We consider the three principal LiBeB evolutionary models, CRI in which the cosmic-ray source at all epochs of Galactic evolution is the average ISM, CRI+LECR in which metal enriched low energy cosmic rays (LECRs) are superimposed onto the CRI cosmic rays, and CRS in which the cosmic-ray source, accelerated in superbubbles, is constant, independent of the ISM metallicity. By considering the evo...

This paper considers a variety of econometric models for the joint distribution of stock and bond returns in the presence of regime switching dynamics. While simple twoor three-state models capture the univariate dynamics in bond and stock returns, a more complicated four state model with regimes characterized as crash, slow growth, bull and bull burst states is required to capture the joint di...

Survival bias is a potential problem when subjects are lost to follow-up, and this selection issue may arise in a wide range of biomedical studies. Controlling for the bias is difficult because subjects may be lost due to unmeasured factors. This article presents a two-step method that adjusts for survival bias in the proportional hazards model, even when unmeasured factors influence survival. ...