The theory of free profinite semigroups, which received its major impetus with the publication of Reiterman’s paper [17] in the early eighties, has proven to be an important tool in the study of pseudovarieties of semigroups and on the varieties of recognizable languages associated with them (via Eilenberg’s Theorem on varieties [13]). The importance of Reiterman’s theorem was immediately under...

For any biordered set of idempotents E there is an initial object IG(E), the free idempotent generated semigroup over E, in the category of semigroups generated by a set of idempotents biorder-isomorphic to E. Recent research on IG(E) has focussed on the behaviour of the maximal subgroups. Inspired by an example of Brittenham, Margolis and Meakin, several proofs have been offered that any group...

Birational rowmotion – a birational map associated to any finite poset P – has been introduced by Einstein and Propp as a far-reaching generalization of the (wellstudied) classical rowmotion map on the set of order ideals of P . Continuing our exploration of this birational rowmotion, we prove that it has order p+q on the (p, q)rectangle poset (i.e., on the product of a p-element chain with a q...

We measure how a network of heroes can legitimize and diffuse extreme political behaviors. exploit newly declassified intelligence files, novel voting data, regimental histories to show that home municipalities French line regiments arbitrarily rotated under Philippe Pétain’s generalship through the heroic World War I battlefield Verdun diverge politically thereafter, particularly following own...

We introduce ROS Commander, an open source system that enables expert users to construct, share, and deploy robot behaviors for home robots. A user builds a behavior in the form of a Hierarchical Finite State Machine (HFSM) out of generic, parameterized building blocks, with a real robot in the develop and test loop. Once constructed, users save behaviors in an open format for direct use with r...

LKB1, the product of a tumour suppressor gene, is a serine/threonine kinase that coordinates disparate cellular processes. Recent data have revealed novel functions for LKB1, providing new insight into the regulation of cell polarity and energy-generating metabolism.