“Oscillations” occur in quite different kinds of many-particle-systems when two groups of particles with different directions of motion meet or intersect at a certain spot. In this work a model of pedestrian motion is presented that is able to reproduce oscillations with different characteristics. The Wald-Wolfowitz test and Gillis’ correlated random walk are shown to include observables that c...

1 The central theme in case-control genetic association studies is to efficiently identify genetic markers associated with case-control status. Powerful statistical methods are critical to accomplishing this goal. A popular statistical method is the model-free Pearson's chi-square test. To achieve increased power, model-based tests have been widely used despite their lack of robustness to model...

BACKGROUND AND PURPOSE Brain metastases (BMs) are typically associated with poor patient prognosis. Radiation therapy remains the primary treatment for BMs, and patient's prognosis is affected by many factors. The aim of this study was to identify prognostic factors and to compare prognostic index scores in patients with BMs who received whole-brain radiotherapy (WBRT). METHODS A retrospectiv...

Non-linear mixed-effects models (NLMEMs) are used to improve information gathering from longitudinal studies and are applied to treatment evaluation in disease-evolution studies, such as human immunodeficiency virus (HIV) infection. The estimation of parameters and the statistical tests are critical issues in NLMEMs since the likelihood and the Fisher information matrix have no closed form. An ...

OBJECTIVE While the protective nature of moderate alcohol consumption against diabetes mellitus is well known, inconsistent findings continue to be reported. The possibility of different mixes of effect modifiers has been raised as a reason for those inconsistent findings. Our study aim was to examine potential effect modifiers that can change the effect of alcohol consumption on type 2 diabete...

Testing the equality of percentiles (quantiles) between populations is an effective method for robust, nonparametric comparison, especially when the distributions are asymmetric or irregularly shaped. Unlike global nonparametric tests for homogeneity such as the Kolmogorv-Smirnov test, testing the equality of a set of percentiles (i.e., a percentile profile) yields an estimate of the location a...

The asymptotic expansion of the distribution of the gradient test statistic is derived for a composite hypothesis under a sequence of Pitman alternative hypotheses converging to the null hypothesis at rate n−1/2, n being the sample size. Comparisons of the local powers of the gradient, likelihood ratio, Wald and score tests reveal no uniform superiority property. The power performance of all fo...

INTRODUCTION We sought to determine the effect of nutritional support and insulin infusion therapy on serum and brain glucose levels and cerebral metabolic crisis after aneurysmal subarachnoid hemorrhage (SAH). METHODS We used a retrospective observational cohort study of 50 mechanically ventilated poor-grade (Hunt-Hess 4 or 5) aneurysmal SAH patients who underwent brain microdialysis monitor...