The precise complexity of complementing Büchi automata is an intriguing and long standing problem. While optimal complementation techniques for finite automata are simple – it suffices to determinize them using a simple subset construction and to dualize the acceptance condition of the resulting automaton – Büchi complementation is more involved. Indeed, the construction of an EXPTIME complemen...

Previous reports showed that treatment with non-steroidal anti-inflammatory agents (NSAIA) can alter the growth profile of a variety of tumours. In this study, the effect of NSAIA treatment on the growth of the primary tumour and the appearance of spontaneous pulmonary metastases, was investigated. A mammary adenocarcinoma of non-detected immunogenicity, C7HI, was grafted subcutaneously in the ...

This year marks the 150th anniversary of the birth of D’Arcy Thompson, the British biologist, classicist, and all round polymath (For more information on D’Arcy Thompson see www. darcythompson.org). Like many, he was fascinated by the appearance and structure of living matter, and in his influential book, On Growth and Form [1], he set out to describe and explain the principles of morphogenesis...

The Paxos algorithm, when presented in plain English, is very simple.

(A, B,C, D, . . . are positive constants), where the symbol means that rn lies between any two successive partial sums of the series. Usually (as in [1, pp. 529–534]) this formula is deduced from Euler’s summation formula. In this note we show how to compute in succession the constants A, B,C, . . . by a very simple technique. Only derivatives and limits of ln and of rational functions are invo...

We present a Haskell library that makes it easy for compiler writers to implement program transformations based on dataflow analyses. The compiler writer must identify (a) a family of logical assertions on which the transformation will be based; (b) an approximate representation of such assertions, which must have a lattice structure such that every assertion can be increased at most finitely m...

Groupoidification is a form of categorification in which vector spaces are replaced by groupoids, and linear operators are replaced by spans of groupoids. We introduce this idea with a detailed exposition of ‘degroupoidification’: a systematic process that turns groupoids and spans into vector spaces and linear operators. Then we present two applications of groupoidification. The first is to Fe...