M igrating cells move forward by harnessing the force of actin polymerization to form a protru-sive lamellipodium at the leading edge. A protein called Lamellipodin (Lpd) promotes lamellipodium formation, but how it does so is unclear. Law et al. reveal that Lpd generates membrane protrusions in association with a key regulator of actin branching called the Scar/WAVE complex and that this inter...

Migrating fi broblasts assemble a dendritic network of branched actin fi laments that drives the formation of a lamellipodial protrusion at their leading edge. Haynes et al. reveal that, like a topiarist guiding the growth of a tree, a protein called GMF␤ " prunes " this actin network in order to guide the cell's migration towards certain directional cues (1). Branched actin networks form when ...

We develop some useful techinques for integrating over Higgs branches in supersymmetric theories with 4 and 8 supercharges. In particular, we define a regularized volume for hyperkahler quotients. We evaluate this volume for certain ALE and ALF spaces in terms of the hyperkahler periods. We also reduce these volumes for a large class of hyperkahler quotients to simpler integrals. These quotient...

The politics of the Internet is a common theme in cybertheory, though commentators work with a variety of different notions of the political. Among the main issues are the question of whether the Internet may enhance or detract from the processes of deliberation traditionally seen as crucial to a strong civil society, along with that of whether online voting could usher in an era direct democra...

This paper discusses an approach for planning the motion of the laser deposition head relative to the part for fabrication of complex 3-D shapes such as parts with overhangs, branches, and internal cavities in direct metal deposition processes such as the LENS‘ process. The proposed approach is based on slicing the solid model of the part into equal-thickness slices perpendicular to the normal ...

The truss design problem is to nd the optimal placement and size of structural bars that can support a given load The problem is nonlinear and in the version addressed here the bars must take certain discrete sizes It is shown that a logic based method that dispenses with integer variables and branches directly on logical disjunctions can solve sub stantially larger problems than mixed integer ...