modeling and Individual Bayesian Estimation

    NARCIS (Netherlands)

    van der Meer, Aize Franciscus; Touw, Daniel J.; Marcus, Marco A. E.; Neef, Cornelis; Proost, Johannes H.

    2012-01-01

    Background: Observational data sets can be used for population pharmacokinetic (PK) modeling. However, these data sets are generally less precisely recorded than experimental data sets. This article aims to investigate the influence of erroneous records on population PK modeling and individual

  4. The Limit Behavior of a Stochastic Logistic Model with Individual Time-Dependent Rates

    Directory of Open Access Journals (Sweden)

    Yilun Shang

    2013-01-01

    Full Text Available We investigate a variant of the stochastic logistic model that allows individual variation and time-dependent infection and recovery rates. The model is described as a heterogeneous density dependent Markov chain. We show that the process can be approximated by a deterministic process defined by an integral equation as the population size grows.

  5. Effects of Individualized Word Retrieval in Kindergarten Vocabulary Intervention

    Science.gov (United States)

    Damhuis, Carmen M. P.; Segers, Eliane; Scheltinga, Femke; Verhoeven, Ludo

    2016-01-01

    We examined the effects of adaptive word retrieval intervention on a classroom vocabulary program on children's vocabulary acquisition in kindergarten. In the experimental condition, word retrieval was provided in a classroom vocabulary program, combining implicit and explicit vocabulary instructions. Children performed extra word retrieval…

  6. Modelling and modal properties of the railway vehicle bogie with two individual wheelset drives

    Directory of Open Access Journals (Sweden)

    Zeman V.

    2007-10-01

    Full Text Available The paper deals with mathematical modelling of vibration and modal analysis of two-axled bogie of a railway vehicle. In comparison with recent publications introducing mathematical models of an individual wheelset drive, this paper is focused on modelling of complex bogie vibration. The bogie frame is linked by primary suspension to the two wheelset drives with hollow shafts and by secondary suspension to the car body. The method is based on the system decomposition into three subsystems – two individual wheelset drives including the mass of the rail and the bogie frame coupled with a half of the car body – and on modelling of couplings among subsystems. The eigenvalues of a linearized autonomous model and stability conditions are investigated in dependence on longitudinal creepage and forward velocity of the railway vehicle. The nonlinear model will be used for investigating the dynamic loading of bogie components caused by different types of excitation.

  7. A Factor-Analytic Model for Assessing Individual Differences in Response Scale Usage.

    Science.gov (United States)

    Ferrando, Pere J

    2014-01-01

    This article proposes a factor-analytic model, intended for graded-response or continuous-response personality and attitude items, which includes an additional multiplicative person parameter that models the individual's response mapping process. The model, which is a modification of Spearman's (1904) factor analysis (FA) model, is parameterized as both an FA model and an item response theory (IRT) model and is fully developed to the extent that it can be used in applications. Procedures for (a) calibrating the items and assessing data fit, (b) obtaining individual estimates of both person parameters, (c) determining measurement precision, and (d) assessing differential predictability are proposed and discussed. The potential advantages of the proposal, its practical relevance, and its relations with other approaches are also discussed. Its functioning is assessed with a simulation study and 3 empirical examples in the personality domain.

  8. Random effect selection in generalised linear models

    DEFF Research Database (Denmark)

    Denwood, Matt; Houe, Hans; Forkman, Björn

    We analysed abattoir recordings of meat inspection codes with possible relevance to onfarm animal welfare in cattle. Random effects logistic regression models were used to describe individual-level data obtained from 461,406 cattle slaughtered in Denmark. Our results demonstrate that the largest...

  9. Beneficial effects of fresh and fermented kimchi in prediabetic individuals.

    Science.gov (United States)

    An, So-Yeon; Lee, Min Suk; Jeon, Ja Young; Ha, Eun Suk; Kim, Tae Ho; Yoon, Ja Young; Ok, Chang-Ok; Lee, Hye-Kyoung; Hwang, Won-Sun; Choe, Sun Jung; Han, Seung Jin; Kim, Hae Jin; Kim, Dae Jung; Lee, Kwan-Woo

    2013-01-01

    With the increased incidence of diabetes mellitus, the importance of early intervention in prediabetes has been emphasized. We previously reported that fermented kimchi, a traditional Korean food, reduced body weight and improved metabolic factors in overweight participants. We hypothesized that kimchi and its fermented form would have beneficial effects on glucose metabolism in patients with prediabetes. A total of 21 participants with prediabetes were enrolled. During the first 8 weeks, they consumed either fresh (1-day-old) or fermented (10-day-old) kimchi. After a 4-week washout period, they switched to the other type of kimchi for the next 8 weeks. Consumption of both types of kimchi significantly decreased body weight, body mass index, and waist circumference. Fermented kimchi decreased insulin resistance, and increased insulin sensitivity, QUICKI and disposition index values (p = 0.004 and 0.028, respectively). Systolic and diastolic blood pressure (BP) decreased significantly in the fermented kimchi group. The percentages of participants who showed improved glucose tolerance were 9.5 and 33.3% in the fresh and fermented kimchi groups, respectively. Consumption of kimchi had beneficial effects on glucose metabolism-related and anthropometric factors in participants with prediabetes. Fermented kimchi had additional effects on BP and insulin resistance/sensitivity. The percentage of participants who showed improvement in glucose tolerance was high in the fermented kimchi group. © 2013 S. Karger AG, Basel.

  10. Age Effects on Cortical Thickness in Cognitively Normal Elderly Individuals

    Directory of Open Access Journals (Sweden)

    Sona Hurtz

    2014-07-01

    Full Text Available Background/Aims: Atrophy in both grey and white matter is found in normal aging. The prefrontal cortex and the frontal lobe white matter are thought to be the most affected regions. Our aim was to examine the effects of normal aging on cortical grey matter using a 3D quantitative cortical mapping method. Methods: We analyzed 1.5-tesla brain magnetic resonance imaging data from 44 cognitively normal elderly subjects using cortical pattern matching and cortical thickness analyses. Linear regression analysis was used to study the effect of age on cortical thickness. 3D map-wide correction for multiple comparisons was conducted with permutation analyses using a threshold of p Results: We found a significant negative association between age and cortical thickness in the right hemisphere (pcorrected = 0.009 and a trend level association in the left hemisphere (pcorrected = 0.081. Age-related changes were greatest in the sensorimotor, bilateral dorsal anterior cingulate and supplementary motor cortices, and the right posterior middle and inferior frontal gyri. Age effects greater in the medial than lateral visual association cortices were also seen bilaterally. Conclusion: Our novel method further validates that normal aging results in diffuse cortical thinning that is most pronounced in the frontal and visual association cortices.

  11. Heterozygosity in an isolated population of a large mammal founded by four individuals is predicted by an individual-based genetic model.

    Directory of Open Access Journals (Sweden)

    Jaana Kekkonen

    Full Text Available Within-population genetic diversity is expected to be dramatically reduced if a population is founded by a low number of individuals. Three females and one male white-tailed deer Odocoileus virginianus, a North American species, were successfully introduced in Finland in 1934 and the population has since been growing rapidly, but remained in complete isolation from other populations.Based on 14 microsatellite loci, the expected heterozygosity H was 0.692 with a mean allelic richness (AR of 5.36, which was significantly lower than what was found in Oklahoma, U.S.A. (H = 0.742; AR = 9.07, demonstrating that a bottleneck occurred. Observed H was in line with predictions from an individual-based model where the genealogy of the males and females in the population were tracked and the population's demography was included.Our findings provide a rare within-population empirical test of the founder effect and suggest that founding a population by a small number of individuals need not have a dramatic impact on heterozygosity in an iteroparous species.

  12. Cost Effectiveness of Screening Individuals With Cystic Fibrosis for Colorectal Cancer.

    Science.gov (United States)

    Gini, Andrea; Zauber, Ann G; Cenin, Dayna R; Omidvari, Amir-Houshang; Hempstead, Sarah E; Fink, Aliza K; Lowenfels, Albert B; Lansdorp-Vogelaar, Iris

    2018-02-01

    Individuals with cystic fibrosis are at increased risk of colorectal cancer (CRC) compared with the general population, and risk is higher among those who received an organ transplant. We performed a cost-effectiveness analysis to determine optimal CRC screening strategies for patients with cystic fibrosis. We adjusted the existing Microsimulation Screening Analysis-Colon model to reflect increased CRC risk and lower life expectancy in patients with cystic fibrosis. Modeling was performed separately for individuals who never received an organ transplant and patients who had received an organ transplant. We modeled 76 colonoscopy screening strategies that varied the age range and screening interval. The optimal screening strategy was determined based on a willingness to pay threshold of $100,000 per life-year gained. Sensitivity and supplementary analyses were performed, including fecal immunochemical test (FIT) as an alternative test, earlier ages of transplantation, and increased rates of colonoscopy complications, to assess if optimal screening strategies would change. Colonoscopy every 5 years, starting at an age of 40 years, was the optimal colonoscopy strategy for patients with cystic fibrosis who never received an organ transplant; this strategy prevented 79% of deaths from CRC. Among patients with cystic fibrosis who had received an organ transplant, optimal colonoscopy screening should start at an age of 30 or 35 years, depending on the patient's age at time of transplantation. Annual FIT screening was predicted to be cost-effective for patients with cystic fibrosis. However, the level of accuracy of the FIT in this population is not clear. Using a Microsimulation Screening Analysis-Colon model, we found screening of patients with cystic fibrosis for CRC to be cost effective. Because of the higher risk of CRC in these patients, screening should start at an earlier age with a shorter screening interval. The findings of this study (especially those on FIT

  13. Cost-Effectiveness of Screening Individuals With Cystic Fibrosis for Colorectal Cancer.

    Science.gov (United States)

    Gini, Andrea; Zauber, Ann G; Cenin, Dayna R; Omidvari, Amir-Houshang; Hempstead, Sarah E; Fink, Aliza K; Lowenfels, Albert B; Lansdorp-Vogelaar, Iris

    2017-12-27

    Individuals with cystic fibrosis are at increased risk of colorectal cancer (CRC) compared to the general population, and risk is higher among those who received an organ transplant. We performed a cost-effectiveness analysis to determine optimal CRC screening strategies for patients with cystic fibrosis. We adjusted the existing Microsimulation Screening Analysis-Colon microsimulation model to reflect increased CRC risk and lower life expectancy in patients with cystic fibrosis. Modeling was performed separately for individuals who never received an organ transplant and patients who had received an organ transplant. We modeled 76 colonoscopy screening strategies that varied the age range and screening interval. The optimal screening strategy was determined based on a willingness to pay threshold of $100,000 per life-year gained. Sensitivity and supplementary analyses were performed, including fecal immunochemical test (FIT) as an alternative test, earlier ages of transplantation, and increased rates of colonoscopy complications, to assess whether optimal screening strategies would change. Colonoscopy every 5 years, starting at age 40 years, was the optimal colonoscopy strategy for patients with cystic fibrosis who never received an organ transplant; this strategy prevented 79% of deaths from CRC. Among patients with cystic fibrosis who had received an organ transplant, optimal colonoscopy screening should start at an age of 30 or 35 years, depending on the patient's age at time of transplantation. Annual FIT screening was predicted to be cost-effective for patients with cystic fibrosis. However, the level of accuracy of the FIT in population is not clear. Using a Microsimulation Screening Analysis-Colon microsimulation model, we found screening of patients with cystic fibrosis for CRC to be cost-effective. Due to the higher risk in these patients for CRC, screening should start at an earlier age with a shorter screening interval. The findings of this study

  14. Probabilistic inference: Task dependency and individual differences of probability weighting revealed by hierarchical Bayesian modelling

    Directory of Open Access Journals (Sweden)

    Moritz eBoos

    2016-05-01

    Full Text Available Cognitive determinants of probabilistic inference were examined using hierarchical Bayesian modelling techniques. A classic urn-ball paradigm served as experimental strategy, involving a factorial two (prior probabilities by two (likelihoods design. Five computational models of cognitive processes were compared with the observed behaviour. Parameter-free Bayesian posterior probabilities and parameter-free base rate neglect provided inadequate models of probabilistic inference. The introduction of distorted subjective probabilities yielded more robust and generalizable results. A general class of (inverted S-shaped probability weighting functions had been proposed; however, the possibility of large differences in probability distortions not only across experimental conditions, but also across individuals, seems critical for the model’s success. It also seems advantageous to consider individual differences in parameters of probability weighting as being sampled from weakly informative prior distributions of individual parameter values. Thus, the results from hierarchical Bayesian modelling converge with previous results in revealing that probability weighting parameters show considerable task dependency and individual differences. Methodologically, this work exemplifies the usefulness of hierarchical Bayesian modelling techniques for cognitive psychology. Theoretically, human probabilistic inference might be best described as the application of individualized strategic policies for Bayesian belief revision.

  15. A small community model for the transmission of infectious diseases: comparison of school closure as an intervention in individual-based models of an influenza pandemic.

    Directory of Open Access Journals (Sweden)

    George J Milne

    Full Text Available BACKGROUND: In the absence of other evidence, modelling has been used extensively to help policy makers plan for a potential future influenza pandemic. METHOD: We have constructed an individual based model of a small community in the developed world with detail down to exact household structure obtained from census collection datasets and precise simulation of household demographics, movement within the community and individual contact patterns. We modelled the spread of pandemic influenza in this community and the effect on daily and final attack rates of four social distancing measures: school closure, increased case isolation, workplace non-attendance and community contact reduction. We compared the modelled results of final attack rates in the absence of any interventions and the effect of school closure as a single intervention with other published individual based models of pandemic influenza in the developed world. RESULTS: We showed that published individual based models estimate similar final attack rates over a range of values for R(0 in a pandemic where no interventions have been implemented; that multiple social distancing measures applied early and continuously can be very effective in interrupting transmission of the pandemic virus for R(0 values up to 2.5; and that different conclusions reached on the simulated benefit of school closure in published models appear to result from differences in assumptions about the timing and duration of school closure and flow-on effects on other social contacts resulting from school closure. CONCLUSION: Models of the spread and control of pandemic influenza have the potential to assist policy makers with decisions about which control strategies to adopt. However, attention needs to be given by policy makers to the assumptions underpinning both the models and the control strategies examined.

  16. Individual differences and the effect of face configuration information in the McGurk effect.

    Science.gov (United States)

    Ujiie, Yuta; Asai, Tomohisa; Wakabayashi, Akio

    2018-01-30

    The McGurk effect, which denotes the influence of visual information on audiovisual speech perception, is less frequently observed in individuals with autism spectrum disorder (ASD) compared to those without it; the reason for this remains unclear. Several studies have suggested that facial configuration context might play a role in this difference. More specifically, people with ASD show a local processing bias for faces-that is, they process global face information to a lesser extent. This study examined the role of facial configuration context in the McGurk effect in 46 healthy students. Adopting an analogue approach using the Autism-Spectrum Quotient (AQ), we sought to determine whether this facial configuration context is crucial to previously observed reductions in the McGurk effect in people with ASD. Lip-reading and audiovisual syllable identification tasks were assessed via presentation of upright normal, inverted normal, upright Thatcher-type, and inverted Thatcher-type faces. When the Thatcher-type face was presented, perceivers were found to be sensitive to the misoriented facial characteristics, causing them to perceive a weaker McGurk effect than when the normal face was presented (this is known as the McThatcher effect). Additionally, the McGurk effect was weaker in individuals with high AQ scores than in those with low AQ scores in the incongruent audiovisual condition, regardless of their ability to read lips or process facial configuration contexts. Our findings, therefore, do not support the assumption that individuals with ASD show a weaker McGurk effect due to a difficulty in processing facial configuration context.

  17. THE DYNAMIC MODEL FOR CONTROL OF STUDENT’S LEARNING INDIVIDUAL TRAJECTORY

    Directory of Open Access Journals (Sweden)

    A. A. Mitsel

    2015-01-01

    Full Text Available In connection with the transition of the educational system to a competence-oriented approach, the problem of learning outcomes assessment and creating an individual learning trajectory of a student has become relevant. Its solution requires the application of modern information technologies. The third generation of Federal state educational standards of higher professional education (FSES HPE defines the requirements for the results of Mastering the basic educational programs (BEP. According to FSES HPE up to 50% of subjects have a variable character, i.e. depend on the choice of a student. It significantly influences on the results of developing various competencies. The problem of forming student’s learning trajectory is analyzed in general and the choice of an individual direction was studied in details. Various methods, models and algorithms of the student’s individual learning trajectory formation were described. The analysis of the model of educational process organization in terms of individual approach makes it possible to develop a decision support system (DSS. DSS is a set of interrelated programs and data used for analysis of situation, development of alternative solutions and selection of the most acceptable alternative. DSSs are often used when building individual learning path, because this task can be considered as a discrete multi-criteria problem, creating a significant burden on the decision maker. A new method of controlling the learning trajectory has been developed. The article discusses problem statement and solution of determining student’s optimal individual educational trajectory as a dynamic model of learning trajectory control, which uses score assessment to construct a sequence of studied subjects. A new model of management learning trajectory is based on dynamic models for tracking the reference trajectory. The task can be converted to an equivalent model of linear programming, for which a reliable solution

  18. Exact solution of gyration radius of individual's trajectory for a simplified human mobility model

    OpenAIRE

    Yan, Xiao-Yong; Han, Xiao-Pu; Zhou, Tao; Wang, Bing-Hong

    2010-01-01

    Gyration radius of individual's trajectory plays a key role in quantifying human mobility patterns. Of particular interests, empirical analyses suggest that the growth of gyration radius is slow versus time except the very early stage and may eventually arrive to a steady value. However, up to now, the underlying mechanism leading to such a possibly steady value has not been well understood. In this Letter, we propose a simplified human mobility model to simulate individual's daily travel wit...

  19. Individual differences in boys' and girls' timing and tempo of puberty: modeling development with nonlinear growth models.

    Science.gov (United States)

    Marceau, Kristine; Ram, Nilam; Houts, Renate M; Grimm, Kevin J; Susman, Elizabeth J

    2011-09-01

    Pubertal development is a nonlinear process progressing from prepubescent beginnings through biological, physical, and psychological changes to full sexual maturity. To tether theoretical concepts of puberty with sophisticated longitudinal, analytical models capable of articulating pubertal development more accurately, we used nonlinear mixed-effects models to describe both the timing and tempo of pubertal development in the sample of 364 White boys and 373 White girls measured across 6 years as part of the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development. Individual differences in timing and tempo were extracted with models of logistic growth. Differential relations emerged for how boys' and girls' timing and tempo of development were related to physical characteristics (body mass index, height, and weight) and psychological outcomes (internalizing problems, externalizing problems, and risky sexual behavior). Timing and tempo are associated in boys but not girls. Pubertal timing and tempo are particularly important for predicting psychological outcomes in girls but only sparsely related to boys' psychological outcomes. Results highlight the importance of considering the nonlinear nature of puberty and expand the repertoire of possibilities for examining important aspects of how and when pubertal processes contribute to development.

  20. Characteristics and Diffusion Model of the Individual Knowledge in the WeChat Mode

    Directory of Open Access Journals (Sweden)

    Zhang Lingzhi

    2017-12-01

    Full Text Available [Purpose/significance] According to the model of the individual knowledge diffusion, we conduct a behavior research and analyze the characteristics of that based on WeChat which is the most popular communication platform in China.[Method/process] By analyzing the methods of the diffusion on WeChat, we analyzed the characteristics of the individual knowledge diffusion. [Result/conclusion]The characteristics of the individual knowledge diffusion include real-time, short-term, speciality, friendship and transmission.

  1. The partnership model: working with individuals, families, and communities toward a new vision of health.

    Science.gov (United States)

    Courtney, R; Ballard, E; Fauver, S; Gariota, M; Holland, L

    1996-06-01

    Increasingly, health professionals must learn to work in new partnership relationships with clients and community to promote health effectively. A partnership requires a transformation of the professional role from chief actor to partner, and the client role from passive recipient to partner. A partnership approach has particular merit in a reformed health care system that increasingly emphasizes active involvement and self-care actions of individuals and families to maintain health and prevent disease. A partnership approach is also important to professionals working with underserved, vulnerable, and/or minority populations. For too long professionals and policymakers have relegated these groups to passive roles in health decision making and action. This article will provide a description of the partnership process as it has been developed and implemented by nurse practitioners in an urban Hispanic community with emphasis on a community partnership. A partnership model is described and compared to the more traditional professional model. A definition and essential criteria for partnership are presented. Finally, a specific example of how the partnership process was implemented at the community level is discussed.

  2. Effect of Centchroman administration in normospermic & oligospermic individuals.

    Science.gov (United States)

    Roy, S; Chatterjee, S; Taneja, S L; Kumari, G L; Allag, I S; Pandey, H C; Jadhav, Y N

    1977-12-01

    The effect of Centchroman, 3,4-trans-2,2-dimethyl-3-phenyl-4-para-(beta -pyrrolidinoethocy)-phenyl-7-methorychroman, administration was investigated in normospermic and oligospermic subjects. 3 normal volunteers, aged 32-40 years, were treated with increasing doses (30, 60, and 120 mg/day, each dose for 2 weeks). The sperm count was decreased in 1 volunteer but the percentages of nonmotile and abnormal spermatozoa were increased in all 3. There was no change in plasma testosterone and urinary 17-ketosteroid (17-KS) levels but the 17-ketogenic steroids (17-KGSs) were decreased in all of them. 3 out of 5 oligospermic subjects, aged 24-35 years, who received 30 mg/day for 6 weeks revealed increased sperm counts. Plasma testosterone levels were decreased in 4, urinary 17-KGSs were decreased in 2, and 17-KSs were decreased in 1 subject. Acid phosphatase, fructose, sialic acid and glycerylphosphoryl choline levels in semen, and serum glutamate oxaloacetate transaminase, serum glutamate pyruvate transaminase, alkaline phosphatase, and urea in blood were not markedly altered in either group.

  3. The effect of individual factors on health behaviors among college students: the mediating effects of eHealth literacy.

    Science.gov (United States)

    Hsu, WanChen; Chiang, ChiaHsun; Yang, ShuChing

    2014-12-12

    College students' health behavior is a topic that deserves attention. Individual factors and eHealth literacy may affect an individual's health behaviors. The integrative model of eHealth use (IMeHU) provides a parsimonious account of the connections among the digital divide, health care disparities, and the unequal distribution and use of communication technologies. However, few studies have explored the associations among individual factors, eHealth literacy, and health behaviors, and IMeHU has not been empirically investigated. This study examines the associations among individual factors, eHealth literacy, and health behaviors using IMeHU. The Health Behavior Scale is a 12-item instrument developed to measure college students' eating, exercise, and sleep behaviors. The eHealth Literacy Scale is a 12-item instrument designed to measure college students' functional, interactive, and critical eHealth literacy. A nationally representative sample of 525 valid college students in Taiwan was surveyed. A questionnaire was administered to collect background information about participants' health status, degree of health concern, major, and the frequency with which they engaged in health-related discussions. This study used Amos 6.0 to conduct a confirmatory factor analysis to identify the best measurement models for the eHealth Literacy Scale and the Health Behavior Scale. We then conducted a multiple regression analysis to examine the associations among individual factors, eHealth literacy, and health behaviors. Additionally, causal steps approach was used to explore indirect (mediating) effects and Sobel tests were used to test the significance of the mediating effects. The study found that perceptions of better health status (t520=2.14-6.12, PeHealth literacy and adoption of healthy eating, exercise, and sleep behaviors. Moreover, eHealth literacy played an intermediary role in the association between individual factors and health behaviors (Sobel test=2.09-2.72, Pe

  4. An individual-based probabilistic model for simulating fisheries population dynamics

    Directory of Open Access Journals (Sweden)

    Jie Cao

    2016-12-01

    Full Text Available The purpose of stock assessment is to support managers to provide intelligent decisions regarding removal from fish populations. Errors in assessment models may have devastating impacts on the population fitness and negative impacts on the economy of the resource users. Thus, accuracte estimations of population size, growth rates are critical for success. Evaluating and testing the behavior and performance of stock assessment models and assessing the consequences of model mis-specification and the impact of management strategies requires an operating model that accurately describe the dynamics of the target species, and can resolve spatial and seasonal changes. In addition, the most thorough evaluations of assessment models use an operating model that takes a different form than the assessment model. This paper presents an individual-based probabilistic model used to simulate the complex dynamics of populations and their associated fisheries. Various components of population dynamics are expressed as random Bernoulli trials in the model and detailed life and fishery histories of each individual are tracked over their life span. The simulation model is designed to be flexible so it can be used for different species and fisheries. It can simulate mixing among multiple stocks and link stock-recruit relationships to environmental factors. Furthermore, the model allows for flexibility in sub-models (e.g., growth and recruitment and model assumptions (e.g., age- or size-dependent selectivity. This model enables the user to conduct various simulation studies, including testing the performance of assessment models under different assumptions, assessing the impacts of model mis-specification and evaluating management strategies.

  5. Effectiveness of individual and group interventions for people with type 2 diabetes1

    Science.gov (United States)

    Imazu, Maria Fernanda Manoel; Faria, Barbara Nascimento; de Arruda, Guilherme Oliveira; Sales, Catarina Aparecida; Marcon, Sonia Silva

    2015-01-01

    OBJECTIVE: to compare the effectiveness of two educational interventions used by a healthcare provider in the monitoring of individuals with type 2 diabetes mellitus (T2DM), regarding knowledge of the disease, impact on quality of life and adoption of self-care actions. METHODS: comparative, longitudinal, prospective study performed with 150 subjects with type 2 diabetes, analyzed according to the type of participation in the program (individual and/or group). Participants of the individual intervention (II) received nursing consultations every six months and those of the group intervention (GI) took part in weekly meetings for three months. Data were collected through four questionnaires: Identification questionnaire, Problem Areas in Diabetes Questionnaire (PAID), Summary of Diabetes Self-Care Activities Questionnaire (SDSCA) and the Diabetes Knowledge Scale (DKN-A). Data were analyzed using the Friedman and Mann Whitney tests, considering a statistical significance of p ≤ 0.05. RESULTS: there was an increase in knowledge about the disease in the II (p<0.003) and GI (p<0.007), with reduction of the impact on the quality of life in the II (p<0.007) and improvement in self-care actions in the GI (p<0.001). CONCLUSION: in both intervention models improvements were observed in the indicators, over the six month monitoring period. PMID:26039289

  6. Nonlinear joint models for individual dynamic prediction of risk of death using Hamiltonian Monte Carlo: application to metastatic prostate cancer

    Directory of Open Access Journals (Sweden)

    Solène Desmée

    2017-07-01

    Full Text Available Abstract Background Joint models of longitudinal and time-to-event data are increasingly used to perform individual dynamic prediction of a risk of event. However the difficulty to perform inference in nonlinear models and to calculate the distribution of individual parameters has long limited this approach to linear mixed-effect models for the longitudinal part. Here we use a Bayesian algorithm and a nonlinear joint model to calculate individual dynamic predictions. We apply this approach to predict the risk of death in metastatic castration-resistant prostate cancer (mCRPC patients with frequent Prostate-Specific Antigen (PSA measurements. Methods A joint model is built using a large population of 400 mCRPC patients where PSA kinetics is described by a biexponential function and the hazard function is a PSA-dependent function. Using Hamiltonian Monte Carlo algorithm implemented in Stan software and the estimated population parameters in this population as priors, the a posteriori distribution of the hazard function is computed for a new patient knowing his PSA measurements until a given landmark time. Time-dependent area under the ROC curve (AUC and Brier score are derived to assess discrimination and calibration of the model predictions, first on 200 simulated patients and then on 196 real patients that are not included to build the model. Results Satisfying coverage probabilities of Monte Carlo prediction intervals are obtained for longitudinal and hazard functions. Individual dynamic predictions provide good predictive performances for landmark times larger than 12 months and horizon time of up to 18 months for both simulated and real data. Conclusions As nonlinear joint models can characterize the kinetics of biomarkers and their link with a time-to-event, this approach could be useful to improve patient’s follow-up and the early detection of most at risk patients.

  7. Effects of Vibroacoustic Music on Challenging Behaviors in Individuals with Autism and Developmental Disabilities

    Science.gov (United States)

    Lundqvist, Lars-Olov; Andersson, Gunilla; Viding, Jane

    2009-01-01

    Vibroacoustic music has been proposed to be an effective treatment for individuals with developmental disorders and challenging behaviors. The present study experimentally tested the effects of vibroacoustic music on self-injurious, stereotypical, and aggressive destructive behaviors in 20 individuals with autism spectrum disorders and…

  8. Interactive effects of individuation, family factors, and stress on adolescent alcohol use.

    Science.gov (United States)

    Bray, J H; Adams, G J; Getz, J G; Stovall, T

    2001-10-01

    A prospective, school-based study of increasing alcohol use in a multi-ethnic sample of 7,540 adolescents showed that the effects of stress, family conflict, and parental monitoring were differentially moderated by two modes of individuation. The effects of stress were moderated by ethnic status and individuation. Implications for prevention and intervention are discussed.

  9. The Effect of Literature on Personality Development of Individuals Using Some Variables

    Science.gov (United States)

    Tatlilioglu, Kasim

    2017-01-01

    The aim of this work is to investigate whether literature has effect on the personality development of individuals or not. This works aims to provide answers to the following research questions: "Does literature have effect on individuals' general harmony level, their social cohesion levels, personal harmony level, self-actualization level,…

  10. The Effect of Using Cooperative and Individual Weblog to Enhance Writing Performance

    Science.gov (United States)

    Karsak, H. Gulhan Orhan; Fer, Seval; Orhan, Feza

    2014-01-01

    Academic writing, whether individual or cooperative, is an essential skill for today's graduates. However, motivating and helping students to learn to write effectively, either in cooperative or individual scenarios, poses many challenges, many of which can be overcome by technical means. The aim of this study is to investigate the effect of using…

  11. Development and validation of a predictive model of acute glucose response to exercise in individuals with type 2 diabetes

    OpenAIRE

    Gibson, Bryan S; Colberg, Sheri R; Poirier, Paul; Vancea, Denise Maria Martins; Jones, Jason; Marcus, Robin

    2013-01-01

    Background Our purpose was to develop and test a predictive model of the acute glucose response to exercise in individuals with type 2 diabetes. Design and methods Data from three previous exercise studies (56 subjects, 488 exercise sessions) were combined and used as a development dataset. A mixed-effects Least Absolute Shrinkage Selection Operator (LASSO) was used to select predictors among 12 potential predictors. Tests of the relative importance of each predictor were conducted using the ...

  12. Individualized 3D printed model-assisted posterior screw fixation for the treatment of craniovertebral junction abnormality: a retrospective study.

    Science.gov (United States)

    Gao, Fangyou; Wang, Qu; Liu, Chuangxi; Xiong, Bing; Luo, Tao

    2017-07-01

    in 31 patients and incomplete reduction in 10 patients (reduction rate > 50%). The postoperative ADI significantly decreased, and the CMA significantly increased. CONCLUSIONS Individualized 3D printed model-assisted posterior internal fixation seems feasible and effective in optimizing the treatment of CVJ abnormalities. In addition, it offers many advantages, including preoperative simulation, intraoperatve guidance, and intraoperative error minimization.

  13. Models for effective prevention.

    Science.gov (United States)

    Perry, C L; Kelder, S H

    1992-07-01

    The social influence models do provide some optimism for primary prevention efforts. Prevention programs appear most effective when 1) the target behavior of the intervention has received increasing societal disapproval (such as cigarette smoking), 2) multiple years of behavioral health education are planned, and 3) community-wide involvement or mass media complement a school-based peer-led program (45,46). Short-term programs and those involving alcohol use have had less favorable outcomes. Future research in primary prevention should address concerns of high-risk groups and high-risk countries, such as lower income populations in the United States or countries that have large adolescent homeless populations. The utilization of adolescent leaders for program dissemination might be particularly critical in these settings. A second major and global concern should focus upon alcohol use and alcohol-related problems. In many communities adolescent alcohol use is normative and even adult supported. Thus, young people are getting quite inconsistent messages on alcohol from their schools, from TV, from peers, and from parents. This inconsistency may translate into many tragic and avoidable deaths for young people. Clearly, in the area of alcohol-related problems, community-wide involvement may be necessary. A third direction for prevention research should involve issues of norms, access, and enforcement including policy interventions, such as involve the availability of cigarette vending machines or the ease of under-age buying or levels of taxation. These methods affect adolescents more acutely since their financial resources, for the most part, are more limited. These policy level methods also signify to adolescents what adults consider appropriate.(ABSTRACT TRUNCATED AT 250 WORDS)

  14. Validation of individual and aggregate global flood hazard models for two major floods in Africa.

    Science.gov (United States)

    Trigg, M.; Bernhofen, M.; Whyman, C.

    2017-12-01

    A recent intercomparison of global flood hazard models undertaken by the Global Flood Partnership shows that there is an urgent requirement to undertake more validation of the models against flood observations. As part of the intercomparison, the aggregated model dataset resulting from the project was provided as open access data. We compare the individual and aggregated flood extent output from the six global models and test these against two major floods in the African Continent within the last decade, namely severe flooding on the Niger River in Nigeria in 2012, and on the Zambezi River in Mozambique in 2007. We test if aggregating different number and combination of models increases model fit to the observations compared with the individual model outputs. We present results that illustrate some of the challenges of comparing imperfect models with imperfect observations and also that of defining the probability of a real event in order to test standard model output probabilities. Finally, we propose a collective set of open access validation flood events, with associated observational data and descriptions that provide a standard set of tests across different climates and hydraulic conditions.

  15. Predictive Models of Alcohol Use Based on Attitudes and Individual Values

    Science.gov (United States)

    Del Castillo Rodríguez, José A. García; López-Sánchez, Carmen; Soler, M. Carmen Quiles; Del Castillo-López, Álvaro García; Pertusa, Mónica Gázquez; Campos, Juan Carlos Marzo; Inglés, Cándido J.

    2013-01-01

    Two predictive models are developed in this article: the first is designed to predict people' attitudes to alcoholic drinks, while the second sets out to predict the use of alcohol in relation to selected individual values. University students (N = 1,500) were recruited through stratified sampling based on sex and academic discipline. The…

  16. Using ROC curves to compare neural networks and logistic regression for modeling individual noncatastrophic tree mortality

    Science.gov (United States)

    Susan L. King

    2003-01-01

    The performance of two classifiers, logistic regression and neural networks, are compared for modeling noncatastrophic individual tree mortality for 21 species of trees in West Virginia. The output of the classifier is usually a continuous number between 0 and 1. A threshold is selected between 0 and 1 and all of the trees below the threshold are classified as...

  17. Modelling collective foraging by means of individual behaviour rules in honey-bees

    NARCIS (Netherlands)

    Vries, Han de; Biesmeijer, J.C.

    1998-01-01

    An individual-oriented model is constructed which simulates the collective foraging behaviour of a colony of honey-bees, Apis mellifera. Each bee follows the same set of behavioural rules. Each rule consists of a set of conditions followed by the behavioural act to be performed if the

  18. Age Differences within Secular IQ Trends: An Individual Growth Modeling Approach

    Science.gov (United States)

    Kanaya, Tomoe; Ceci, Stephen J.; Scullin, Matthew H.

    2005-01-01

    Age differences within the yo-yo trend in IQ, caused when aging norms that produce inflated scores are replaced with new norms, were examined using longitudinal WISC, WISC-R and WISC-III records of students tested for special education services from 10 school districts. Descriptive and individual growth modeling analyses revealed that while the…

  19. Selection through Individualized Review: A Report on Phase IV of the Admissions Models Project

    Science.gov (United States)

    Rigol, Gretchen W.

    2004-01-01

    This is the fourth monograph in the admissions models series. Based on discussions at a June 2004 conference and conversations with numerous admissions experts, this publication describes different approaches to individualized review and covers topics such as standardizing elements of the application, reader training and guidelines, consistency…

  20. Adjudicating between face-coding models with individual-face fMRI responses.

    Directory of Open Access Journals (Sweden)

    Johan D Carlin

    2017-07-01

    Full Text Available The perceptual representation of individual faces is often explained with reference to a norm-based face space. In such spaces, individuals are encoded as vectors where identity is primarily conveyed by direction and distinctiveness by eccentricity. Here we measured human fMRI responses and psychophysical similarity judgments of individual face exemplars, which were generated as realistic 3D animations using a computer-graphics model. We developed and evaluated multiple neurobiologically plausible computational models, each of which predicts a representational distance matrix and a regional-mean activation profile for 24 face stimuli. In the fusiform face area, a face-space coding model with sigmoidal ramp tuning provided a better account of the data than one based on exemplar tuning. However, an image-processing model with weighted banks of Gabor filters performed similarly. Accounting for the data required the inclusion of a measurement-level population averaging mechanism that approximates how fMRI voxels locally average distinct neuronal tunings. Our study demonstrates the importance of comparing multiple models and of modeling the measurement process in computational neuroimaging.

  1. Comparison of parametric, orthogonal, and spline functions to model individual lactation curves for milk yield in Canadian Holsteins

    Directory of Open Access Journals (Sweden)

    Corrado Dimauro

    2010-11-01

    Full Text Available Test day records for milk yield of 57,390 first lactation Canadian Holsteins were analyzed with a linear model that included the fixed effects of herd-test date and days in milk (DIM interval nested within age and calving season. Residuals from this model were analyzed as a new variable and fitted with a five parameter model, fourth-order Legendre polynomials, with linear, quadratic and cubic spline models with three knots. The fit of the models was rather poor, with about 30-40% of the curves showing an adjusted R-square lower than 0.20 across all models. Results underline a great difficulty in modelling individual deviations around the mean curve for milk yield. However, the Ali and Schaeffer (5 parameter model and the fourth-order Legendre polynomials were able to detect two basic shapes of individual deviations among the mean curve. Quadratic and, especially, cubic spline functions had better fitting performances but a poor predictive ability due to their great flexibility that results in an abrupt change of the estimated curve when data are missing. Parametric and orthogonal polynomials seem to be robust and affordable under this standpoint.

  2. Automated MRI segmentation for individualized modeling of current flow in the human head

    Science.gov (United States)

    Huang, Yu; Dmochowski, Jacek P.; Su, Yuzhuo; Datta, Abhishek; Rorden, Christopher; Parra, Lucas C.

    2013-12-01

    Objective. High-definition transcranial direct current stimulation (HD-tDCS) and high-density electroencephalography require accurate models of current flow for precise targeting and current source reconstruction. At a minimum, such modeling must capture the idiosyncratic anatomy of the brain, cerebrospinal fluid (CSF) and skull for each individual subject. Currently, the process to build such high-resolution individualized models from structural magnetic resonance images requires labor-intensive manual segmentation, even when utilizing available automated segmentation tools. Also, accurate placement of many high-density electrodes on an individual scalp is a tedious procedure. The goal was to develop fully automated techniques to reduce the manual effort in such a modeling process. Approach. A fully automated segmentation technique based on Statical Parametric Mapping 8, including an improved tissue probability map and an automated correction routine for segmentation errors, was developed, along with an automated electrode placement tool for high-density arrays. The performance of these automated routines was evaluated against results from manual segmentation on four healthy subjects and seven stroke patients. The criteria include segmentation accuracy, the difference of current flow distributions in resulting HD-tDCS models and the optimized current flow intensities on cortical targets.Main results. The segmentation tool can segment out not just the brain but also provide accurate results for CSF, skull and other soft tissues with a field of view extending to the neck. Compared to manual results, automated segmentation deviates by only 7% and 18% for normal and stroke subjects, respectively. The predicted electric fields in the brain deviate by 12% and 29% respectively, which is well within the variability observed for various modeling choices. Finally, optimized current flow intensities on cortical targets do not differ significantly.Significance. Fully

  3. The effects of electron-hole separation on the photoconductivity of individual metal oxide nanowires

    International Nuclear Information System (INIS)

    Prades, J D; Hernandez-Ramirez, F; Jimenez-Diaz, R; Manzanares, M; Andreu, T; Cirera, A; Romano-Rodriguez, A; Morante, J R

    2008-01-01

    The responses of individual ZnO nanowires to UV light demonstrate that the persistent photoconductivity (PPC) state is directly related to the electron-hole separation near the surface. Our results demonstrate that the electrical transport in these nanomaterials is influenced by the surface in two different ways. On the one hand, the effective mobility and the density of free carriers are determined by recombination mechanisms assisted by the oxidizing molecules in air. This phenomenon can also be blocked by surface passivation. On the other hand, the surface built-in potential separates the photogenerated electron-hole pairs and accumulates holes at the surface. After illumination, the charge separation makes the electron-hole recombination difficult and originates PPC. This effect is quickly reverted after increasing either the probing current (self-heating by Joule dissipation) or the oxygen content in air (favouring the surface recombination mechanisms). The model for PPC in individual nanowires presented here illustrates the intrinsic potential of metal oxide nanowires to develop optoelectronic devices or optochemical sensors with better and new performances.

  4. Contextual and individual determinants of periodontal disease: Multilevel analysis based on Andersen's model.

    Science.gov (United States)

    Valente, Maria I B; Vettore, Mario V

    2017-11-17

    To investigate the relationship of contextual and individual factors with periodontal disease in dentate adults and older people using the Andersen's behavioural model. Secondary individual data from 6011 adults and 2369 older people from the Brazilian Oral Health Survey (2010) were combined with contextual data for 27 cities. Attachment loss (AL) categories for each sextant were coded and summed to obtain the periodontal disease measure. The association of predisposing, enabling and need characteristics at city and individual level with periodontal disease was assessed using an adapted version of the Andersen's behavioural model. Multilevel Poisson regression was used to estimate rate ratios (RR) and 95% CIs. Periodontal disease was associated with contextual predisposing (RR 0.93; 95% CI = 0.87-0.99) and enabling factors (RR 0.99; 95% CI = 0.98-0.99) in adults. Contextual predisposing was also associated with periodontal disease in older people (RR 0.82; 95% CI = 0.73-0.92). Individual predisposing (age, sex and schooling) and need characteristics (perceived treatment need) were common predictors of periodontal disease in adults and older people. Periodontal disease was also associated with behaviours in the latter age group. Contextual predisposing factors and individual characteristics influenced periodontal disease experience in adults and older people. Contextual enabling factors were also meaningful determinants of periodontal disease in the former age group. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. Modeling socioeconomic status effects on language development.

    Science.gov (United States)

    Thomas, Michael S C; Forrester, Neil A; Ronald, Angelica

    2013-12-01

    Socioeconomic status (SES) is an important environmental predictor of language and cognitive development, but the causal pathways by which it operates are unclear. We used a computational model of development to explore the adequacy of manipulations of environmental information to simulate SES effects in English past-tense acquisition, in a data set provided by Bishop (2005). To our knowledge, this is the first application of computational models of development to SES. The simulations addressed 3 new challenges: (a) to combine models of development and individual differences in a single framework, (b) to expand modeling to the population level, and (c) to implement both environmental and genetic/intrinsic sources of individual differences. The model succeeded in capturing the qualitative patterns of regularity effects in both population performance and the predictive power of SES that were observed in the empirical data. The model suggested that the empirical data are best captured by relatively wider variation in learning abilities and relatively narrow variation in (and good quality of) environmental information. There were shortcomings in the model's quantitative fit, which are discussed. The model made several novel predictions, with respect to the influence of SES on delay versus giftedness, the change of SES effects over development, and the influence of SES on children of different ability levels (gene-environment interactions). The first of these predictions was that SES should reliably predict gifted performance in children but not delayed performance, and the prediction was supported by the Bishop data set. Finally, the model demonstrated limits on the inferences that can be drawn about developmental mechanisms on the basis of data from individual differences. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  6. Crowd of individuals walking in opposite directions. A toy model to study the segregation of the group into lanes of individuals moving in the same direction

    Science.gov (United States)

    Goldsztein, Guillermo H.

    2017-08-01

    Consider a corridor, street or bridge crowded with pedestrians walking in both directions. The individuals do not walk in a completely straight line. They adjust their path to avoid colliding with incoming pedestrians. As a result of these adjustments, the whole group sometimes end up split into lanes of individuals moving in the same direction. While this formation of lanes facilitates the flow and benefits the whole group, it is believed that results from the actions of the individuals acting only on their behalf, without considering others. This phenomenon is an example of self-organization. We analyze a simple model. We assume that individuals move around a two-lane circular track. All of them at the same speed. Half of them in one direction and the rest in the opposite direction. Each time two individuals collide, one of them moves to the other lane. The individual changing lanes is selected randomly. The system self-organizes. Eventually each lane is occupied with individuals moving in only one direction. We show that the time required for the system to self-organize is bounded by a linear function on the number of individuals. This toy model provides an example where global self-organization occurs even though each member of the group acts without considering the rest.

  7. Individual-level space-time analyses of emergency department data using generalized additive modeling

    Directory of Open Access Journals (Sweden)

    Vieira Verónica M

    2012-08-01

    Full Text Available Abstract Background Although daily emergency department (ED data is a source of information that often includes residence, its potential for space-time analyses at the individual level has not been fully explored. We propose that ED data collected for surveillance purposes can also be used to inform spatial and temporal patterns of disease using generalized additive models (GAMs. This paper describes the methods for adapting GAMs so they can be applied to ED data. Methods GAMs are an effective approach for modeling spatial and temporal distributions of point-wise data, producing smoothed surfaces of continuous risk while adjusting for confounders. In addition to disease mapping, the method allows for global and pointwise hypothesis testing and selection of statistically optimum degree of smoothing using standard statistical software. We applied a two-dimensional GAM for location to ED data of overlapping calendar time using a locally-weighted regression smoother. To illustrate our methods, we investigated the association between participants’ address and the risk of gastrointestinal illness in Cape Cod, Massachusetts over time. Results The GAM space-time analyses simultaneously smooth in units of distance and time by using the optimum degree of smoothing to create data frames of overlapping time periods and then spatially analyzing each data frame. When resulting maps are viewed in series, each data frame contributes a movie frame, allowing us to visualize changes in magnitude, geographic size, and location of elevated risk smoothed over space and time. In our example data, we observed an underlying geographic pattern of gastrointestinal illness with risks consistently higher in the eastern part of our study area over time and intermittent variations of increased risk during brief periods. Conclusions Spatial-temporal analysis of emergency department data with GAMs can be used to map underlying disease risk at the individual-level and view

  8. MODEL OF EMERGENCY DEPARTMENT NURSE PERFORMANCE IMPROVEMENT BASED ON ASSOCIATION OF INDIVIDUAL CHARACTERISTIC, ORGANIZATION CHARACTERISTIC AND JOB CHARACTERISTIC

    Directory of Open Access Journals (Sweden)

    Maria Margaretha Bogar

    2017-04-01

    Full Text Available Introduction: Nursing care is integral part of health care and having important role in management of patient with emergency condition. The purpose of this research was to develop nurse performance improvement model based on individual, organization and job characteristics association in Emergency Department of RSUD dr TC Hillers Maumere. Method: This was an explanative survey by cross sectional approach held on July -August 2012. Respondents in this study were 22 nurses and 44 patients were obtained by purposive sampling technique. Data were analyzed by partial least square test and signi fi cant t value > 1.64 (alpha 10%. Result: Results showed that individual characteristic had effect on nurse performance (t = 7.59, organization characteristic had effect on nurse performance (t = 2.03 and job characteristic didn’t have effect on nurse performance (t = 0.88. Nurse performance had effect on patient satisfaction (t = 6.54 but nurse satisfaction didn’t have effect on nurse performance (t = 1.31, and nurse satisfaction didn’t have effect either on patient satisfaction (t = 0.94. Discussion: This research concluded that individual characteristics which in fl uence nurse performance in nursing care were ability and skill, experience, age, sex, attitude and motivation. Organization characteristic that influence nurse performance was reward while job characteristic that include job design and feedback didn’t influence nurse performance in nursing care. Nurse performance influenced patient satisfaction but nurse satisfaction didn’t influence patient satisfaction and nurse performance.

  9. A place-based model of local activity spaces: individual place exposure and characteristics

    Science.gov (United States)

    Hasanzadeh, Kamyar; Laatikainen, Tiina; Kyttä, Marketta

    2018-01-01

    Researchers for long have hypothesized relationships between mobility, urban context, and health. Despite the ample amount of discussions, the empirical findings corroborating such associations remain to be marginal in the literature. It is growingly believed that the weakness of the observed associations can be largely explained by the common misspecification of the geographical context. Researchers coming from different fields have developed a wide range of methods for estimating the extents of these geographical contexts. In this article, we argue that no single approach yet has sufficiently been capable of capturing the complexity of human mobility patterns. Subsequently, we discuss that reaching a better understanding of individual activity spaces can be possible through a spatially sensitive estimation of place exposure. Following this discussion, we take an integrative person and place-based approach to create an individualized residential exposure model (IREM) to estimate the local activity spaces (LAS) of the individuals. This model is created using data collected through public participation GIS. Following a brief comparison of IREM with other commonly used LAS models, the article continues by presenting an empirical study of aging citizens in Helsinki area to demonstrate the usability of the proposed framework. In this study, we identify the main dimensions of LASs and seek their associations with socio-demographic characteristics of individuals and their location in the region. The promising results from comparisons and the interesting findings from the empirical part suggest both a methodological and conceptual improvement in capturing the complexity of local activity spaces.

  10. The effect of relationship quality on individual perceptions of social responsibility in the US

    Science.gov (United States)

    Thornton, Joseph C.

    2015-01-01

    Social responsibility (SR) has been of continuing interest in the U.S. and around the world. Organizations make a wide variety of SR decisions that represent differing viewpoints. While a number of definitions of SR exist, many of these definitions indicate that SR decisions may be viewed as existing of various facets, such as legal/regulatory, financial/economic, ethical, environmental, and voluntary. While drivers of SR have been proposed, there has been limited research at a micro-level on how individuals perceive SR activities by the organizations where they work. Based on a prior qualitative study (Thornton and Byrd, 2013) that found SR decisions are related to several traits and influenced by relationships, a model was proposed and tested in this research. The traits found relevant in the qualitative research were conscientiousness, especially in the sense of being responsible, and self-efficacy. Relationship quality was assessed based on positive and negative emotional attractors as proposed in intentional change theory. Perceptions of individuals in management and non-management showed that relationship quality mediated the effect of conscientiousness and general self-efficacy on the SR. Because there are multiple facets, the author made use of Carroll’s (1991) pyramid of SR to identify activities that business owners and managers consider relevant. The findings indicate that conscientiousness is related to specific SR activities in the areas of legal/regulatory, ethical and discretionary dimensions while general self-efficacy is related to financial/economic and legal/regulatory dimensions. The presence of relationship quality enhanced the effects of both conscientiousness and general self-efficacy on the various SR dimensions. This suggests that individuals perceived SR activities along different traits and that enhancing these traits might improve perceptions of SR decisions. PMID:26113830

  11. The effect of relationship quality on individual perceptions of social responsibility in the US.

    Science.gov (United States)

    Thornton, Joseph C

    2015-01-01

    Social responsibility (SR) has been of continuing interest in the U.S. and around the world. Organizations make a wide variety of SR decisions that represent differing viewpoints. While a number of definitions of SR exist, many of these definitions indicate that SR decisions may be viewed as existing of various facets, such as legal/regulatory, financial/economic, ethical, environmental, and voluntary. While drivers of SR have been proposed, there has been limited research at a micro-level on how individuals perceive SR activities by the organizations where they work. Based on a prior qualitative study (Thornton and Byrd, 2013) that found SR decisions are related to several traits and influenced by relationships, a model was proposed and tested in this research. The traits found relevant in the qualitative research were conscientiousness, especially in the sense of being responsible, and self-efficacy. Relationship quality was assessed based on positive and negative emotional attractors as proposed in intentional change theory. Perceptions of individuals in management and non-management showed that relationship quality mediated the effect of conscientiousness and general self-efficacy on the SR. Because there are multiple facets, the author made use of Carroll's (1991) pyramid of SR to identify activities that business owners and managers consider relevant. The findings indicate that conscientiousness is related to specific SR activities in the areas of legal/regulatory, ethical and discretionary dimensions while general self-efficacy is related to financial/economic and legal/regulatory dimensions. The presence of relationship quality enhanced the effects of both conscientiousness and general self-efficacy on the various SR dimensions. This suggests that individuals perceived SR activities along different traits and that enhancing these traits might improve perceptions of SR decisions.

  12. The effect of relationship quality on individual perceptions of social responsibility in the US

    Directory of Open Access Journals (Sweden)

    Joseph C. Thornton

    2015-06-01

    Full Text Available Social responsibility (SR has been of continuing interest in the United States and around the world. Organizations make a wide variety of SR decisions that represent differing viewpoints. While a number of definitions of SR exist, many of these definitions indicate that SR decisions may be viewed as existing of various facets, such as legal/regulatory, financial/economic, ethical, environmental, and voluntary. While drivers of SR have been proposed, there has been limited research at a micro-level on how individuals perceive SR activities by the organizations where they work. Based on a prior qualitative study (Thornton and Byrd, 2013 that found SR decisions are related to several traits and influenced by relationships, a model was proposed and tested in this research. The traits found relevant in the qualitative research were conscientiousness, especially in the sense of being responsible, and self-efficacy. Relationship quality was assessed based on positive and negative emotional attractors (PNEA as proposed in Intentional Change Theory (ICT. Perceptions of individuals in management and non-management showed that relationship quality mediated the effect of conscientiousness and general self-efficacy on the SR. Because there are multiple facets, the author made use of Carroll’s (1991 pyramid of social responsibility to identify activities that business owners and managers consider relevant. The findings indicate that conscientiousness is related to specific SR activities in the areas of legal/regulatory, ethical and discretionary dimensions while general self-efficacy is related to financial/economic and legal/regulatory dimensions. The presence of relationship quality enhanced the effects of both conscientiousness and general self-efficacy on the various SR dimensions. This suggests that individuals perceived SR activities along different traits and that enhancing these traits might improve perceptions of SR decisions.

  13. Coping among individuals with multiple sclerosis: Evaluating a goodness-of-fit model.

    Science.gov (United States)

    Roubinov, Danielle S; Turner, Aaron P; Williams, Rhonda M

    2015-05-01

    Multiple sclerosis (MS) is a chronic illness involving both controllable and uncontrollable stressors. The goodness-of-fit hypothesis posits that managing stressors effectively requires the use of different coping approaches in the face of controllable and uncontrollable stressors. To test the applicability of the goodness-of-fit model in a sample of adults with MS, we evaluated the ratio of 2 types of coping (an active problem-solving approach and an emotion-based meaning-focused approach) as a moderator of the relations between stress uncontrollability and mental health outcomes. Participants were veterans with MS (N = 90) receiving medical services through the Veterans Health Administration who completed telephone-based interviews. Regression analyses tested the interaction of stress uncontrollability and the problem- and meaning-focused coping ratio on anxious and depressive symptoms. Significant interactions were probed at 1 SD above the mean of coping (use of predominantly problem-focused coping) and 1 SD below the mean of coping (use of predominantly meaning-focused coping). Findings largely supported the goodness-of-fit hypothesis. Anxiety and depressive symptoms were elevated when participants used more problem-focused strategies relative to meaning-focused strategies in the face of perceived uncontrollable stress. Conversely, symptoms of anxiety and depression were lower when uncontrollable stress was met with predominantly meaning-focused coping; however, the relations did not reach statistical significance. The impact of uncontrollable stressors on mental health outcomes for individuals with MS may vary depending on the degree to which problem-focused versus meaning-focused coping strategies are employed, lending support to the goodness-of-fit model. (c) 2015 APA, all rights reserved).

  14. Combining xenoestrogens at levels below individual no-observed-effect concentrations dramatically enhances steroid hormone action.

    Science.gov (United States)

    Rajapakse, Nissanka; Silva, Elisabete; Kortenkamp, Andreas

    2002-09-01

    The low potency of many man-made estrogenic chemicals, so-called xenoestrogens, has been used to suggest that risks arising from exposure to individual chemicals are negligible. Another argument used to dismiss concerns of health effects is that endogenous steroidal estrogens are too potent for xenoestrogens to contribute significantly to estrogenic effects. Using a yeast reporter gene assay with the human estrogen receptoralpha, we tested these ideas experimentally by assessing the ability of a combination of 11 xenoestrogens to affect the actions of 17ss-estradiol. Significantly, each xenoestrogen was present at a level well below its no-observed-effect concentration (NOEC). To derive accurate descriptions of low effects, we recorded concentration-response relationships for each xenoestrogen and for 17ss-estradiol. We used these data to predict entire concentration-response curves of mixtures of xenoestrogens with 17ss-estradiol, assuming additive combination effects. Over a large range of concentrations, the experimentally observed responses decisively confirmed the model predictions. The combined additive effect of the 11 xenoestrogens led to a dramatic enhancement of the hormone's action, even when each single agent was present below its NOEC. Our results show that not even sub-NOEC levels of xenoestrogens can be considered to be without effect on potent steroidal estrogens when they act in concert with a large number of similarly acting chemicals. It remains to be seen to what degree these effects can be neutralized by environmental chemicals with antiestrogenic activity. Nevertheless, potential human and wildlife responses induced by additive combination effects of xenoestrogens deserve serious consideration.

  15. A standard protocol for describing individual-based and agent-based models

    Science.gov (United States)

    Grimm, Volker; Berger, Uta; Bastiansen, Finn; Eliassen, Sigrunn; Ginot, Vincent; Giske, Jarl; Goss-Custard, John; Grand, Tamara; Heinz, Simone K.; Huse, Geir; Huth, Andreas; Jepsen, Jane U.; Jorgensen, Christian; Mooij, Wolf M.; Muller, Birgit; Pe'er, Guy; Piou, Cyril; Railsback, Steven F.; Robbins, Andrew M.; Robbins, Martha M.; Rossmanith, Eva; Ruger, Nadja; Strand, Espen; Souissi, Sami; Stillman, Richard A.; Vabo, Rune; Visser, Ute; DeAngelis, Donald L.

    2006-01-01

    Simulation models that describe autonomous individual organisms (individual based models, IBM) or agents (agent-based models, ABM) have become a widely used tool, not only in ecology, but also in many other disciplines dealing with complex systems made up of autonomous entities. However, there is no standard protocol for describing such simulation models, which can make them difficult to understand and to duplicate. This paper presents a proposed standard protocol, ODD, for describing IBMs and ABMs, developed and tested by 28 modellers who cover a wide range of fields within ecology. This protocol consists of three blocks (Overview, Design concepts, and Details), which are subdivided into seven elements: Purpose, State variables and scales, Process overview and scheduling, Design concepts, Initialization, Input, and Submodels. We explain which aspects of a model should be described in each element, and we present an example to illustrate the protocol in use. In addition, 19 examples are available in an Online Appendix. We consider ODD as a first step for establishing a more detailed common format of the description of IBMs and ABMs. Once initiated, the protocol will hopefully evolve as it becomes used by a sufficiently large proportion of modellers.

  16. Do local unemployment rates modify the effect of individual labour market status on psychological distress?

    Science.gov (United States)

    Flint, Ellen; Shelton, Nicola; Bartley, Mel; Sacker, Amanda

    2013-09-01

    This study investigates whether the unemployment rate of the area in which an individual lives affects their level of psychological distress, and the extent to which this is dependent on their own labour market status. Data were taken from the British Household Panel Survey (1991-2008) and longitudinal multiple membership multilevel modelling was carried out in order to account for the complex hierarchical structure of the data. The results suggest that living in an area with a high unemployment rate, defined by the claimant count, confers a degree of protection against the negative psychological effects of unemployment. However, psychological distress levels among unemployed people were still significantly and substantially higher than among their securely employed counterparts. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  17. An individual reproduction model sensitive to milk yield and body condition in Holstein dairy cows.

    Science.gov (United States)

    Brun-Lafleur, L; Cutullic, E; Faverdin, P; Delaby, L; Disenhaus, C

    2013-08-01

    To simulate the consequences of management in dairy herds, the use of individual-based herd models is very useful and has become common. Reproduction is a key driver of milk production and herd dynamics, whose influence has been magnified by the decrease in reproductive performance over the last decades. Moreover, feeding management influences milk yield (MY) and body reserves, which in turn influence reproductive performance. Therefore, our objective was to build an up-to-date animal reproduction model sensitive to both MY and body condition score (BCS). A dynamic and stochastic individual reproduction model was built mainly from data of a single recent long-term experiment. This model covers the whole reproductive process and is composed of a succession of discrete stochastic events, mainly calving, ovulations, conception and embryonic loss. Each reproductive step is sensitive to MY or BCS levels or changes. The model takes into account recent evolutions of reproductive performance, particularly concerning calving-to-first ovulation interval, cyclicity (normal cycle length, prevalence of prolonged luteal phase), oestrus expression and pregnancy (conception, early and late embryonic loss). A sensitivity analysis of the model to MY and BCS at calving was performed. The simulated performance was compared with observed data from the database used to build the model and from the bibliography to validate the model. Despite comprising a whole series of reproductive steps, the model made it possible to simulate realistic global reproduction outputs. It was able to well simulate the overall reproductive performance observed in farms in terms of both success rate (recalving rate) and reproduction delays (calving interval). This model has the purpose to be integrated in herd simulation models to usefully test the impact of management strategies on herd reproductive performance, and thus on calving patterns and culling rates.

  18. Religious Pluralism and the Individual: The Effects and Meaning of Inter-religious Contact

    OpenAIRE

    Scott Draper; Paul Froese; Buster Smith

    2015-01-01

    This study tests three competing hypotheses regarding the effect of religious pluralism on individual-level religiosity. Although most theory in this area focuses on the individual, most measures of religious pluralism only take account of the macro-level. Inter-religious contact is a measure that takes more direct account of individuals' experiences of religious pluralism. Using a random national sample from The Religion and Diversity Survey (2003), we conduct multivariate regressions that i...

  19. Individual differences in response to automation: the five factor model of personality.

    Science.gov (United States)

    Szalma, James L; Taylor, Grant S

    2011-06-01

    This study examined the relationship of operator personality (Five Factor Model) and characteristics of the task and of adaptive automation (reliability and adaptiveness-whether the automation was well-matched to changes in task demand) to operator performance, workload, stress, and coping. This represents the first investigation of how the Five Factors relate to human response to automation. One-hundred-sixty-one college students experienced either 75% or 95% reliable automation provided with task loads of either two or four displays to be monitored. The task required threat detection in a simulated uninhabited ground vehicle (UGV) task. Task demand exerted the strongest influence on outcome variables. Automation characteristics did not directly impact workload or stress, but effects did emerge in the context of trait-task interactions that varied as a function of the dimension of workload and stress. The pattern of relationships of traits to dependent variables was generally moderated by at least one task factor. Neuroticism was related to poorer performance in some conditions, and all five traits were associated with at least one measure of workload and stress. Neuroticism generally predicted increased workload and stress and the other traits predicted decreased levels of these states. However, in the case of the relation of Extraversion and Agreeableness to Worry, Frustration, and avoidant coping, the direction of effects varied across task conditions. The results support incorporation of individual differences into automation design by identifying the relevant person characteristics and using the information to determine what functions to automate and the form and level of automation.

  20. Effectiveness of individual counselling and activity monitors to promote physical activity among university students.

    Science.gov (United States)

    Maselli, Marco; Gobbi, Erica; Carraro, Attilio

    2017-12-01

    Physical activity (PA) promotion among university students is important to contribute to a lifelong healthy lifestyle. Nevertheless, research in the field is still limited in quantity, quality and generalizability. This study aimed at evaluating the effectiveness of two individual-based strategies for promoting PA among university students in such university contexts where course-based interventions are difficult to implement. Thirty-three university students were recruited by means of face-to-face interviews and randomly assigned to three groups. The first group attended individual counselling sessions (based on the Social-Cognitive theory and the Transtheoretical model of behaviour change) via videoconferencing calls, the second used wearable PA monitors designed to motivate to PA, and the third served as control. Interventions lasted 12 weeks. Measures of weekly PA (self-reported by questionnaires and recorded by ActiGraph-GT3X+ monitors) and the stage of change of participants were collected at baseline (t0), immediately after the 12-week intervention (t1), and after a 3-month follow-up (t2). Students in the individual counselling group increased self-reported energy expenditure between t0 and t1 and maintained this improvement at t2; on the contrary, there was no increase in ActiGraph measures of PA. Progression through stages of changes was observed in the same group at t1, followed by some relapses at t2. No significant differences were found neither in the group of students who used the PA monitors nor in the control group. Although measures of self-reported PA and stage of change suggest the effectiveness of the counselling intervention, the results obtained with accelerometers are contrasting, probably due to the fact that some types of PA participants engaged in could not be recorder by accelerometers. Further studies are needed to determine the efficacy of individual counselling to promote PA in university students. The autonomous use of PA monitors had

  1. Safeguards system effectiveness modeling

    International Nuclear Information System (INIS)

    Bennett, H.A.; Boozer, D.D.; Chapman, L.D.; Daniel, S.L.; Engi, D.; Hulme, B.L.; Varnado, G.B.

    1976-01-01

    A general methodology for the comparative evaluation of physical protection system effectiveness at nuclear facilities is presently under development. The approach is applicable to problems of sabotage or theft at fuel cycle facilities. The overall methodology and the primary analytic techniques used to assess system effectiveness are briefly outlined

  2. Safeguards system effectiveness modeling

    International Nuclear Information System (INIS)

    Bennett, H.A.; Boozer, D.D.; Chapman, L.D.; Daniel, S.L.; Engi, D.; Hulme, B.L.; Varnado, G.B.

    1976-01-01

    A general methodology for the comparative evaluation of physical protection system effectiveness at nuclear facilities is presently under development. The approach is applicable to problems of sabotage or theft at fuel cycle facilities. In this paper, the overall methodology and the primary analytic techniques used to assess system effectiveness are briefly outlined

  3. Long-run labour market and health effects of individual sports activities.

    Science.gov (United States)

    Lechner, Michael

    2009-07-01

    This microeconometric study analyzes the effects of individual leisure sports participation on long-term labour market variables, health and subjective well-being indicators for West Germany based on individual data from the German Socio-Economic Panel study (GSOEP) 1984-2006. Econometric problems due to individuals choosing their own level of sports activities are tackled by combining informative data and flexible semiparametric estimation methods with a specific way to use the panel dimension of the data. The paper shows that sports activities have sizeable positive long-term labour market effects in terms of earnings and wages, as well as positive effects on health and subjective well-being.

  4. Biodiversity patterns from an individual-based competition model on niche and physical spaces

    International Nuclear Information System (INIS)

    Fort, H; Inchausti, P

    2012-01-01

    We formulate a microscopic (individual-based and spatially explicit) ecological model to assess whether key patterns of community structure, species-packing and the spatial distribution of species are robust to relaxing the mean-field approximation made in classical ecological models. In this model of community dynamics species compete both locally in physical space and along a niche axis and it includes just two free parameters, σ, controlling the extent of competition in niche space, and t, the simulation time. This minimalistic model (1) reproduces with considerable accuracy the dynamic sequence of relative species abundances, biodiversity indices and species–area relationships that are empirically found in censuses of trees in a well-studied tropical forest; (2) shows that the clumpy pattern of niches leading to long-lasting species coexistence obtained by classical competition models is robust to relaxing the mean-field assumption. Nevertheless species that are clumped in niche space are simultaneously spatially segregated

  5. Combined effects of irritants and allergens. Synergistic effects of nickel and sodium lauryl sulfate in nickel- sensitized individuals

    DEFF Research Database (Denmark)

    Agner, Tove; Johansen, Jeanne Duus; Overgaard, Lene

    2002-01-01

    (nickel chloride) and sodium lauryl sulfate (SLS) alone and in combination. Evaluation of skin reactions was performed by colorimetry, measurement of transepidermal water loss and clinical evaluation, and the data were analyzed by logistic dose-response models. A synergistic effect was found of combined...... of combined exposure on skin barrier impairment was not found, since the barrier function is significantly influenced by SLS-exposure only and not by NiCl2. Concentration limits are used by industry and government agencies to protect consumers. The present results clearly illustrate that elicitation......Knowledge of the combined effects of irritants and allergens is of interest with respect to accurate risk assessment. The threshold for elicitation of allergic contact dermatitis in previously sensitized individuals may theoretically be markedly influenced by the simultaneous presence of irritants...

  6. The Effectiveness of Using Online Blogging for Students' Individual and Group Writing

    Science.gov (United States)

    Alsamadani, Hashem A.

    2018-01-01

    The current research study investigates the effectiveness of online blogging for students' individual and group writing skills. The participants were divided into individual learners and group learners. They produced pre-writing and post-writing samples through blogging practices. The study conducted lasted for 14 weeks so that blogging could be…

  7. Within-Individual Variation in Preferences Equity Effects of Congestion Charges

    DEFF Research Database (Denmark)

    Borjesson, Maria; Cherchi, Elisabetta; Bierlaire, Michel

    2013-01-01

    that variation in VTT between observed trips reflects the variation in the average VTT between individuals, which is usually made in equity analyses, will over-state the between-individual variation. The results suggest that if intraindividual variation in preferences is not taken into account, the negative...... equity effects of congestion charges are likely to be overestimated....

  8. The Moderating Effect of Psychological Empowerment on the Relationship between Network Centrality and Individual Job Performance

    Science.gov (United States)

    2012-03-22

    T. R., Holtom, B. C., Lee, T. W., Sablynski, C. J., & Erez, M. (2001). Why People Stay: Using Job Embeddedness to Predict Voluntary Turnover. Academy...THE MODERATING EFFECT OF PSYCHOLOGICAL EMPOWERMENT ON THE RELATIONSHIP BETWEEN NETWORK CENTRALITY AND INDIVIDUAL JOB PERFORMANCE...BETWEEN NETWORK CENTRALITY AND INDIVIDUAL JOB PERFORMANCE THESIS Presented to the Faculty Department of Systems and Engineering

  9. Effects of Frequency of Feedback on the Learning of Motor Skill in Individuals with Cerebral Palsy

    Science.gov (United States)

    Hemayattalab, Rasool; Rostami, Leila Rashidi

    2010-01-01

    The purpose of this study was to investigate the effect of frequency of knowledge of results (KR) on the learning of dart in individuals with cerebral palsy type I. Twenty-four individuals with cerebral palsy (CP) between the ages of 5 and 17 were chosen for this study. They were put into 3 homogenous groups according to their records after 20…

  10. Costs and cost-effectiveness of family CBT versus individual CBT in clinically anxious children

    NARCIS (Netherlands)

    Bodden, D.H.M.; Dirksen, C.D.; Bögels, S.M.; Nauta, M.H.; de Haan, E.; Ringrose, J.; Appelboom, C.; Brinkman, A.G.; Appelboom-Geerts, K.C.M.M.J.

    2008-01-01

    The objective of this study was to investigate the cost-effectiveness of family cognitive-behavioral therapy (CBT) compared with individual CBT in children with anxiety disorders. Clinically anxious children (aged 8—18 years) referred for treatment were randomly assigned to family or individual CBT

  11. Applying and Individual-Based Model to Simultaneously Evaluate Net Ecosystem Production and Tree Diameter Increment

    Science.gov (United States)

    Fang, F. J.

    2017-12-01

    Reconciling observations at fundamentally different scales is central in understanding the global carbon cycle. This study investigates a model-based melding of forest inventory data, remote-sensing data and micrometeorological-station data ("flux towers" estimating forest heat, CO2 and H2O fluxes). The individual tree-based model FORCCHN was used to evaluate the tree DBH increment and forest carbon fluxes. These are the first simultaneous simulations of the forest carbon budgets from flux towers and individual-tree growth estimates of forest carbon budgets using the continuous forest inventory data — under circumstances in which both predictions can be tested. Along with the global implications of such findings, this also improves the capacity for forest sustainable management and the comprehensive understanding of forest ecosystems. In forest ecology, diameter at breast height (DBH) of a tree significantly determines an individual tree's cross-sectional sapwood area, its biomass and carbon storage. Evaluation the annual DBH increment (ΔDBH) of an individual tree is central to understanding tree growth and forest ecology. Ecosystem Carbon flux is a consequence of key ecosystem processes in the forest-ecosystem carbon cycle, Gross and Net Primary Production (GPP and NPP, respectively) and Net Ecosystem Respiration (NEP). All of these closely relate with tree DBH changes and tree death. Despite advances in evaluating forest carbon fluxes with flux towers and forest inventories for individual tree ΔDBH, few current ecological models can simultaneously quantify and predict the tree ΔDBH and forest carbon flux.

  12. Mechanistic Physiologically Based Pharmacokinetic (PBPK) Model of the Heart Accounting for Inter-Individual Variability: Development and Performance Verification.

    Science.gov (United States)

    Tylutki, Zofia; Mendyk, Aleksander; Polak, Sebastian

    2018-04-01

    Modern model-based approaches to cardiac safety and efficacy assessment require accurate drug concentration-effect relationship establishment. Thus, knowledge of the active concentration of drugs in heart tissue is desirable along with inter-subject variability influence estimation. To that end, we developed a mechanistic physiologically based pharmacokinetic model of the heart. The models were described with literature-derived parameters and written in R, v.3.4.0. Five parameters were estimated. The model was fitted to amitriptyline and nortriptyline concentrations after an intravenous infusion of amitriptyline. The cardiac model consisted of 5 compartments representing the pericardial fluid, heart extracellular water, and epicardial intracellular, midmyocardial intracellular, and endocardial intracellular fluids. Drug cardiac metabolism, passive diffusion, active efflux, and uptake were included in the model as mechanisms involved in the drug disposition within the heart. The model accounted for inter-individual variability. The estimates of optimized parameters were within physiological ranges. The model performance was verified by simulating 5 clinical studies of amitriptyline intravenous infusion, and the simulated pharmacokinetic profiles agreed with clinical data. The results support the model feasibility. The proposed structure can be tested with the goal of improving the patient-specific model-based cardiac safety assessment and offers a framework for predicting cardiac concentrations of various xenobiotics. Copyright © 2018 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  13. Population-level consequences of spatially heterogeneous exposure to heavy metals in soil: An individual-based model of springtails

    DEFF Research Database (Denmark)

    Meli, Mattia; Auclerc, Apolline; Palmqvist, Annemette

    2013-01-01

    Contamination of soil with toxic heavy metals poses a major threat to the environment and human health. Anthropogenic sources include smelting of ores, municipal wastes, fertilizers, and pesticides. In assessing soil quality and the environmental and ecological risk of contamination with heavy...... species for ecotoxicological risk assessment. In the model, individuals were assumed to sense and avoid contaminated habitat with a certain probability that depends on contamination level. Avoidance of contaminated areas thus influenced the individuals’ movement and feeding, their exposure, and in turn...... thus be used as a tool for extrapolating from short-term effects at the individual level to long-term effects at the population level under more realistic conditions. It can thus be used to develop and extrapolate from standard ecotoxicological tests in the laboratory to ecological risk assessments....

  14. Repetitive model predictive approach to individual pitch control of wind turbines

    DEFF Research Database (Denmark)

    Adegas, Fabiano Daher; Stoustrup, Jakob; Odgaard, Peter Fogh

    2011-01-01

    Wind turbines are inherently exposed to nonuniform wind fields with of wind shear, tower shadow, and possible wake contributions. Asymmetrical aerodynamic rotor loads are a consequence of such periodic, repetitive wind disturbances experienced by the blades. A controller may estimate and use this....... A simulation comparison betweeen the proposed controller and an industry-standard PID controller shows better mitigation of drive-train, blade and tower loads.......Wind turbines are inherently exposed to nonuniform wind fields with of wind shear, tower shadow, and possible wake contributions. Asymmetrical aerodynamic rotor loads are a consequence of such periodic, repetitive wind disturbances experienced by the blades. A controller may estimate and use...... this peculiar disturbance pattern to better attenuate loads and regulate power by controlling the blade pitch angles individually. A novel model predictive (MPC) approach for individual pitch control of wind turbines is proposed in this paper. A repetitive wind disturbance model is incorporated into the MPC...

  15. Accounting for genetic interactions improves modeling of individual quantitative trait phenotypes in yeast.

    Science.gov (United States)

    Forsberg, Simon K G; Bloom, Joshua S; Sadhu, Meru J; Kruglyak, Leonid; Carlborg, Örjan

    2017-04-01

    Experiments in model organisms report abundant genetic interactions underlying biologically important traits, whereas quantitative genetics theory predicts, and data support, the notion that most genetic variance in populations is additive. Here we describe networks of capacitating genetic interactions that contribute to quantitative trait variation in a large yeast intercross population. The additive variance explained by individual loci in a network is highly dependent on the allele frequencies of the interacting loci. Modeling of phenotypes for multilocus genotype classes in the epistatic networks is often improved by accounting for the interactions. We discuss the implications of these results for attempts to dissect genetic architectures and to predict individual phenotypes and long-term responses to selection.

  16. Mathematical Analysis of a General Two-Patch Model of Tuberculosis Disease with Lost Sight Individuals

    Directory of Open Access Journals (Sweden)

    Abdias Laohombé

    2014-01-01

    Full Text Available A two-patch model, SEi1,…,EinIiLi,  i=1,2, is used to analyze the spread of tuberculosis, with an arbitrary number n of latently infected compartments in each patch. A fraction of infectious individuals that begun their treatment will not return to the hospital for the examination of sputum. This fact usually occurs in sub-Saharan Africa, due to many reasons. The model incorporates migrations from one patch to another. The existence and uniqueness of the associated equilibria are discussed. A Lyapunov function is used to show that when the basic reproduction ratio is less than one, the disease-free equilibrium is globally and asymptotically stable. When it is greater than one, there exists at least one endemic equilibrium. The local stability of endemic equilibria can be illustrated using numerical simulations. Numerical simulation results are provided to illustrate the theoretical results and analyze the influence of lost sight individuals.

  17. A bioenergetic approach to model and reconstruct individual life traits from fish otoliths

    DEFF Research Database (Denmark)

    Fablet, Ronan; Pecquerie, Laure; Høie, Hans

    2012-01-01

    Otoliths are biocalcified bodies connected to the sensory system in the inner ears of fish. Their layered, biorhythm‐following formation provides individual records of the age, the individual history, and the natural environment of extinct and living fish species. Such data are critical for ecosy...... observations of otolith formation. It represents a unique simulation tool to improve otolith interpretation and applications, and, beyond, to address the effects of both climate change and ocean acidification on other biomineralizing organisms such as corals and bivalves...

  18. PENGGUNAAN MODEL TEAMS ASSISTED INDIVIDUALIZATION (TAI TERHADAP HASIL BELAJAR IPS TERPADU

    Directory of Open Access Journals (Sweden)

    Hoirunnisa Ana

    2017-11-01

    Full Text Available The purpose of this study is to determine the effect of cooperative learning type team assisted individualization to study result of IPS Integrated. The type of this research is experiment with Non-equivalent control group design. The data are collected by using observation, interview, documentation and multiple choice tests. The data analysis which is used is simple linier regression. The result of the research shows that the value of hypothesis test Tcount = 2,42 > ttable = 1,70 (α = 0,05, so Ha is accepted team assisted individualization in cooperative learning to study result of IPS Integrated.

  19. The Effect of Serum Vitamin D on Serum ALT Levels in Healthy Individuals.

    Science.gov (United States)

    Shehata, Elaine; Qayyum, Rehan

    2016-10-01

    Several studies have examined the relationship between vitamin D (VD) and liver disease but none have explored this relationship in adults with normal liver enzymes. Our aim was to explore an independent association of VD with alanine aminotransferase (ALT) in a large sample of the US adults with liver enzymes in normal range (≤39 U/L). We used the continuous National Health and Nutrition Examination Survey from 2001 to 2006. We excluded individuals with serum ALT>39 U/L. We built linear regression models to estimate unadjusted and adjusted (age, sex, race, diabetes, hypertension, alcohol use, smoking, and body mass index) effect sizes, taking into account the complex probability survey design. Of the 12,155 participants, 6635 (54.6%) were women, mean±SD age was 49.9±19.4 years, VD was 21.9±9.2 ng/mL, and ALT was 20.9±6.9 U/L. In unadjusted analysis, VD was significantly associated with serum ALT (0.02 U/L/ng/mL of VD, P=0.007). After adjustment for confounders, VD remained statistically significantly associated with serum ALT levels (0.04 U/L, PALT than those in the lowest quartile (unadjusted difference=0.98 U/L, PALT after excluding individuals with suspected active liver injury (ALT>39 U/L). The underlying mechanisms for this association are not known and needs further study.

  20. Development and Validation of a Prediction Model to Estimate Individual Risk of Pancreatic Cancer.

    Science.gov (United States)

    Yu, Ami; Woo, Sang Myung; Joo, Jungnam; Yang, Hye-Ryung; Lee, Woo Jin; Park, Sang-Jae; Nam, Byung-Ho

    2016-01-01

    There is no reliable screening tool to identify people with high risk of developing pancreatic cancer even though pancreatic cancer represents the fifth-leading cause of cancer-related death in Korea. The goal of this study was to develop an individualized risk prediction model that can be used to screen for asymptomatic pancreatic cancer in Korean men and women. Gender-specific risk prediction models for pancreatic cancer were developed using the Cox proportional hazards model based on an 8-year follow-up of a cohort study of 1,289,933 men and 557,701 women in Korea who had biennial examinations in 1996-1997. The performance of the models was evaluated with respect to their discrimination and calibration ability based on the C-statistic and Hosmer-Lemeshow type χ2 statistic. A total of 1,634 (0.13%) men and 561 (0.10%) women were newly diagnosed with pancreatic cancer. Age, height, BMI, fasting glucose, urine glucose, smoking, and age at smoking initiation were included in the risk prediction model for men. Height, BMI, fasting glucose, urine glucose, smoking, and drinking habit were included in the risk prediction model for women. Smoking was the most significant risk factor for developing pancreatic cancer in both men and women. The risk prediction model exhibited good discrimination and calibration ability, and in external validation it had excellent prediction ability. Gender-specific risk prediction models for pancreatic cancer were developed and validated for the first time. The prediction models will be a useful tool for detecting high-risk individuals who may benefit from increased surveillance for pancreatic cancer.

  1. Effects of Measurement Errors on Individual Tree Stem Volume Estimates for the Austrian National Forest Inventory

    Science.gov (United States)

    Ambros Berger; Thomas Gschwantner; Ronald E. McRoberts; Klemens. Schadauer

    2014-01-01

    National forest inventories typically estimate individual tree volumes using models that rely on measurements of predictor variables such as tree height and diameter, both of which are subject to measurement error. The aim of this study was to quantify the impacts of these measurement errors on the uncertainty of the model-based tree stem volume estimates. The impacts...

  2. Individualized computer-aided education in mammography based on user modeling: concept and preliminary experiments.

    Science.gov (United States)

    Mazurowski, Maciej A; Baker, Jay A; Barnhart, Huiman X; Tourassi, Georgia D

    2010-03-01

    The authors propose the framework for an individualized adaptive computer-aided educational system in mammography that is based on user modeling. The underlying hypothesis is that user models can be developed to capture the individual error making patterns of radiologists-in-training. In this pilot study, the authors test the above hypothesis for the task of breast cancer diagnosis in mammograms. The concept of a user model was formalized as the function that relates image features to the likelihood/extent of the diagnostic error made by a radiologist-in-training and therefore to the level of difficulty that a case will pose to the radiologist-in-training (or "user"). Then, machine learning algorithms were implemented to build such user models. Specifically, the authors explored k-nearest neighbor, artificial neural networks, and multiple regression for the task of building the model using observer data collected from ten Radiology residents at Duke University Medical Center for the problem of breast mass diagnosis in mammograms. For each resident, a user-specific model was constructed that predicts the user's expected level of difficulty for each presented case based on two BI-RADS image features. In the experiments, leave-one-out data handling scheme was applied to assign each case to a low-predicted-difficulty or a high-predicted-difficulty group for each resident based on each of the three user models. To evaluate whether the user model is useful in predicting difficulty, the authors performed statistical tests using the generalized estimating equations approach to determine whether the mean actual error is the same or not between the low-predicted-difficulty group and the high-predicted-difficulty group. When the results for all observers were pulled together, the actual errors made by residents were statistically significantly higher for cases in the high-predicted-difficulty group than for cases in the low-predicted-difficulty group for all modeling

  3. Effects of emotion regulation strategies on music-elicited emotions: An experimental study explaining individual differences

    NARCIS (Netherlands)

    Karreman, A.; Laceulle, O.M.; Hanser, Waldie; Vingerhoets, Ad

    This experimental study examined if emotional experience can be manipulated by applying an emotion regulation strategy during music listening and if individual differences in effects of strategies can be explained by person characteristics. Adults (N = 466) completed questionnaires and rated

  4. Effects of emotion regulation strategies on music elicited emotions : An experimental study explaining individual differences

    NARCIS (Netherlands)

    Karreman, A.; Laceulle, O.M.; Hanser, W.E.; Vingerhoets, A.J.J.M.

    2017-01-01

    This experimental study examined if emotional experience can be manipulated by applying an emotion regulation strategy during music listening and if individual differences in effects of strategies can be explained by person characteristics. Adults (N = 466) completed questionnaires and rated

  5. Individual and group-based learning from complex cognitive tasks: Effects on retention and transfer efficiency

    NARCIS (Netherlands)

    Kirschner, Femke; Paas, Fred; Kirschner, Paul A.

    2009-01-01

    Kirschner, F., Paas, F., & Kirschner, P. (2009). Individual and group-based learning from complex cognitive tasks: Effects on retention and transfer efficiency. Computers in Human Behavior, 25, 306-314.

  6. An individual-based model for population viability analysis of humpback chub in Grand Canyon

    Science.gov (United States)

    Pine, William Pine; Healy, Brian; Smith, Emily Omana; Trammell, Melissa; Speas, Dave; Valdez, Rich; Yard, Mike; Walters, Carl; Ahrens, Rob; Vanhaverbeke, Randy; Stone, Dennis; Wilson, Wade

    2013-01-01

    We developed an individual-based population viability analysis model (females only) for evaluating risk to populations from catastrophic events or conservation and research actions. This model tracks attributes (size, weight, viability, etc.) for individual fish through time and then compiles this information to assess the extinction risk of the population across large numbers of simulation trials. Using a case history for the Little Colorado River population of Humpback Chub Gila cypha in Grand Canyon, Arizona, we assessed extinction risk and resiliency to a catastrophic event for this population and then assessed a series of conservation actions related to removing specific numbers of Humpback Chub at different sizes for conservation purposes, such as translocating individuals to establish other spawning populations or hatchery refuge development. Our results suggested that the Little Colorado River population is generally resilient to a single catastrophic event and also to removals of larvae and juveniles for conservation purposes, including translocations to establish new populations. Our results also suggested that translocation success is dependent on similar survival rates in receiving and donor streams and low emigration rates from recipient streams. In addition, translocating either large numbers of larvae or small numbers of large juveniles has generally an equal likelihood of successful population establishment at similar extinction risk levels to the Little Colorado River donor population. Our model created a transparent platform to consider extinction risk to populations from catastrophe or conservation actions and should prove useful to managers assessing these risks for endangered species such as Humpback Chub.

  7. A holistic model for evaluating the impact of individual technology-enhanced learning resources.

    Science.gov (United States)

    Pickering, James D; Joynes, Viktoria C T

    2016-12-01

    The use of technology within education has now crossed the Rubicon; student expectations, the increasing availability of both hardware and software and the push to fully blended learning environments mean that educational institutions cannot afford to turn their backs on technology-enhanced learning (TEL). The ability to meaningfully evaluate the impact of TEL resources nevertheless remains problematic. This paper aims to establish a robust means of evaluating individual resources and meaningfully measure their impact upon learning within the context of the program in which they are used. Based upon the experience of developing and evaluating a range of mobile and desktop based TEL resources, this paper outlines a new four-stage evaluation process, taking into account learner satisfaction, learner gain, and the impact of a resource on both the individual and the institution in which it has been adapted. A new multi-level model of TEL resource evaluation is proposed, which includes a preliminary evaluation of need, learner satisfaction and gain, learner impact and institutional impact. Each of these levels are discussed in detail, and in relation to existing TEL evaluation frameworks. This paper details a holistic, meaningful evaluation model for individual TEL resources within the specific context in which they are used. It is proposed that this model is adopted to ensure that TEL resources are evaluated in a more meaningful and robust manner than is currently undertaken.

  8. Individual and combined effects of multiple global change drivers on terrestrial phosphorus pools: A meta-analysis.

    Science.gov (United States)

    Yue, Kai; Yang, Wanqin; Peng, Yan; Peng, Changhui; Tan, Bo; Xu, Zhenfeng; Zhang, Li; Ni, Xiangyin; Zhou, Wei; Wu, Fuzhong

    2018-07-15

    Human activity-induced global change drivers have dramatically changed terrestrial phosphorus (P) dynamics. However, our understanding of the interactive effects of multiple global change drivers on terrestrial P pools remains elusive, limiting their incorporation into ecological and biogeochemical models. We conducted a meta-analysis using 1751 observations extracted from 283 published articles to evaluate the individual, combined, and interactive effects of elevated CO 2 , warming, N addition, P addition, increased rainfall, and drought on P pools of plant (at both single-plant and plant-community levels), soil and microbial biomass. Our results suggested that (1) terrestrial P pools showed the most sensitive responses to the individual effects of warming and P addition; (2) P pools were consistently stimulated by P addition alone or in combination with simultaneous N addition; (3) environmental and experimental setting factors such as ecosystem type, climate, and latitude could significantly influence both the individual and combined effects; and (4) the interactive effects of two-driver pairs across multiple global change drivers are more likely to be additive rather than synergistic or antagonistic. Our findings highlighting the importance of additive interactive effects among multiple global change drivers on terrestrial P pools would be useful for incorporating P as controls on ecological processes such as photosynthesis and plant growth into ecosystem models used to analyze effects of multiple drivers under future global change. Copyright © 2018 Elsevier B.V. All rights reserved.

  9. The Roy Adaptation Model: A Theoretical Framework for Nurses Providing Care to Individuals With Anorexia Nervosa.

    Science.gov (United States)

    Jennings, Karen M

    Using a nursing theoretical framework to understand, elucidate, and propose nursing research is fundamental to knowledge development. This article presents the Roy Adaptation Model as a theoretical framework to better understand individuals with anorexia nervosa during acute treatment, and the role of nursing assessments and interventions in the promotion of weight restoration. Nursing assessments and interventions situated within the Roy Adaptation Model take into consideration how weight restoration does not occur in isolation but rather reflects an adaptive process within external and internal environments, and has the potential for more holistic care.

  10. Oxygen consumption prediction models for individual and combination materials handling tasks.

    Science.gov (United States)

    Dempsey, Patrick G; Ciriello, Vincent M; Maikala, Rammohan V; O'Brien, Niall V

    2008-11-01

    An experiment was conducted to develop models to predict oxygen consumption of males and females engaged in common materials handling tasks including lifting, lowering, pushing, pulling, (de)palletising and combination tasks involving lifting or lowering a box and carrying it a set distance and lifting or lowering it to the destination. Nineteen male and 19 female subjects participated in the study. A psychophysical approach was used to set load limits for individual subjects for the oxygen consumption protocol. The 8398 oxygen consumption values collected were entered into the initial regression analyses and 168 potential outliers were removed before the final models were run. In addition to relevant task variables, body weight was a significant predictor variable in all models. The r(2) values for the final models ranged from 0.54 to 0.82 and the root mean square errors ranged from 90.2 ml to 294.8 ml.

  11. An individual-based model for biofilm formation at liquid surfaces.

    Science.gov (United States)

    Ardré, Maxime; Henry, Hervé; Douarche, Carine; Plapp, Mathis

    2015-12-10

    The bacterium Bacillus subtilis frequently forms biofilms at the interface between the culture medium and the air. We present a mathematical model that couples a description of bacteria as individual discrete objects to the standard advection-diffusion equations for the environment. The model takes into account two different bacterial phenotypes. In the motile state, bacteria swim and perform a run-and-tumble motion that is biased toward regions of high oxygen concentration (aerotaxis). In the matrix-producer state they excrete extracellular polymers, which allows them to connect to other bacteria and to form a biofilm. Bacteria are also advected by the fluid, and can trigger bioconvection. Numerical simulations of the model reproduce all the stages of biofilm formation observed in laboratory experiments. Finally, we study the influence of various model parameters on the dynamics and morphology of biofilms.

  12. Modelling and Bayesian adaptive prediction of individual patients’ tumour volume change during radiotherapy

    International Nuclear Information System (INIS)

    Tariq, Imran; Chen, Tao; Kirkby, Norman F; Jena, Rajesh

    2016-01-01

    The aim of this study is to develop a mathematical modelling method that can predict individual patients’ response to radiotherapy, in terms of tumour volume change during the treatment. The main concept is to start from a population-average model, which is subsequently updated from an individual’s tumour volume measurement. The model becomes increasingly personalised and so too does the prediction it produces. This idea of adaptive prediction was realised by using a Bayesian approach for updating the model parameters. The feasibility of the developed method was demonstrated on the data from 25 non-small cell lung cancer patients treated with helical tomotherapy, during which tumour volume was measured from daily imaging as part of the image-guided radiotherapy. The method could provide useful information for adaptive treatment planning and dose scheduling based on the patient’s personalised response. (paper)

  13. Randomized trial of the effects of individual nutritional counseling in cancer patients

    DEFF Research Database (Denmark)

    Møller, Grith; Pedersen, Louise Lindkvist; Østerlind, Kell

    2014-01-01

    Cancer-related malnutrition is multifactorial and related to a bad prognosis. The aim of this study was to investigate the effect of intensive, individual dietary counseling of patients in radiotherapy and/or chemotherapy for gynecologic-, gastric-, or esophageal cancer.......Cancer-related malnutrition is multifactorial and related to a bad prognosis. The aim of this study was to investigate the effect of intensive, individual dietary counseling of patients in radiotherapy and/or chemotherapy for gynecologic-, gastric-, or esophageal cancer....

  14. Individualized model predicts brain current flow during transcranial direct-current stimulation treatment in responsive stroke patient.

    Science.gov (United States)

    Datta, Abhishek; Baker, Julie M; Bikson, Marom; Fridriksson, Julius

    2011-07-01

    Although numerous published reports have demonstrated the beneficial effects of transcranial direct-current stimulation (tDCS) on task performance, fundamental questions remain regarding the optimal electrode configuration on the scalp. Moreover, it is expected that lesioned brain tissue will influence current flow and should therefore be considered (and perhaps leveraged) in the design of individualized tDCS therapies for stroke. The current report demonstrates how different electrode configurations influence the flow of electrical current through brain tissue in a patient who responded positively to a tDCS treatment targeting aphasia. The patient, a 60-year-old man, sustained a left hemisphere ischemic stroke (lesion size = 87.42 mL) 64 months before his participation. In this study, we present results from the first high-resolution (1 mm(3)) model of tDCS in a brain with considerable stroke-related damage; the model was individualized for the patient who received anodal tDCS to his left frontal cortex with the reference cathode electrode placed on his right shoulder. We modeled the resulting brain current flow and also considered three additional reference electrode positions: right mastoid, right orbitofrontal cortex, and a "mirror" configuration with the anode over the undamaged right cortex. Our results demonstrate the profound effect of lesioned tissue on resulting current flow and the ability to modulate current pattern through the brain, including perilesional regions, through electrode montage design. The complexity of brain current flow modulation by detailed normal and pathologic anatomy suggest: (1) That computational models are critical for the rational interpretation and design of individualized tDCS stroke-therapy; and (2) These models must accurately reproduce head anatomy as shown here. Copyright © 2011 Elsevier Inc. All rights reserved.

  15. The Impact of Individual Differences, Types of Model and Social Settings on Block Building Performance among Chinese Preschoolers.

    Science.gov (United States)

    Tian, Mi; Deng, Zhu; Meng, Zhaokun; Li, Rui; Zhang, Zhiyi; Qi, Wenhui; Wang, Rui; Yin, Tingting; Ji, Menghui

    2018-01-01

    Children's block building performances are used as indicators of other abilities in multiple domains. In the current study, we examined individual differences, types of model and social settings as influences on children's block building performance. Chinese preschoolers ( N = 180) participated in a block building activity in a natural setting, and performance was assessed with multiple measures in order to identify a range of specific skills. Using scores generated across these measures, three dependent variables were analyzed: block building skills, structural balance and structural features. An overall MANOVA showed that there were significant main effects of gender and grade level across most measures. Types of model showed no significant effect in children's block building. There was a significant main effect of social settings on structural features, with the best performance in the 5-member group, followed by individual and then the 10-member block building. These findings suggest that boys performed better than girls in block building activity. Block building performance increased significantly from 1st to 2nd year of preschool, but not from second to third. The preschoolers created more representational constructions when presented with a model made of wooden rather than with a picture. There was partial evidence that children performed better when working with peers in a small group than when working alone or working in a large group. It is suggested that future study should examine other modalities rather than the visual one, diversify the samples and adopt a longitudinal investigation.

  16. The Impact of Individual Differences, Types of Model and Social Settings on Block Building Performance among Chinese Preschoolers

    Science.gov (United States)

    Tian, Mi; Deng, Zhu; Meng, Zhaokun; Li, Rui; Zhang, Zhiyi; Qi, Wenhui; Wang, Rui; Yin, Tingting; Ji, Menghui

    2018-01-01

    Children’s block building performances are used as indicators of other abilities in multiple domains. In the current study, we examined individual differences, types of model and social settings as influences on children’s block building performance. Chinese preschoolers (N = 180) participated in a block building activity in a natural setting, and performance was assessed with multiple measures in order to identify a range of specific skills. Using scores generated across these measures, three dependent variables were analyzed: block building skills, structural balance and structural features. An overall MANOVA showed that there were significant main effects of gender and grade level across most measures. Types of model showed no significant effect in children’s block building. There was a significant main effect of social settings on structural features, with the best performance in the 5-member group, followed by individual and then the 10-member block building. These findings suggest that boys performed better than girls in block building activity. Block building performance increased significantly from 1st to 2nd year of preschool, but not from second to third. The preschoolers created more representational constructions when presented with a model made of wooden rather than with a picture. There was partial evidence that children performed better when working with peers in a small group than when working alone or working in a large group. It is suggested that future study should examine other modalities rather than the visual one, diversify the samples and adopt a longitudinal investigation. PMID:29441031

  17. The Impact of Individual Differences, Types of Model and Social Settings on Block Building Performance among Chinese Preschoolers

    Directory of Open Access Journals (Sweden)

    Mi Tian

    2018-01-01

    Full Text Available Children’s block building performances are used as indicators of other abilities in multiple domains. In the current study, we examined individual differences, types of model and social settings as influences on children’s block building performance. Chinese preschoolers (N = 180 participated in a block building activity in a natural setting, and performance was assessed with multiple measures in order to identify a range of specific skills. Using scores generated across these measures, three dependent variables were analyzed: block building skills, structural balance and structural features. An overall MANOVA showed that there were significant main effects of gender and grade level across most measures. Types of model showed no significant effect in children’s block building. There was a significant main effect of social settings on structural features, with the best performance in the 5-member group, followed by individual and then the 10-member block building. These findings suggest that boys performed better than girls in block building activity. Block building performance increased significantly from 1st to 2nd year of preschool, but not from second to third. The preschoolers created more representational constructions when presented with a model made of wooden rather than with a picture. There was partial evidence that children performed better when working with peers in a small group than when working alone or working in a large group. It is suggested that future study should examine other modalities rather than the visual one, diversify the samples and adopt a longitudinal investigation.

  18. Determining the Best Strategies for Maternally Targeted Pertussis Vaccination Using an Individual-Based Model.

    Science.gov (United States)

    Campbell, Patricia Therese; McVernon, Jodie; Geard, Nicholas

    2017-07-01

    Rising pertussis incidence has prompted a number of countries to implement maternally targeted vaccination strategies to protect vulnerable infants, but questions remain about the optimal design of such strategies. We simulated pertussis transmission within an individual-based model parameterized to match Australian conditions, explicitly linking infants and their mothers to estimate the effectiveness of alternative maternally targeted vaccination strategies (antenatal delivery vs. postnatal delivery) and the benefit of revaccination over the course of multiple pregnancies. For firstborn infants aged less than 2 months, antenatal immunization reduced annual pertussis incidence by 60%, from 780 per 100,000 firstborn children under age 2 months (interquartile range (IQR), 682-862) to 315 per 100,000 (IQR, 260-370), while postnatal vaccination produced a minimal reduction, with an incidence of 728 per 100,000 (IQR, 628-789). Subsequent infants obtained limited protection from a single antenatal dose, but revaccinating mothers during every pregnancy decreased incidence for these infants by 58%, from 1,878 per 100,000 subsequent children under age 2 months (IQR, 1,712-2,076) to 791 per 100,000 (IQR, 683-915). Subsequent infants also benefited from household-level herd immunity when antenatal vaccination for every pregnancy was combined with a toddler booster dose at age 18 months; incidence was reduced to 626 per 100,000 (IQR, 548-691). Our approach provides useful information to aid consideration of alternative maternally targeted vaccination strategies and can inform development of outcome measures for program evaluation. © The Author 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  19. STUDYING THE EFFECTS OF SPORTING HABITS ON THE SELF-ESTEEM OF DISABLED INDIVIDUALS

    OpenAIRE

    Erdoğan; Bülent; Gökhan; Serkan Tevabil

    2014-01-01

    It is considered that whether disabled individuals have low or high self- esteem Serkan T. AKA3 affects their interactions with the other individuals and how they cope with the challenges they come across in a society. Therefore, it is great significance to study the factors that are effective in boosting the self-esteem of such individuals. Bülent TATLISU2 The purpose of this study is to investigate the effects of sporting habits and different variables on the self-esteem level of ...

  20. The impact of individual and organisational factors on engagement of individuals with intellectual disability living in community group homes: a multilevel model.

    Science.gov (United States)

    Qian, X; Tichá, R; Larson, S A; Stancliffe, R J; Wuorio, A

    2015-06-01

    Being engaged in daily activities is a strong indicator of quality of life for individuals with intellectual disability (ID) who live in small community group homes. This study aimed to identify individual and organisational factors that predict high levels of engagement. Individuals with ID (n = 78), direct support professionals (DSPs; n = 174) and supervisors (n = 21) from 21 US group homes participated in the study. For each individual with ID, we conducted 80 min of observation at the person's residence. Information was also gathered regarding demographic characteristics, DSP competence, supervisor years of experience and management practices. Data were analysed using multilevel modelling. On average, individuals were engaged in social activities 12% of observed time and non-social activities 35% of the time. Individuals with greater adaptive skills who were supported by more competent staff showed significantly higher levels of social engagement. Individuals with less severe deficits in adaptive behaviours and less challenging behaviour showed higher levels of non-social engagement. Although none of the factors related to group homes were significant, 24% of the variance in non-social engagement existed among group homes. These results suggested that engagement is a dynamic construct. The extent to which an individual with ID is engaged in daily life is a result of interplay between the individual's characteristics and the group home environment. Future research is needed to investigate the influence of variables specific to the group home on the engagement level of individuals with disabilities. © 2014 MENCAP and International Association of the Scientific Study of Intellectual and Developmental Disabilities and John Wiley & Sons Ltd.

  1. Knowledge-based IMRT planning for individual liver cancer patients using a novel specific model.

    Science.gov (United States)

    Yu, Gang; Li, Yang; Feng, Ziwei; Tao, Cheng; Yu, Zuyi; Li, Baosheng; Li, Dengwang

    2018-03-27

    The purpose of this work is to benchmark RapidPlan against clinical plans for liver Intensity-modulated radiotherapy (IMRT) treatment of patients with special anatomical characteristics, and to investigate the prediction capability of the general model (Model-G) versus our specific model (Model-S). A library consisting of 60 liver cancer patients with IMRT planning was used to set up two models (Model-S, Model-G), using the RapidPlan knowledge-based planning system. Model-S consisted of 30 patients with special anatomical characteristics where the distance from planning target volume (PTV) to the right kidney was less than three centimeters and Model-G was configurated using all 60 patients in this library. Knowledge-based IMRT plans were created for the evaluation group formed of 13 patients similar to those included in Model-S by Model-G, Model-S and manually (M), named RPG-plans, RPS-plans and M-plans, respectively. The differences in the dose-volume histograms (DVHs) were compared, not only between RP-plans and their respective M-plans, but also between RPG-plans and RPS-plans. For all 13 patients, RapidPlan could automatically produce clinically acceptable plans. Comparing RP-plans to M-plans, RP-plans improved V 95% of PTV and had greater dose sparing in the right kidney. For the normal liver, RPG-plans delivered similar doses, while RPS-plans delivered a higher dose than M-plans. With respect to RapidPlan models, RPS-plans had better conformity index (CI) values and delivered lower doses to the right kidney V 20Gy and maximizing point doses to spinal cord, while delivering higher doses to the normal liver. The study shows that RapidPlan can create high-quality plans, and our specific model can improve the CI of PTV, resulting in more sparing of OAR in IMRT for individual liver cancer patients.

  2. Transparent Reporting of a Multivariable Prediction Model for Individual Prognosis or Diagnosis (TRIPOD): The TRIPOD Statement.

    Science.gov (United States)

    Collins, Gary S; Reitsma, Johannes B; Altman, Douglas G; Moons, Karel G M

    2015-06-01

    Prediction models are developed to aid health care providers in estimating the probability or risk that a specific disease or condition is present (diagnostic models) or that a specific event will occur in the future (prognostic models), to inform their decision making. However, the overwhelming evidence shows that the quality of reporting of prediction model studies is poor. Only with full and clear reporting of information on all aspects of a prediction model can risk of bias and potential usefulness of prediction models be adequately assessed. The Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis (TRIPOD) Initiative developed a set of recommendations for the reporting of studies developing, validating, or updating a prediction model, whether for diagnostic or prognostic purposes. This article describes how the TRIPOD Statement was developed. An extensive list of items based on a review of the literature was created, which was reduced after a Web-based survey and revised during a 3-day meeting in June 2011 with methodologists, health care professionals, and journal editors. The list was refined during several meetings of the steering group and in e-mail discussions with the wider group of TRIPOD contributors. The resulting TRIPOD Statement is a checklist of 22 items, deemed essential for transparent reporting of a prediction model study. The TRIPOD Statement aims to improve the transparency of the reporting of a prediction model study regardless of the study methods used. The TRIPOD Statement is best used in conjunction with the TRIPOD explanation and elaboration document. To aid the editorial process and readers of prediction model studies, it is recommended that authors include a completed checklist in their submission (also available at www.tripod-statement.org). The Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis (TRIPOD) Initiative developed a set of recommendations

  3. STELLAR POPULATION MODELS AND INDIVIDUAL ELEMENT ABUNDANCES. II. STELLAR SPECTRA AND INTEGRATED LIGHT MODELS

    NARCIS (Netherlands)

    Lee, Hyun-Chul; Worthey, Guy; Dotter, Aaron; Chaboyer, Brian; Jevremovic, Darko; Baron, E.; Briley, Michael M.; Ferguson, Jason W.; Coelho, Paula; Trager, Scott C.

    2009-01-01

    The first paper in this series explored the effects of altering the chemical mixture of the stellar population on an element-by-element basis on stellar evolutionary tracks and isochrones to the end of the red giant branch. This paper extends the discussion by incorporating the fully consistent

  4. Individual Alpha Peak Frequency Predicts 10 Hz Flicker Effects on Selective Attention.

    Science.gov (United States)

    Gulbinaite, Rasa; van Viegen, Tara; Wieling, Martijn; Cohen, Michael X; VanRullen, Rufin

    2017-10-18

    Rhythmic visual stimulation ("flicker") is primarily used to "tag" processing of low-level visual and high-level cognitive phenomena. However, preliminary evidence suggests that flicker may also entrain endogenous brain oscillations, thereby modulating cognitive processes supported by those brain rhythms. Here we tested the interaction between 10 Hz flicker and endogenous alpha-band (∼10 Hz) oscillations during a selective visuospatial attention task. We recorded EEG from human participants (both genders) while they performed a modified Eriksen flanker task in which distractors and targets flickered within (10 Hz) or outside (7.5 or 15 Hz) the alpha band. By using a combination of EEG source separation, time-frequency, and single-trial linear mixed-effects modeling, we demonstrate that 10 Hz flicker interfered with stimulus processing more on incongruent than congruent trials (high vs low selective attention demands). Crucially, the effect of 10 Hz flicker on task performance was predicted by the distance between 10 Hz and individual alpha peak frequency (estimated during the task). Finally, the flicker effect on task performance was more strongly predicted by EEG flicker responses during stimulus processing than during preparation for the upcoming stimulus, suggesting that 10 Hz flicker interfered more with reactive than proactive selective attention. These findings are consistent with our hypothesis that visual flicker entrained endogenous alpha-band networks, which in turn impaired task performance. Our findings also provide novel evidence for frequency-dependent exogenous modulation of cognition that is determined by the correspondence between the exogenous flicker frequency and the endogenous brain rhythms. SIGNIFICANCE STATEMENT Here we provide novel evidence that the interaction between exogenous rhythmic visual stimulation and endogenous brain rhythms can have frequency-specific behavioral effects. We show that alpha-band (10 Hz) flicker impairs stimulus

  5. Genetic analysis of body weights of individually fed beef bulls in South Africa using random regression models.

    Science.gov (United States)

    Selapa, N W; Nephawe, K A; Maiwashe, A; Norris, D

    2012-02-08

    The aim of this study was to estimate genetic parameters for body weights of individually fed beef bulls measured at centralized testing stations in South Africa using random regression models. Weekly body weights of Bonsmara bulls (N = 2919) tested between 1999 and 2003 were available for the analyses. The model included a fixed regression of the body weights on fourth-order orthogonal Legendre polynomials of the actual days on test (7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, and 84) for starting age and contemporary group effects. Random regressions on fourth-order orthogonal Legendre polynomials of the actual days on test were included for additive genetic effects and additional uncorrelated random effects of the weaning-herd-year and the permanent environment of the animal. Residual effects were assumed to be independently distributed with heterogeneous variance for each test day. Variance ratios for additive genetic, permanent environment and weaning-herd-year for weekly body weights at different test days ranged from 0.26 to 0.29, 0.37 to 0.44 and 0.26 to 0.34, respectively. The weaning-herd-year was found to have a significant effect on the variation of body weights of bulls despite a 28-day adjustment period. Genetic correlations amongst body weights at different test days were high, ranging from 0.89 to 1.00. Heritability estimates were comparable to literature using multivariate models. Therefore, random regression model could be applied in the genetic evaluation of body weight of individually fed beef bulls in South Africa.

  6. The effects of individual and team competitions on performance, emotions, and effort.

    Science.gov (United States)

    Cooke, Andrew; Kavussanu, Maria; McIntyre, David; Ring, Christopher

    2013-04-01

    It is well documented that competition can affect performance and emotion in sport. However, our understanding of the comparative effects of individual and team competitions on performance and emotion is limited. We also know little about emotion-based mechanisms underlying the effects of different types of competition on performance. To address these issues, 64 participants completed a handgrip endurance task during time-trial, one-on-one, two-on-two, and four-on-four competitions while self-report and possible corroborative physiological measures of enjoyment, anxiety, and effort were assessed. Results indicated that performance, enjoyment, anxiety, and effort increased from individual to team competitions. The observed increases in performance were mediated by increased enjoyment and effort. Our findings illustrate differential effects of individual and team competitions on performance and emotion. Moreover, they indicate that both enjoyment-based and anxiety-based mechanisms can explain changes in performance among different types of individual and team competition.

  7. Measurement invariance within and between individuals: a distinct problem in testing the equivalence of intra- and inter-individual model structures.

    Science.gov (United States)

    Adolf, Janne; Schuurman, Noémi K; Borkenau, Peter; Borsboom, Denny; Dolan, Conor V

    2014-01-01

    We address the question of equivalence between modeling results obtained on intra-individual and inter-individual levels of psychometric analysis. Our focus is on the concept of measurement invariance and the role it may play in this context. We discuss this in general against the background of the latent variable paradigm, complemented by an operational demonstration in terms of a linear state-space model, i.e., a time series model with latent variables. Implemented in a multiple-occasion and multiple-subject setting, the model simultaneously accounts for intra-individual and inter-individual differences. We consider the conditions-in terms of invariance constraints-under which modeling results are generalizable (a) over time within subjects, (b) over subjects within occasions, and (c) over time and subjects simultaneously thus implying an equivalence-relationship between both dimensions. Since we distinguish the measurement model from the structural model governing relations between the latent variables of interest, we decompose the invariance constraints into those that involve structural parameters and those that involve measurement parameters and relate to measurement invariance. Within the resulting taxonomy of models, we show that, under the condition of measurement invariance over time and subjects, there exists a form of structural equivalence between levels of analysis that is distinct from full structural equivalence, i.e., ergodicity. We demonstrate how measurement invariance between and within subjects can be tested in the context of high-frequency repeated measures in personality research. Finally, we relate problems of measurement variance to problems of non-ergodicity as currently discussed and approached in the literature.

  8. Navigational efficiency in a biased and correlated random walk model of individual animal movement.

    Science.gov (United States)

    Bailey, Joseph D; Wallis, Jamie; Codling, Edward A

    2018-01-01

    Understanding how an individual animal is able to navigate through its environment is a key question in movement ecology that can give insight into observed movement patterns and the mechanisms behind them. Efficiency of navigation is important for behavioral processes at a range of different spatio-temporal scales, including foraging and migration. Random walk models provide a standard framework for modeling individual animal movement and navigation. Here we consider a vector-weighted biased and correlated random walk (BCRW) model for directed movement (taxis), where external navigation cues are balanced with forward persistence. We derive a mathematical approximation of the expected navigational efficiency for any BCRW of this form and confirm the model predictions using simulations. We demonstrate how the navigational efficiency is related to the weighting given to forward persistence and external navigation cues, and highlight the counter-intuitive result that for low (but realistic) levels of error on forward persistence, a higher navigational efficiency is achieved by giving more weighting to this indirect navigation cue rather than direct navigational cues. We discuss and interpret the relevance of these results for understanding animal movement and navigation strategies. © 2017 by the Ecological Society of America.

  9. Effective modelling of acoustofluidic devices

    DEFF Research Database (Denmark)

    Ley, Mikkel Wennemoes Hvitfeld

    , and 3) acoustic streaming patterns in the devices considered in model 2). 1) We derive an effective model for numerical studies of hydrodynamic particle-particle interactions in microfluidic high-concentration suspensions. A suspension of microparticles placed in a microfluidic channel and influenced...... and travelling waves as well as absorption. We model the connective tubing at the outlets, either as being free reflecting surfaces or perfect absorbers of outgoing acoustic waves, and we make an effective description of the mechanical actuation of the attached piezoelectric transducer. 3) Using the model...

  10. Predicting the efficacy of radiotherapy in individual glioblastoma patients in vivo: a mathematical modeling approach

    International Nuclear Information System (INIS)

    Rockne, R; Alvord, E C Jr; Swanson, K R; Rockhill, J K; Kalet, I; Hendrickson, K; Mrugala, M; Spence, A M; Lai, A; Cloughesy, T

    2010-01-01

    Glioblastoma multiforme (GBM) is the most malignant form of primary brain tumors known as gliomas. They proliferate and invade extensively and yield short life expectancies despite aggressive treatment. Response to treatment is usually measured in terms of the survival of groups of patients treated similarly, but this statistical approach misses the subgroups that may have responded to or may have been injured by treatment. Such statistics offer scant reassurance to individual patients who have suffered through these treatments. Furthermore, current imaging-based treatment response metrics in individual patients ignore patient-specific differences in tumor growth kinetics, which have been shown to vary widely across patients even within the same histological diagnosis and, unfortunately, these metrics have shown only minimal success in predicting patient outcome. We consider nine newly diagnosed GBM patients receiving diagnostic biopsy followed by standard-of-care external beam radiation therapy (XRT). We present and apply a patient-specific, biologically based mathematical model for glioma growth that quantifies response to XRT in individual patients in vivo. The mathematical model uses net rates of proliferation and migration of malignant tumor cells to characterize the tumor's growth and invasion along with the linear-quadratic model for the response to radiation therapy. Using only routinely available pre-treatment MRIs to inform the patient-specific bio-mathematical model simulations, we find that radiation response in these patients, quantified by both clinical and model-generated measures, could have been predicted prior to treatment with high accuracy. Specifically, we find that the net proliferation rate is correlated with the radiation response parameter (r = 0.89, p = 0.0007), resulting in a predictive relationship that is tested with a leave-one-out cross-validation technique. This relationship predicts the tumor size post-therapy to within inter

  11. Differential expression among tissues in morbidly obese individuals using a finite mixture model under BLUP approach

    DEFF Research Database (Denmark)

    Kogelman, Lisette; Trabzuni, Daniah; Bonder, Marc Jan

    effects of the interactions between tissues and probes using BLUP (Best Linear Unbiased Prediction) linear models correcting for gender, which were subsequently used in a finite mixture model to detect DE genes in each tissue. This approach evades the multiple-testing problem and is able to detect...

  12. The Relationships between Individualism, Nationalism, Ethnocentrism, and Authoritarianism in Flanders: A Continuous Time-Structural Equation Modeling Approach.

    Science.gov (United States)

    Angraini, Yenni; Toharudin, Toni; Folmer, Henk; Oud, Johan H L

    2014-01-01

    This article analyzes the relationships among nationalism (N), individualism (I), ethnocentrism (E), and authoritarianism (A) in continuous time (CT), estimated as a structural equation model. The analysis is based on the General Election Study for Flanders, Belgium, for 1991, 1995, and 1999. We find reciprocal effects between A and E and between E and I as well as a unidirectional effect from A on I. We furthermore find relatively small, but significant, effects from both I and E on N but no effect from A on N or from N on any of the other variables. Because of its central role in the N-I-E-A complex, mitigation of authoritarianism has the largest potential to reduce the spread of nationalism, ethnocentrism, and racism in Flanders.

  13. Effects of Adult Romantic Attachment and Social Support on Resilience and Depression in Individuals with Spinal Cord Injuries.

    Science.gov (United States)

    Dodd, Zane; Driver, Simon; Warren, Ann Marie; Riggs, Shelley; Clark, Mike

    2015-01-01

    Spinal cord injury (SCI) can cause psychological consequences that negatively affect quality of life. It is increasingly recognized that factors such as resilience and social support may produce a buffering effect and are associated with improved health outcomes. However the influence of adult attachment style on an individual's ability to utilize social support after SCI has not been examined. The purpose of this study was to examine relationships between adult romantic attachment perceived social support depression and resilience in individuals with SCI. In addition we evaluated potential mediating effects of social support and adult attachment on resilience and depression. Participants included 106 adults with SCI undergoing inpatient rehabilitation. Individuals completed measures of adult attachment (avoidance and anxiety) social support resilience and depression. Path analysis was performed to assess for presence of mediation effects. When accounting for the smaller sample size support was found for the model (comparative fit index = .927; chi square = 7.86, P = .01; β = -0.25, standard error [SE] = -2.93, P effect of social support on the association between attachment avoidance and resilience was the only hypothesized mediating effect found to be significant (β = -0.25, SE = -2.93, P < .05). Results suggest that individuals with SCI with higher levels of attachment avoidance have lower perceived social support which relates to lower perceived resilience. Assessing attachment patterns during inpatient rehabilitation may allow therapists to intervene to provide greater support.

  14. Optimization of an individual re-identification modeling process using biometric features

    Energy Technology Data Exchange (ETDEWEB)

    Heredia-Langner, Alejandro; Amidan, Brett G.; Matzner, Shari; Jarman, Kristin H.

    2014-09-24

    We present results from the optimization of a re-identification process using two sets of biometric data obtained from the Civilian American and European Surface Anthropometry Resource Project (CAESAR) database. The datasets contain real measurements of features for 2378 individuals in a standing (43 features) and seated (16 features) position. A genetic algorithm (GA) was used to search a large combinatorial space where different features are available between the probe (seated) and gallery (standing) datasets. Results show that optimized model predictions obtained using less than half of the 43 gallery features and data from roughly 16% of the individuals available produce better re-identification rates than two other approaches that use all the information available.

  15. Criteria for calculation of effective dose from the individual monitoring; Criterios para calculo de dose efetiva a partir da monitoracao individual

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-11-15

    This Regulation refers to the requirements of the Regulation CNEN-NN.3.01. 'Basic Act of Radiological Protection', as expressed in the section 5.9, and its application to the effective dose calculation for individual occupationally exposed. from the internal and external individual monitoring data

  16. Effects of EFL Individual Learner Variables on Foreign Language Reading Anxiety and Metacognitive Reading Strategy Use.

    Science.gov (United States)

    Lien, Hsin-Yi

    2016-08-01

    Past research has shown an association between foreign language reading anxiety and reading strategy. However, individual variables tend to affect foreign language anxiety and strategy use. The present study examined a hypothesized model that specified direct and indirect effects among English and foreign languages readers' distinct variables, including academic level; self-perceived English level; and satisfaction with reading proficiency, reading anxiety, and metacognitive awareness of reading strategies. A total of 523 volunteer Taiwanese college students provided 372 valid responses to a written questionnaire (281 women and 91 men; M age = 19.7 years, SD = 1.1) containing the translated versions of Foreign Language Reading Anxiety Scale, Survey of Reading Strategies Inventory, and self-assessment background questionnaire. The results showed that self-evaluation of reading proficiency did not correlate with academic level and readers' perceptions. Satisfaction had a direct effect on foreign language reading anxiety but not on metacognitive awareness of reading strategies. Results of path analysis demonstrated that the perception learners who had their own reading proficiency predicted their foreign language reading anxiety and was a mediating variable for metacognitive reading strategy use. © The Author(s) 2016.

  17. A Review and Treatment Selection Model for Individuals with Developmental Disabilities Who Engage in Inappropriate Sexual Behavior.

    Science.gov (United States)

    Davis, Tonya N; Machalicek, Wendy; Scalzo, Rachel; Kobylecky, Alicia; Campbell, Vincent; Pinkelman, Sarah; Chan, Jeffrey Michael; Sigafoos, Jeff

    2016-12-01

    Some individuals with developmental disabilities develop inappropriate sexual behaviors such as public masturbation, disrobing, and touching others in an unwanted sexual manner. Such acts are problematic given the taboo nature of the behaviors and the potential for significant negative consequences, such as restricted community access, injury, and legal ramifications. Therefore, it is necessary to equip caregivers and practitioners with effective treatment options. The purpose of this paper is to review studies that have evaluated behavioral treatments to reduce inappropriate sexual behavior in persons with developmental disabilities. The strengths and weaknesses of each treatment are reviewed, and a model for treatment selection is provided.

  18. USING ECO-EVOLUTIONARY INDIVIDUAL-BASED MODELS TO INVESTIGATE SPATIALLY-DEPENDENT PROCESSES IN CONSERVATION GENETICS

    Science.gov (United States)

    Eco-evolutionary population simulation models are powerful new forecasting tools for exploring management strategies for climate change and other dynamic disturbance regimes. Additionally, eco-evo individual-based models (IBMs) are useful for investigating theoretical feedbacks ...

  19. [Reconstruction of mandibular bone defects using three-dimensional skull model and individualized titanium prosthetics from computer assisted design].

    Science.gov (United States)

    Gong, Zhenyu; Li, Guohua; Liu, Yanpu; He, Lisheng; Zhou, Bing; Li, Dichen

    2012-01-01

    To evaluate the feasibility and effectiveness of reconstruction of mandibular bone defects using three-dimensional skull model and individualized titanium prosthetics from computer assisted design. Between July 2002 and November 2009, 9 patients with mandibular defects accepted restorative operation using individualized bone prosthetics. Among 9 cases, 4 were male and 5 were female, aged 19-55 years. The causes of mandibulectomy were benign lesions in 8 patients and carcinoma of gingival in 1 patient. Mandibular defects exceeded midline in 2 cases, involved condylar in 4 cases, and was limited in one side without involvement of temporo-mandibular joint in 3 cases. The range of bone defects was 9.0 cm x 2.5 cm-17.0 cm x 2.5 cm. The preoperative spiral CT scan was performed and three-dimensional skull model was obtained. Titanium prosthetics of mandibular defects were designed and fabricated through multi-step procedure of reverse engineering and rapid prototyping. Titanium prosthetics were used for one-stage repair of mandibular bone defects, then two-stage implant denture was performed after 6 months. The individualized titanium prosthetics were inserted smoothly with one-stage operative time of 10-23 minutes. All the cases achieved incision healing by first intention and the oblique mandibular movement was corrected. They all got satisfactory face, had satisfactory contour and good occlusion. In two-stage operation, no loosening of the implants was observed and the abutments were in good position with corresponding teeth which were designed ideally before operation. All cases got satisfactory results after 1-9 years of follow-up. At last follow-up, X-ray examinations showed no loosening of implants with symmetry contour. Computer assisted design and three-dimensional skull model techniques could accomplish the design and manufacture of individualized prosthetic for the repair of mandibular bone defects.

  20. Effects of Cooperative versus Individual Study on Learning and Motivation after Reward-Removal

    Science.gov (United States)

    Sears, David A.; Pai, Hui-Hua

    2012-01-01

    Rewards are frequently used in classrooms and recommended as a key component of well-researched methods of cooperative learning (e.g., Slavin, 1995). While many studies of cooperative learning find beneficial effects of rewards, many studies of individuals find negative effects (e.g., Deci, Koestner, & Ryan, 1999; Lepper, 1988). This may be…

  1. Effectiveness and feasibility of eccentric and task-oriented strength training in individuals with stroke

    NARCIS (Netherlands)

    Folkerts, Mireille A; Hijmans, Juha M.; Elsinghorst, Anne L.; Mulderij, Yvon; Murgia, Alessio; Dekker, Rienk

    2017-01-01

    BACKGROUND: Strength training can increase function in individuals with stroke. However it is unclear which type of strength training is most effective and feasible. OBJECTIVE: To assess the effect and feasibility of an intervention combining eccentric and task-oriented strength training in

  2. A community model of ciliate Tetrahymena and bacteria E. coli. Part 1: Individual-based models of Tetrahymena and E. coli populations

    Energy Technology Data Exchange (ETDEWEB)

    Jaworska, J.S.; Hallam, T.G.; Schultz, T.W. [Univ. of Tennessee, Knoxville, TN (United States)

    1996-03-01

    The dynamics of a microbial community consisting of a eucaryotic ciliate Tetrahymena pyriformis and procaryotic. Escherichia coli in a batch culture is explored by employing an individual-based approach. In this portion of the article, Part 1, population models are presented. Because both models are individual-based, models of individual organisms are developed prior to construction of the population models. The individual models use an energy budget method in which growth depends on energy gain from feeding and energy sinks such as maintenance and reproduction. These models are not limited by simplifying assumptions about constant yield, constant energy sinks and Monod growth kinetics as are traditional models of microbial organisms. Population models are generated from individual models by creating distinct individual types and assigning to each type the number of real individuals they represent. A population is a compilation of individual types that vary in a phase of cell cycle and physiological parameters such as filtering rate for ciliates and maximum anabolic rate for bacteria. An advantage of the developed models is that they realistically describe the growth of the individual cells feeding on resource which varies in density and composition. Part 2, the core of the project, integrates models into a dynamic microbial community and provides model analysis based upon available data.

  3. Group or Individual treatment: What is More Effective in Childhood and Juvenile Obesity?

    Directory of Open Access Journals (Sweden)

    Rita de Cássia Garcia Pereira

    2015-01-01

    Full Text Available Objective: the objective was to compare the efficacy of individual treatment (consulting and group treatment combined with individualized care, in childhood and juvenile obesity situations. Methodology: The study was carried out in 2 different places: in the Nutrition Clinic of the Integrated Health Clinic of UNIARA and in another clinical school. In both places there was a treatment with individual consultations, however, in the Integrated Health Clinic of UNIARA treatment was also done in group care. The target individuals were composed of children and adolescents of both sexes who participated in the consultations, however, only patients who were above the 85th percentile for BMI, according to the international reference population (NCHS, 2000, were included in the sample which was composed of 58 individuals. The choice of clinical records occurred at random in both places. Results: the most effective program in the positive change in dietary habits was group together with individual treatment, where 20 patients (68.96% showed some change in eating behavior. In individual treatment, 11 patients (37.93% showed some change in dietary habits existing before treatment. There was a reduction in the rate of obesity of 24% for patients in groups, however, both types of treatment were favorable to changes in dietary habits and weight reduction. The findings showed that the strategy of individualized care together with group care is an alternative for the treatment of overweight.

  4. The Educational Effect on Cognitive Functioning: National versus Individual Educational Attainment

    OpenAIRE

    Weber, D.; Skirbekk, V.

    2014-01-01

    Maintaining good cognitive performance at all ages in light of demographic changes represents a social, economic, and health-related challenge, particularly in aging countries. A strong positive relation between individual level education and cognitive performance has already been identified in earlier research, but the differences in relation to national education across countries are uncertain. This study adds to the literature by disentangling the effect of national and individual educatio...

  5. Effects of Sleep Deprivation on Brain Bioenergetics, Sleep, and Cognitive Performance in Cocaine-Dependent Individuals

    OpenAIRE

    Trksak, George H.; Bracken, Bethany K.; Jensen, J. Eric; Plante, David T.; Penetar, David M.; Tartarini, Wendy L.; Maywalt, Melissa A.; Dorsey, Cynthia M.; Renshaw, Perry F.; Lukas, Scott E.

    2013-01-01

    In cocaine-dependent individuals, sleep is disturbed during cocaine use and abstinence, highlighting the importance of examining the behavioral and homeostatic response to acute sleep loss in these individuals. The current study was designed to identify a differential effect of sleep deprivation on brain bioenergetics, cognitive performance, and sleep between cocaine-dependent and healthy control participants. 14 healthy control and 8 cocaine-dependent participants experienced consecutive nig...

  6. Cost-effectiveness of individual versus group psychotherapy for sexually abused girls

    OpenAIRE

    Paul R. McCrone; Tara Weeramanthri; Martin R.J. Knapp; Alan Rushton; Judith Trowell; Gillian Miles; Israel Kolvin

    2005-01-01

    Children who have been sexually abused may suffer from emotional and behavioural difficulties. Recent research found that individual and group psychotherapy have similar outcomes. In this study we compare the costs and cost-effectiveness of the two therapies and support for carers. Subjects were recruited to two clinics in London and randomly allocated to treatments. Total mean costs of individual therapy were found to be £1246 greater than for group therapy. Costs as they would apply in rout...

  7. The effects of strength training on finger strength and hand dexterity in healthy elderly individuals

    OpenAIRE

    Olafsdottir, Halla B.; Zatsiorsky, Vladimir M.; Latash, Mark L.

    2008-01-01

    We investigated the effect of 6 wk of strength training on maximal pressing (MVC) force, indexes of finger individuation (enslaving), and performance in accurate force production tests and in functional hand tests in healthy, physically fit, elderly individuals. Twelve participants (average age 76 yr) exercised with both hands. One of the hands exercised by pressing with the proximal phalanges (targeting mainly intrinsic hand muscles), whereas the other hand exercised by pressing with the fin...

  8. Representing the acquisition and use of energy by individuals in agent-based models of animal populations

    Science.gov (United States)

    Sibly, Richard M.; Grimm, Volker; Martin, Benjamin T.; Johnston, Alice S.A.; Kulakowska, Katarzyna; Topping, Christopher J.; Calow, Peter; Nabe-Nielsen, Jacob; Thorbek, Pernille; DeAngelis, Donald L.

    2013-01-01

    1. Agent-based models (ABMs) are widely used to predict how populations respond to changing environments. As the availability of food varies in space and time, individuals should have their own energy budgets, but there is no consensus as to how these should be modelled. Here, we use knowledge of physiological ecology to identify major issues confronting the modeller and to make recommendations about how energy budgets for use in ABMs should be constructed. 2. Our proposal is that modelled animals forage as necessary to supply their energy needs for maintenance, growth and reproduction. If there is sufficient energy intake, an animal allocates the energy obtained in the order: maintenance, growth, reproduction, energy storage, until its energy stores reach an optimal level. If there is a shortfall, the priorities for maintenance and growth/reproduction remain the same until reserves fall to a critical threshold below which all are allocated to maintenance. Rates of ingestion and allocation depend on body mass and temperature. We make suggestions for how each of these processes should be modelled mathematically. 3. Mortality rates vary with body mass and temperature according to known relationships, and these can be used to obtain estimates of background mortality rate. 4. If parameter values cannot be obtained directly, then values may provisionally be obtained by parameter borrowing, pattern-oriented modelling, artificial evolution or from allometric equations. 5. The development of ABMs incorporating individual energy budgets is essential for realistic modelling of populations affected by food availability. Such ABMs are already being used to guide conservation planning of nature reserves and shell fisheries, to assess environmental impacts of building proposals including wind farms and highways and to assess the effects on nontarget organisms of chemicals for the control of agricultural pests.

  9. Development of a shortleaf pine individual-tree growth equation using non-linear mixed modeling techniques

    Science.gov (United States)

    Chakra B. Budhathoki; Thomas B. Lynch; James M. Guldin

    2010-01-01

    Nonlinear mixed-modeling methods were used to estimate parameters in an individual-tree basal area growth model for shortleaf pine (Pinus echinata Mill.). Shortleaf pine individual-tree growth data were available from over 200 permanently established 0.2-acre fixed-radius plots located in naturally-occurring even-aged shortleaf pine forests on the...

  10. Meta-analysis of individual and combined effects of mycotoxins on growing pigs

    Directory of Open Access Journals (Sweden)

    Ines Andretta

    2016-08-01

    Full Text Available ABSTRACT Little is known about the toxicity of concomitantly occurring mycotoxins in pig diets. This study was conducted to evaluate, through meta-analysis, the individual and the combined effects of mycotoxins on pig performance. The meta-analysis followed three sequential analyses (graphical, correlation, and variance-covariance based on a database composed of 85 published papers, 1,012 treatments and 13,196 animals. Contamination of diets with individual mycotoxins reduced (p < 0.05 feed intake by 14 % and weight gain by 17 %, while combined mycotoxins reduced the same responses by 42 % and 45 %, respectively, in comparison with the non-challenged group. The correlation (p < 0.05 between reduction in weight gain (ΔG and reduction in feed intake (ΔFI was 0.67 in individual challenges and 0.93 in combined challenges. The estimated ΔG was –6 % in individual challenges and –7 % in combined challenges when ΔFI was zero, suggesting an increase in the maintenance requirements of challenged animals. Most of ΔG (58 % in individual challenges and 84 % in combined challenges was attributed to the changes in feed efficiency. The association of mycotoxins enhances individual toxic effects and the ΔFI is important in explaining the deleterious effects on the growth of challenged pigs.

  11. The Importance of Tree Height in Estimating Individual Tree Biomass While Considering Errors in Measurements and Allometric Models

    OpenAIRE

    Phalla, Thuch; Ota, Tetsuji; Mizoue, Nobuya; Kajisa, Tsuyoshi; Yoshida, Shigejiro; Vuthy, Ma; Heng, Sokh

    2018-01-01

    This study evaluated the uncertainty of individual tree biomass estimated by allometric models by both including and excluding tree height independently. Using two independent sets of measurements on the same trees, the errors in the measurement of diameter at breast height and tree height were quantified, and the uncertainty of individual tree biomass estimation caused by errors in measurement was calculated. For both allometric models, the uncertainties of the individual tree biomass estima...

  12. Modeling individual differences in randomized experiments using growth models: Recommendations for design, statistical analysis and reporting of results of internet interventions

    Directory of Open Access Journals (Sweden)

    Hugo Hesser

    2015-05-01

    Full Text Available Growth models (also known as linear mixed effects models, multilevel models, and random coefficients models have the capability of studying change at the group as well as the individual level. In addition, these methods have documented advantages over traditional data analytic approaches in the analysis of repeated-measures data. These advantages include, but are not limited to, the ability to incorporate time-varying predictors, handle dependence among repeated observations in a very flexible manner, and to provide accurate estimates with missing data under fairly unrestrictive missing data assumptions. The flexibility of the growth curve modeling approach to the analysis of change makes it the preferred choice in the evaluation of direct, indirect and moderated intervention effects. Although offering many benefits, growth models present challenges in terms of design, analysis and reporting of results. This paper provides a nontechnical overview of growth models in the analysis of change in randomized experiments and advocates for their use in the field of internet interventions. Practical recommendations for design, analysis and reporting of results from growth models are provided.

  13. Quantifying the Effectiveness of Dose Individualization by Simulation for a Drug With Moderate Pharmacokinetic Variability.

    Science.gov (United States)

    Liefaard, Lia; Chen, Chao

    2015-10-01

    Dose individualization can reduce variability in exposure. The objective of this work was to quantify, through pharmacokinetic (PK) simulation, the potential for reducing the variability in exposure by dose individualization for a drug with moderate PK variability between subjects and between occasions within a subject, and a narrow therapeutic window. Using a population PK model that includes between-subject and between-occasion variability for apparent clearance, individual PK profiles in a trial of 300 subjects after a test dose were simulated. From the simulated data, datasets were created mimicking various sampling regimens (from single predose sample to full profile samples over 12 hours) on 1 or more occasions (1, 2, 3, 5, or 10 visits). Using these datasets, individual apparent clearance values were estimated, which were then used to calculate an individualized dose for a predefined target area under the concentration-time curve (AUC), based on the available formulation strengths. The proportion of people whose mean AUC was within a predefined therapeutic AUC range was calculated for the test (before) and the individualized dose (after), and compared between the different sampling scenarios. The maximum increase in proportion of subjects with an AUC within the range was 20%. To achieve this benefit, PK samples over 4 hours from 100 dosing occasions were required. As a result of the dose adjustment, the AUC of 7.3% of the subjects moved from inside the therapeutic range to outside of the range. This work shows how modeling and simulation can help assess the benefit and risk of dose individualization for a compound with variability between subjects and between occasions. The framework can be applied to similar situations with a defined set of conditions (eg, therapeutic window, tablet strengths, and PK and/or pharmacodynamic sampling scheme) to inform dose change and to assess the utility of dose individualization against certain success criteria.

  14. Midterm peer feedback in problem-based learning groups: the effect on individual contributions and achievement.

    Science.gov (United States)

    Kamp, Rachelle J A; van Berkel, Henk J M; Popeijus, Herman E; Leppink, Jimmie; Schmidt, Henk G; Dolmans, Diana H J M

    2014-03-01

    Even though peer process feedback is an often used tool to enhance the effectiveness of collaborative learning environments like PBL, the conditions under which it is best facilitated still need to be investigated. Therefore, this study investigated the effects of individual versus shared reflection and goal setting on students' individual contributions to the group and their academic achievement. In addition, the influence of prior knowledge on the effectiveness of peer feedback was studied. In this pretest-intervention-posttest study 242 first year students were divided into three conditions: condition 1 (individual reflection and goal setting), condition 2 (individual and shared reflection and goal setting), and condition 3 (control group). Results indicated that the quality of individual contributions to the tutorial group did not improve after receiving the peer feedback, nor did it differ between the three conditions. With regard to academic achievement, only males in conditions 1 and 2 showed better academic achievement compared with condition 3. However, there was no difference between both ways of reflection and goal setting with regard to achievement, indicating that both ways are equally effective. Nevertheless, it is still too early to conclude that peer feedback combined with reflection and goal setting is not effective in enhancing students' individual contributions. Students only had a limited number of opportunities to improve their contributions. Therefore, future research should investigate whether an increase in number of tutorial group meetings can enhance the effectiveness of peer feedback. In addition, the effect of quality of reflection and goal setting could be taken into consideration in future research.

  15. Determinants of functioning and well-being among individuals with schizophrenia: An integrated model

    Science.gov (United States)

    Yanos, P.T.; Moos, R.H.

    2006-01-01

    Outcomes for health conditions are typically the result of multiple factors; however, studies tend to focus on a narrow class of variables. Functioning and well-being outcomes for schizophrenia are diverse and have resisted simple explanation; however, prior research has not offered an integrated understanding of the relative contributions of enduring and episodic environmental factors, personal resources and psychiatric factors, and cognitive appraisal and coping, on functioning and well-being outcomes in schizophrenia. The present article sets out an integrated model of the determinants of functioning and well-being among individuals with schizophrenia. To examine evidence that bears on the model, literature on hypothesized relationships is reviewed to identify areas for which there is strong evidence and areas where more research is needed. The article suggests areas for further research, and directs researchers and practitioners toward areas of intervention that can enhance functioning and well-being for persons diagnosed with schizophrenia. PMID:16480804

  16. Extrapolating toxic effects on individuals to the population level: the role of dynamic energy budgets

    NARCIS (Netherlands)

    Jager, T.; Klok, T.C.

    2010-01-01

    The interest of environmental management is in the long-term health of populations and ecosystems. However, toxicity is usually assessed in short-term experiments with individuals. Modelling based on dynamic energy budget (DEB) theory aids the extraction of mechanistic information from the data,

  17. Extrapolating toxic effects on individuals to the population level; the role of dynamic energy budgets.

    NARCIS (Netherlands)

    Jager, T.; Klok, C.

    2010-01-01

    The interest of environmental management is in the long-term health of populations and ecosystems. However, toxicity is usually assessed in short-term experiments with individuals. Modelling based on dynamic energy budget (DEB) theory aids the extraction of mechanistic information from the data,

  18. Beyond Individual Differences: Exploring School Effects on SAT® Scores. Research Report No. 2004-3

    Science.gov (United States)

    Everson, Howard T.; Millsap, Roger E.

    2004-01-01

    This paper explores the complex, hierarchical relationship among school characteristics, individual differences in academic achievement, extracurricular activities, and socioeconomic background on performance on the SAT Reasoning Test™ verbal and mathematical sections. Using multilevel structural equation models (SEMs) with latent means, data from…

  19. Forecasting Individual Headache Attacks Using Perceived Stress: Development of a Multivariable Prediction Model for Persons With Episodic Migraine.

    Science.gov (United States)

    Houle, Timothy T; Turner, Dana P; Golding, Adrienne N; Porter, John A H; Martin, Vincent T; Penzien, Donald B; Tegeler, Charles H

    2017-07-01

    To develop and validate a prediction model that forecasts future migraine attacks for an individual headache sufferer. Many headache patients and physicians believe that precipitants of headache can be identified and avoided or managed to reduce the frequency of headache attacks. Of the numerous candidate triggers, perceived stress has received considerable attention for its association with the onset of headache in episodic and chronic headache sufferers. However, no evidence is available to support forecasting headache attacks within individuals using any of the candidate headache triggers. This longitudinal cohort with forecasting model development study enrolled 100 participants with episodic migraine with or without aura, and N = 95 contributed 4626 days of electronic diary data and were included in the analysis. Individual headache forecasts were derived from current headache state and current levels of stress using several aspects of the Daily Stress Inventory, a measure of daily hassles that is completed at the end of each day. The primary outcome measure was the presence/absence of any headache attack (head pain > 0 on a numerical rating scale of 0-10) over the next 24 h period. After removing missing data (n = 431 days), participants in the study experienced a headache attack on 1613/4195 (38.5%) days. A generalized linear mixed-effects forecast model using either the frequency of stressful events or the perceived intensity of these events fit the data well. This simple forecasting model possessed promising predictive utility with an AUC of 0.73 (95% CI 0.71-0.75) in the training sample and an AUC of 0.65 (95% CI 0.6-0.67) in a leave-one-out validation sample. This forecasting model had a Brier score of 0.202 and possessed good calibration between forecasted probabilities and observed frequencies but had only low levels of resolution (ie, sharpness). This study demonstrates that future headache attacks can be forecasted for a diverse group of

  20. Statistics and Stochastic Models of an Individual Motion of Photosensitive Alga Euglena gracilis

    Science.gov (United States)

    Ogawa, Takuma; Izumi, Shunsuke; Iima, Makoto

    2017-07-01

    The motion of individual Euglena gracilis was experimentally analyzed. The flow field of E. gracilis during free swimming was visualized by the particle image velocimetry method to show that the time-averaged flow field is well represented by two Stokeslets, suggesting that the flow around E. gracilis is categorized as the typical puller type. The orbit of swimming E. gracilis in a uniform environment was also analyzed. The orbit was classified into two modes, "moving" and "stationary", to obtain statistics on waiting time, swimming length during a single motion, and the directional change between two successive swimming directions. For the distribution of waiting time and swimming length, power laws were obtained. On the basis of the results, biased random walk models were constructed to discuss the long-time diffusion behavior of an individual motion. The swimming behavior of E. gracilis in a nonuniform light environment was analyzed by focusing on the directional change behavior, whereby a Markov chain model was proposed to reproduce the observed behavior.

  1. Profit-Based Model Selection for Customer Retention Using Individual Customer Lifetime Values.

    Science.gov (United States)

    Óskarsdóttir, María; Baesens, Bart; Vanthienen, Jan

    2018-03-01

    The goal of customer retention campaigns, by design, is to add value and enhance the operational efficiency of businesses. For organizations that strive to retain their customers in saturated, and sometimes fast moving, markets such as the telecommunication and banking industries, implementing customer churn prediction models that perform well and in accordance with the business goals is vital. The expected maximum profit (EMP) measure is tailored toward this problem by taking into account the costs and benefits of a retention campaign and estimating its worth for the organization. Unfortunately, the measure assumes fixed and equal customer lifetime value (CLV) for all customers, which has been shown to not correspond well with reality. In this article, we extend the EMP measure to take into account the variability in the lifetime values of customers, thereby basing it on individual characteristics. We demonstrate how to incorporate the heterogeneity of CLVs when CLVs are known, when their prior distribution is known, and when neither is known. By taking into account individual CLVs, our proposed approach of measuring model performance gives novel insights when deciding on a customer retention campaign. The method is dependent on the characteristics of the customer base as is compliant with modern business analytics and accommodates the data-driven culture that has manifested itself within organizations.

  2. Modelling southern elephant seals Mirounga leonina using an individual-based model coupled with a dynamic energy budget.

    Science.gov (United States)

    Goedegebuure, Merel; Melbourne-Thomas, Jessica; Corney, Stuart P; McMahon, Clive R; Hindell, Mark A

    2018-01-01

    Higher trophic-level species are an integral component of any marine ecosystem. Despite their importance, methods for representing these species in end-to-end ecosystem models often have limited representation of life histories, energetics and behaviour. We built an individual-based model coupled with a dynamic energy budget for female southern elephant seals Mirounga leonina to demonstrate a method for detailed representation of marine mammals. We aimed to develop a model which could i) simulate energy use and life histories, as well as breeding traits of southern elephant seals in an emergent manner, ii) project a stable population over time, and iii) have realistic population dynamics and structure based on emergent life history features (such as age at first breeding, lifespan, fecundity and (yearling) survival). We evaluated the model's ability to represent a stable population over long time periods (>10 generations), including the sensitivity of the emergent properties to variations in key parameters. Analyses indicated that the model is sensitive to changes in resource availability and energy requirements for the transition from pup to juvenile, and juvenile to adult stage. This was particularly the case for breeding success and yearling survival. This model is suitable for use as a standalone tool for investigating the impacts of changes to behaviour and population responses of southern elephant seals.

  3. Individualized Physical 3-dimensional Kidney Tumor Models Constructed From 3-dimensional Printers Result in Improved Trainee Anatomic Understanding.

    Science.gov (United States)

    Knoedler, Margaret; Feibus, Allison H; Lange, Andrew; Maddox, Michael M; Ledet, Elisa; Thomas, Raju; Silberstein, Jonathan L

    2015-06-01

    To evaluate the effect of 3-dimensionally (3D) printed physical renal models with enhancing masses on medical trainee characterization, localization, and understanding of renal malignancy. Proprietary software was used to import standard computed tomography (CT) cross-sectional imaging into 3D printers to create physical models of renal units with enhancing renal lesions in situ. Six different models were printed from a transparent plastic resin; the normal parenchyma was printed in a clear, translucent plastic, with a red hue delineating the suspicious renal lesion. Medical students, who had completed their first year of training, were given an overview and tasked with completion of RENAL nephrometry scores, separately using CT imaging and 3D models. Trainees were also asked to complete a questionnaire about their experience. Variability between trainees was assessed by intraclass correlation coefficients (ICCs), and kappa statistics were used to compare the trainee to experts. Overall trainee nephrometry score accuracy was significantly improved with the 3D model vs CT scan (P <.01). Furthermore, 3 of the 4 components of the nephrometry score (radius, nearness to collecting system, and location) showed significant improvement (P <.001) using the models. There was also more consistent agreement among trainees when using the 3D models compared with CT scans to assess the nephrometry score (intraclass correlation coefficient, 0.28 for CT scan vs 0.72 for 3D models). Qualitative evaluation with questionnaires filled out by the trainees further confirmed that the 3D models improved their ability to understand and conceptualize the renal mass. Physical 3D models using readily available printing techniques improve trainees' understanding and characterization of individual patients' enhancing renal lesions. Published by Elsevier Inc.

  4. Effects of individual resilience intervention on indigenous people who experienced Typhoon Morkot in Taiwan

    Directory of Open Access Journals (Sweden)

    Su-Fen Cheng

    2012-02-01

    Full Text Available In 2009, Typhoon Morakot struck Taiwan and caused serious harm to the indigenous peoples living in the southern mountainous regions. The objective of this study is to examine the effects of and the factors involved in individual resilience intervention of typhoon victims. Quantitative research was performed from October 2009 through September 2010. Purposive sampling yielded 77 indigenous persons who were willing to serve as participants in this study. These participants all maintained legal or actual residence in the areas of Kaohsiung that were affected by the typhoon. An individual resilience intervention program was implemented. The findings show the following: (1 after completing the individual resilience intervention program, the participants had higher individual resilience scores than before participating in the intervention program; and (2 individual resilience scores were significantly affected by residency after the typhoon. These findings suggest that an individual resilience intervention program is a useful approach that can be used to enhance the individual resilience of a victim and that professionals should pay more attention to victims who have to leave their hometowns after disasters.

  5. A long-term mechanistic computational model of physiological factors driving the onset of type 2 diabetes in an individual.

    Directory of Open Access Journals (Sweden)

    Joydeep Sarkar

    Full Text Available A computational model of the physiological mechanisms driving an individual's health towards onset of type 2 diabetes (T2D is described, calibrated and validated using data from the Diabetes Prevention Program (DPP. The objective of this model is to quantify the factors that can be used for prevention of T2D. The model is energy and mass balanced and continuously simulates trajectories of variables including body weight components, fasting plasma glucose, insulin, and glycosylated hemoglobin among others on the time-scale of years. Modeled mechanisms include dynamic representations of intracellular insulin resistance, pancreatic beta-cell insulin production, oxidation of macronutrients, ketogenesis, effects of inflammation and reactive oxygen species, and conversion between stored and activated metabolic species, with body-weight connected to mass and energy balance. The model was calibrated to 331 placebo and 315 lifestyle-intervention DPP subjects, and one year forecasts of all individuals were generated. Predicted population mean errors were less than or of the same magnitude as clinical measurement error; mean forecast errors for weight and HbA1c were ~5%, supporting predictive capabilities of the model. Validation of lifestyle-intervention prediction is demonstrated by synthetically imposing diet and physical activity changes on DPP placebo subjects. Using subject level parameters, comparisons were made between exogenous and endogenous characteristics of subjects who progressed toward T2D (HbA1c > 6.5 over the course of the DPP study to those who did not. The comparison revealed significant differences in diets and pancreatic sensitivity to hyperglycemia but not in propensity to develop insulin resistance. A computational experiment was performed to explore relative contributions of exogenous versus endogenous factors between these groups. Translational uses to applications in public health and personalized healthcare are discussed.

  6. Atomic Models for Motional Stark Effects Diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Gu, M F; Holcomb, C; Jayakuma, J; Allen, S; Pablant, N A; Burrell, K

    2007-07-26

    We present detailed atomic physics models for motional Stark effects (MSE) diagnostic on magnetic fusion devices. Excitation and ionization cross sections of the hydrogen or deuterium beam traveling in a magnetic field in collisions with electrons, ions, and neutral gas are calculated in the first Born approximation. The density matrices and polarization states of individual Stark-Zeeman components of the Balmer {alpha} line are obtained for both beam into plasma and beam into gas models. A detailed comparison of the model calculations and the MSE polarimetry and spectral intensity measurements obtained at the DIII-D tokamak is carried out. Although our beam into gas models provide a qualitative explanation for the larger {pi}/{sigma} intensity ratios and represent significant improvements over the statistical population models, empirical adjustment factors ranging from 1.0-2.0 must still be applied to individual line intensities to bring the calculations into full agreement with the observations. Nevertheless, we demonstrate that beam into gas measurements can be used successfully as calibration procedures for measuring the magnetic pitch angle through {pi}/{sigma} intensity ratios. The analyses of the filter-scan polarization spectra from the DIII-D MSE polarimetry system indicate unknown channel and time dependent light contaminations in the beam into gas measurements. Such contaminations may be the main reason for the failure of beam into gas calibration on MSE polarimetry systems.

  7. Effect of lead exposure on the immune response of some occupationally exposed individuals

    International Nuclear Information System (INIS)

    Mishra, Kamla Prasad; Singh, Vijay Kumar; Rani, Reena; Yadav, Virendra Singh; Chandran, Vinod; Srivastava, Satya Prakash; Seth, Prahlad Kishore

    2003-01-01

    Lead is a ubiquitous pollutant in the industrial environment, which poses serious threats to human health. In the past 20 years increasing attention has been paid to the effects of lead exposure on health. This toxic metal alters the immune response of animals as well as humans. To study the immunological effects of occupational exposure to lead, we examined lymphocyte proliferation, natural killer (NK) cell cytotoxicity and interferon-γ production with peripheral blood mononuclear cells (PBMCs) of individuals occupationally exposed to lead. We selected three different groups of individuals exposed to lead: three-wheeler drivers (30), battery workers (34) and silver jewelery makers (20); and unexposed healthy volunteers (30) as control for comparison. Our results indicate that though lymphocyte proliferation to phytohaemagglutinin (PHA) is inhibited in lead exposed individuals as compared with unexposed volunteers, there is no correlation between inhibition of lymphocyte proliferation and blood lead level. NK cell cytotoxicity remains unaffected in individuals exposed to lead as compared with controls. On the other hand, we observed that interferon-γ (IFN-γ) was significantly elevated in T cell mitogen, PHA, stimulated PBMCs culture supernatant of lead exposed individuals. We found significant positive correlation between blood lead levels and IFN-γ produced in culture supernatant on stimulation with PHA. In brief, this study demonstrates that lead can affect the immune response of the occupationally exposed individuals such as three-wheeler drivers, battery reconditioning workers and silver jewelery makers

  8. Intervention effects of supplying homeless individuals with permanent housing: a 3-year prospective study.

    Science.gov (United States)

    Fichter, M M; Quadflieg, N

    2006-01-01

    To describe the intervention effects of supplying homeless individuals with permanent housing. In a prospective study, 109 male and 20 female homeless individuals were assessed at baseline and at 1- and 3-year follow-up concerning mental illness (SCID-I), psychopathology, global assessment of functioning, emotional lability and alcohol consumption. A high proportion (86%) of the individuals was able to maintain or improve stability of housing. Only minor changes were observed concerning mental illness and global functioning. Extensive alcohol consumption and high psychopathology increased the risk of losing the stable housing. The placement of homeless individuals in board and care homes or community housing after social counselling seems to be a necessary measure to remedy homelessness. However, supplying more permanent housing is not sufficient to decisively improve mental health status.

  9. Dynamic modeling of vaccinating behavior as a function of individual beliefs.

    Directory of Open Access Journals (Sweden)

    Flávio Codeço Coelho

    2009-07-01

    Full Text Available Individual perception of vaccine safety is an important factor in determining a person's adherence to a vaccination program and its consequences for disease control. This perception, or belief, about the safety of a given vaccine is not a static parameter but a variable subject to environmental influence. To complicate matters, perception of risk (or safety does not correspond to actual risk. In this paper we propose a way to include the dynamics of such beliefs into a realistic epidemiological model, yielding a more complete depiction of the mechanisms underlying the unraveling of vaccination campaigns. The methodology proposed is based on Bayesian inference and can be extended to model more complex belief systems associated with decision models. We found the method is able to produce behaviors which approximate what has been observed in real vaccine and disease scare situations. The framework presented comprises a set of useful tools for an adequate quantitative representation of a common yet complex public-health issue. These tools include representation of beliefs as Bayesian probabilities, usage of logarithmic pooling to combine probability distributions representing opinions, and usage of natural conjugate priors to efficiently compute the Bayesian posterior. This approach allowed a comprehensive treatment of the uncertainty regarding vaccination behavior in a realistic epidemiological model.

  10. Global precedence effects account for individual differences in both face and object recognition performance

    DEFF Research Database (Denmark)

    Gerlach, Christian; Starrfelt, Randi

    2018-01-01

    There has been an increase in studies adopting an individual difference approach to examine visual cognition and in particular in studies trying to relate face recognition performance with measures of holistic processing (the face composite effect and the part-whole effect). In the present study we...... examine whether global precedence effects, measured by means of non-face stimuli in Navon’s paradigm, can also account for individual differences in face recognition and, if so, whether the effect is of similar magnitude for faces and objects. We find evidence that global precedence effects facilitate...... both face and object recognition, and to a similar extent. Our results suggest that both face and object recognition are characterized by a coarse-to-fine temporal dynamic, where global shape information is derived prior to local shape information, and that the efficiency of face and object recognition...

  11. An example of population-level risk assessments for small mammals using individual-based population models

    DEFF Research Database (Denmark)

    Schmitt, Walter; Auteri, Domenica; Bastiansen, Finn

    2016-01-01

    . However, further investigation and agreement are needed to develop recommendations for landscape attributes such as size, structure, and crop rotation to define appropriate regulatory risk assessment scenarios. Overall, the application of IBMs provides multiple advantages to higher tier ecological risk......This article presents a case study demonstrating the application of 3 individual-based, spatially explicit population models (IBMs, also known as agent-based models) in ecological risk assessments to predict long-term effects of a pesticide to populations of small mammals. The 3 IBMs each used...... and structural complexity. The toxicological profile of FungicideX was defined so that the deterministic long-term first tier risk assessment would result in high risk to small mammals, thus providing the opportunity to use the IBMs for risk assessment refinement (i.e., higher tier risk assessment). Despite...

  12. Caregiver Burden Among Caregivers of Individuals With Severe Mental Illness: Testing the Moderation and Mediation Models of Resilience.

    Science.gov (United States)

    Mulud, Zamzaliza Abdul; McCarthy, Geraldine

    2017-02-01

    The association between the socio-demographic characteristics of caregivers, such as gender and caregiver burden, is well documented; however, the process underlying this relationship is poorly understood. Based on the stress process model, we designed a cross-sectional study to examine the mediating and moderating effect of resilience on the relationship between gender and caregiver burden. Caregivers of individuals with severe mental illness (n=201) were recruited in two psychiatric outpatient clinics in Malaysia. The relationship between the gender of the caregiver and caregiver burden was mediated by resilience, thus supporting the stress process model. The findings from the present research contribute to the growing evidence of the interaction between socio-demographic variables of caregivers and resilience, and caregiver burden. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. The Effects of Individual Factors on the Formation of Cognitive Maps

    Directory of Open Access Journals (Sweden)

    Zahra Alinam

    2017-06-01

    Full Text Available Human’s weakened bond to residential areas, compromised identity and stability of residents in residential areas, have resulted in higher rate of transfer. Individual and collective understanding of the environment could be seen as a major force in shaping that environment through the action of human choices and behavior. In this regard, Cognitive maps are of great theoretical and practical importance for understanding how humans interact with their environment. This research is aimed to investigate the effects of the individual factors on the formation of cognitive maps in the neighborhood. Research seeks to answer the question: "How and to what extent the individual factors affect the cognitive and metal maps of the residents in the neighborhood?" Research is a combination of qualitative (interview and quantitative (questionnaire methods which is conducted on 297 residents of a neighborhood in the city of Tabriz. Results indicate that individual characteristics such as gender, age, occupational status, housing ownership status, length of residence, transport mode and duration of walking have a significant relationship within the formation of three components of cognitive map (landmark, route-road and survey knowledge. Educational status is the only variable that does not interact significantly with the cognition knowledge of the neighborhood. Achievement of this research is to introduce the effective individual factors in the formation of cognitive and mental image within the neighborhood and effectiveness rate of each in this process.

  14. Recognizing "me" benefits "we": Investigating the positive spillover effects of formal individual recognition in teams.

    Science.gov (United States)

    Li, Ning; Zheng, Xiaoming; Harris, T Brad; Liu, Xin; Kirkman, Bradley L

    2016-07-01

    Many organizations use formal recognition programs (e.g., "employee of the month") as a way to publically acknowledge an individual employee's outstanding performance and motivate continued high performance. However, it remains unclear whether emphasizing individual achievement in a team context is beneficial or detrimental for recipients' teammates and, by extension, the team as a whole. Drawing on a social influence perspective, we examine potential spillover effects of individual formal recognition programs in teams. We hypothesize that a single team member's recognition will produce positive spillover effects on other team members' performance, as well as overall team performance, via social influence processes, especially when the award recipient is located in a central position in a team. Findings from 2 lab experiments of 24 teams and 40 teams (Study 1 and Study 2, respectively) and a field experiment of 52 manufacturing teams (Study 3) reveal that formally recognizing a team member leads to positive changes in her/his teammates' individual and collective performance. Thus, formal social recognition programs can potentially provide a motivational effect beyond individual recipients. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  15. Modeling variability in air pollution-related health damages from individual airport emissions.

    Science.gov (United States)

    Penn, Stefani L; Boone, Scott T; Harvey, Brian C; Heiger-Bernays, Wendy; Tripodis, Yorghos; Arunachalam, Sarav; Levy, Jonathan I

    2017-07-01

    In this study, we modeled concentrations of fine particulate matter (PM 2.5 ) and ozone (O 3 ) attributable to precursor emissions from individual airports in the United States, developing airport-specific health damage functions (deaths per 1000t of precursor emissions) and physically-interpretable regression models to explain variability in these functions. We applied the Community Multiscale Air Quality model using the Decoupled Direct Method to isolate PM 2.5 - or O 3 -related contributions from precursor pollutants emitted by 66 individual airports. We linked airport- and pollutant-specific concentrations with population data and literature-based concentration-response functions to create health damage functions. Deaths per 1000t of primary PM 2.5 emissions ranged from 3 to 160 across airports, with variability explained by population patterns within 500km of the airport. Deaths per 1000t of precursors for secondary PM 2.5 varied across airports from 0.1 to 2.7 for NOx, 0.06 to 2.9 for SO 2 , and 0.06 to 11 for VOCs, with variability explained by population patterns and ambient concentrations influencing particle formation. Deaths per 1000t of O 3 precursors ranged from -0.004 to 1.0 for NOx and 0.03 to 1.5 for VOCs, with strong seasonality and influence of ambient concentrations. Our findings reinforce the importance of location- and source-specific health damage functions in design of health-maximizing emissions control policies. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Effects of Individual, Spousal, and Offspring Socioeconomic Status on Mortality Among Elderly People in China.

    Science.gov (United States)

    Yang, Lei; Martikainen, Pekka; Silventoinen, Karri

    2016-11-05

    The relationship between socio-economic status and health among elderly people has been well studied, but less is known about how spousal or offspring's education affects mortality, especially in non-Western countries. We investigated these associations using a large sample of Chinese elderly. The data came from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) from the years 2005 to 2011 (n = 15 355, aged 65-105 years at baseline; 5046 died in 2008, and 2224 died in 2011). Educational attainment, occupational status, and household income per capita were used as indicators of socio-economic status. Spousal and offspring's education were added into the final models. The Cox proportional hazards model was used to study mortality risk by gender. Adjusted for age, highly educated males and females had, on average, 29% and 37% lower mortality risk, respectively, than those with a lower education. Particularly among men, this effect was observed among those whose children had intermediate education only. A higher household income was also associated with lower mortality risk among the elderly. Male elderly living with a well-educated spouse (HR 0.79; 95% CI, 0.64-0.99) had a lower mortality risk than those living with a low-educated spouse. Both the socio-economic status of the individual and the educational level of a co-resident spouse or child are associated with mortality risk in elderly people. The socio-economic position of family members plays an important role in producing health inequality among elderly people.

  17. Effects of individual cohesion and patient interpersonal style on outcome in psychodynamically oriented inpatient group psychotherapy.

    Science.gov (United States)

    Dinger, Ulrike; Schauenburg, Henning

    2010-01-01

    The influence of patients' interpersonal traits in interaction with experienced individual cohesion (i.e., each patient's feeling of belonging to the group) was investigated in a sample of 327 inpatients with mixed diagnoses. High cohesion and an increase in cohesion emerged as predictive for symptom improvement in a multilevel regression model. This influence was moderated by the affiliation dimension: In dismissive patients, an increase of cohesion over the course of treatment was helpful; in affiliative patients, symptom improvement was correlated with a slight decrease of cohesion. The findings highlight the therapeutic importance of group therapy and point to the differential influence of individually experienced group cohesion.

  18. Modeling individual differences in text reading fluency: a different pattern of predictors for typically developing and dyslexic readers

    Directory of Open Access Journals (Sweden)

    Pierluigi eZoccolotti

    2014-11-01

    Full Text Available This study was aimed at predicting individual differences in text reading fluency. The basic proposal included two factors, i.e., the ability to decode letter strings (measured by discrete pseudo-word reading and integration of the various sub-components involved in reading (measured by Rapid Automatized Naming, RAN. Subsequently, a third factor was added to the model, i.e., naming of discrete digits. In order to use homogeneous measures, all contributing variables considered the entire processing of the item, including pronunciation time. The model, which was based on commonality analysis, was applied to data from a group of 43 typically developing readers (11- to 13-year-olds and a group of 25 chronologically matched dyslexic children. In typically developing readers, both orthographic decoding and integration of reading sub-components contributed significantly to the overall prediction of text reading fluency. The model prediction was higher (from ca. 37% to 52% of the explained variance when we included the naming of discrete digits variable, which had a suppressive effect on pseudo-word reading. In the dyslexic readers, the variance explained by the two-factor model was high (69% and did not change when the third factor was added. The lack of a suppression effect was likely due to the prominent individual differences in poor orthographic decoding of the dyslexic children. Analyses on data from both groups of children were replicated by using patches of colours as stimuli (both in the RAN task and in the discrete naming task obtaining similar results. We conclude that it is possible to predict much of the variance in text-reading fluency using basic processes, such as orthographic decoding and integration of reading sub-components, even without taking into consideration higher-order linguistic factors such as lexical, semantic and contextual abilities. The approach validity of using proximal vs distal causes to predict reading fluency is

  19. “Space, the Final Frontier”: How Good are Agent-Based Models at Simulating Individuals and Space in Cities?

    Directory of Open Access Journals (Sweden)

    Alison Heppenstall

    2016-01-01

    Full Text Available Cities are complex systems, comprising of many interacting parts. How we simulate and understand causality in urban systems is continually evolving. Over the last decade the agent-based modeling (ABM paradigm has provided a new lens for understanding the effects of interactions of individuals and how through such interactions macro structures emerge, both in the social and physical environment of cities. However, such a paradigm has been hindered due to computational power and a lack of large fine scale datasets. Within the last few years we have witnessed a massive increase in computational processing power and storage, combined with the onset of Big Data. Today geographers find themselves in a data rich era. We now have access to a variety of data sources (e.g., social media, mobile phone data, etc. that tells us how, and when, individuals are using urban spaces. These data raise several questions: can we effectively use them to understand and model cities as complex entities? How well have ABM approaches lent themselves to simulating the dynamics of urban processes? What has been, or will be, the influence of Big Data on increasing our ability to understand and simulate cities? What is the appropriate level of spatial analysis and time frame to model urban phenomena? Within this paper we discuss these questions using several examples of ABM applied to urban geography to begin a dialogue about the utility of ABM for urban modeling. The arguments that the paper raises are applicable across the wider research environment where researchers are considering using this approach.

  20. Is outdoor vector control needed for malaria elimination? An individual-based modelling study.

    Science.gov (United States)

    Zhu, Lin; Müller, Günter C; Marshall, John M; Arheart, Kristopher L; Qualls, Whitney A; Hlaing, WayWay M; Schlein, Yosef; Traore, Sekou F; Doumbia, Seydou; Beier, John C

    2017-07-03

    Residual malaria transmission has been reported in many areas even with adequate indoor vector control coverage, such as long-lasting insecticidal nets (LLINs). The increased insecticide resistance in Anopheles mosquitoes has resulted in reduced efficacy of the widely used indoor tools and has been linked with an increase in outdoor malaria transmission. There are considerations of incorporating outdoor interventions into integrated vector management (IVM) to achieve malaria elimination; however, more information on the combination of tools for effective control is needed to determine their utilization. A spatial individual-based model was modified to simulate the environment and malaria transmission activities in a hypothetical, isolated African village setting. LLINs and outdoor attractive toxic sugar bait (ATSB) stations were used as examples of indoor and outdoor interventions, respectively. Different interventions and lengths of efficacy periods were tested. Simulations continued for 420 days, and each simulation scenario was repeated 50 times. Mosquito populations, entomologic inoculation rates (EIRs), probabilities of local mosquito extinction, and proportion of time when the annual EIR was reduced below one were compared between different intervention types and efficacy periods. In the village setting with clustered houses, the combinational intervention of 50% LLINs plus outdoor ATSBs significantly reduced mosquito population and EIR in short term, increased the probability of local mosquito extinction, and increased the time when annual EIR is less than one per person compared to 50% LLINs alone; outdoor ATSBs alone significantly reduced mosquito population in short term, increased the probability of mosquito extinction, and increased the time when annual EIR is less than one compared to 50% LLINs alone, but there was no significant difference in EIR in short term between 50% LLINs and outdoor ATSBs. In the village setting with dispersed houses, the

  1. Individual Attitudes Towards Trade

    DEFF Research Database (Denmark)

    Jäkel, Ina Charlotte; Smolka, Marcel

    2013-01-01

    Using the 2007 wave of the Pew Global Attitudes Project, this paper finds statistically significant and economically large Stolper-Samuelson effects in individuals’ preference formation towards trade policy. High-skilled individuals are substantially more pro-trade than low-skilled individuals......-Ohlin model in shaping free trade attitudes, relative to existing literature....

  2. Modelling the dynamics and economics of health in individual dairy herds

    DEFF Research Database (Denmark)

    Enevoldsen, Carsten; Sørensen, J.T.

    1994-01-01

    -life problems for the dairy farmer and the practicing veterinarian. The veterinarian was able to supply detailed information concerning managerial routines applied on the farm. Epidemiologic analyses of the collected data produced input for herd-specific modelling of herd dynamic and economic effects...

  3. How will predicted land-use change affect waterfowl spring stopover ecology? Inferences from an individual-based model

    Science.gov (United States)

    Beatty, William; Kesler, Dylan C.; Webb, Elisabeth B.; Naylor, Luke W.; Raedeke, Andrew H.; Humburg, Dale D.; Coluccy, John M.; Soulliere, Gregory J.

    2017-01-01

    Habitat loss, habitat fragmentation, overexploitation and climate change pose familiar and new challenges to conserving natural populations throughout the world. One approach conservation planners may use to evaluate the effects of these challenges on wildlife populations is scenario planning.We developed an individual-based model to evaluate the effects of future land use and land cover changes on spring-migrating dabbling ducks in North America. We assessed the effects of three Intergovernmental Panel on Climate Change emission scenarios (A1B, A2 and B1) on dabbling duck stopover duration, movement distances and mortality. We specifically focused on migration stopover duration because previous research has demonstrated that individuals arriving earlier on the nesting grounds exhibit increased reproductive fitness.Compared to present conditions, all three scenarios increased stopover duration and movement distances of agent ducks.Although all three scenarios presented migrating ducks with increased amounts of wetland habitat, scenarios also contained substantially less cropland, which decreased overall carrying capacity of the study area.Synthesis and applications. Land-use change may increase waterfowl spring migration stopover duration in the midcontinent region of North America due to reduced landscape energetic carrying capacity. Climate change will alter spatial patterns of crop distributions with corn and rice production areas shifting to different regions. Thus, conservation planners will have to address population-level energetic implications of shifting agricultural food resources and increased uncertainty in yearly precipitation patterns within the next 50 years.

  4. Light Effects on Behavioural Performance Depend on the Individual State of Vigilance

    Science.gov (United States)

    Barba, Antonio; Padilla, Francisca

    2016-01-01

    Research has shown that exposure to bright white light or blue-enriched light enhances alertness, but this effect is not consistently observed in tasks demanding high-level cognition (e.g., Sustained Attention to Response Task—SART, which measures inhibitory control). Individual differences in sensitivity to light effects might be mediated by variations in the basal level of arousal. We tested this hypothesis by measuring the participants’ behavioural state of vigilance before light exposure, through the Psychomotor Vigilance Task. Then we compared the effects of a blue-enriched vs. dim light at nighttime on the performance of the auditory SART, by controlling for individual differences in basal arousal. The results replicated the alerting effects of blue-enriched light, as indexed by lower values of both proximal temperature and distal-proximal gradient. The main finding was that lighting effects on SART performance were highly variable across individuals and depended on their prior state of vigilance. Specifically, participants with higher levels of basal vigilance before light exposure benefited most from blue-enriched lighting, responding faster in the SART. These results highlight the importance of considering basal vigilance to define the boundary conditions of light effects on cognitive performance. Our study adds to current research delineating the complex and reciprocal interactions between lighting effects, arousal, cognitive task demands and behavioural performance. PMID:27820822

  5. Combining Individual-Based Modeling and Food Microenvironment Descriptions To Predict the Growth of Listeria monocytogenes on Smear Soft Cheese

    Science.gov (United States)

    Ferrier, Rachel; Hezard, Bernard; Lintz, Adrienne; Stahl, Valérie

    2013-01-01

    An individual-based modeling (IBM) approach was developed to describe the behavior of a few Listeria monocytogenes cells contaminating smear soft cheese surface. The IBM approach consisted of assessing the stochastic individual behaviors of cells on cheese surfaces and knowing the characteristics of their surrounding microenvironments. We used a microelectrode for pH measurements and micro-osmolality to assess the water activity of cheese microsamples. These measurements revealed a high variability of microscale pH compared to that of macroscale pH. A model describing the increase in pH from approximately 5.0 to more than 7.0 during ripening was developed. The spatial variability of the cheese surface characterized by an increasing pH with radius and higher pH on crests compared to that of hollows on cheese rind was also modeled. The microscale water activity ranged from approximately 0.96 to 0.98 and was stable during ripening. The spatial variability on cheese surfaces was low compared to between-cheese variability. Models describing the microscale variability of cheese characteristics were combined with the IBM approach to simulate the stochastic growth of L. monocytogenes on cheese, and these simulations were compared to bacterial counts obtained from irradiated cheeses artificially contaminated at different ripening stages. The simulated variability of L. monocytogenes counts with the IBM/microenvironmental approach was consistent with the observed one. Contrasting situations corresponding to no growth or highly contaminated foods could be deduced from these models. Moreover, the IBM approach was more effective than the traditional population/macroenvironmental approach to describe the actual bacterial behavior variability. PMID:23872572

  6. Modeling quantization effects in field effect transistors

    CERN Document Server

    Troger, C

    2001-01-01

    Numerical simulation in the field of semiconductor device development advanced to a valuable, cost-effective and flexible facility. The most widely used simulators are based on classical models, as they need to satisfy time and memory constraints. To improve the performance of field effect transistors such as MOSFETs and HEMTs these devices are continuously scaled down in their dimensions. Consequently the characteristics of such devices are getting more and more determined by quantum mechanical effects arising from strong transversal fields in the channel. In this work an approach based on a two-dimensional electron gas is used to describe the confinement of the carriers. Quantization is considered in one direction only. For the derivation of a one-dimensional Schroedinger equation in the effective mass framework a non-parabolic correction for the energy dispersion due to Kane is included. For each subband a non-parabolic dispersion relation characterized by subband masses and subband non-parabolicity coeffi...

  7. Environmental and Individual Determinants of Female Entrepreneurship in Algeria: Applying the Structural Equation Modeling

    Directory of Open Access Journals (Sweden)

    Abderrezzak BENHABIB

    2014-03-01

    Full Text Available On the basis of the seminal work of Fishbein and Ajzen (1975, we try  to clarify  how  individual  and  environment  factors  influence  the students’  attitudes towards Entrepreneurship and Entrepreneurial Intention. After a short review of literature, we present the results of an empirical study conducted among a sample of 290 final year students by using a structural  equation  modeling  validated  through  the  use  of  a  two-stage  analysis  of Anderson  and  Gerbing  (1988  and  a  factorial  confirmatory  analysis  and  a measurement adjustment (Hair et al.1998. Attitude driven from individual variables is negative while that derived from environmental  variables  is  positive.  Our  results  show  furthermore,  that  the  role  of media and institutions is still Limited and needs redeployment. Woman is now recognized as one of the  sources of  economic  growth  (Arasti  2008.  Although  female  entrepreneurship  is  attracting more and more researchers, it is still considered as an understudied field of research (De Bruin et al.2006, 2007; Brush, De Bruin, & Welter, 2009. Research  on  female  entrepreneurship  has  intensified since  the  early  80s,  but  few  have  explored  the  influence  of  environmental  and individual factors related to female entrepreneurship.

  8. Effects of sweeteners on individual feed intake characteristics and performance in group-housed weanling pigs

    NARCIS (Netherlands)

    Sterk, A.R.; Schlegel, P.; Mul, A.J.; Ubbink-Blanksma, M.; Bruininx, E.M.A.M.

    2008-01-01

    To assess the effects of 2 high intensity sodium saccharine based sweeteners on individual feed intake characteristics and performance of group-housed weaned pigs, 198 26-d-old weanling pigs were given ad libitum access to 3 dietary treatments: containing no additional sweetener (Control), 150 mg

  9. Individualism, Collectivism, Client Expression, and Counselor Effectiveness among South Korean International Students

    Science.gov (United States)

    Seo, Young Seok

    2010-01-01

    The present study examined how individualism, collectivism, and counselor emphasis of client expression (cognition vs. emotion) are related to perceived counselor effectiveness among South Korean international students. Data were collected through mail surveys from 127 South Korean international students attending a Midwestern university. As…

  10. Individualism, Collectivism, and Client Expression of Different Emotions: Their Relations to Perceived Counselor Effectiveness

    Science.gov (United States)

    Seo, Young Seok

    2011-01-01

    This study examined how individualism, collectivism, and counselor emphasis of different client emotions were related to perceived counselor effectiveness. Data were collected from 192 (122 women and 70 men) Korean students attending a large university in South Korea and from 170 (115 women and 55 men) American students attending a large…

  11. Prognostic profiles and the effectiveness of assisted conception: secondary analyses of individual patient data

    NARCIS (Netherlands)

    van den Boogaard, N. M.; Bensdorp, A. J.; Oude Rengerink, K.; Barnhart, K.; Bhattacharya, S.; Custers, I. M.; Coutifaris, C.; Goverde, A. J.; Guzick, D. S.; Hughes, E. C.; Factor-Litvak, P.; Steures, P.; Hompes, P. G. A.; van der Veen, F.; Mol, B. W. J.; Bossuyt, P.

    2014-01-01

    At present, it is unclear which treatment strategy is best for couples with unexplained or mild male subfertility. We hypothesized that the prognostic profile influences the effectiveness of assisted conception. We addressed this issue by analysing individual patient data (IPD) from randomized

  12. Energy Drink vs. Coffee: The Effects on Levels of Alertness in Fatigued Individuals

    Science.gov (United States)

    2013-06-01

    supplements, and energy drinks . Multiple studies have demonstrated the effectiveness of caffeine to increase alertness and improve cognitive...performance in sleep-deprived individuals. Energy drinks contain caffeine and sugar, similar to a soft drink , but there are additional nonregulated...TERMS Fatigue, alertness, stimulant, caffeine , energy drinks , coffee, aviation 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT

  13. The effect of combined antiretroviral therapy on the overall mortality of HIV-infected individuals

    NARCIS (Netherlands)

    Phillips, A. N.; Gilson, R.; Easterbrook, P.; Fisher, M.; Gazzard, B.; Johnson, M.; Walsh, J.; Leen, C.; Orkin, C.; Anderson, J.; Pillay, D.; Delpech, V.; Schwenk, A.; Dunn, D.; Gompels, M.; Hill, T.; Porter, K.; Babiker, A.; Sabin, C.; Waters, A.; Crates, D.; Mohamed-Saad, S.; Perry, N.; Pullin, A.; Churchill, D.; Harris, W.; Nelson, M.; Asboe, D.; Bulbeck, S.; Mandalia, S.; Clarke, J.; Dodds, J.; Rider, A.; Youle, M.; Lampe, F.; Smith, C.; Gumley, H.; Chaloner, C.; Ismajani, D.; Weber, J.; Cashin, S.; Kemble, C.; Mackie, N.; Thomas, R.; Jones, K.; Gann, S.; Wilson, A.; Ainsworth, J.; de Wolf, F.; Bezemer, D. O.; Gras, L. A. J.; Kesselring, A. M.; van Sighem, A. I.; Smit, C.; Zhang, S.; Zaheri, S.; Prins, J. M.; Bos, J. C.; Eeftinck-Schattenkerk, J. K. M.; Geerlings, S. E.; Godfried, M. H.; Lange, J. M. A.; van der Meer, J. T. M.; Nellen, F. J. B.; Olszyna, D. P.; van der Poll, M.; Reiss, P.; Sankatsing, S. U. C.; Steingrover, R.; van der Valk, M.; Vermeulen, J. N.; Vrouenraets, S. M. E.; van Vugt, M.; Wit, F. W. M. N.; Schreij, G.; van der Geest, S.; Oude Lashof, A.; Lowe, S.; Verbon, A.; Kuijpers, T. W.; Pajkrt, D.; Scherpbier, H. J.; van der Ende, M. E.; Bax, H.; van der Feltz, M.; Gelinck, L. B. S.; Nouwen, J. L.; Rijnders, B. J. A.; de Ruiter, E. D.; Slobbe, L.; Schurink, C. A. M.; de Vries, T. E. M. S.; Driessen, G.; van der Flier, M.; Hartwig, N. G.; Branger, J.; Kauffmann, R. H.; Schippers, E. F.; Groeneveld, P. H. P.; Alleman, M. A.; ten Kate, R. W.; Soetekouw, R.; Kroon, F. P.; Arend, S. M.; de Boer, M. G. J.; van den Broek, P. J.; van Dissel, J. T.; van Nieuwkoop, C.; den Hollander, J. G.; Bronsveld, W.; Vriesendorp, R.; Jeurissen, F. J. F.; Leyten, E. M. S.; van Houte, D.; Polée, M. B.; ten Napel, C. H. H.; Kootstra, G. J.; Brinkman, K.; van den Berk, G. E. L.; Blok, W. L.; Frissen, P. H. J.; Schouten, W. E. M.; van Eeden, A.; Verhagen, D. W. M.; Mulder, J. W.; van Gorp, E. C. M.; Mairuhu, A. T. A.; Wagenaar, J.; Juttmann, J. R.; van Kasteren, M. E. E.; Veenstra, J.; Vasmel, W. L. E.; Koopmans, P. P.; Brouwer, A. M.; Dofferhoff, A. S. M.; de Groot, R.; ter Hofstede, H. J. M.; Keuter, M.; van der Ven, A. J. A. M.; Sprenger, H. G.; van Assen, S.; van Leeuwen, J. T. M.; Stek, C. J.; Doedens, R.; Scholvinck, E. H.; Hoepelman, I. M.; Schneider, M. M. E.; Bonten, M. J. M.; Ellerbroek, P. M.; Jaspers, C. A. J. J.; Maarschalk-Ellerbroek, L. J.; Oosterheert, J. J.; Peters, E. J. G.; Mudrikova, T.; Wassenberg, M. W. M.; Weijer, S.; Geelen, S. P. M.; Wolfs, T. F. W.; Danner, S. A.; van Agtmael, M. A.; Bierman, W. F. W.; Claessen, F. A. P.; Hillebrand, M. E.; de Jong, E. V.; Kortmann, W.; Perenboom, R. M.; bij de Vaate, E. A.; Richter, C.; van der Berg, J.; Gisolf, E. H.; Tanis, A. A.; Duits, A. J.; Winkel, K.; Elisabeth, S. T.; Abgrall, S.; Barin, F.; Bentata, M.; Billaud, E.; Boué, F.; Burty, C.; Cabié, A.; Costagliola, D.; Cotte, L.; de Truchis, P.; Duval, X.; Duvivier, C.; Enel, P.; Fredouille-Heripret, L.; Gasnault, J.; Gaud, C.; Gilquin, J.; Grabar, S.; Katlama, C.; Khuong, M. A.; Lang, J. M.; Lascaux, A. S.; Launay, O.; Mahamat, A.; Mary-Krause, M.; Matheron, S.; Meynard, J. L.; Pavie, J.; Pialoux, G.; Pilorgé, F.; Poizot-Martin, I.; Pradier, C.; Reynes, J.; Rouveix, E.; Simon, A.; Tattevin, P.; Tissot-Dupont, H.; Viard, J. P.; Viget, N.; Salomon, Valérie; Jacquemet, N.; Guiguet, M.; Lanoy, E.; Liévre, L.; Selinger-Leneman, H.; Lacombe, J. M.; Potard, V.; Bricaire, F.; Herson, S.; Desplanque, N.; Girard, P. M.; Meyohas, M. C.; Picard, O.; Cadranel, J.; Mayaud, C.; Clauvel, J. P.; Decazes, J. M.; Gerard, L.; Molina, J. M.; Diemer, M.; Sellier, P.; Honoré, P.; Jeantils, V.; Tassi, S.; Mechali, D.; Taverne, B.; Berthé, H.; Dupont, C.; Chandemerle, C.; Mortier, E.; Tisne-Dessus, D.; Weiss, L.; Salmon, D.; Auperin, I.; Roudière, L.; Fior, R.; Delfraissy, J. F.; Goujard, C.; Jung, C.; Lesprit, P. H.; Vittecoq, D.; Fraisse, P.; Rey, D.; Beck-Wirth, G.; Stahl, J. P.; Lecercq, P.; Gourdon, F.; Laurichesse, H.; Fresard, A.; Lucht, F.; Bazin, C.; Verdon, R.; Chavanet, P.; Arvieux, C.; Michelet, C.; Choutet, P.; Goudeau, A.; Maître, M. F.; Hoen, B.; Eglinger, P.; Faller, J. P.; Borsa-Lebas, F.; Caron, F.; Daures, J. P.; May, T.; Rabaud, C.; Berger, J. L.; Rémy, G.; Arlet-Suau, E.; Cuzin, L.; Massip, P.; Legrand, M. F. Thiercelin; Pontonnier, G.; Yasdanpanah, Y.; Dellamonica, P.; Pugliese, P.; Aleksandrowicz, K.; Quinsat, D.; Ravaux, I.; Delmont, J. P.; Moreau, J.; Gastaut, J. A.; Retornaz, F.; Soubeyrand, J.; Galinier, A.; Ruiz, J. M.; Allegre, T.; Blanc, P. A.; Bonnet-Montchardon, D.; Lepeu, G.; Granet-Brunello, P.; Esterni, J. P.; Pelissier, L.; Cohen-Valensi, R.; Nezri, M.; Chadapaud, S.; Laffeuillade, A.; Raffi, F.; Boibieux, A.; Peyramond, D.; Livrozet, J. M.; Touraine, J. L.; Trepo, C.; Strobel, M.; Bissuel, F.; Pradinaud, R.; Sobesky, M.; Contant, M.; Aebi, C.; Battegay, M.; Bernasconi, E.; Böni, J.; Brazzola, P.; Bucher, H. C.; Bürgisser, P. H.; Calmy, A.; Cattacin, S.; Cavassini, M.; Cheseaux, J.-J.; Drack, G.; Dubs, R.; Egger, M.; Elzi, L.; Fischer, M.; Flepp, M.; Fontana, A.; Francioli, P.; Furrer, H. J.; Fux, C.; Gayet-Ageron, A.; Gerber, S.; Gorgievski, M.; Günthard, H.; Gyr, T. H.; Hirsch, H.; Hirschel, B.; Hösli, I.; Hüsler, M.; Kaiser, L.; Kahlert, C. H.; Karrer, U.; Kind, C.; Klimkait, T. H.; Ledergerber, B.; Martinetti, G.; Martinez, B.; Müller, N.; Nadal, D.; Paccaud, F.; Pantaleo, G.; Raio, L.; Rauch, A.; Regenass, S.; Rickenbach, M.; Rudin, C.; Schmid, P.; Schultze, D.; Schüpbach, J.; Speck, R.; Taffé, P.; Telenti, A.; Trkola, A.; Vernazza, P.; Weber, R.; Wyler, C.-A.; Yerly, S.; Casabona, J.; Miró, J. M.; Alquézar, A.; Isern, V.; Esteve, A.; Podzamczer, D.; Murillas, J.; Gatell, J. M.; Agüero, F.; Tural, C.; Clotet, B.; Ferrer, E.; Riera, M.; Segura, F.; Navarro, G.; Force, L.; Vilaró, J.; Masabeu, A.; García, I.; Guadarrama, M.; Romero, A.; Agustí, C.; Montoliu, A.; Ortega, N.; Lazzari, E.; Puchol, E.; Sanchez, M.; Blanco, J. L.; Garcia-Alcaide, F.; Martínez, E.; López-Dieguez, M.; García-Goez, J. F.; Sirera, G.; Romeu, J.; Jou, A.; Negredo, E.; Miranda, C.; Capitan, M. C.; Olmo, M.; Barragan, P.; Saumoy, M.; Bolao, F.; Cabellos, C.; Peña, C.; Sala, M.; Cervantes, M.; Amengual, M. J.; Navarro, M.; Penelo, E.; Berenguer, J.; del Amo, J.; García, F.; Gutiérrez, F.; Labarga, P.; Moreno, S.; Muñoz, M. A.; Caro-Murillo, A. M.; Sobrino, P.; Jarrín, I.; Sirvent, J. L. Gómez; Rodríguez, P.; Alemán, M. R.; Alonso, M. M.; López, A. M.; Hernández, M. I.; Soriano, V.; Barreiro, P.; Medrano, J.; Rivas, P.; Herrero, D.; Blanco, F.; Vispo, M. E.; Martín, L.; Ramírez, G.; de Diego, M.; Rubio, R.; Pulido, F.; Moreno, V.; Cepeda, C.; Hervás, R. I.; Iribarren, J. A.; Arrizabalaga, J.; Aramburu, M. J.; Camino, X.; Rodríguez-Arrondo, F.; von Wichmann, M. A.; Pascual, L.; Goenaga, M. A.; Masiá, M.; Ramos, J. M.; Padilla, S.; Sánchez-Hellín, V.; Bernal, E.; Escolano, C.; Montolio, F.; Peral, Y.; López, J. C.; Miralles, P.; Cosín, J.; Sánchez, M.; Gutiérrez, I.; Ramírez, M.; Padilla, B.; Vidal, F.; Sanjuan, M.; Peraire, J.; Veloso, S.; Viladés, C.; López-Dupla, M.; Olona, M.; Vargas, M.; Aldeguer, J. L.; Blanes, M.; Lacruz, J.; Salavert, M.; Montero, M.; Cuéllar, S.; de los Santos, I.; Sanz, J.; Oteo, J. A.; Blanco, J. R.; Ibarra, V.; Metola, L.; Sanz, M.; Pérez-Martínez, L.; Sola, J.; Uriz, J.; Castiello, J.; Reparaz, J.; Arriaza, M. J.; Irigoyen, C.; Antela, A.; Casado, J. L.; Dronda, F.; Moreno, A.; Pérez, M. J.; López, D.; Gutiérrez, C.; Hernández, B.; Pumares, M.; Martí, P.; García, L.; Page, C.; Hernández, J.; Peña, A.; Muñoz, L.; Parra, J.; Viciana, P.; Leal, M.; López-Cortés, L. F.; Trastoy, M.; Mata, R.; Justice, A. C.; Fiellin, D. A.; Rimland, D.; Jones-Taylor, C.; Oursler, K. A.; Titanji, R.; Brown, S.; Garrison, S.; Rodriguez-Barradas, M.; Masozera, N.; Goetz, M.; Leaf, D.; Simberkoff, M.; Blumenthal, D.; Leung, J.; Butt, A.; Hoffman, E.; Gibert, C.; Peck, R.; Mattocks, K.; Braithwaite, S.; Brandt, C.; Bryant, K.; Cook, R.; Conigliaro, J.; Crothers, K.; Chang, J.; Crystal, S.; Day, N.; Erdos, J.; Freiberg, M.; Kozal, M.; Gandhi, N.; Gaziano, M.; Gerschenson, M.; Good, B.; Gordon, A.; Goulet, J. L.; Hernán, M. A.; Kraemer, K.; Lim, J.; Maisto, S.; Miller, P.; Mole, L.; O'Connor, P.; Papas, R.; Robins, J. M.; Rinaldo, C.; Roberts, M.; Samet, J.; Tierney, B.; Whittle, J.; Phillips, A.; Brettle, R.; Darbyshire, J.; Fidler, S.; Goldberg, D.; Hawkins, D.; Jaffe, H.; McLean, K.; Porter, Kholoud; Cursley, Adam; Ewings, Fiona; Fairbrother, Keith; Gnatiuc, Louisa; Lodi, Sara; Murphy, Brendan; Douglas, G.; Kennedy, N.; Pritchard, J.; Andrady, U.; Gwynedd, Ysbyty; Rajda, N.; Maw, R.; McKernan, S.; Drake, S.; Gilleran, G.; White, D.; Ross, J.; Toomer, S.; Hewart, R.; Wilding, H.; Woodward, R.; Dean, G.; Heald, L.; Horner, P.; Glover, S.; Bansaal, D.; Eduards, S.; Carne, C.; Browing, M.; Das, R.; Stanley, B.; Estreich, S.; Magdy, A.; O'Mahony, C.; Fraser, P.; Hayman, B.; Jebakumar, S. P. R.; Joshi, U.; Ralph, S.; Wade, A.; Mette, R.; Lalik, J.; Summerfield, H.; El-Dalil, A.; France, A. J.; White, C.; Robertson, R.; Gordon, S.; McMillan, S.; Morris, S.; Lean, C.; Vithayathil, K.; McLean, L.; Winter, A.; Gale, D.; Jacobs, S.; Tayal, S.; Short, L.; Green, S.; Williams, G.; Sivakumar, K.; Bhattacharyya, D. N.; Monteiro, E.; Minton, J.; Dhar, J.; Nye, F.; DeSouza, C. B.; Isaksen, A.; McDonald, L.; Franca, A.; William, L.; Jendrulek, I.; Shaunak, S.; El-Gadi, S.; Easterbrook, P. J.; Mazhude, C.; Johnstone, R.; Fakoya, A.; Mchale, J.; Kegg, S.; Mitchell, S.; Byrne, P.; Rice, P.; Mullaney, S. A.; McCormack, S.; David, D.; Melville, R.; Phillip, K.; Balachandran, T.; Mabey-Puttock, S.; Sukthankar, A.; Murphy, C.; Wilkins, E.; Ahmad, S.; Haynes, J.; Evans, E.; Ong, E.; Grey, R.; Meaden, J.; Bignell, C.; Loay, D.; Peacock, K.; Girgis, M. R.; Morgan, B.; Palfreeman, A.; Wilcox, J.; Tobin, J.; Tucker, L.; Saeed, A. M.; Chen, F.; Deheragada, A.; Williams, O.; Lacey, H.; Herman, S.; Kinghorn, D.; Devendra, S. V.; Wither, J.; Dawson, S.; Rowen, D.; Harvey, J.; Bridgwood, A.; Singh, G.; Chauhan, M.; Kellock, D.; Young, S.; Dannino, S.; Kathir, Y.; Rooney, G.; Currie, J.; Fitzgerald, M.; Devendra, S.; Keane, F.; Booth, G.; Green, T.; Arumainayyagam, J.; Chandramani, S.; Rajamanoharan, S.; Robinson, T.; Curless, E.; Gokhale, R.; Tariq, A.; Luzzi, G.; Fairley, I.; Wallis, F.; Smit, E.; Ward, F.; Morlat, P.; Bonarek, M.; Bonnet, F.; Nouts, C.; Louis, J.; Reliquet, V.; Sauser, F.; Biron, C.; Mounoury, O.; Hue, H.; Brosseau, D.; Ghosn, J.; Rannou, M. T.; Bergmann, J. F.; Badsi, E.; Rami, A.; Parrinello, M.; Samanon-Bollens, D.; Campa, P.; Tourneur, M.; Desplanques, N.; Jeanblanc, F.; Chiarello, P.; Makhloufi, D.; Blanc, A. P.; Allègre, T.; Baillat, V.; Lemoing, V.; de Boever, C. Merle; Tramoni, C.; Sobesky, G.; Abel, S.; Beaujolais, V.; Slama, L.; Chakvetadze, C.; Berrebi, V.; Yeni, P.; Bouvet, E.; Fournier, I.; Gerbe, J.; Koffi, K.; Augustin-Normand, C.; Miailhes, P.; Thoirain, V.; Brochier, C.; Souala, F.; Ratajczak, M.; Beytoux, J.; Jacomet, C.; Morelon, S.; Olivier, C.; Lortholary, O.; Dupont, B.; Maignan, A.; Ragnaud, J. M.; Raymond, I.; Leport, C.; Jadand, C.; Jestin, C.; Longuet, P.; Boucherit, S.; Sereni, D.; Lascoux, C.; Prevoteau, F.; Sobel, A.; Levy, Y.; Lelièvre, J. D.; Dominguez, S.; Dumont, C.; Aumaître, H.; Delmas, B.; Saada, M.; Medus, M.; Guillevin, L.; Tahi, T.; Yazdanpanah, Y.; Pavel, S.; Marien, M. C.; Drenou, B.; Beck, C.; Benomar, M.; Tubiana, R.; Mohand, H. Ait; Chermak, A.; Abdallah, S. Ben; Touam, F.; Drobacheff, C.; Folzer, A.; Obadia, M.; Prudhomme, L.; Bonnet, E.; Balzarin, F.; Pichard, E.; Chennebault, J. M.; Fialaire, P.; Loison, J.; Galanaud, P.; Bornarel, D.; Six, M.; Ferret, P.; Batisse, D.; Gonzales-Canali, G.; Devidas, A.; Chevojon, P.; Turpault, I.; Lafeuillade, A.; Cheret, A.; Philip, G.; Morel, P.; Timsit, J.; Amirat, N.; Brancion, C.; Cabane, J.; Tredup, J.; Stein, A.; Ravault, I.; Chavanet, C.; Buisson, M.; Treuvetot, S.; Nau, P.; Bastides, F.; Boyer, L.; Wassoumbou, S.; Oksenhendeler, E.; Gérard, L.; Bernard, L.; Domart, Y.; Merrien, D.; Belan, A. Greder; Gayraud, M.; Bodard, L.; Meudec, A.; Beuscart, C.; Daniel, C.; Pape, E.; Vinceneux, P.; Simonpoli, A. M.; Zeng, A.; Fournier, L.; Fuzibet, J. G.; Sohn, C.; Rosenthal, E.; Quaranta, M.; Chaillou, S.; Sabah, M.; Audhuy, B.; Schieber, A.; Moreau, P.; Niault, M.; Vaillant, O.; Huchon, G.; Compagnucci, A.; Szmania, I. De Lacroix; Richier, L.; Lamaury, I.; Saint-Dizier, F.; Garipuy, D.; Drogoul, M. P.; Martin, I. Poizot; Fabre, G.; de Cursay, G. Lambert; Abraham, B.; Perino, C.; Lagarde, P.; David, F.; Roche-Sicot, J.; Saraux, J. L.; Leprêtre, A.; Fampin, B.; Uludag, A.; Morin, A. S.; Bletry, O.; Zucman, D.; Regnier, A.; Girard, J. J.; Quinsat, D. T.; Heripret, L.; Grihon, F.; Houlbert, D.; Ruel, M.; Chemlal, K.; Debab, Y.; Tremollieres, F.; Perronne, V.; Slama, B.; Perré, P.; Miodovski, C.; Guermonprez, G.; Dulioust, A.; Boudon, P.; Malbec, D.; Patey, O.; Semaille, C.; Deville, J.; Remy, G.; Béguinot, I.; Boue, F.; Chambrin, V.; Pignon, C.; Estocq, G. A.; Levy, A.; Duracinsky, M.; Le Bras, P.; Ngussan, M. S.; Peretti, D.; Medintzeff, N.; Lambert, T.; Segeral, O.; Lezeau, P.; Laurian, Y.; Piketty, C.; Karmochkine, M.; Eliaszewitch, M.; Jayle, D.; Tisne- Dessus, D.; Kazatchkine, M.; Colasante, U.; Nouaouia, W.; Vilde, J. L.; Bollens, D.; Binet, D.; Diallo, B.; Fonquernie, L.; Lagneau, J. L.; Pietrie, M. P.; Sicard, D.; Stieltjes, N.; Michot, J.; Bourdillon, F.; Lelievre, J. D.; Obenga, G.; Escaut, L.; Bolliot, C.; Schneider, L.; Iguertsira, M.; Tomei, C.; Dhiver, C.; Dupont, H. Tissot; Vallon, A.; Gallais, J.; Gallais, H.; Durant, J.; Mondain, V.; Perbost, I.; Cassuto, J. P.; Karsenti, J. M.; Venti, H.; Ceppi, C.; Krivitsky, J. A.; Bouchaud, O.; Honore, P.; Delgado, J.; Rouzioux, C.; Burgard, M.; Boufassa, L.; Peynet, J.; Hoyos, S. Pérez; Ferreros, I.; Hurtado, I.; González, C.; Caro, A. M.; Muga, R.; Sanvicens, A.; Tor, J.; del Romero, J.; Raposo, P.; Rodríguez, C.; García, Soledad; Alastrue, I.; Belda, J.; Trullen, P.; Fernández, E.; Santos, C.; Tasa, T.; Zafra, T.; Guerrero, R.; Marco, A.; Quintana, M.; Ruiz, I.; Nuñez, R.; Pérez, R.; Castilla, J.; Guevara, M.; de Mendoza, C.; Zahonero, N.

    2010-01-01

    OBJECTIVE: To estimate the effect of combined antiretroviral therapy (cART) on mortality among HIV-infected individuals after appropriate adjustment for time-varying confounding by indication. DESIGN: A collaboration of 12 prospective cohort studies from Europe and the United States (the HIV-CAUSAL

  14. Effects of Presentation Mode on Veridical and False Memory in Individuals with Intellectual Disability

    Science.gov (United States)

    Carlin, Michael; Toglia, Michael P.; Belmonte, Colleen; DiMeglio, Chiara

    2012-01-01

    In the present study the effects of visual, auditory, and audio-visual presentation formats on memory for thematically constructed lists were assessed in individuals with intellectual disability and mental age-matched children. The auditory recognition test included target items, unrelated foils, and two types of semantic lures: critical related…

  15. The effect of training on cardiovascular responses to arm exercise in individuals with tetraplegia

    NARCIS (Netherlands)

    Hopman, M T; Dallmeijer, A J; Snoek, G; van der Woude, L H

    1996-01-01

    The aim of this study was to investigate the physiological responses to maximal and submaximal arm-cranking exercise in 21 individuals with tetraplegia (TP) and to evaluate the effect of a 3 and 6-month training period (mean frequency of 1.5 h.week-1, mean intensity at 35% of the training time above

  16. The Effect of Vibration on Postural Response of Down Syndrome Individuals on the Seesaw

    Science.gov (United States)

    Carvalho, Regiane Luz; Almeida, Gil Lucio

    2009-01-01

    In order to better understand the role of proprioception in postural adjustments on unstable surfaces, we analyzed the effect of vibration on the pattern of muscle activity and joint displacements (ankle, knee and hip) of eight intellectually normal participants (control group-CG) and eight individuals with Down syndrome (DS) while balancing on…

  17. Developing teacher sensitivity to individual learning differences (ILDs) : Studies on increasing teacher effectiveness

    NARCIS (Netherlands)

    Rosenfeld, M.N.

    2008-01-01

    Effective teachers are sensitive to individual learning differences (ILDs). This dissertation investigates teacher changes as a result of eight long-term professional development (PD) courses (56-hours and 28-hours) designed to help them become more sensitive to ILDs. In these courses, the

  18. Supporting Individuals with Fetal Alcohol Spectrum Disorders:a Summary of Effective Practices

    Science.gov (United States)

    Riggie, Jennifer; Xu, Tingting

    2013-01-01

    Fetal alcohol spectrum disorder (FASD) is a lifelong condition that significantly affects the individual's learning, development, behavior, family, and quality of life. Diagnosing children with this condition and providing effective supports is challenging for professionals because little intervention research has been performed with the…

  19. Effect of Rehabilitation Technology Services on Vocational Rehabilitation Outcomes of Individuals with Multiple Sclerosis

    Science.gov (United States)

    Chiu, Chung-Yi; Tansey, Timothy N.; Chan, Fong; Strauser, David; Frain, Michael P.; Arora, Simran

    2015-01-01

    Objectives: To examine the effect of rehabilitation technology interventions on the employment or job retention outcomes of individuals with multiple sclerosis (MS) served by the state-federal vocational rehabilitation program using a case-control study design. Participants: Data for this study were extracted from the Rehabilitation Services…

  20. The effects of physiotherapy for female urinary incontinence: individual compared with group treatment.

    NARCIS (Netherlands)

    Janssen, C.C.M.; Lagro-Janssen, A.L.M.; Felling, A.J.A.

    2001-01-01

    OBJECTIVES: To compare, in a randomized trial, the effects of individual and group physiotherapy for urinary incontinence in women referred by their general practitioner (GP). PATIENTS AND METHODS: The study included women of all ages (mean 47.8 years) with stress, urge or mixed incontinence; 126

  1. The effects of physiotherapy for female urinary incontinence: individual compared with group treatment

    NARCIS (Netherlands)

    Janssen, C.C.M.; Lagro-Janssen, A.L.M.; Felling, A.J.A.

    2001-01-01

    OBJECTIVES: To compare, in a randomized trial, the effects of individual and group physiotherapy for urinary incontinence in women referred by their general practitioner (GP). PATIENTS AND METHODS: The study included women of all ages (mean 47.8 years) with stress, urge or mixed incontinence; 126

  2. Individuation instructions decrease the Cross-Race Effect in a face matching task

    Directory of Open Access Journals (Sweden)

    2015-09-01

    Conclusions: Individuation instructions are an effective moderator of the CRE even within a face matching paradigm. Since unfamiliar face matching tasks most closely simulate document verification tasks, specifically passport screening, instructional techniques such as these may improve task performance within applied settings of significant practical importance.

  3. Optimize Knowledge Sharing, Team Effectiveness, and Individual Learning within the Flipped Team-Based Classroom

    Science.gov (United States)

    Huang, Chung-Kai; Lin, Chun-Yu; Lin, Zih-Cin; Wang, Cui; Lin, Chia-Jung

    2017-01-01

    Due to the competitive and fast-changing nature of external business environments, university students should acquire knowledge of how to cooperate, share knowledge, and enhance team effectiveness and individual learning in the future workplace. Consequently, the redesign of business courses in higher education merits more discussion. Based on the…

  4. The Effects of Diversity Management on Job Satisfaction and Individual Performance of Teachers

    Science.gov (United States)

    Ordu, Aydan

    2016-01-01

    In this research, the effects of teachers' perceptions of the diversity management on their job satisfaction and individual performance were examined. Teachers who are working in public high schools during 2014 to 2015 academic year constituted the study group of the research. The data of the research in which quantitative method used were…

  5. Effects of Situated Learning on Students' Knowledge Acquisition: An Individual Differences Perspective

    Science.gov (United States)

    Zheng, Robert

    2010-01-01

    This study focuses on the effects of situated learning on students' knowledge acquisition by investigating the influence of individual differences in such learning. Seventy-nine graduates were recruited from an educational department and were assigned to situated learning and traditional learning based on a randomized block design. Results…

  6. A Standardized Mean Difference Effect Size for Multiple Baseline Designs across Individuals

    Science.gov (United States)

    Hedges, Larry V.; Pustejovsky, James E.; Shadish, William R.

    2013-01-01

    Single-case designs are a class of research methods for evaluating treatment effects by measuring outcomes repeatedly over time while systematically introducing different condition (e.g., treatment and control) to the same individual. The designs are used across fields such as behavior analysis, clinical psychology, special education, and…

  7. Cognitive behavioral therapy age effects in child and adolescent anxiety : An individual patient data metaanalysis

    NARCIS (Netherlands)

    Bennett, Kathryn; Manassis, Katharina; Walter, Stephen D.; Cheung, Amy; Wilansky-Traynor, Pamela; Diaz-Granados, Natalia; Duda, Stephanie; Rice, Maureen; Baer, Susan; Barrett, Paula; Bodden, Denise; Cobham, Vanessa E.; Dadds, Mark R.; Flannery-Schroeder, Ellen; Ginsburg, Golda; Heyne, David; Hudson, Jennifer L.; Kendall, Philip C.; Liber, Juliette; Warner, Carrie Masia; Mendlowitz, Sandra; Nauta, Maaike H.; Rapee, Ronald M.; Silverman, Wendy; Siqueland, Lynne; Spence, Susan H.; Utens, Elisabeth; Wood, Jeffrey J.

    Background Investigations of age effects on youth anxiety outcomes in randomized trials (RCTs) of cognitive behavior therapy (CBT) have failed to yield a clear result due to inadequate statistical power and methodologic weaknesses. We conducted an individual patient data metaanalysis to address this

  8. Examination of Effects of Regular Sports Training on Individual Skills in Trainable Children with Autism

    Science.gov (United States)

    Akyüz, Murat; Odabas, Cansu; Akyüz, Öznur; Dogru, Yeliz; Senel, Ömer; Tas, Murat; Besikçi, Tolga

    2016-01-01

    Purpose: The aim of this study is to examine the effects of regular sport training implemented at Integrated Disabled Athlete Department on autistic children's adolescence development of individual abilities as motor proficiencies. Method: The subject group of this study is composed of 12 boys with autism who practiced physical education programs…

  9. Individual taper models for natural cedar and Taurus fir mixed stands of Bucak Region, Turkey

    Directory of Open Access Journals (Sweden)

    Ramazan Özçelik

    2017-11-01

    Full Text Available In this study, we assessed the performance of different types of taper equations for predicting tree diameters at specific heights and total stem volumes for mixed stands of Taurus cedar (Cedrus libani A. Rich. and Taurus fir (Abies cilicica Carr.. We used data from mixed stands containing a total of 131 cedar and 124 Taurus fir trees. We evaluated six commonly used and well-known forestry taper functions developed by a variety of researchers (Biging (1984, Zakrzewski (1999, Muhairwe (1999, Fang et al. (2000, Kozak (2004, and Sharma and Zhang (2004. To address problems related to autocorrelation and multicollinearity in the hierarchical data associated with the construction of taper models, we used appropriate statistical procedures for the model fitting. We compared model performances based on the analysis of three goodness-of-fit statistics and found the compatible segmented model of Fang et al. (2000 to be superior in describing the stem profile and stem volume of both tree species in mixed stands. The equation used by Zakrzewski (1999 exhibited the poorest fitting results of the three taper equations. In general, we found segmented taper equations to provide more accurate predictions than variable-form models for both tree species. Results from the non-linear extra sum of squares method indicate that stem tapers differ among tree species in mixed stands. Therefore, a different taper function should be used for each tree species in mixed stands in the Bucak district. Using individual-specific taper equations yields more robust estimations and, therefore, will enhance the prediction accuracy of diameters at different heights and volumes in mixed stands.

  10. Joint modelling of longitudinal 3MS scores and the risk of mortality among cognitively impaired individuals.

    Directory of Open Access Journals (Sweden)

    Chris B Guure

    Full Text Available Modified Mini-Mental State Examination (3MS is an instrument administered by trained personnel to examine levels of participants' cognitive function. However, the association between changes in scores over time and the risk of death (mortality is not known. The aims of this study are to examine the association between 3MS scores and mortality via cognitive impairment among older women and to determine individuals' risk of changes in scores to better predict their survival and mortality rates.We propose a Bayesian joint modelling approach to determine mortality due to cognitive impairment via repeated measures of 3MS scores trajectories over a 21-year follow-up period. Data for this study are taken from the Osteoporotic Fracture longitudinal study among women aged 65+ which started in 1986-88.The standard relative risk model from the analyses with a baseline 3MS score after adjusting for all the significant covariates demonstrates that, every unit decrease in a 3MS score corresponds to a non-significant 1.059 increase risk of mortality with a 95% CI of (0.981, 1.143, while the extended model results in a significant 0.09% increased risk in mortality. The joint modelling approach found a strong association between the 3MS scores and the risk of mortality, such that, every unit decrease in 3MS scores results in a 1.135 (13% increased risk of death via cognitive impairment with a 95% CI of (1.056, 1.215.It has been demonstrated that a decrease in 3MS results has a significant increase risk of mortality due to cognitive impairment via joint modelling, but insignificant when considered under the standard relative risk approach.

  11. Interpreting "Personality" Taxonomies: Why Previous Models Cannot Capture Individual-Specific Experiencing, Behaviour, Functioning and Development. Major Taxonomic Tasks Still Lay Ahead.

    Science.gov (United States)

    Uher, Jana

    2015-12-01

    As science seeks to make generalisations, a science of individual peculiarities encounters intricate challenges. This article explores these challenges by applying the Transdisciplinary Philosophy-of-Science Paradigm for Research on Individuals (TPS-Paradigm) and by exploring taxonomic "personality" research as an example. Analyses of researchers' interpretations of the taxonomic "personality" models, constructs and data that have been generated in the field reveal widespread erroneous assumptions about the abilities of previous methodologies to appropriately represent individual-specificity in the targeted phenomena. These assumptions, rooted in everyday thinking, fail to consider that individual-specificity and others' minds cannot be directly perceived, that abstract descriptions cannot serve as causal explanations, that between-individual structures cannot be isomorphic to within-individual structures, and that knowledge of compositional structures cannot explain the process structures of their functioning and development. These erroneous assumptions and serious methodological deficiencies in widely used standardised questionnaires have effectively prevented psychologists from establishing taxonomies that can comprehensively model individual-specificity in most of the kinds of phenomena explored as "personality", especially in experiencing and behaviour and in individuals' functioning and development. Contrary to previous assumptions, it is not universal models but rather different kinds of taxonomic models that are required for each of the different kinds of phenomena, variations and structures that are commonly conceived of as "personality". Consequently, to comprehensively explore individual-specificity, researchers have to apply a portfolio of complementary methodologies and develop different kinds of taxonomies, most of which have yet to be developed. Closing, the article derives some meta-desiderata for future research on individuals' "personality".

  12. MENGATASI MASALAH LOW SELF ESTEEM SISWA MELALUI KONSELING INDIVIDU MODEL PERSON CENTERED THERAPHY

    Directory of Open Access Journals (Sweden)

    Azmi Hanifah

    2017-03-01

    Full Text Available This research applied based on the phenomenon in SMPN 25 Semarang which indicates several students who have low self-esteem, through the results of the DCM’s analysis distributed to the students of 9th grade. This research used to show the students’ self-esteem before and after having individual counseling model of person-centered Therapy and whether the model of person-centered Therapy counseling can overcome the problem of low self-esteem students. This research design is experimental research which using one group pretest-posttest design. The participants of this study were six students. The writer use Wilcoxon test as Hypothesis testing by comparing the level of the smallest of the pre and posttest. Obtained results Zcount 2,206 > Z table = 1.645, which means Ha accepted and Ho rejected. The research findings showed that (1 the pretest of the experiment of sixth counselees was 48.45% (2 In another hand the posttest result of the experiment sixth counselees was 75.65% (3 The problem of low self-esteem students can be solved through counseling models centered person theraphy. The result of the study shows that there is positive result and significant improvement of students’ self-esteem when teacher using Person Centered Therapy to solve low self-esteem problem.

  13. Model features as the basis of preparation of boxers individualization principal level (elite

    Directory of Open Access Journals (Sweden)

    O.J. Pavelec

    2013-10-01

    Full Text Available Purpose to improve the system of training boxers of higher categories (elite. Individualization of the training process using the model characteristics special physical preparedness. Materials : The study was conducted during 2000-2010. Participated boxers national team of Ukraine in the amount of 43 people. Of those honored masters of sport 6, masters of sports of international class 16, masters of sports 21. The average age of the athletes 23.5 years. Results : justified and features a specially designed model of physical fitness boxing class. It is established that the boxers middle weight classes (64 75 kg have an advantage over other boxers weight categories (light and after a hard in the development of speed and strength endurance. The presented model characteristics can guide the professional fitness boxing (elite, as representatives of the sport. Conclusions : It is established that the structure of the special physical training boxers depends on many components, such as weight category, tactical fighter role, skill level, stage of preparation.

  14. Active Aging for Individuals with Parkinson’s Disease: Definitions, Literature Review, and Models

    Directory of Open Access Journals (Sweden)

    Seyed-Mohammad Fereshtehnejad

    2014-01-01

    Full Text Available Active aging has been emerged to optimize different aspects of health opportunities during the aging process in order to enhance quality of life. Yet, most of the efforts are on normal aging and less attention has been paid for the elderly suffering from a chronic illness such as Parkinson’s disease (PD. The aim of this review was to investigate how the concept of “active aging” fit for the elderly with PD and to propose a new model for them using the recent improvements in caring models and management approaches. For this purpose, biomedical databases have been assessed using relevant keywords to find out appropriate articles. Movement problems of PD affect physical activity, psychiatric symptoms lessen social communication, and cognitive impairment could worsen mental well-being in elderly with PD, all of which could lead to earlier retirement and poorer quality of life compared with healthy elderly. Based on the multisystematic nature of PD, a new “Active Aging Model for Parkinson’s Disease” is proposed consisting of self-care, multidisciplinary and interdisciplinary care, palliative care, patient-centered care, and personalized care. These strategies could potentially help the individuals with PD to have a better management approach for their condition towards the concept of active aging.

  15. Active aging for individuals with Parkinson's disease: definitions, literature review, and models.

    Science.gov (United States)

    Fereshtehnejad, Seyed-Mohammad; Lökk, Johan

    2014-01-01

    Active aging has been emerged to optimize different aspects of health opportunities during the aging process in order to enhance quality of life. Yet, most of the efforts are on normal aging and less attention has been paid for the elderly suffering from a chronic illness such as Parkinson's disease (PD). The aim of this review was to investigate how the concept of "active aging" fit for the elderly with PD and to propose a new model for them using the recent improvements in caring models and management approaches. For this purpose, biomedical databases have been assessed using relevant keywords to find out appropriate articles. Movement problems of PD affect physical activity, psychiatric symptoms lessen social communication, and cognitive impairment could worsen mental well-being in elderly with PD, all of which could lead to earlier retirement and poorer quality of life compared with healthy elderly. Based on the multisystematic nature of PD, a new "Active Aging Model for Parkinson's Disease" is proposed consisting of self-care, multidisciplinary and interdisciplinary care, palliative care, patient-centered care, and personalized care. These strategies could potentially help the individuals with PD to have a better management approach for their condition towards the concept of active aging.

  16. Individualizing Management of Complex Esophageal Pathology Using Three-Dimensional Printed Models.

    Science.gov (United States)

    Dickinson, Karen J; Matsumoto, Jane; Cassivi, Stephen D; Reinersman, J Matthew; Fletcher, Joel G; Morris, Jonathan; Wong Kee Song, Louis M; Blackmon, Shanda H

    2015-08-01

    In complex esophageal cases, conventional two-dimensional imaging is limited in demonstrating anatomic relationships. We describe the utility of three-dimensional (3D) printed models for complex patients to individualize care. Oral effervescent agents, with positive enteric contrast, distended the esophagus during computed tomography (CT) scanning to facilitate segmentation during post-processing. The CT data were segmented, converted into a stereolithography file, and printed using photopolymer materials. In 1 patient with a left pneumonectomy, aortic bypass, and esophageal diversion, 3D printing enabled visualization of the native esophagus and facilitated endoscopic mucosal resection, followed by hiatal dissection and division of the gastroesophageal junction as treatment. In a second patient, 3D printing allowed enhanced visualization of multiple esophageal diverticula, allowing for optimization of the surgical approach. Printing of 3D anatomic models in patients with complex esophageal pathology facilitates planning the optimal surgical approach and anticipating potential difficulties for the multidisciplinary team. These models are invaluable for patient education. Copyright © 2015 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  17. Studying Individual Differences in Predictability With Gamma Regression and Nonlinear Multilevel Models.

    Science.gov (United States)

    Culpepper, Steven Andrew

    2010-01-29

    Statistical prediction remains an important tool for decisions in a variety of disciplines. An equally important issue is identifying factors that contribute to more or less accurate predictions. The time series literature includes well developed methods for studying predictability and volatility over time. This article develops distribution-appropriate methods for studying individual differences in predictability for settings in psychological research. Specifically, 3 different approaches are discussed for modeling predictability. The 1st is a bivariate measure of predictability discussed previously in the psychology literature, the squared or absolute valued difference between criterion and predictor, which is shown to follow the gamma distribution. The 2nd method extended limitations of previous research and involved understanding predictability in regression models. The 3rd method used nonlinear multilevel models to study predictability in settings where participants are nested within clusters. An application was presented using SAS NLMIXED to understand the predictability of college grade point average by student demographic characteristics. The findings from the application suggest that the 1st-year college performance of English as a second language students were, on average, less predictable whereas females and Whites tended to demonstrate more predictable academic performance than their male or racial/ethnic minority counterparts.

  18. Numerical investigation of complete mandibular dentures stabilized by conventional or mini implants in patient individual models.

    Science.gov (United States)

    Lohmann, Anna; Keilig, Ludger; Heinemann, Friedhelm; Bourauel, Christoph; Hasan, Istabrak

    2018-02-08

    Poor stability of a complete denture is a common problem due to bone atrophy of the edentulous ridge. The aim of the present study was to analyze denture stability after receiving implants and to study the biomechanical properties of denture implants and the bone bed using conventional or mini implants. Five models based on computed tomography (CT) data of edentulous patients were created. The overdentures' connection to the implants was assured by means of ball head abutments and rubber rings. In three models, the denture was supported by two to four conventional implants and in two models, the overdenture was supported by three to five mini implants. The dentures were loaded according to the individual biting forces which was clinically measured by means of pressure sheets. After implantation, the biting forces and displacements of overdentures increased in comparison to complete dentures. Displacements and stresses were higher with mini implants than with conventional ones. Stress in the implants was markedly below the yield stress of titanium grade 5 (880 MPa). An increase in the stress in the bone around the implants was noticed as compared to the situation with complete dentures which was below the physiological range of bone loading (<4 MPa).

  19. Individual and Familial Susceptibility to MPTP in a Common Marmoset Model for Parkinson's Disease.

    Science.gov (United States)

    Franke, Sigrid K; van Kesteren, Ronald E; Hofman, Sam; Wubben, Jacqueline A M; Smit, August B; Philippens, Ingrid H C H M

    2016-01-01

    Insight into susceptibility mechanisms underlying Parkinson's disease (PD) would aid the understanding of disease etiology, enable target finding and benefit the development of more refined disease-modifying strategies. We used intermittent low-dose MPTP (0.5 mg/kg/week) injections in marmosets and measured multiple behavioral and neurochemical parameters. Genetically diverse monkeys from different breeding families were selected to investigate inter- and intrafamily differences in susceptibility to MPTP treatment. We show that such differences exist in clinical signs, in particular nonmotor PD-related behaviors, and that they are accompanied by differences in neurotransmitter levels. In line with the contribution of a genetic component, different susceptibility phenotypes could be traced back through genealogy to individuals of the different families. Our findings show that low-dose MPTP treatment in marmosets represents a clinically relevant PD model, with a window of opportunity to examine the onset of the disease, allowing the detection of individual variability in disease susceptibility, which may be of relevance for the diagnosis and treatment of PD in humans. © 2016 S. Karger AG, Basel.

  20. The Effects of Creatine Supplementation on Explosive Performance and Optimal Individual Postactivation Potentiation Time

    Directory of Open Access Journals (Sweden)

    Chia-Chi Wang

    2016-03-01

    Full Text Available Creatine plays an important role in muscle energy metabolism. Postactivation potentiation (PAP is a phenomenon that can acutely increase muscle power, but it is an individualized process that is influenced by muscle fatigue. This study examined the effects of creatine supplementation on explosive performance and the optimal individual PAP time during a set of complex training bouts. Thirty explosive athletes performed tests of back squat for one repetition maximum (1RM strength and complex training bouts for determining the individual optimal timing of PAP, height and peak power of a counter movement jump before and after the supplementation. Subjects were assigned to a creatine or placebo group and then consumed 20 g of creatine or carboxymethyl cellulose per day for six days. After the supplementation, the 1RM strength in the creatine group significantly increased (p < 0.05. The optimal individual PAP time in the creatine group was also significant earlier than the pre-supplementation and post-supplementation of the placebo group (p < 0.05. There was no significant difference in jump performance between the groups. This study demonstrates that creatine supplementation improves maximal muscle strength and the optimal individual PAP time of complex training but has no effect on explosive performance.

  1. Combining xenoestrogens at levels below individual no-observed-effect concentrations dramatically enhances steroid hormone action.

    OpenAIRE

    Rajapakse, Nissanka; Silva, Elisabete; Kortenkamp, Andreas

    2002-01-01

    The low potency of many man-made estrogenic chemicals, so-called xenoestrogens, has been used to suggest that risks arising from exposure to individual chemicals are negligible. Another argument used to dismiss concerns of health effects is that endogenous steroidal estrogens are too potent for xenoestrogens to contribute significantly to estrogenic effects. Using a yeast reporter gene assay with the human estrogen receptoralpha, we tested these ideas experimentally by assessing the ability o...

  2. Personality prototypes in individuals with compulsive buying based on the Big Five Model.

    Science.gov (United States)

    Mueller, Astrid; Claes, Laurence; Mitchell, James E; Wonderlich, Steve A; Crosby, Ross D; de Zwaan, Martina

    2010-09-01

    Personality prototypes based on the Big Five factor model were investigated in a treatment-seeking sample of 68 individuals with compulsive buying (CB). Cluster analysis of the NEO Five-Factor Inventory (NEO-FFI) scales yielded two distinct personality clusters. Participants in cluster II scored significantly higher than those in cluster I on neuroticism and lower on the other four personality traits. Subjects in cluster II showed higher severity of CB, lower degree of control over CB symptoms, and were more anxious, interpersonally sensitive and impulsive. Furthermore, cluster II was characterized by higher rates of comorbid anxiety disorders, and cluster B personality disorders. The two personality prototypes did not differ with respect to obsessive-compulsive features. Finally and of considerable clinical significance, participants in cluster II reported lower remission rates after undergoing cognitive-behavioral therapy. Implications of the results for treatment are discussed. 2010 Elsevier Ltd. All rights reserved.

  3. Are Creative Individuals Bad Apples? A Dual Pathway Model of Unethical Behavior.

    Science.gov (United States)

    Keem, Sejin; Shalley, Christina E; Kim, Eugene; Jeong, Inseong

    2017-12-14

    Research has been inconsistent in its quest to discover whether dispositional creativity is associated with more or less unethical behavior. Drawing on social cognitive theory, we propose that moral disengagement and moral imagination are 2 parallel mechanisms that encourage or inhibit unethical behavior, and that which of these mediation processes occur depends on moral identity. Study 1, a 3-wave study of a food service organization, shows that employees high on both dispositional creativity and moral identity are less likely to be morally disengaged and behave less unethically. The results of Study 2 replicate Study 1's findings in a scenario-based study of college students, and further show that individuals who are high on both dispositional creativity and moral identity are more likely to be morally imaginative and to behave less unethically. Theoretical and practical implications of our model are discussed. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  4. Meningkatkan Prestasi Belajar IPS Materi Interaksi Sosial Melalui Penggunaan Model Pembelajaran Team Assisted Individualization (TAI

    Directory of Open Access Journals (Sweden)

    Juliastuti .

    2017-01-01

    Full Text Available Berdasarkan hasil observasi dan wawancara dengan guru mata pelajaran IPS di SMPN 33 Surabaya Kota Surabaya, diperoleh bahwa nilai rata-rata penguasaan materi siswa kelas X1 pada materi Interaksi Sosial tahun pelajaran 2012/2013 masih rendah. Aktivitas siswa yang relevan dengan pembelajaran rendah. Salah satu upaya untuk meningkatkan aktivitas siswa dan penguasaan materi Interaksi Sosial adalah dengan menerapkan model pembelajaran kooperatif tipe TAI (Team Asissted Individualization. Tujuan penelitian ini adalah mendeskripsikan penggunaan pembelajaran kooperatif tipe TAI untuk meningkatkan persentase rata-rata : (1 tiap jenis aktivitas siswa; (2 penguasaan materi siswa dari siklus ke siklus. Penelitian ini adalah penelitian tindakan kelas yang dilakukan sebanyak tiga siklus. Data penelitian ini terdiri dari data kualitatif, yaitu data aktivitas on task siswa yang diperoleh dari lembar observasi, serta data kuantitatif berupa nilai penguasaan materi interaksi sosial yang diperoleh melalui tes formatif. Hasil penelitian ini menunjukkan bahwa penggunaan model pembelajaran kooperatif tipe memiliki dampak positif dalam meningkatkan prestasi belajar siswa yang ditandai dengan peningkatan ketuntasan belajar siswa dalam setiap siklus, yaitu siklus I 65,63%, siklus II 100%. Kata Kunci : Team Assisted Individualization ( TAI , Prestasi Belajar, IPS                                                                                                                        Based on observations and interviews with a social studies teacher at SMPN 33 Surabaya Surabaya, found that the average value of students' mastery of the material in the material class X1 Social Interaction in the academic year 2012/2013 is still low. Activities relevant to the learning of students is low. One effort to increase student activity and mastery of Social Interaction

  5. Parent Report of Antidepressant, Anxiolytic, and Antipsychotic Medication Use in Individuals with Williams Syndrome: Effectiveness and Adverse Effects

    Science.gov (United States)

    Martens, Marilee A.; Seyfer, Daisha L.; Andridge, Rebecca R.; Foster, Jessica E. A.; Chowdhury, Monali; McClure, Kelsey E.; Coury, Daniel L.

    2012-01-01

    Williams syndrome (WS) is a neurodevelopmental genetic disorder characterized in part by anxiety and behavioral difficulties. We examine the effectiveness and adverse effects of antidepressant, anxiolytic, and antipsychotic medications in individuals with WS. A total of 513 parents/caregivers completed a survey of psychotropic medication usage…

  6. PEMBELAJARAN GARIS LURUS DENGAN MODEL ELICITING ACTIVITIES DAN TEAM ASSISTED INDIVIDUALIZATION DITINJAU DARI GAYA KOGNITIF

    Directory of Open Access Journals (Sweden)

    author Ari Suningsih

    2015-01-01

    Full Text Available The aims of the research were to determine to the effect of learning models on mathematics achievement viewed from students cognitive style. The learning model compared were model elicting activities, team assisted Individualition, and direct instruction. The kind of research was a quasi experimental research with 3 x 2 factorial design. The population was the students of Junior high school in SMP N Pringsewu. The size of the sample was 208 students. The instruments used were mathematics achievement test and questionnaire. Hypothesis analysis test used two ways analysis of variance with unbalanced cells. The conclusions were as follow. model elicting activities gave better mathematics learning achievement than the students who used Cooperative Learning TAI type and Direct Instruction Assisted Powerpoint, and the students who used Cooperative Learning TAI type gave better mathematics learning achievement than the students who used Direct Instruction Assisted Powerpoint; For all types of students cognitive style give the different effect for mathematics learning achievement of students, In each model of learning, students with cognitive style types field independent gave better mathematics learning achievement than field dependent.Keywords: Kooperatif; MEas; TAI; Gaya Kognitif

  7. The Effects of Natural and Anthropogenic Microparticles on Individual Fitness in Daphnia magna.

    Directory of Open Access Journals (Sweden)

    Martin Ogonowski

    Full Text Available Concerns are being raised that microplastic pollution can have detrimental effects on the feeding of aquatic invertebrates, including zooplankton. Both small plastic fragments (microplastics, MPs produced by degradation of larger plastic waste (secondary MPs; SMPs and microscopic plastic spheres used in cosmetic products and industry (primary MPs; PMPs are ubiquitously present in the environment. However, despite the fact that most environmental MPs consist of weathered plastic debris with irregular shape and broad size distribution, experimental studies of organism responses to MP exposure have largely used uniformly sized spherical PMPs. Therefore, effects observed for PMPs in such experiments may not be representative for MP-effects in situ. Moreover, invertebrate filter-feeders are generally well adapted to the presence of refractory material in seston, which questions the potential of MPs at environmentally relevant concentrations to measurably affect digestion in these organisms. Here, we compared responses to MPs (PMPs and SMPs and naturally occurring particles (kaolin clay using the cladoceran Daphnia magna as a model organism. We manipulated food levels (0.4 and 9 μg C mL-1 and MP or kaolin contribution to the feeding suspension (<1 to 74% and evaluated effects of MPs and kaolin on food uptake, growth, reproductive capacity of the daphnids, and maternal effects on offspring survival and feeding. Exposure to SMPs caused elevated mortality, increased inter-brood period and decreased reproduction albeit only at high MP levels in the feeding suspension (74% by particle count. No such effects were observed in either PMP or kaolin treatments. In daphnids exposed to any particle type at the low algal concentration, individual growth decreased by ~15%. By contrast, positive growth response to all particle types was observed at the high algal concentration with 17%, 54% and 40% increase for kaolin, PMP and SMP, respectively. When test particles

  8. Exact Solution of the Gyration Radius of an Individual's Trajectory for a Simplified Human Regular Mobility Model

    Science.gov (United States)

    Yan, Xiao-Yong; Han, Xiao-Pu; Zhou, Tao; Wang, Bing-Hong

    2011-12-01

    We propose a simplified human regular mobility model to simulate an individual's daily travel with three sequential activities: commuting to workplace, going to do leisure activities and returning home. With the assumption that the individual has a constant travel speed and inferior limit of time at home and in work, we prove that the daily moving area of an individual is an ellipse, and finally obtain an exact solution of the gyration radius. The analytical solution captures the empirical observation well.

  9. Sandeel ( Ammodytes marinus ) larval transport patterns in the North Sea from an individual-based hydrodynamic egg and larval model

    DEFF Research Database (Denmark)

    Christensen, Asbjørn; Jensen, Henrik; Mosegaard, Henrik

    2008-01-01

    is modelled by a stochastic, nonlinear degree-day model describing the extended hatch period. The larval growth model is parameterized by individually back-tracking the local physical environment of larval survivors from their catch location and catch time. Using a detailed map of sandeel habitats...

  10. Modeling of Individual and Organizational Factors Affecting Traumatic Occupational Injuries Based on the Structural Equation Modeling: A Case Study in Large Construction Industries.

    Science.gov (United States)

    Mohammadfam, Iraj; Soltanzadeh, Ahmad; Moghimbeigi, Abbas; Akbarzadeh, Mehdi

    2016-09-01

    Individual and organizational factors are the factors influencing traumatic occupational injuries. The aim of the present study was the short path analysis of the severity of occupational injuries based on individual and organizational factors. The present cross-sectional analytical study was implemented on traumatic occupational injuries within a ten-year timeframe in 13 large Iranian construction industries. Modeling and data analysis were done using the structural equation modeling (SEM) approach and the IBM SPSS AMOS statistical software version 22.0, respectively. The mean age and working experience of the injured workers were 28.03 ± 5.33 and 4.53 ± 3.82 years, respectively. The portions of construction and installation activities of traumatic occupational injuries were 64.4% and 18.1%, respectively. The SEM findings showed that the individual, organizational and accident type factors significantly were considered as effective factors on occupational injuries' severity (P factors and their indicator variables are very influential on the severity of traumatic occupational injuries. So, these should be considered to reduce occupational accidents' severity in large construction industries.

  11. Modeling Incoherent Electron Cloud Effects

    International Nuclear Information System (INIS)

    Vay, Jean-Luc; Benedetto, E.; Fischer, W.; Franchetti, G.; Ohmi, K.; Schulte, D.; Sonnad, K.; Tomas, R.; Vay, J.-L.; Zimmermann, F.; Rumolo, G.; Pivi, M.; Raubenheimer, T.

    2007-01-01

    Incoherent electron effects could seriously limit the beam lifetime in proton or ion storage rings, such as LHC, SPS, or RHIC, or blow up the vertical emittance of positron beams, e.g., at the B factories or in linear-collider damping rings. Different approaches to modeling these effects each have their own merits and drawbacks. We describe several simulation codes which simplify the descriptions of the beam-electron interaction and of the accelerator structure in various different ways, and present results for a toy model of the SPS. In addition, we present evidence that for positron beams the interplay of incoherent electron-cloud effects and synchrotron radiation can lead to a significant increase in vertical equilibrium emittance. The magnitude of a few incoherent e+e- scattering processes is also estimated. Options for future code development are reviewed

  12. Effects of Scenario Planning on Participant Mental Models

    Science.gov (United States)

    Glick, Margaret B.; Chermack, Thomas J.; Luckel, Henry; Gauck, Brian Q.

    2012-01-01

    Purpose: The purpose of this paper is to assess the effects of scenario planning on participant mental model styles. Design/methodology/approach: The scenario planning literature is consistent with claims that scenario planning can change individual mental models. These claims are supported by anecdotal evidence and stories from the practical…

  13. Using Dirichlet Processes for Modeling Heterogeneous Treatment Effects across Sites

    Science.gov (United States)

    Miratrix, Luke; Feller, Avi; Pillai, Natesh; Pati, Debdeep

    2016-01-01

    Modeling the distribution of site level effects is an important problem, but it is also an incredibly difficult one. Current methods rely on distributional assumptions in multilevel models for estimation. There it is hoped that the partial pooling of site level estimates with overall estimates, designed to take into account individual variation as…

  14. Effect of functional fatigue on vertical ground-reaction force in individuals with flat feet.

    Science.gov (United States)

    Boozari, Sahar; Jamshidi, Ali Ashraf; Sanjari, Mohammad Ali; Jafari, Hassan

    2013-08-01

    Flat foot is one of the lower extremity deformities that might change kinetic variables of gait. Fatigue is one of the factors that can alter the vertical ground-reaction force (GRF). The effect of a fatiguing condition on vertical GRF has not been documented in individuals with flat feet. To examine the fatigue effect on vertical GRF in individuals with flat feet compared with a normal group during barefoot walking. Repeated-measure ANOVA for the effects of fatigue on individuals with flat feet and normal feet. Biomechanics laboratory. 17 subjects with flat feet and 17 normal subjects (recruited according to their arch-height ratio). Three vertical GRF measures (F1, the first peak force; F2, minimum force; and F3, the second peak force) were extracted before and after a functional fatigue protocol. No significant interaction between fatigue and group was observed for the 3 vertical GRF measures. For F2, fatigue and group effects were significant (P = .001 and P = .02, respectively). Furthermore, F2 was higher in the flat-feet group than in the normal group; F2 also increased after fatigue. For F3, only a significant fatigue effect was observed (P = .004). F3 decreased after fatigue in both groups. In the flat-feet group, a decrease in the variation of vertical GRF might be due to more flexible foot joints. After fatigue, muscles might lose their ability to control the foot joints and cause higher F2 in the flat-feet group.

  15. Tablet-based interventions for individuals with ASD: Evidence of generalization and maintenance effects.

    Science.gov (United States)

    Hong, Ee Rea; Kawaminami, Sawako; Neely, Leslie; Morin, Kristi; Davis, John L; Gong, Li-Yuan

    2018-02-05

    Despite positive effects of and established empirical evidence for tablet-based interventions for individuals with autism spectrum disorder (ASD), it is not known whether such findings can be applicable to maintenance and generalization effects of those interventions. This systematic review evaluated peer-reviewed single-case experimental design (SCED) studies concerning evidence of generalization and maintenance effects of tablet-based interventions for individuals with ASD. To evaluate the methodological rigor of the literature in terms of generalization and maintenance effects, the authors adopted four of the basic design standards developed by What Works Clearinghouse (WWC; Kratochwill et al., 2010/2014). In addition, the authors used Tau-U effect size measure and attempted to calculate effect sizes differentiated by the type of generalization and maintenance teaching strategies. A total of 21 studies assessed generalization and/or maintenance effects. In the first evaluation of evidence of generalization and maintenance effects, it was found that more than half of the studies included in this review collected interobserver agreement (IOA) on at least 20% of sessions across all generalization and maintenance conditions and met the minimum quality thresholds of IOA. Meanwhile, less than one third of the studies included more than three data points in each generalization and maintenance condition. With regard to maintenance of effects, about half of the reviewed studies did not report the latency to the maintenance measure, which may hamper the assessment of the clinical and practical significance of the effect of the tablet-based intervention. In the second evaluation, the omnibus Tau-U effect size for baseline to generalization comparisons resulted in a moderate effect. For the contrasts between intervention and generalization comparisons resulted in a small effect. The omnibus Tau-U effect size for baseline and maintenance comparisons resulted in a strong

  16. Evaluating the efficacy of Regulated 12-Session Matrix Model in reducing susceptibility in methamphetamine-dependent individuals

    Directory of Open Access Journals (Sweden)

    Zahra Amiri

    2016-02-01

    Full Text Available Methamphetamine (abuse have gained popularity among youth and is increasingly become a part of mainstream culture. Methamphetamine(abuse is dangerous because of its wide range adverse outcomes and hazardous sustaining side effects. Its dependence is hardly withdrawn by routine therapeutic methods. This study is devoted to evaluate the efficacy of Regulated 12-Session Matrix Model in outpatient methamphetamine-dependent individuals. 24 individuals were chosen according to inclusion/exclusion criteria of the study and randomly assigned to equal experimental (age range 19-41; mean age: 46.9 and control groups (age range: 21-42; mean age: 27.8. Experimental group members partook Regulated 12-Session Matrix Model once a week in 12 consecutive weeks, while control group members remained at waitlist. Independent t-test in 12th week showed that experimental group had lower methamphetamine use, comparing to control group (p<.05.Phillai’s Trace, Wilk’s Lambda, HotellingLawley's trace, and Roy's largest root showed that there are significant association between experimental and control groups in reduction of methamphetamine-use lapse (p<.05.Within-subject F ratio revealed that “methamphetamine use” was significantly reduced in experimental group after clinical intervention (p<.001. Findings of the study indicate the efficacy of Regulated 12-Session Matrix Model in craving management and control as well as reduction of lapse and substance (abuse in methamphetamine-dependent patients. It appears that the Regulated 12-Session Matrix Model would be a new reliable solution to treat methamphetamine-dependence in Iran and other alike cultural and social atmospheres. Limitations and future implications are discussed.

  17. Sustained virological response with intravenous silibinin: individualized IFN-free therapy via real-time modelling of HCV kinetics.

    Science.gov (United States)

    Dahari, Harel; Shteingart, Shimon; Gafanovich, Inna; Cotler, Scott J; D'Amato, Massimo; Pohl, Ralf T; Weiss, Gali; Ashkenazi, Yaakov J; Tichler, Thomas; Goldin, Eran; Lurie, Yoav

    2015-02-01

    Intravenous silibinin (SIL) is a potent antiviral agent against hepatitis C virus (HCV) genotype-1. In this proof of concept case-study we tested: (i) whether interferon-alfa (IFN)-free treatment with SIL plus ribavirin (RBV) can achieve sustained virological response (SVR); (ii) whether SIL is safe and feasible for prolonged duration of treatment and (iii) whether mathematical modelling of early on-treatment HCV kinetics can guide duration of therapy to achieve SVR. A 44 year-old female HCV-(genotype-1)-infected patient who developed severe psychiatric adverse events to a previous course of pegIFN+RBV, initiated combination treatment with 1200 mg/day of SIL, 1200 mg/day of RBV and 6000 u/day vitamin D. Blood samples were collected frequently till week 4, thereafter every 1-12 weeks until the end of therapy. The standard biphasic mathematical model with time-varying SIL effectiveness was used to predict the duration of therapy to achieve SVR. Based on modelling the observed viral kinetics during the first 3 weeks of treatment, SVR was predicted to be achieved within 34 weeks of therapy. Provided with this information, the patient agreed to complete 34 weeks of treatment. IFN-free treatment with SIL+RBV was feasible, safe and achieved SVR (week-33). We report, for the first time, the use of real-time mathematical modelling of HCV kinetics to individualize duration of IFN-free therapy and to empower a patient to participate in shared decision making regarding length of treatment. SIL-based individualized therapy provides a treatment option for patients who do not respond to or cannot receive other HCV agents and should be further validated. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. Exploring the persistence of stream-dwelling trout populations under alternative real-world turbidity regimes with an individual-based model

    Science.gov (United States)

    Bret C. Harvey; Steven F. Railsback

    2009-01-01

    We explored the effects of elevated turbidity on stream-resident populations of coastal cutthroat trout Oncorhynchus clarkii clarkii using a spatially explicit individual-based model. Turbidity regimes were contrasted by means of 15-year simulations in a third-order stream in northwestern California. The alternative regimes were based on multiple-year, continuous...

  19. Taxonomic analysis of perceived risk: modeling individual and group perceptions within homogeneous hazard domains

    International Nuclear Information System (INIS)

    Kraus, N.N.; Slovic, P.

    1988-01-01

    Previous studies of risk perception have typically focused on the mean judgments of a group of people regarding the riskiness (or safety) of a diverse set of hazardous activities, substances, and technologies. This paper reports the results of two studies that take a different path. Study 1 investigated whether models within a single technological domain were similar to previous models based on group means and diverse hazards. Study 2 created a group taxonomy of perceived risk for only one technological domain, railroads, and examined whether the structure of that taxonomy corresponded with taxonomies derived from prior studies of diverse hazards. Results from Study 1 indicated that the importance of various risk characteristics in determining perceived risk differed across individuals and across hazards, but not so much as to invalidate the results of earlier studies based on group means and diverse hazards. In Study 2, the detailed analysis of railroad hazards produced a structure that had both important similarities to, and dissimilarities from, the structure obtained in prior research with diverse hazard domains. The data also indicated that railroad hazards are really quite diverse, with some approaching nuclear reactors in their perceived seriousness. These results suggest that information about the diversity of perceptions within a single domain of hazards could provide valuable input to risk-management decisions

  20. Limitations of individual causal models, causal graphs, and ignorability assumptions, as illustrated by random confounding and design unfaithfulness.

    Science.gov (United States)

    Greenland, Sander; Mansournia, Mohammad Ali

    2015-10-01

    We describe how ordinary interpretations of causal models and causal graphs fail to capture important distinctions among ignorable allocation mechanisms for subject selection or allocation. We illustrate these limitations in the case of random confounding and designs that prevent such confounding. In many experimental designs individual treatment allocations are dependent, and explicit population models are needed to show this dependency. In particular, certain designs impose unfaithful covariate-treatment distributions to prevent random confounding, yet ordinary causal graphs cannot discriminate between these unconfounded designs and confounded studies. Causal models for populations are better suited for displaying these phenomena than are individual-level models, because they allow representation of allocation dependencies as well as outcome dependencies across individuals. Nonetheless, even with this extension, ordinary graphical models still fail to capture distinctions between hypothetical superpopulations (sampling distributions) and observed populations (actual distributions), although potential-outcome models can be adapted to show these distinctions and their consequences.

  1. A comparison of regression methods for model selection in individual-based landscape genetic analysis.

    Science.gov (United States)

    Shirk, Andrew J; Landguth, Erin L; Cushman, Samuel A

    2018-01-01

    Anthropogenic migration barriers fragment many populations and limit the ability of species to respond to climate-induced biome shifts. Conservation actions designed to conserve habitat connectivity and mitigate barriers are needed to unite fragmented populations into larger, more viable metapopulations, and to allow species to track their climate envelope over time. Landscape genetic analysis provides an empirical means to infer landscape factors influencing gene flow and thereby inform such conservation actions. However, there are currently many methods available for model selection in landscape genetics, and considerable uncertainty as to which provide the greatest accuracy in identifying the true landscape model influencing gene flow among competing alternative hypotheses. In this study, we used population genetic simulations to evaluate the performance of seven regression-based model selection methods on a broad array of landscapes that varied by the number and type of variables contributing to resistance, the magnitude and cohesion of resistance, as well as the functional relationship between variables and resistance. We also assessed the effect of transformations designed to linearize the relationship between genetic and landscape distances. We found that linear mixed effects models had the highest accuracy in every way we evaluated model performance; however, other methods also performed well in many circumstances, particularly when landscape resistance was high and the correlation among competing hypotheses was limited. Our results provide guidance for which regression-based model selection methods provide the most accurate inferences in landscape genetic analysis and thereby best inform connectivity conservation actions. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

  2. Effect of Mandatory Unit and Individual Physical Training on Fitness in Military Men and Women.

    Science.gov (United States)

    Anderson, Morgan K; Grier, Tyson; Canham-Chervak, Michelle; Bushman, Timothy T; Nindl, Bradley C; Jones, Bruce H

    2017-09-01

    The purpose of this study was to look at the effect of additional individual physical training (PT) in addition to mandatory unit PT as well as other risk factors on physical fitness. A cross-sectional design. This study was conducted on a US military installation. Participants were 6290 male and 558 female active duty US Army soldiers in 3 light infantry brigades. Participants completed self-administered questionnaires asking about individual characteristics, PT, and physical fitness. Cut points were established for soldiers scoring within the top 33% for each of the 3 Army Physical Fitness Test events (2-mile run, sit-ups, and push-ups) and top 50% in each of the tests combined for overall performance. Odds ratios and 95% confidence intervals from multivariate analyses were calculated. Variables impacting physical fitness performance of men and women included increased body mass index, leading unit PT sessions, and individual distance running mileage. Other variables impacting physical performance for men included increased age, smoking, and individual resistance training. Soldiers performing additional individual PT demonstrated a positive influence on fitness compared to unit PT participation alone. Increased age and being overweight/obese negatively influenced physical fitness. To enhance fitness performance through unit PT, running by ability groups and resistance training should be encouraged by leadership.

  3. The consistency of individual differences in behaviour: temperature effects on antipredator behaviour in garter snakes.

    Science.gov (United States)

    Brodie; Russell

    1999-02-01

    Differences among individuals are necessary for natural selection to occur. The extent and expression of these differences can limit the power of selection to cause evolutionary change. When individuals inconsistently express a trait, selection is less powerful. Labile traits such as behaviour are most likely to be inconsistent in their expression, because of the substantial role of environmental factors in their immediate expression. Previous work has focused on the consistency, or repeatability, of individual behaviour across different environments or within a single environment; little is known about how repeatability within an environment changes across environments. To address this issue, we examined the consistency of antipredator behaviour in juvenile garter snakes in different thermal environments. A group of 59 laboratory-born garter snakes Thamnophis ordinoides, was repeatedly assayed for sprint speed, distance crawled, and number of reversals performed during flight and antipredator display. Antipredator display showed very little variation and could not be analysed. Each individual was tested three times at each of three temperatures chosen to span the range of temperatures that snakes encounter in the field (15, 22.5, 30 degrees C). Temperature had substantial effects on the average expression of each behaviour; snakes crawled more slowly, for shorter distances, and performed fewer reversals at cooler temperatures. Individuals showed significant consistency in their behaviour, and this consistency of expression was not affected by temperature. Copyright 1999 The Association for the Study of Animal Behaviour.

  4. Test of a behavior-based individual-based model: response of shorebird mortality to habitat loss.

    Science.gov (United States)

    Goss-Custard, John D; Burton, Niall H K; Clark, Nigel A; Ferns, Peter N; McGrorty, Selwyn; Reading, Christopher J; Rehfisch, Mark M; Stillman, Richard A; Townend, Ian; West, Andrew D; Worrall, David H

    2006-12-01

    In behavior-based individual-based models (IBMs), demographic functions are emergent properties of the model and are not built into the model structure itself, as is the case with the more widely used demography-based IBMs. Our behavior-based IBM represents the physiology and behavioral decision making of individual animals and, from that, predicts how many survive the winter nonbreeding season, an important component of fitness. This paper provides the first test of such a model by predicting the change in winter mortality of a charadriid shorebird following removal of intertidal feeding habitat, the main effect of which was to increase bird density. After adjusting one calibration parameter to the level required to replicate the observed mortality rate before habitat loss, the model predicted that mortality would increase by 3.65%, which compares well with the observed increase of 3.17%. The implication that mortality was density-dependent was confirmed by predicting mortality over a range of bird densities. Further simulations showed that the density dependence was due to an increase in both interference and depletion competition as bird density increased. Other simulations suggested that an additional area of mudflat, equivalent to only 10% of the area that had been lost, would be needed by way of mitigation to return mortality to its original level. Being situated at a high shore level with the flow of water in and out impeded by inlet pipes, the mitigating mudflat would be accessible to birds when all mudflats in the estuary were covered at high tide, thus providing the birds with extra feeding time and not just a small replacement mudflat. Apart from providing the first, and confidence-raising, test of a behavior-based IBM, the results suggest (1) that the chosen calibration procedure was effective; (2) that where no new fieldwork is required, and despite being parameter rich, a behavior-based IBM can be parameterized quickly (few weeks), and thus cheaply

  5. Identifying effective methods for teaching sex education to individuals with intellectual disabilities: a systematic review.

    Science.gov (United States)

    Schaafsma, Dilana; Kok, Gerjo; Stoffelen, Joke M T; Curfs, Leopold M G

    2015-01-01

    Sex education for individuals with intellectual disabilities is important. However, our knowledge about effective methods for teaching sex education to this population is limited. We report the results of a systematic review identifying methods for sex education programs aimed at individuals with intellectual disabilities. In all, 20 articles were included that met the criteria set in terms of topic--the effectiveness of sex education programs--and population of interest--individuals with intellectual disabilities. In these articles, methods for increasing knowledge and for improving skills and attitudes were reported. However, the studies revealed that generalization of skills to real-life situations was often not achieved. There are indications that the maintenance of knowledge and skills still needs extra attention. Moreover, detailed descriptions of the program materials, program goals, and methods used in the programs were often lacking in the reports. Although there is some evidence for methods that may improve knowledge, attitudes, and skills with regard to sex education aimed at individuals with intellectual disabilities, due to the lack of detailed descriptions provided it is unclear under which conditions these methods work. We therefore suggest that authors provide additional detail about methods in future publications or in online supplements.

  6. Effect of individualized physical rehabilitation programs on respiratory function in women with post-mastectomy syndrome.

    Science.gov (United States)

    Odinets, Tatiana; Briskin, Yuriy; Pityn, Maryan

    2018-02-26

    The purpose of this study was to determine the effectiveness of an individualized physical rehabilitation programs aimed at improving respiratory function in women with post-mastectomy syndrome. In a randomized controlled trial 50 women with post-mastectomy syndrome were enrolled in the experimental group (EG, n = 25) or the comparison group (CG, n = 25). The program for the EG included: aqua aerobics (i.e. aqua jogging, aqua building, and aqua stretching); conditional swimming; and recreational aerobics. The program for the CG included: conditional swimming and Pilates exercises. Both intervention groups attended individualized physical rehabilitation programs three times per week for 48 weeks. The primary outcome measure was spirometry of the patients measured before, 6 and 12 months after the intervention. This study demonstrated that most of the respiratory function parameters increased significantly in both groups over the year of exercise training. After the year of training the individualized physical rehabilitation program for the EG was significantly better (p < 0.01) as compared with the CG, except for inspiratory reserve volume and maximal voluntary ventilation, which were not statistically different. The results of the study suggest that individual programs of physical rehabilitation could be considered effective for the improvement of respiratory function of the patients with post-mastectomy syndrome. The results obtained could serve as a basis for more widespread clinical program development.

  7. Effect of sericin on preimplantation development of bovine embryos cultured individually.

    Science.gov (United States)

    Isobe, T; Ikebata, Y; Onitsuka, T; Wittayarat, M; Sato, Y; Taniguchi, M; Otoi, T

    2012-09-01

    The silk protein sericin has been identified as a potent antioxidant in mammalian cells. This study was conducted to examine the effects of sericin on preimplantation development and quality of bovine embryos cultured individually. When two-cell-stage embryos were cultured individually for 7 days in CR1aa medium supplemented with 0, 0.1, 0.5, or 1% sericin, rates of total blastocyst formation and development to expanded blastocysts from embryos cultured with 0.5% sericin were higher (P sericin. When embryos were cultured individually for 7 days in the CR1aa medium supplemented with 0 or 0.5% sericin under two oxidative stress conditions (50 or 100 μm H(2)O(2)), the addition of sericin significantly improved the blastocyst formation rate of embryos exposed to 100 μm H(2)O(2). However, the protective effect of sericin was not observed in development of embryos exposed to 50 μm H(2)O(2). When embryos were exposed to 100 μm H(2)O(2) during culture, the DNA fragmentation index of total blastocysts from embryos cultured with 0.5% sericin was lower than blastocysts derived from embryos cultured without sericin (4.4 vs. 6.8%; P sericin to in vitro culture medium improved preimplantation development and quality of bovine embryos cultured individually by preventing oxidative stress. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. The Effect of Individualized Instruction System on the Academic Achievement Scores of Students

    Directory of Open Access Journals (Sweden)

    Ferhat Bahçeci

    2016-01-01

    Full Text Available A web-based learning portal offering individualized learning was developed by utilizing rule-based knowledge representation and artificial intelligence techniques of expert systems in order to reduce the uncertainties of learning to minimum and to construct an intelligent tutoring system. This portal offers individualized learning content based on the individual’s level of cognitive knowledge. In order to determine the effects of the developed system on the student achievement, the system was tested in an 8-week-long study on the students of Software Engineering Department of Technology Faculty. The pretest-posttest control group experimental design was used in the study. The experimental group received education with Individualized Instruction Portal while the control group received education in traditional learning environment. Academic achievement test was used as the data collection tool. In order to test the research hypotheses, data obtained from the data collection tools were analysed in terms of frequency, percentages, and dependent-independent t-test with statistical software program. Based on the results, no significant differences were found between the groups in terms of the pretest. On the other hand, significant differences were found between experimental and control group in terms of the posttest. It was concluded that individualized learning portal had positive effect on the students’ learning when used in combination with traditional learning environment.

  9. Fish Individual-based Numerical Simulator (FINS): A particle-based model of juvenile salmonid movement and dissolved gas exposure history in the Columbia River Basin

    International Nuclear Information System (INIS)

    Scheibe, Timothy D.; Richmond, Marshall C.

    2002-01-01

    This paper describes a numerical model of juvenile salmonid migration in the Columbia and Snake Rivers. The model, called the Fish Individual-based Numerical Simulator or FINS, employs a discrete, particle-based approach to simulate the migration and history of exposure to dissolved gases of individual fish. FINS is linked to a two-dimensional (vertically-averaged) hydrodynamic simulator that quantifies local water velocity, temperature, and dissolved gas levels as a function of river flow rates and dam operations. Simulated gas exposure histories can be input to biological mortality models to predict the effects of various river configurations on fish injury and mortality due to dissolved gas supersaturation. Therefore, FINS serves as a critical linkage between hydrodynamic models of the river system and models of biological impacts. FINS was parameterized and validated based on observations of individual fish movements collected using radiotelemetry methods during 1997 and 1998 . A quasi-inverse approach was used to decouple fish swimming movements from advection with the local water velocity, allowing inference of time series of non-advective displacements of individual fish from the radiotelemetry data. Statistical analyses of these displacements are presented, and confirm that strong temporal correlation of fish swimming behavior persists in some cases over several hours. A correlated random-walk model was employed to simulate the observed migration behavior, and parameters of the model were estimated that lead to close correspondence between predictions and observations

  10. Effects of Nursing Home Residency on Diabetes Care in Individuals with Dementia: An Explorative Analysis Based on German Claims Data

    Directory of Open Access Journals (Sweden)

    Larissa Schwarzkopf

    2017-02-01

    Full Text Available Aims: This claims data-based study compares the intensity of diabetes care in community dwellers and nursing home residents with dementia. Methods: Delivery of diabetes-related medical examinations (DRMEs was compared via logistic regression in 1,604 community dwellers and 1,010 nursing home residents with dementia. The intra-individual effect of nursing home transfer was evaluated within mixed models. Results: Delivery of DRMEs decreases with increasing care dependency, with more community-living individuals receiving DRMEs. Moreover, DRME provision decreases after nursing home transfer. Conclusion: Dementia patients receive fewer DRMEs than recommended, especially in cases of higher care dependency and particularly in nursing homes. This suggests lacking awareness regarding the specific challenges of combined diabetes and dementia care.

  11. Effects of Individual Health Topic Familiarity on Activity Patterns During Health Information Searches

    Science.gov (United States)

    Moriyama, Koichi; Fukui, Ken–ichi; Numao, Masayuki

    2015-01-01

    Background Non-medical professionals (consumers) are increasingly using the Internet to support their health information needs. However, the cognitive effort required to perform health information searches is affected by the consumer’s familiarity with health topics. Consumers may have different levels of familiarity with individual health topics. This variation in familiarity may cause misunderstandings because the information presented by search engines may not be understood correctly by the consumers. Objective As a first step toward the improvement of the health information search process, we aimed to examine the effects of health topic familiarity on health information search behaviors by identifying the common search activity patterns exhibited by groups of consumers with different levels of familiarity. Methods Each participant completed a health terminology familiarity questionnaire and health information search tasks. The responses to the familiarity questionnaire were used to grade the familiarity of participants with predefined health topics. The search task data were transcribed into a sequence of search activities using a coding scheme. A computational model was constructed from the sequence data using a Markov chain model to identify the common search patterns in each familiarity group. Results Forty participants were classified into L1 (not familiar), L2 (somewhat familiar), and L3 (familiar) groups based on their questionnaire responses. They had different levels of familiarity with four health topics. The video data obtained from all of the participants were transcribed into 4595 search activities (mean 28.7, SD 23.27 per session). The most frequent search activities and transitions in all the familiarity groups were related to evaluations of the relevancy of selected web pages in the retrieval results. However, the next most frequent transitions differed in each group and a chi-squared test confirmed this finding (Pinformation search patterns

  12. Consumer responses to advertising on the Internet: the effect of individual difference on ambivalence and avoidance.

    Science.gov (United States)

    Jin, Chang Hyun; Villegas, Jorge

    2007-04-01

    The purpose of this study was to understand the effect that individual characteristics have on consumer advertising processing under high- and low-interactivity circumstances on the Web. Tests on the relationship between individual differences and advertising responses form the basis of this empirical study on the Web. The results indicated that consumers have a higher tendency to avoid or experience ambivalence about Internet advertisements under low-interactivity circumstances, and attitudinal ambivalence lead to avoidance when responding to advertisements on the Internet. Personality variables are the main factors in consumer decision-making behaviors and Internet characteristics, such as levels of interactivity, can greatly influence the effectiveness of advertising in online environments. Advertising credibility could influence people's consumer attitudes, beliefs, or behaviors over time on the Web.

  13. Individual Difference Variables and the Occurrence and Effectiveness of Faking Behavior in Interviews

    Science.gov (United States)

    Buehl, Anne-Kathrin; Melchers, Klaus G.

    2017-01-01

    There is widespread fear that applicants can fake during selection interviews and that this impairs the quality of selection decisions. Several theories assume that faking occurrence is influenced by personality and attitudes, which together influence applicants’ motivation to show faking behavior. However, for faking behavior to be effective, interviewees also need certain skills and abilities. To investigate the impact of several relevant individual difference variables on faking behavior and interview success, we conducted two studies. In Study 1, we surveyed 222 individuals to assess different personality variables, attitude toward faking, cognitive ability, self-reported faking behavior, and success in previous interviews, and in Study 2, we assessed cognitive ability, social skills, faking behavior, and interview performance in an interview simulation with 108 participants. Taken together, personality, as well as attitude toward faking, influenced who showed faking behavior in an interview, but there was no evidence for the assumed moderating effect of cognitive ability or social skills on interview success. PMID:28539895

  14. Effect of Aromatherapy Massage on Agitation and Depressive Mood in Individuals With Dementia.

    Science.gov (United States)

    Yang, Ya-Ping; Wang, Chi-Jane; Wang, Jing-Jy

    2016-09-01

    The current study examined the effects of aromatherapy massage on alleviating agitation and depressive mood in individuals with dementia. A randomized controlled trial and repeated measures design was conducted. A total of 59 participants were randomly assigned to intervention or control groups. The intervention group received aromatherapy massage once per week for 8 weeks. Results indicated no significant changes over time in overall agitation for either group, but agitation decreased from Week 1 to Week 5 for the intervention group. In addition, the overall depressive symptoms decreased significantly over time for the intervention group compared to the control group (p aromatherapy massage showed some significant changes in Weeks 5 and 9. Aromatherapy massage can be an effective and safe intervention to alleviate specific agitated behaviors and depressive mood in individuals with dementia. [Journal of Gerontological Nursing, 42(9), 38-46.]. Copyright 2016, SLACK Incorporated.

  15. The effects of individually tailored nurse navigation for patients with newly diagnosed breast cancer

    DEFF Research Database (Denmark)

    Mertz, Birgitte Goldschmidt; Dunn-Henriksen, Anne Katrine; Kroman, Niels

    2017-01-01

    AIM: Our aim was to determine the feasibility and effectiveness of an individual, nurse-navigator intervention for relieving distress, anxiety, depression and health-related quality of life in women who have been treated for breast cancer (BC) and are experiencing moderate-to-severe psychological...... and the secondary outcomes were anxiety, depression, health-related quality of life and feasibility of the intervention. RESULTS: Women in the intervention group reported significantly greater satisfaction with treatment and rehabilitation and lower levels of distress (mean 2.7 vs. 5.1, p.... 7.8, p = .02) and depression (mean 2.2 vs. 4.4, p = .04) after 12 months compared to the control group. No significant effects were seen on health-related quality of life. CONCLUSIONS: The study shows promising feasibility of the individually tailored nurse-navigation intervention and while...

  16. Individual diet has sex-dependent effects on vertebrate gut microbiota

    Science.gov (United States)

    Bolnick, Daniel I.; Snowberg, Lisa K.; Hirsch, Philipp E.; Lauber, Christian L.; Org, Elin; Parks, Brian; Lusis, Aldons J.; Knight, Rob; Caporaso, J. Gregory; Svanbäck, Richard

    2014-01-01

    Vertebrates harbour diverse communities of symbiotic gut microbes. Host diet is known to alter microbiota composition, implying that dietary treatments might alleviate diseases arising from altered microbial composition (‘dysbiosis’). However, it remains unclear whether diet effects are general or depend on host genotype. Here we show that gut microbiota composition depends on interactions between host diet and sex within populations of wild and laboratory fish, laboratory mice and humans. Within each of two natural fish populations (threespine stickleback and Eurasian perch), among-individual diet variation is correlated with individual differences in gut microbiota. However, these diet–microbiota associations are sex dependent. We document similar sex-specific diet–microbiota correlations in humans. Experimental diet manipulations in laboratory stickleback and mice confirmed that diet affects microbiota differently in males versus females. The prevalence of such genotype by environment (sex by diet) interactions implies that therapies to treat dysbiosis might have sex-specific effects. PMID:25072318

  17. Effects of policies designed to keep firearms from high-risk individuals.

    Science.gov (United States)

    Webster, Daniel W; Wintemute, Garen J

    2015-03-18

    This article summarizes and critiques available evidence from studies published between 1999 and August 2014 on the effects of policies designed to keep firearms from high-risk individuals in the United States. Some prohibitions for high-risk individuals (e.g., those under domestic violence restraining orders, violent misdemeanants) and procedures for checking for more types of prohibiting conditions are associated with lower rates of violence. Certain laws intended to prevent prohibited persons from accessing firearms-rigorous permit-to-purchase, comprehensive background checks, strong regulation and oversight of gun dealers, and requiring gun owners to promptly report lost or stolen firearms-are negatively associated with the diversion of guns to criminals. Future research is needed to examine whether these laws curtail nonlethal gun violence and whether the effects of expanding prohibiting conditions for firearm possession are modified by the presence of policies to prevent diversion.

  18. Ultraclean individual suspended single-walled carbon nanotube field effect transistor

    Science.gov (United States)

    Liu, Siyu; Zhang, Jian; Nshimiyimana, Jean Pierre; Chi, Xiannian; Hu, Xiao; Wu, Pei; Liu, Jia; Wang, Gongtang; Sun, Lianfeng

    2018-04-01

    In this work, we report an effective technique of fabricating ultraclean individual suspended single-walled carbon nanotube (SWNT) transistors. The surface tension of molten silver is utilized to suspend an individual SWNT between a pair of Pd electrodes during annealing treatment. This approach avoids the usage and the residues of organic resist attached to SWNTs, resulting ultraclean SWNT devices. And the resistance per micrometer of suspended SWNTs is found to be smaller than that of non-suspended SWNTs, indicating the effect of the substrate on the electrical properties of SWNTs. The ON-state resistance (˜50 kΩ), mobility of 8600 cm2 V-1 s-1 and large on/off ratio (˜105) of semiconducting suspended SWNT devices indicate its advantages and potential applications.

  19. Characterization of Atomoxetine Biotransformation and Implications for Development of PBPK Models for Dose Individualization in Children

    Science.gov (United States)

    Pearce, Robin E.; Van Haandel, Leon; Gaedigk, Andrea; Leeder, J. Steven

    2016-01-01

    Atomoxetine (ATX) is a second-line nonstimulant medication used to control symptoms of attention deficit hyperactivity disorder (ADHD). Inconsistent therapeutic efficacy has been reported with ATX, which may be related to variable CYP2D6-mediated drug clearance. We characterized ATX metabolism in a panel of human liver samples as a basis for a bottom-up PBPK model to aid in ATX exposure prediction and control. Km, Vmax, and Clint values in pooled human liver microsomes (HLMs) were 2.4 µM, 479 pmol/min/mg protein, and 202 µl/min/mg protein, respectively. Mean population values of kinetic parameters are not adequate to describe variability in a population, given that Km, Vmax, and Clint values from single-donor HLMs ranged from 0.93 to 79.2 µM, 20.0 to 1600 pmol/min/mg protein, and 0.3 to 936 µl/min/mg protein. All kinetic parameters were calculated from 4-hydroxyatomoxetine (4-OH-ATX) formation. CYP2E1 and CYP3A contributed to 4-OH-ATX formation in livers with CYP2D6 intermediate and poor metabolizer status. In HLMs with lower CYP2D6 activity levels, 2-hydroxymethylatomoxetine (2-CH2OH-ATX) formation became a more predominant pathway of metabolism, which appeared to be catalyzed by CYP2B6. ATX biotransformation at clinically relevant plasma concentrations was characterized in a panel of pediatric HLM (n = 116) samples by evaluating primary metabolites. Competing pathways of ATX metabolism [N-desmethylatomoxetine (NDM-ATX) and 2-CH2OH-ATX formation] had increasing importance in livers with lesser CYP2D6 activity, but, overall ATX clearance was still compromised. Modeling ATX exposure to individualize therapy would require comprehensive knowledge of factors that affect CYP2D6 activity as well as an understanding of competing pathways, particularly for individuals with lower CYP2D6 activity. PMID:27052878

  20. Assessing Individual Weather Risk-Taking and Its Role in Modeling Likelihood of Hurricane Evacuation

    Science.gov (United States)

    Stewart, A. E.

    2017-12-01

    This research focuses upon measuring an individual's level of perceived risk of different severe and extreme weather conditions using a new self-report measure, the Weather Risk-Taking Scale (WRTS). For 32 severe and extreme situations in which people could perform an unsafe behavior (e. g., remaining outside with lightning striking close by, driving over roadways covered with water, not evacuating ahead of an approaching hurricane, etc.), people rated: 1.their likelihood of performing the behavior, 2. The perceived risk of performing the behavior, 3. the expected benefits of performing the behavior, and 4. whether the behavior has actually been performed in the past. Initial development research with the measure using 246 undergraduate students examined its psychometric properties and found that it was internally consistent (Cronbach's a ranged from .87 to .93 for the four scales) and that the scales possessed good temporal (test-retest) reliability (r's ranged from .84 to .91). A second regression study involving 86 undergraduate students found that taking weather risks was associated with having taken similar risks in one's past and with the personality trait of sensation-seeking. Being more attentive to the weather and perceiving its risks when it became extreme was associated with lower likelihoods of taking weather risks (overall regression model, R2adj = 0.60). A third study involving 334 people examined the contributions of weather risk perceptions and risk-taking in modeling the self-reported likelihood of complying with a recommended evacuation ahead of a hurricane. Here, higher perceptions of hurricane risks and lower perceived benefits of risk-taking along with fear of severe weather and hurricane personal self-efficacy ratings were all statistically significant contributors to the likelihood of evacuating ahead of a hurricane. Psychological rootedness and attachment to one's home also tend to predict lack of evacuation. This research highlights the