A new grid method for computing the Snell envelop of a function of a R d -valued Markov chain (Xk)0≤k≤n is proposed. (This problem is typically non linear and cannot be solved by the standard Monte Carlo method.) Every Xk is replaced by a “quantized approximation” X̂k taking its values in a grid Γk of size Nk. The n grids and their transition probability matrices make up a discrete tree on which...

The involvement of mammalian target of rapamycin (mTOR) in lifespan control in invertebrates, calorie-restricted rodents, and extension of mouse lifespan by rapamycin have prompted speculation that diminished mTOR function may contribute to mammalian longevity in several settings. We show here that mTOR complex-1 (mTORC1) activity is indeed lower in liver, muscle, heart, and kidney tissue of Sn...

Previous reports from this laboratory have shown that pantothenic acid is essential for the growth of every species of lactic acid bacteria tested (Snell et al., 1937). It has also been shown that while some species of lactic acid bacteria require riboflavin for growth, several do not (Snell and Strong, 1939). In a study of the activity of certain synthetic flavins, a close correlation was foun...

The literature on the immunological aspects of tumor transplantation has been well reviewed by Hauschka (9), so it is necessary only to point out certain technical problems that form the basis for the present communication. The most striking recent advances in our knowledge of the genetics of tumor transplanta tion have been due to the work of Snell and his colleagues on the H-2 locus (13) and ...

In this paper we study the pricing problem of multiple exercise options in continuous time on a finite time horizon. For the corresponding multiple stopping problem, we prove, under quite general assumptions, the existence of the Snell envelope, a reduction principle as nested single stopping problems, and a Doob-Meyer type decomposition for the Snell envelope. The main technical difficulty ari...

The inspection of residuals is a fundamental step to investigate the quality of adjustment of a parametric model to data. For spatial point processes, the concept of residuals has been recently proposed by Baddeley et al. Baddeley et al. (2005) as an empirical counterpart of the Campbell equilibrium equation for marked Gibbs point processes. The present paper focuses on stationary marked Gibbs ...

We take a fresh look at Theil’s BLUS residuals and ask why they have gone out of fashion. All our simulation experiments indicate that tests based on BLUS residuals have higher power than those based on the more popular recursive residuals, even in those cases (structural breaks) where intuition would favour the recursive residuals. JEL Classification: B23; C10; C13; C20