Tarski monoids: Matui's spatial realization theorem

We introduce a class of inverse monoids, called Tarski monoids, that can be regarded as non-commutative generalizations of the unique countable, atomless Boolean algebra. These inverse monoids are related to a class of etale topological groupoids under a non-commutative generalization of classical Stone duality and, significantly, they arise naturally in the theory of dynamical systems as developed by Matui. We are thereby able to reinterpret a theorem of Matui on a class of \'etale groupoids as an equivalent theorem about a class of Tarski monoids: two simple Tarski monoids are isomorphic if and only if their groups of units are isomorphic. The inverse monoids in question may also be viewed as countably infinite generalizations of finite symmetric inverse monoids. Their groups of units therefore generalize the finite symmetric groups and include amongst their number the classical Thompson groups.Comment: arXiv admin note: text overlap with arXiv:1407.147

CAD and creativity: does the computer really help?

We are frequently told by its exponents that computeraided design (CAD) liberates designers and gives them new ways of envisioning their work, but is this really true? CAD in architecture is examined to see to what extent it has enhanced creativity in design. This is partly done by applying a test of creativity advanced by contemporary architect Herman Hertzberger. In this analysis, CAD is found somewhat wanting, and some suggestions are made as to why this might be so

The Meaning of Animals

This research examines the social construction of animals by a rural Allegheny culture using a linguistic approach based on estimating the set of attributes associated with the words they used to describe animals. We asked 268 respondents to free-associate with the nouns, chicken and deer when seen in a context of other words related to nature. Their responses were coded and the frequencies of of words and word groupings were tabulated for sub-samples of differing age, gender and occupation. Response words were categorized into seven typologies including two affective types. The results indicate that except for possibly the very young, the social meanings of chicken and deer did not vary with gender, age or occupation. The respondents interpretation of living chicken was indistinguishable from that of unprepared food. Their interpretation of deer was broader and primarily one of interaction with a lesser adversary

Consumer Goods and Deforestation: An Analysis of the Extent and Nature of Illegality in Forest Conversion for Agriculture and Timber Plantations

A comprehensive new analysis released earlier this month says that nearly half (49%) of all recent tropical deforestation is the result of illegal clearing for commercial agriculture. The study also finds that around half of this illegal destruction was driven by overseas demand for agricultural commodities including palm oil, beef, soy, and wood products. In addition to devastating impacts on forest-dependent people and biodiversity, the illegal conversion of tropical forests for commercial agriculture is estimated to produce 1.47 gigatonnes of carbon each year -- equivalent to 25% of the EU's annual fossil fuel-based emissions. The world must wake up to the scale of how much of this agricultural production is taking place on land that has been illegally cleared. According to the study 90% of the deforestation in Brazil from 2000 to 2012 was illegal, primarily due to the failure to conserve a percentage of natural forests in large-scale cattle and soy plantations, as required by Brazilian law. (Much of this occurred prior to 2004, when the Brazilian government took steps to successfully reduce deforestation.) And in the forests of Indonesia, 80% of deforestation was illegal -- mostly for large-scale plantations producing palm oil and timber, 75% of which is exported. While other countries also experience high levels of illegal deforestation, Brazil and Indonesia produce the highest level of agricultural commodities destined for global markets, many of which wind up in cosmetics or household goods (palm oil), animal feed (soy), and packaging (wood products)

The Shimura curve of discriminant 15 and topological automorphic forms

We find defining equations for the Shimura curve of discriminant 15 over Z[1/15]. We then determine the graded ring of automorphic forms over the 2-adic integers, as well as the higher cohomology. We apply this to calculate the homotopy groups of a spectrum of "topological automorphic forms" associated to this curve, as well as one associated to a quotient by an Atkin-Lehner involution.Comment: 36 pages, 5 figures, updated with corrections and new introduction (this version corrects image issues in the previous

The EU Rights Based Approach to Disability: Some Strategies for Shaping an Inclusive Society

[Excerpt] The past ten years have witnessed a marked change in the legal and policy responses of many European countries, and of the EU itself, to the issue of disability. This new (and still emerging) response is often termed the ‘rights based approach’. In this paper I will attempt to clarify the nature of this approach and to suggest a number of ways in which disability organisations might work towards establishing it in their own countries. My starting point will be a brief examination of the more traditional approach to disability, however, as it is difficult to grasp the essence of the new approach without an appreciation of its contrast with the old

Margaret Court and the Hypocrisy of Professional Tennis

A short article calling attention to the wanton hypocrisy plaguing professional tennis