The dynamics of alternative pathways to compensatory substitution

The role of epistatic interactions among loci is a central question in evolutionary biology and is increasingly relevant in the genomic age. While the population genetics of compensatory substitution have received considerable attention, most studies have focused on the case when natural selection is very strong against deleterious intermediates. In the biologically-plausible scenario of weak to moderate selection there exist two alternate pathways for compensatory substitution. In one pathway, a deleterious mutation becomes fixed prior to occurrence of the compensatory mutation. In the other, the two loci are simultaneously polymorphic. The rates of compensatory substitution along these two pathways and their relative probabilities are functions of the population size, selection strength, mutation rate, and recombination rate. In this paper these rates and path probabilities are derived analytically and verified using population genetic simulations. The expected time durations of these two paths are similar when selection is moderate, but not when selection is weak. The effect of recombination on the dynamics of the substitution process are explored using simulation. Using the derived rates, a phylogenetic substitution model of the compensatory evolution process is presented that could be used for inference of population genetic parameters from interspecific data.Comment: 17 pages, 9 figures, 1 table. Accepted to RECOMB Comparative Genomics Meeting 2013, to be published in BMC Bioinformatic

Catégorisation et stigmatisation policières á Sheffield au milieu du XIXe siècle [Numbering crimes and measuring space: policing Sheffield in the mid-nineteenth century]

The city in the nineteenth century was often defined as a place of crime: yet from within, the its authorities sought to represent crime as something external to it. The presentation of the criminal statistical returns of the English city of Sheffield can be shown to be distorted in several ways, all of which were consistent with the project of rendering the criminal as firmly 'other'. The town's returns followed the national requirement of establishing numbers of 'resident criminals' and their haunts, but it also went beyond this. Information about residence, ethnicity and literacy was presented in a way that tried to set a boundary between the 'true' city and the people in it who were deemed to be committing the majority of crime. The tactic of labelling was pursued in an effort to symbolically isolate a discrete 'criminal class'. In addition, the mania for sub-division of certain sorts of crime replaced worryingly large numbers of total crimes committed with reassuringly small numbers of crimes that fell into small sub-categories. The returns were a conscious project to create an image of an incorruptible and professional police force successfully securing and thus separating the city from a crime threat that was mainly external, 'alien' or safely under surveillance

Review of 'Education in Parapsychology: Student and Instructor Perspectives' by Harvey Irwin

Book review of Education in Parapsychology: Student and Instructor Perspectives by Harvey Irwin. Foreword by Nancy Zingrone. Gladesville, NSW, Australia: AIPR Mongraphs, 2013. Pp xv + 106. (paperback). ISBN 9780987077219

Environmental Education in the Public Sphere: Comparing Practice with Psychosocial Determinants of Behavior and Societal Change

Environmental education of the general public is widely practiced by a variety of types of organizations. Dedicated environmental groups, nature centers, zoos, parks, and other entities work on issues ranging from local threats to air, water, and habitat to global problems such as climate change and deforestation. A great deal of those efforts focus largely on providing information and raising awareness. Behavioral research and change models, however, suggest other factors are important in order to effect change on an individual, regional, or societal level. An analysis of environmental education in practice, examining methods and materials in use, showed the degree to which there were alignments between the content and psychosocial determinants of change, as well as how actions related to change theories. This mixed-methods study of groups doing environmental education in the public sphere compared their practices with the factors shown to help predict pro-environmental behavior, why people change their actions and habits. Through this survey research and multiple case study, increased knowledge and understanding can help inform future efforts at change on critical local, national, and world environmental problems. It can also lead to further research into environmental education, using behavior and change theories

Non-commutativity and non-associativity of the doubled string in non-geometric backgrounds

We use a T-duality invariant action to investigate the behaviour of a string in non-geometric backgrounds, where there is a non-trivial global $O(D,D)$ patching or monodromy. This action leads to a set of Dirac brackets describing the dynamics of the doubled string, with these brackets determined only by the monodromy. This allows for a simple derivation of non-commutativity and non-associativity in backgrounds which are (even locally) non-geometric. We focus here on the example of the three-torus with H-flux, finding non-commutativity but not non-associativity, and also comment on the relation to the exotic $5^2_2$ brane, which shares the same monodromy.Comment: 31 pages, v2: refs added, corrections to sec 5, results updated, v3: published version with additional discussion in sec

Modelling the costs of non-conventional oil: A case study of Canadian bitumen

Keywords JEL Classification High crude oil prices, uncertainties about the consequences of climate change and the eventual decline of conventional oil production raise the issue of alternative fuels, such as non-conventional oil and biofuels. This paper describes a simple probabilistic model of the costs of nonconventional oil, including the role of learning-by-doing in driving down costs. This forward-looking analysis quantifies the effects of both learning and production constraints on the costs of supplying bitumen which can then be upgraded into synthetic crude oil, a substitute to conventional oil. The results show large uncertainties in the future costs of supplying bitumen from Canadian oil sands deposits, with a 90% confidence interval of $8 to$12 in 2025, and $7 to$15 in 2050 (2005 US$). The influence of each parameter on the supply costs is examined, with the minimum supply cost, the learning rate, and the depletion curve exponent having the largest influence. Over time, the influence of the learning rate on the supply costs decreases, while the influence of the depletion curve exponent increases. Climate change; Non-conventional oil; Exhaustible resources; Technological change; Uncertainty

Conserved Currents of Double Field Theory

We find the conserved current associated to invariance under generalised diffeomorphisms in double field theory. This can be used to define a generalised Komar integral. We comment on its applications to solutions, in particular to the fundamental string/pp-wave. We also discuss the current in the context of Scherk-Schwarz compactifications. We calculate the current for both the original double field theory action, corresponding to the NSNS sector alone, and for the RR sector.Comment: 30 pages + appendix, v2: belated update to match published version (typos + refs fixed, some minor comments added