A proper circular-arc (PCA) model is a pairM = (C,A) where C is a circle and A is a family of inclusion-free arcs on C in which no two arcs of A cover C. A PCA model U is a (c, `, d, ds)-CA model when C has circumference c, all the arcs in A have length `, all the extremes of the arcs in A are at a distance at least d, and all the beginning points of the arcs in A are at a distance at least d+ ...

A full classification (up to equivalence) of all complete k-arcs in the Desarguesian projective planes of order 27 and 29 was obtained by computer. The resulting numbers of complete arcs are tabulated according to size of the arc and type of the automorphism group, and also according to the type of algebraic curve into which they can be embedded. For the arcs with the larger automorphism groups...

The vitality of an arc/node of a graph with respect to the maximum flow between two fixed nodes is defined as the reduction of the maximum flow caused by the removal of that arc/node. In this paper we address the issue of determining the vitality of arcs and/or nodes for the network flow problem over various classes of graphs and digraphs. First of all we show how to compute the vitality of all...

In all species of the genus Shewanella, the redox-sensing Arc two-component system consists of the response regulator ArcA, the sensor kinase ArcS, and the separate phosphotransfer protein HptA. Compared to its counterpart ArcB in Escherichia coli, ArcS has a significantly different domain structure. Resequencing and reannotation revealed that in the N-terminal part, ArcS possesses a periplasmi...

The actin cytoskeleton and cytoplasmic intermediate filaments contribute to cell migration and morphogenesis, but the interplay between these two central cytoskeletal elements has remained elusive. Here, we find that specific actin stress fiber structures, transverse arcs, interact with vimentin intermediate filaments and promote their retrograde flow. Consequently, myosin-II-containing arcs ar...

We use angle-resolved photoemission spectroscopy and a new quantitative approach based on the partial density of states to study properties of seemingly disconnected portions of the Fermi surface (FS) that are present in the pseudogap state of cuprates called Fermi arcs. We find that the normal state FS collapses very abruptly into Fermi arcs at the pseudogap temperature (T*). Surprisingly, the...

Stories move us emotionally by physically moving their protagonists, from place to place or from state to state. The most psychologically compelling stories are stories of change, in which characters learn and evolve as they fulfil their dreams or become what they most despise. Character-driven stories must do more than maneouver their protagonists as game pieces on a board, but move them along...

Given a set of n circular-arcs, the problem of finding a minimum number of circular-arcs whose union covers the whole circle has been considered both in sequential and parallel computational models. Here we present a parallel algorithm in the EREW PRAM model that Iuns in O(logn) time using O(n) processors if the arcs are not given already sorted, and using Den/logn) processors otherwise. OUI al...

A volumetric modulated arc therapy (VMAT) approach to total body irradiation (TBI) has recently been introduced at our institution. The planning target volume (PTV) is divided into separate sub-volumes, each being treated with 2 arcs with their own isocentre. Pre-treatment quality assurance of beams is performed on a Sun Nuclear ArcCHECK diode array. Measurement of junction regions between VMAT...

In the minimization of the number of subtours made by an SMD placement machine the following variant of the minimum cost flow problem arised: in a network with n vertices and m arcs a set F of arcs (parametrized arcs) is given and the cost of the flow is equal to the maximum of flow values along the arcs from F . This problem can be solved by a sequence of maximum flow computations in modified ...