An explanation is proposed for the fact that pp–waves superpose linearly when they propagate parallely, while they interact nonlinearly, scatter and form singularities or Cauchy horizons if they are antiparallel. Parallel pp–waves do interact, but a generalized gravitoelectric force is exactly cancelled by a gravitomagnetic force. In an analogy, the interaction of light beams in linearized gene...

We study the superconducting vortex states induced by the interplay of long-range Pearl repulsion and short-range intervortex attraction using Langevin dynamics simulations. We show that at low temperatures the vortices form an ordered Abrikosov lattice both in low and high fields. The vortices show distinctive modulated structures at intermediate fields depending on the effective intervortex a...

Henrich and Boyd (2002) were the first to propose a formal model of the role of attraction in cultural evolution. Th ey came to the surprising conclusion that, when both attraction and selection are at work, final outcomes are determined by selection alone. Th is result is based on a determistic view of cultural attraction, different from the probabilistic view introduced in Sperber (1996). We ...

What causes same-sex attraction? Or, more broadly, what controls sex/gender-based attraction? Over the years there have been numerous theories, but more recently scientists have focused on the biology and, more specifically, the neurobiology of gender-based attraction. This article takes the reader through a critical review of the current literature related to sex/gender-based attraction. In ex...

Do people who work hard also tend to play hard? We tested this hypothesis using an online questionnaire-based study of a large volunteer sample of university undergraduate students. Participants responded to questions designed to detect variation in attraction to accomplishment/fame (or ‘work’) and attraction to leisure (or ‘play’). Additional questions were asked, for use in posthoc explorator...

We investigated host fishes, timing and modes of glochidial release, and host-attraction strategies for 7 species of freshwater mussels from the Buttahatchee and Sipsey rivers (Mobile Basin), Alabama and Mississippi, USA. We determined hosts as fish species that produced juvenile mussels from laboratory-induced glochidial infections. We established the following primary mussel/host relationship...

Applicant attraction was examined in the context of Web-based recruitment. A person-organization (P-O) fit framework was adopted to examine how the provision of feedback to individuals regarding their potential P-O fit with an organization related to attraction. Objective and subjective P-O fit, agreement with fit feedback, and self-esteem also were examined in relation to attraction. Results o...

A learning method using domains of attraction in three-layered neural networks is proposed. The method is a combination of output error minimization learning with maximization learning of domains of attraction in one-layered perceptrons. To simplify the structure of the network, a successive learning technique is employed for hidden units. Domains of attraction in the network is derived by rest...

Subpixel mapping (SPM) is a technique that produces hard classification maps at a spatial resolution finer than that of the input images produced when handling mixed pixels. Existing spatial attraction model (SAM) techniques have been proven to be an effective SPM method. The techniques mostly differ in the way in which they compute the spatial attraction, for example, from the surrounding pixe...

We studied the orientational order of one-patch colloidal particles (Janus particles) in a close-packed monolayer. In an experiment on hemispherically patched particles, we realized a highly ordered zigzag stripe pattern by inducing directional growth of the pattern via a phase transition of the solvent. Upon spontaneous ordering by strengthening the inter-patch attraction, however, the particl...