Polarimetry in the Visible and Infrared: Application to CMB Polarimetry

Interstellar polarization from aligned dust grains can be measured both in transmission at visible and near-infrared wavelengths and in emission at far-infrared and sub-mm wavelengths. These observations can help predict the behavior of foreground contamination of CMB polarimetry by dust in the Milky Way. Fractional polarization in emission from aligned dust grains will be at the higher range of currently observed values of 4-10%. Away from the galactic plane, fluctuations in Q and U will be dominated by fluctuations in intensity, and less influenced by fluctuations in fractional polarization and position angle.Comment: To be published in the proceedings of "The Cosmic Microwave Background and its Polarization", New Astronomy Reviews, (eds. S. Hanany and K.A. Olive

Hypermedia for language learning: The FREE model at Coventry University

Coventry University is pioneering the integration of hypermedia into the curriculum for the teaching of Italian language and society with the creation of a package based on Nerino Rossi's novel La neve nel bicchiere. The novel was already in use as a basic course text, and developing a hypermedia package was felt to be the ideal way of creating a more stimulating means of access to it. The procedure used in creating the package is described, as are its contents, the ways in which the students use it and the tasks they are given to perform, the feedback from the students, and its impact on their performance. The testing of the prototype has helped in creating a new cognitive model: the FREE (Fluid Role‐Exchange Environment) which functions as a fluid and interactive ‘pool’ where the three main actors, or act ants, ie. the learner, the lecturer and the computer, exchange roles. Within the FREE, students were involved in the construction and evaluation of the courseware, as well as testing the various versions of the prototype. The development and use of hypermedia inside and outside the classroom has made it possible to change both the students’ and the lecturer's attitude towards the material being learnt. However, the courseware does not seem to equip students sufficiently for essay writing, and this problem needs further investigation

Race as Technology: From Posthuman Cyborg to Human Industry

Cyborg and prosthetic technologies frame prominent posthumanist approaches to understanding the nature of race. But these frameworks struggle to accommodate the phenomena of racial passing and racial travel, and their posthumanist orientation blurs useful distinctions between racialized humans and their social contexts. We advocate, instead, a humanist approach to race, understanding racial hierarchy as an industrial technology. Our approach accommodates racial passing and travel. It integrates a wide array of research across disciplines. It also helpfully distinguishes among grounds of racialization and conditions facilitating impacts of such racialization

Self-Inverse and Exchangeable Random Variables

A random variable Z will be called self-inverse if it has the same distribution as its reciprocal 1/Z. It is shown that if Z is defined as a ratio, X/Y, of two rv's X and Y (with Pr[X=0]=Pr[Y=0]=0), then Z is self-inverse if and only if X and Y are (or can be chosen to be) exchangeable. In general, however, there may not exist iid X and Y in the ratio representation of Z.Comment: Statistics and Probability Letters (to appear, 6 pages

Relatively Congruence-free Regular Semigroups

Yu, Wang, Wu and Ye call a semigroup S τ -congruence-free, where τ is an equivalence relation on S, if any congruence ρ on S is either disjoint from τ or contains τ . A congruence-free semigroup is then just an ω-congruence-free semigroup, where ω is the universal relation. They determined the completely regular semigroups that are τ -congruence-free with respect to each of the Green’s relations. The goal of this paper is to extend their results to all regular semigroups. Such a semigroup is J –congruence-free if and only if it is either a semilattice or has a single nontrivial J -class, J, say, and either J is a subsemigroup, in which case it is congruence-free, or otherwise its principal factor is congruence-free. Given the current knowledge of congruence-free regular semigroups, this result is probably best possible. When specialized to completely semisimple semigroups, however, a complete answer is obtained, one that specializes to that of Yu et al. A similar outcome is obtained for L and R. In the case of H, only the completely semisimple case is fully resolved, again specializing to those of Yu et al

Exploiting Environmental Computation in a Multi-Agent Model of Slime Mould

Very simple organisms, such as the single-celled amoeboid slime mould Physarum polycephalum possess no neural tissue yet, despite this, are known to exhibit complex biological and computational behaviour. Given such limited resources, can environmental stimuli play a role in generating the complexity of slime mould behaviour? We use a multi-agent collective model of slime mould to explore a two-way mechanism where the collective behaviour is influenced by simulated chemical concentration gradient fields and, in turn, this behaviour alters the spatial pattern of the concentration gradients. This simple mechanism yields complex behaviour amid the dynamically changing gradient profiles and suggests how the apparently intelligent response of the slime mould could possibly be due to outsourcing of computation to the environment.Comment: 2014 ABBII International Symposium on Artificial, Biological and Bio-Inspired Intelligence, 27-28th September, Rhodes, Greec

Dying to be Seen: Snuff-Fiction's Problematic Fantasies of "Reality"

The mythic Snuff film has remained a persistent cinematic rumour since the mid-1970s. The discourses that surround Snuff are preoccupied by two factors: (a) the formal aesthetic, and (b) their alleged role as a kind of titillating pornography. Although critical narratives have been established to account for the subgenre, little has been done to unpick a recent wave of hardcore horror pseudo-Snuff texts, and the cultural climate they enter into. Exploring the August Underground trilogy (2001-2007) in particular, I investigate how contemporary faux-Snuff fits into and challenges Snuff’s established rhetorical paradigms. This discussion is informed by the legacy of 1970s anti-porn feminism as well as the age of reality culture, torture porn, and extreme pornography that immediately situates 21st century hardcore horror

Variation in bacterial populations in time and space

Obtaining a reliable estimate of the bacterial population is one of the main problems facing the bacterial ecologist. The author discusses the various methods available and concludes that the observed variability in bacterial populations depends on the sampling interval used