A polymer must reach a certain size to exhibit significant excluded-volume interactions and adopt a swollen random-walk configuration. We show that single-molecule measurements can sense the onset of swelling by modulating the effective chain size with force: as the force is reduced from a large value, the polymer is first highly aligned, then a Gaussian coil, then finally a swollen chain, with each regime exhibiting a distinct elasticity. We use this approach to quantify the structural parameters of poly(ethylene glycol) and show that they vary in the expected manner with changes in solvent.

We describe an algebraic approach to the time-dependent noncommutative geometry of a six-dimensional Cahen-Wallach pp-wave string background supported by a constant Neveu-Schwarz flux, and develop a general formalism to construct and analyse quantum field theories defined thereon. Various star-products are derived in closed explicit form and the Hopf algebra of twisted isometries of the plane wave is constructed. Scalar field theories are defined using explicit forms of derivative operators, traces and noncommutative frame fields for the geometry, and various physical features are described. Noncommutative worldvolume field theories of D-branes in the pp-wave background are also constructed.

We characterize the worldvolume theories on symmetric D-branes in a six-dimensional Cahen-Wallach pp-wave supported by a constant Neveu-Schwarz three-form flux. We find a class of flat noncommutative euclidean D3-branes analogous to branes in a constant magnetic field, as well as curved noncommutative lorentzian D3-branes analogous to branes in an electric background. In the former case the noncommutative field theory on the branes is constructed from first principles, related to dynamics of fuzzy spheres in the worldvolumes, and used to analyse the flat space limits of the string theory. The worldvolume theories on all other symmetric branes in the background are local field theories. The physical origins of all these theories are described through the interplay between isometric embeddings of branes in the spacetime and the Penrose-Güven limit of AdS 3 × S 3 with Neveu-Schwarz three-form flux. The noncommutative field theory of a non-symmetric spacetime-filling D-brane is also constructed, giving a spatially varying but time-independent noncommutativity analogous to that of the Dolan-Nappi model.

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This paper surveys a range of scientific, popular scientific and literary texts from the late-19th-to the early 20th-centuries in order to demonstrate electricity's importance within theories of sexuality, in general, and homosexuality, in particular.Unless the sun were enveloped in the body of darkness, would a cast shadow run with me as I walk? Unless the night lay within the embrace of light, would the fish gleam phosphorescent in the sea, would the light break out of the black coals of the hearth, would the electricity gleam out of itself, declaring an opposite being? D. H. Lawrence, 'The Crown ' (1915; Lawrence, 1988, p. 258) In the atraction [sic., passim] of material electricity, friction leads to a gradually acumulating atraction, which suddenly reaches the point of explozion or instant discharge; and then the two bodies becuming identical in polarity, repel each other. The analogy between this and the generativ function of [a person's] sexual batteries is too obvious to require elucidation.