the Shimura subgroup Σp of Jo(p), viewed as a subgroup of Jo(p) 2 via the antidiagonal embedding x 7→ (x,−x). Thus we have A = Jo(p)/Σp and, analogously, B = Jo(q) /Σq. Since A and B are known, we consider that to understand A + B is to understand A ∩ B, which is a finite abelian group. The main purpose of this note is to identify A ∩B, up to groups of 2-power order. In other words, we identify...

We study properties of Z–vortices in the crossover region of the 3D SU(2) Higgs model. Correlators of the vortex currents with gauge field energy and Higgs field squared (“quantum vortex profile”) reveal a structure that can be compared with a classical vortex. We define a core size and a penetration depth from the vortex profile. Z–vortices are found to interact with each other analogously to ...

Given a tree T (V, E) endowed with a length function l and a cost function c, the diameter lowering problem consists in finding the reals 0 ≤ x(e) ≤ l(e), e E such that the tree obtained from T by decreasing the length of every edge e by x(e) units has a minimal diameter subject to the constraint ¥e Ec(e)x(e) ≤ B, where B is the available budget (analogously, one can minimize the cost of loweri...

A bacterial strain, Pseudomonas sp. POB 310, was enriched with 4-carboxy biphenyl ether as sole source of carbon and energy. Resting cells of POB 310 co-oxidize a substrate analogue, 4-carboxybenzophenone, yielding 1,2-dihydro-1,2-dihydroxy-4-carboxy-benzophenone. The ether bond of 3- and 4-carboxy biphenyl ether is cleaved analogously by initial 1,2-dioxygenation, yielding a hemiacetal which i...

Specific-purpose microfluidic devices have had considerable impact on the biological and chemical sciences, yet their use has largely remained limited to specialized laboratories. Here we present a general-purpose software-programmable microfluidic device which is capable of performing a multitude of lowand high-level functions without requiring any hardware modifications. To demonstrate the ap...

Primate visual systems support an elaborate specialization for processing color information. Concentrating on the hue component, we observe that, contrary to Mondrian-like assumptions, hue varies in a smooth manner for ecologically important natural imagery. To represent these smooth variations, and to support those information processing tasks that utilize hue, a piecewise smooth hue field is ...

The combinatorial Ricci curvature of Forman, which is defined at the edges of a CW complex, and which makes use of only the face relations of the cells in the complex, does not satisfy an analog of the Gauss-Bonnet Theorem, and does not behave analogously to smooth surfaces with respect to negative curvature. We extend this curvature to vertices and faces in such a way that the problems with co...

The nature and status of psychological laws are a long-standing controversy. I will argue that part of the controversy stems from the distinctive nature of an important subset of those laws, which I’ll call “supple laws.” An emergent-model strategy taken by the new interdisciplinary field of artificial life provides a strikingly successful understanding of analogously supple laws in biology. So...

Schrödinger’s equation with scalar and vector potentials is shown to describe “nothing but” hopping of a quantum particle on a lattice; any spatial variation of the hopping amplitudes acts like an external electric and/or magnetic field. The main point of the argument is the superposition principle for state vectors; Lagrangians, path integrals, or classical Hamiltonians are not (!) required. A...

Naive feature orientation runs into problems with large software systems, such as telephone switching systems. With naive feature orientation, a feature extends a base system by an arbitrary increment of functionality. Information hiding helps to structure a large software system design into modules such that it can be maintained. We focus on the requirements of a software system. Requirements ...