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...

We consider the complexity of problems for highly compressed 2-dimensional texts: compressed pattern-matching (when the pattern is not compressed and the text is compressed) and fully compressed pattern-matching (when also the pattern is compressed). First we consider 2-dimensional compression in terms of straight-line programs, see 9]. It is a natural way for representing very highly compresse...

For more than 40 years now, the developing kidney has served as a model paradigm for epithelial-mesenchymal interactions. The principles of inductive signaling, epithelial cell differentiation, and pattern formation are now being addressed with modern genetic and biochemical tools. In addition to the mammalian kidney organ culture model, both zebrafish and Xenopus laevis demonstrate great poten...

based on the compressed sensing theory, if a signal is sparse in a suitable space, by using the optimization methods, signal could be accurately reconstructed from measurements that are significantly less than the theoretical shannon requirements. the sparse representation may exist for the signal and it is not available for the noise; this could be used to distinguish these two. on the other h...