1. Let X be a Banach space, and B(X) the Banach algebra of all bounded linear operators in X. The closed two sided ideals of B(X) (actually, of any Banach algebra) form a complete lattice L(X). Aside from very concrete cases, L(X) has not yet been determined; for instance, when X = l, l ^ p < « > , L(X) is a chain (i.e., totally ordered) with three elements: {o}, B(X) and the ideal C(X) of comp...

Let be a nite alphabet, and let h : ! be a morphism. Finite and innnite xed points of morphisms | i.e., those words w such that h(w) = w | play an important role in formal language theory. Head characterized the nite xed points of h, and later, Head and Lando characterized the one-sided innnite xed points of h. In this paper, we complete the characterization of xed points of morphisms by descri...

We introduce a new traffic analysis attack: the Two-sided Statistical Disclosure Attack, that tries to uncover the receivers of messages sent through an anonymizing network supporting anonymous replies. We provide an abstract model of an anonymity system with users that reply to messages. Based on this model, we propose a linear approximation describing the likely receivers of sent messages. Us...

The (two-sided) Mullins-Sekerka model is a nonlocal evolution model for closed hypersurfaces, which was originally proposed as a model for phase transitions of materials of negligible specific heat. Under this evolution the propagating interfaces maintain the enclosed volume while the area of the interfaces decreases. We will show by means of an example that the Mullins-Sekerka flow does not pr...

The investigation of human placental nutrient transfer and hormonal secretion presents a particular challenge because these processes depend on the intactness and orientation of the unicellular epithelial sheet of villous syncytiotrophoblast that mediates them. The isolated perfused placental cotyledon retains the architecture of the villi and has been very useful, but the presence of the non-t...

This paper considers a dynamical system, which models a two-sided market. I evaluate the volume of users from each side of the market as a function of time. I formulate and prove theorems describing the long-term behavior and tendency of the market. Even though I consider generic attachment functions, I obtain a concrete result, formulated in terms of properties of attachment functions. I concl...

Most short-lived eukaryotic proteins are degraded by the proteasome. A proteolytic core particle (CP) capped by regulatory particles (RPs) constitutes the 26S proteasome complex. RP biogenesis culminates with the joining of two large subcomplexes, the lid and base. In yeast and mammals, the lid appears to assemble completely before attaching to the base, but how this hierarchical assembly is en...

We study optimal experimentation by a monopolistic platform in a two-sided market. The platform provider faces uncertainty about the strength of the externality each side is exerting on the other. It maximizes the expected present value of its pro t stream in a continuous-time in nite-horizon framework by setting participation fees or quantities on both sides. We show that a price-setting platf...

Most of the two-sided matching literature maintains the assumption that agents are never indifferent between any two members of the opposite side. In practice, however, ties in preferences arise naturally and are widespread. Market design needs to handle ties carefully, because in the presence of indifferences, stability no longer implies Pareto efficiency, and the deferred acceptance algorithm...