In this paper, we investigate the standard Yule model, and a recently studied model of speciation and extinction, the "critical branching process." We develop an analytic way-as opposed to the common simulation approach-for calculating the speciation times in a reconstructed phylogenetic tree. Simple expressions for the density and the moments of the speciation times are obtained. Methods for d...

Using male/female and Caucasian/African American comparison groups, this study examined the practical ramifications of using two IRT-based analytic methods, DFIT and the Likelihood Ratio Test (LRT), in assessing the measurement invariance of a 21-item leadership development scale under ten sample size conditions (e.g., 200, 500, & 1000). In nine of ten conditions, the LRT identified multiple it...

Spatial normalization--applying standardized coordinates as anatomical addresses within a reference space--was introduced to human neuroimaging research nearly 30 years ago. Over these three decades, an impressive series of methodological advances have adopted, extended, and popularized this standard. Collectively, this work has generated a methodologically coherent literature of unprecedented ...

We study avalanche dynamics on scale-free networks, following a power-law degree distribution, pd ðkÞ k ; through the Bak–Tang–Wiesenfeld sandpile model. The threshold height of a node i is set to be k 1 Z i with 0pZo1: We obtain the exponents for the avalanche size and the duration distributions analytically as a function of g and Z by using the branching process approach. The analytic solutio...

Previous research has suggested that the factor structure of anxiety measures is different in African American samples compared to majority population samples. However, these findings may be due to misuse of analytic methods rather than meaningful differences in the underlying presentation of anxiety. To address this, we examined the factor structure of two measures of child anxiety: the Revise...

As a statistical measure of large-scale structure of the universe, the genus number is presented in analytic form for realistic non-Gaussian distributions, i.e., weakly non-Gaussian, lognormal and chi-square distributions. These formulae are compared with the results of N-body simulation. It is shown that the weakly non-Gaussian formula describes the behavior of genus in weakly nonlinear regime...

Including contributions of scale-dependent vacuum expectation values, we derive new analytic formulas and obtain substantially different numerical predictions for the running masses of quarks and charged-leptons at higher scales in the SM, 2HDM and MSSM. These formulas exhibit significantly different behaviours with respect to their dependence on gauge and Yukawa couplings than those derived ea...

We investigate the impact on low energy flavour mixing phenomena of the renormalisation group running of parameters in supersymmetric theories. We have explicitly chosen flavour dependent supergravity couplings. The renormalisation group equations are displayed in general matrix form. We work in a scale dependent basis such that the hierarchy in the quark masses can be more easily utilised. Sim...