scholarly journals Predicting Mixture Effects over Time with Toxicokinetic–Toxicodynamic Models (GUTS): Assumptions, Experimental Testing, and Predictive Power

2021 ◽  
Vol 55 (4) ◽  
pp. 2430-2439
Author(s):  
Sylvain Bart ◽  
Tjalling Jager ◽  
Alex Robinson ◽  
Elma Lahive ◽  
David J. Spurgeon ◽  
...  
Keyword(s):  
Predictive Power ◽  
Experimental Testing ◽  
Mixture Effects ◽  
Over Time

Longitudinal Stability of Personality

1992 ◽  
Vol 70 (2) ◽  
pp. 483-498 ◽  
Author(s):  
David D. Smith
Keyword(s):  
Human Brain ◽  
Predictive Power ◽  
Total Variance ◽  
Global Dynamics ◽  
Longitudinal Stability ◽  
Normal Human Brain ◽  
Adult Personality ◽  
Normal Human ◽  
Personality Theories ◽  
Over Time

Estimates of the longitudinal stability of the normal adult personality decrease with increase in the length of the assessment-reassessment interval over which stability is measured, regardless of the method employed. This randomness in the evolution of personality is attributed to the inherent indeterminacy of the global dynamics of the normal human brain. The predictive power of theories of personality is fundamentally constrained. Explanatory personality theories should not be evaluated in terms of the proportion of the total variance that they predict over time but rather on the proportion of the predictable variance they account for.

The Future is a Moving Target: Predicting Political Instability

2019 ◽  
Vol 50 (4) ◽  
pp. 1405-1417 ◽  
Author(s):  
Drew Bowlsby ◽  
Erica Chenoweth ◽  
Cullen Hendrix ◽  
Jonathan D. Moyer
Keyword(s):  
Political Institutions ◽  
Armed Conflict ◽  
Predictive Power ◽  
Political Instability ◽  
Explanatory Power ◽  
State Level ◽  
Recent Period ◽  
Arab Uprisings ◽  
Out Of Sample ◽  
Over Time

AbstractPrevious research by Goldstone et al. (2010) generated a highly accurate predictive model of state-level political instability. Notably, this model identifies political institutions – and partial democracy with factionalism, specifically – as the most compelling factors explaining when and where instability events are likely to occur. This article reassesses the model’s explanatory power and makes three related points: (1) the model’s predictive power varies substantially over time; (2) its predictive power peaked in the period used for out-of-sample validation (1995–2004) in the original study and (3) the model performs relatively poorly in the more recent period. The authors find that this decline is not simply due to the Arab Uprisings, instability events that occurred in autocracies. Similar issues are found with attempts to predict nonviolent uprisings (Chenoweth and Ulfelder 2017) and armed conflict onset and continuation (Hegre et al. 2013). These results inform two conclusions: (1) the drivers of instability are not constant over time and (2) care must be exercised in interpreting prediction exercises as evidence in favor or dispositive of theoretical mechanisms.

scholarly journals Working over Time: Dynamic Inconsistency in Real Effort Tasks *

2015 ◽  
Vol 130 (3) ◽  
pp. 1067-1115 ◽  
Author(s):  
Ned Augenblick ◽  
Muriel Niederle ◽  
Charles Sprenger
Keyword(s):  
Predictive Power ◽  
Experimental Tests ◽  
Time Inconsistency ◽  
Policy Implications ◽  
Dynamic Inconsistency ◽  
Time Dynamic ◽  
Present Bias ◽  
Monetary Rewards ◽  
Real Effort ◽  
Over Time

Abstract Experimental tests of dynamically inconsistent time preferences have largely relied on choices over time-dated monetary rewards. Several recent studies have failed to find the standard patterns of present bias. However, such monetary studies contain often-discussed confounds. In this article, we sidestep these confounds and investigate choices over consumption (real effort) in a longitudinal experiment. We pair this effort study with a companion monetary discounting study. We confirm very limited time inconsistency in monetary choices. However, subjects show considerably more present bias in effort. Furthermore, present bias in the allocation of work has predictive power for demand of a meaningfully binding commitment device. Therefore our findings validate a key implication of models of dynamic inconsistency, with corresponding policy implications.

Time-dependence of NIHSS in predicting functional outcome of patients with acute ischemic stroke treated with intravenous thrombolysis

2019 ◽  
Vol 95 (1122) ◽  
pp. 181-186 ◽  
Author(s):  
Zimu Wu ◽  
Minyan Zeng ◽  
Chao Li ◽  
Hongyan Qiu ◽  
Haixia Feng ◽  
...  
Keyword(s):  
Functional Outcome ◽  
Predictive Power ◽  
Intravenous Thrombolysis ◽  
Recombinant Tissue Plasminogen Activator ◽  
Time Dependent ◽  
Nihss Score ◽  
Receiver Operating Characteristic Curves ◽  
Youden’S Index ◽  
Over Time ◽  
Treatment Sensitivity

ObjectivesThe National Institute of Health Stroke Scale (NIHSS) is a predictor for the prognosis of acute ischaemic stroke (AIS) and its prediction is time-dependent. We examined the performance of NIHSS at different timepoints in predicting functional outcome of patients with thrombolysed AIS.MethodsThis prospective study included 269 patients with AIS treated with recombinant tissue plasminogen activator (rt-PA). Unfavourable functional outcome was defined as modified Rankin Scale score 4–6 at 3 months after rt-PA treatment. Receiver operating characteristic curves were used to examine the predictive power of NIHSS score at admission and 2 hours/24 hours/7 days/10 days after rt-PA treatment. Youden’s index was used to select the threshold of NIHSS score. Logistic regression was used to estimate the ORs of unfavourable functional outcome for patients with NIHSS score higher than the selected thresholds.ResultsThe threshold of NIHSS score at admission was 12 (sensitivity: 0.51, specificity: 0.84) with an acceptable predictive power (area under curve [AUC] 0.74) for unfavourable functional outcome. The threshold changed to 5 at 24 hours after rt-PA treatment (sensitivity: 0.83, specificity: 0.65) and remained unchanged afterwards. The predictive power and sensitivity sequentially increased over time and peaked at 10 days after rt-PA treatment (AUC 0.92, sensitivity: 0.85, specificity: 0.80). NIHSS scores higher than the thresholds were associated with elevated risk of unfavourable functional outcome at all timepoints (all p<0.001).ConclusionsNIHSS is time-dependent in predicting AIS prognosis with increasing predictive power over time. Since patients whose NIHSS score ≥ 12 are likely to have unfavourable functional outcome with rt-PA treatment only, mechanical thrombectomy should be largely taken into consideration for these patients.

Student and teacher ratings of instructional quality: Consistency of ratings over time, agreement, and predictive power.

2016 ◽  
Vol 108 (5) ◽  
pp. 705-721 ◽  
Author(s):  
Wolfgang Wagner ◽  
Richard Göllner ◽  
Sarah Werth ◽  
Thamar Voss ◽  
Bernhard Schmitz ◽  
...  
Keyword(s):  
Predictive Power ◽  
Instructional Quality ◽  
Teacher Ratings ◽  
Over Time

Testing and Analysis of Fasteners

2021 ◽  
Vol 9 (10) ◽  
pp. 235-243
Author(s):  
Omkar Adhikari
Keyword(s):  
Biaxial Loading ◽  
Experimental Testing ◽  
Axial Loading ◽  
Control Valve ◽  
Pneumatic Cylinder ◽  
Flow Control Valve ◽  
Mode Of Failure ◽  
Long Time ◽  
Upward Direction ◽  
Over Time

Abstract: By considering the tightening process, the experimental testing will be conducted to explore the mechanism of bolt selfloosening under biaxial loading. The most common mode of failure is overloading: Operating forces of the application produce loads that exceed the clamp load, causing the joint to loosen over time or fail catastrophically. Over torque might cause failure by damaging the threads and deforming the fastener, though this can happen over a very long time. Also, the bolts may fail under fatigue. The components used in the system are bolts, pneumatic cylinder and flow control valve. The pneumatic cylinder is actuated with the help of compressor. The flow of air in the cylinder will be controlled with the help of pneumatic cylinder which will be acted on the bolts in two directions that is from downward & upward direction. This means the load will be tensile and shearing load. The bolts are attached to the plates. Because of actuation of the pneumatic cylinder the bolts will become loose. These bolts will be tested by using biaxial loading. The result & conclusion was drawn after the experimental testing. Keywords: Bi-axial Loading, Fasteners, Bolt Loosening, Residual Torque, Fastener Overloading

scholarly journals Investigating the impact of structural factors upon that/zero complementizer alternation patterns in verbs of cognition: a diachronic corpus-based multifactorial analysis

2018 ◽  
pp. 83-112
Author(s):  
Christopher Shank ◽  
Koen Plevoets
Keyword(s):  
Predictive Power ◽  
Structural Features ◽  
Stepwise Logistic Regression ◽  
Large Set ◽  
Structural Factors ◽  
Quantitative Methodology ◽  
Stepwise Logistic Regression Analysis ◽  
Conditioning Factors ◽  
The Impact ◽  
Over Time

This corpus-based study examines the diachronic development of the that/zero alternation with nine verbs of cognition, viz. think, believe, feel, guess, imagine, know, realize, suppose and understand by means of a stepwise logistic regression analysis. The data comprised a total of (n=5,812) think, (n=3,056) believe, (n=1,273) feel, (n=1,885) guess, (n=2,225) imagine, (n=1,805) know, (n=1,244) realize, (n=2,836) suppose and (n=3,395) understand tokens from both spoken and written corpora from 1580–2012. Taking our cue from previous research suggesting that there has been a diachronic increase in the use of the zero complementizer form from Late Middle / Early Modern to Present-day English, we use a large set of parallel spoken and written diachronic data and a rigorous quantitative methodology to test this claim with the nine aforementioned verbs. In addition, we also investigate the impact of eleven structural features, which have been claimed to act as predictors for the use or presence of the zero complementizer form for ‘panchronic’ (i.e. effects are aggregated over all time periods) and diachronic effects. The objectives of this study are to examine the following: (i) whether there is indeed a diachronic trend towards more zero use; (ii) whether the conditioning factors proposed in the literature indeed predict the zero form; (iii) to what extent these factors interact; and (iv) whether the predictive power of the conditioning factors becomes stronger or weaker over time. The analysis shows that, contrary to the aforementioned belief that the zero form has been on the increase, there is in fact a steady decrease in zero use, but the extent of this decrease is not the same for all verbs. In addition, the analysis of interactions with verb type indicates differences between verbs in terms of the predictive power of the conditioning factors. Additional significant interactions emerged, notably with verb, mode (i.e. spoken or written data) and period. The interactions with period show that certain factors that are good predictors of the zero form overall lose predictive power over time.

scholarly journals An Analysis of Socio-Economic Strains and Population Gains: Urban and Rural Communities of Canada 1981-2001

2007 ◽  
Vol 34 (2) ◽  
pp. 191
Author(s):  
Fernando Mata ◽  
Ray D. Bollman
Keyword(s):  
Rural Communities ◽  
Structural Equation ◽  
Predictive Power ◽  
Structural Equation Models ◽  
Population Changes ◽  
Data Set ◽  
Rural And Urban ◽  
Statistics Canada ◽  
Demographic Shifts ◽  
Over Time

Important demographic shifts have occurred in Canada in the last decades. As a consequence of these shifts, many geographical communities have won or lost substantial number of residents between 1981 and 2001. Using the CCS (consolidated census subdivision) data set of the Agriculture Division of Statistics Canada, the paper explores the linkages between socio-economic strains and population changes affecting communities in a variety of regional and provincial contexts. A total of 2,607 rural and urban consolidated census subdivisions were examined across five census periods. Quasi simplex structural equation models using unemployment, earnings and poverty as indicators were tested on a variety of communities located in various OECD regions and provinces. Although the predictive power of strains on population gains was found to be limited in the models, a higher level of strain was persistently found to be negatively associated with population gains regardless of regional and provincial groupings of communities. Socio-economic strains were also observed to be relatively stable over time across a variety of geographies.

Indicators of Deprivation in People and Places: Longitudinal Perspectives

1998 ◽  
Vol 30 (6) ◽  
pp. 1055-1076 ◽  
Author(s):  
A Sloggett ◽  
H Joshi
Keyword(s):  
Predictive Power ◽  
Individual Characteristics ◽  
Housing Tenure ◽  
Area Deprivation ◽  
Spatial Mobility ◽  
Multivariate Models ◽  
National Statistics ◽  
The Individual ◽  
Over Time

The Office for National Statistics Longitudinal Study of England and Wales is used to describe the prevalence in individuals, over time, of a set of variables commonly used in the construction of indicators of area deprivation. These variables are: housing tenure, car access, low skill, and unemployment. Over three censuses between 1971 and 1991, these states appear neither completely permanent nor entirely random. The picture is one of changing fortunes; many individuals temporarily disadvantaged revolving around a core of those experiencing more long-term disadvantage. This is especially true of unemployment. Used in multivariate models to predict health and deprivation outcomes in 1991, the individual characteristics from both 1971 and 1981 have stronger predictive power than ward scores on deprivation indicators. The relation between spatial mobility and the health and social outcomes appears favourable only for young adults.

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