AIMS To quantitatively evaluate the changes in corneal irregular astigmatism after laser in situ keratomileusis (LASIK) in relation to the amount of laser ablation. METHODS In 189 eyes of 116 patients undergoing LASIK for myopia, corneal topography was obtained before and 1 month after surgery. Using Fourier harmonic analysis of the topography data, corneal irregular astigmatism (asymmetry an...

The prognostic value of mTOR in ESCC is much controversial; this study aimed to determine the prognostic importance of mTOR and PTEN in patients with ESCC. A total of 148 consecutive patients who underwent esophagectomy from 2010 to 2012 were included in this study, tested by western bolt and immunohistochemistry for mTOR and PTEN expression. Correlation coefficient was calculated using Pearson...

In the current issue of the Journal, Gansevoort et al. (1) raise concerns about our paper (2) that compared the strengths and weaknesses of the urinary albumin concentration and the albumin:creatinine ratio as alternatives to the ‘‘gold standard’’ 24-hour urinary albumin excretion in the International Study of Macronutrients and Blood Pressure (INTERMAP). In that report, which used albumin excr...

Let {X,Xk,i; i ≥ 1, k ≥ 1} be a double array of nondegenerate i.i.d. random variables and let {pn; n ≥ 1} be a sequence of positive integers such that n/pn is bounded away from 0 and ∞. This work is devoted to the solution to an open problem posed in Li, Liu, and Rosalsky (2010) on the asymptotic distribution of the largest entry Ln = max1≤i<j≤pn ∣∣ρ̂(n) i,j ∣∣ of the sample correlation matrix Γ...

We derive sufficient conditions for the cross-correlation coefficient of a multivariate spatial process to vary with location when the spatial model is augmented with nugget effects. The derived class is valid for any choice of covariance functions, and yields substantial flexibility between multiple processes. The key is to identify the cross-correlation coefficient matrix with a contraction m...

We hypothesized that a better correlation between MRI and clinical measures of neurological disability using the expanded disability status scale (EDSS) in multiple sclerosis could be obtained by assessing lesion load only in and around the corticospinal tracts, since the EDSS is weighted towards motor and ambulatory deficits. Multiple sclerosis lesions in cerebral MRIs from 39 patients with re...

where X and Y are random returns. The main innovation introduced by Markowitz is to measure the risk of a portfolio via the joint (multivariate) distribution of returns of all assets. Multivariate distributions are characterized by the statistical (marginal) properties of all component random variables and by their dependence structure. Markowitz described the former by the first two moments of...

In this study, we first build two empirical cross-correlationmatrices in the US stockmarket by two different methods, namely the Pearson’s correlation coefficient and the detrended cross-correlation coefficient (DCCA coefficient). Then, combining the twomatriceswith the method of random matrix theory (RMT), we mainly investigate the statistical properties of cross-correlations in the US stock m...

In order to undertake controlled investigations into perceptual effects that relate to the interaural cross-correlation coefficient, experiment stimuli that meet a tight set of criteria are required. The requirements of each stimulus are that it is narrow band, normally has a constant cross-correlation coefficient over time, and can be altered to cover the full range of values of cross-correlat...