Hairdressing in groups: a survey of combings and formal languages

A group is combable if it can be represented by a language of words satisfying a fellow traveller property; an automatic group has a synchronous combing which is a regular language. This article surveys results for combable groups, in particular in the case where the combing is a formal language.Comment: 17 pages. Published copy, also available at http://www.maths.warwick.ac.uk/gt/GTMon1/paper24.abs.htm

Man's transportation to space

Saturn i, saturn ib, and saturn v launch vehicle

Are textbook references to Darwin close to extinction?

The textbooks used to teach GCE A-level biology 30 years ago tended to concentrate on traditional zoology and botany, with just a passing reference to evolution. As biology established itself as a new discipline, books (and syllabuses) began to take an integrated approach, and evolution became an important theme that helped students to appreciate the interrelationships between plants and animals, cells and molecules, biochemistry and physiology, systematics and genetics, and ecology and behaviour. With the modularisation of modern specifications this theme has all but disappeared from textbooks and a detailed discussion of Darwin and the evidence for evolution has been replaced by perfunctory references to variation and selection and, in some cases, politically correct acknowledgements of creationism

Human rights trauma and the mental health of West Papuan refugees resettled in Australia

This article finds that West Papuan refugees resettled in Australia report a wide range of premigration potentially traumatic events (PTEs) including human rights violations as well as symptoms of PTSD and distress.Abstract Objectives: To document the extent and nature of human rights violations and other traumatic events reported by West Papuan refugees resettled in Australia and to assess trauma-related psychological disorders, distress and disability.Design and setting: Australian-based sample, mixed-methods design with 44 participants, conducted in Australia between October 2007 and November 2010 in communities in North Queensland and Melbourne.Participants: West Papuan refugees aged 18 years and over (88% response rate).Main outcome measures: Post-traumatic stress disorder (PTSD) symptoms (Harvard Trauma Questionnaire) and premigration potentially traumatic events (PTEs), psychological distress (Kessler Psychological Distress Scale [K10]), post-migration living difficulties, days out of role.Results: Of the 44 West Papuan refugees, 40 reported one or more PTE, including inability to access medical care for family (40), lack of food and water (39) and lack of access to medical treatment (38). The most frequent postmigration stressors were separation from and worries about family members remaining in West Papua (43) and being unable to return home in an emergency because of ongoing conflict (41). Twenty-six participants reached a lower threshold for PTSD symptoms of 2.0, and 13 reached the clinical threshold of 2.5. Fourteen reported severe psychological distress.Conclusions: West Papuan refugees resettled in Australia report a wide range of premigration PTEs including human rights violations, as well as symptoms of PTSD and distress. The data add to concerns about the state of human rights and mental health among West Papuans.Authored by Susan Rees, Derrick M Silove, Kuowei Tay and Moses Kareth

Taxation and the Household

Previous analyses of demand systems and the welfare effects of taxing male and female labour supplies suppress the analysis of household resource allocation by assuming a household utility function. To analyse the implications of assuming this is not the case, we construct a simple but fairly general model of household resource allocation and use the properties of the equilibrium of this model to characterise the effects of tax policy on individual utilities, as determined by the household resource allocation proces