A ctin fi laments lie in a wide range of orientations in the leading edge of a migrating cell, according to images from Stefan Koestler, Victor Small (Austrian Academy of Sciences, Vienna, Austria), and colleagues. What looks like disorder might help organize both protrusion at the front and retraction behind. The work casts doubt on the textbook view of the network in the very front of a migra...

We study ve extensions of the polymorphically typed lambda-calculus (system F) by type constructs intended to model xed-points of monotone operators. Building on work by H. Geuvers concerning the relation between term rewrite systems for least pre-xed-points and greatest post-xed-points of positive type schemes (i. e., non-nested positive inductive and coinductive types) and so-called retract t...

We show that the input-output function computed by a network of asynchronous real-time processes is denoted by the unique xed point of a Scott continuous functional even though the network or its components may compute a discontinuous function. This extends a well-known principle of Kahn [Kahn, 1974] to an important class of parallel systems that has resisted the traditional xed point approach....

Let C be a binary self-dual code with an automorphism g of order 2p, where p is an odd prime, such that g is a xed point free involution. If C is extremal of length a multiple of 24 all the involutions are xed point free, except the Golay Code and eventually putative codes of length 120. Connecting module theoretical properties of a self-dual code C with coding theoretical ones of the subcode C...

We prove this conjecture in case (a) and signi cantly extend the range of p and q for which it is known in case (b). In cases (a) and (b), these questions are equivalent to global stability of the xed point (L;L) of the planar map (u; v) = (v; f(u; v)). For as in case (a), we consider natural four dimensional extensions T of 3 and S of . For 0 q < p, we prove that (L;L; L; L) is a global stable...

This paper addresses the problem of reconstructing the trajectory of a point viewed by an uncalibrated moving camera, in which at each frame all that is known is the 3D position of the camera. When the camera's inner parameters are also given it is trivial to reconstruct a xed point in space, which is the intersection of the rays given by the camera's centers and the viewed pixels. When the 3D ...

Given a set S of n points in IR D , D 2. Each point p 2 S is assigned a color c(p) chosen from a xed color set. The All-Nearest-Foreign-Neighbors Problem (ANFNP) is to nd for each point p 2 S its nearest foreign neighbors, i.e. the set of all points in Snfpg that are closest to p among the points in S with a color diierent from c(p). We introduce the Well Separated Color Decomposition (WSCD) wh...

abstract. In this article we study interpolation properties for the minimal system of interpretability logic IL. We prove that arrow interpolation holds for IL and that turnstile interpolation and interpolation for the-modality easily follow from this result. Furthermore , these properties are extended to the system ILP. Failure of arrow interpolation for ILW is established by providing an expl...

We introduce Partitioned Dependency Graphs (PDGs), an abstract framework for the speciication and evaluation of arbitrarily nested alternating xed points. The generality of PDGs subsumes that of similarly proposed models of nested xed-point computation such as Boolean graphs, Boolean equation systems, and the propositional modal mu-calculus. Our main result is an eecient local algorithm for eva...

Consider a \black box" having I input channels and J output channels. Each arrival on an input channel gets routed through the black box and appears on an output channel. The system is monitored for a xed time period and a record is made of the number of arrivals on each input channel and the number of departures on each output channel. The OD (origination-destination) matrix estimation problem...