When ambients cannot be opened

When Ambients Cannot Be Opened

We investigate expressiveness of a fragment of the ambient calculus, a formalism for describing distributed and mobile computations. More precisely, we study expressiveness of the pure and public ambient calculus from which the capability has been removed, in terms of the reachability problem of the reduction relation. Surprisingly, we show that even for this very restricted fragment, the reach...

When the Bellman Equation Cannot Be Solved Analytically

Many questions in managerial decision making imply —if uncertainty is involved— stochastic optimization problems of the form V (S) = max x E {∫ ∞ 0 e−ρtf(S, x) dt } where the state transition dS = g(S, x) dt + σ(S) dz describes the underlying stochastic process S as an Itō process and dz is a Brownian motion. For very simple problems, results can be obtained analytically by solving the correspo...

When two memories can and cannot be retrieved concurrently.

We examined whether two memories can be retrieved concurrently from long-term memory. In Experiment 1, the subjects recalled words, either from two categories--alternating between the two--or from just one category. In Experiment 2, the subjects recalled two words belonging to either the same category or different categories, and the category prompts for these two responses appeared either simu...

Treating cancer when pRb and p53 cannot be reactivated

Activation of oncoproteins and inactivation of tumor suppressors induces tumorigenesis. When these events happen upstream of pRb and p53, cancer therapies may initially succeed and then fail when pRb and p53 are activated and then re-inactivated. Therapies might succeed if they remain effective when pRb and p53 are genetically inactivated.

Knock and it shall be opened...