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Interleukin-7 (IL-7), a product of stromal cells, provides critical signals to lymphoid cells at early stages in their development. Two types of cellular responses to IL-7 have been identified in lymphoid progenitors: (1) a trophic effect and (2) an effect supporting V(D)J recombination. The IL-7 receptor is comprised of two chains, IL-7R alpha and(More)
— Modular robots consist of many small units that attach together and can perform local motions. By combining these motions, we can achieve a reconfiguration of the global shape. The term modular comes from the idea of grouping together a fixed number of units into a module, which behaves as a larger individual component. Recently, a fair amount of research(More)
Interleukin-7 (IL-7) receptor signaling begins with activation of the Janus tyrosine kinases Jak1 and Jak3, which are associated with the receptor complex. To identify potential targets of these kinases, we examined Pyk2 (a member of the focal adhesion kinase family) using an IL-7-dependent murine thymocyte line, D1. We demonstrate that stimulation of D1(More)
We introduce the problem of <i>shape replication</i> in the Wang tile self-assembly model. Given an input shape, we consider the problem of designing a self-assembly system which will replicate that shape into either a specific number of copies, or an unbounded number of copies. Motivated by practical DNA implementations of Wang tiles, we consider a model(More)
We present a universal crease pattern—known in geometry as the tetrakis tiling and in origami as box pleating—that can fold into any object made up of unit cubes joined face-to-face (polycubes). More precisely, there is one universal finite crease pattern for each number n of unit cubes that need to be folded. This result contrasts previous universality(More)
Based on the affinity for concanavalin A (Con A), human alpha 1-acid glycoprotein (AGP) can be separated by chromatography on Con A-Sepharose gel into three variants: Con A unreactive AGP, Con A weakly reactive AGP, and Con A strongly reactive AGP. When exposed to native AGP or to its glycan variants, murine peritoneal macrophages released a factor that(More)
(2011). Planning to fold multiple objects from a single self-folding sheet. SUMMARY This paper considers planning and control algorithms that enable a programmable sheet to realize different shapes by autonomous folding. Prior work on self-reconfiguring machines has considered modular systems in which independent units coordinate with their neighbors to(More)
The empty space around n disjoint line segments in the plane can be partitioned into n + 1 convex faces by extending the segments in some order. The dual graph of such a partition is the plane graph whose vertices correspond to the n + 1 convex faces, and every segment end-point corresponds to an edge between the two incident faces on opposite sides of the(More)
We address the question: How many edge guards are needed to guard an orthogonal polyhedron of e edges, r of which are reflex? It was previously established [3] that e/12 are sometimes necessary and e/6 always suffice. In contrast to the closed edge guards used for these bounds, we introduce a new model, open edge guards (excluding the endpoints of the(More)