Regularity of Polynomials in Free Variables

We show that the spectral measure of any non-commutative polynomial of a non-commutative $n$-tuple cannot have atoms if the free entropy dimension of that $n$-tuple is $n$ (see also work of Mai, Speicher, and Weber). Under stronger assumptions on the $n$-tuple, we prove that the spectral measure is not singular, and measures of intervals surrounding any point may not decay slower than polynomially as a function of the interval's length.Comment: The second version (joint with I. Charlesworth) considerably improves our previous results. The main new result is non-singularity of the spectral measure of a non-commutative polynomial of n variables under assumptions of existence of Voiculescu's dual syste

Dynamic mimicry in an Indo-Malayan octopus

During research dives in Indonesia (Sulawesi and Bali), we filmed a distinctive long-armed octopus, which is new to science. Diving over 24 h periods revealed that the 'mimic octopus' emerges during daylight hours to forage on sand substrates in full view of pelagic fish predators. We observed nine individuals of this species displaying a repertoire of postures and body patterns, several of which are clearly impersonations of venomous animals co-occurring in this habitat. This 'dynamic mimicry' avoids the genetic constraints that may limit the diversity of genetically polymorphic mimics but has the same effect of decreasing the frequency with which predators encounter particular mimics. Additionally, our observations suggest that the octopus makes decisions about the most appropriate form of mimicry to use, allowing it to enhance further the benefits of mimicking toxic models by employing mimicry according to the nature of perceived threats

Influence of a small fraction of individuals with enhanced mutations on a population genetic pool

Computer simulations of the Penna ageing model suggest that already a small fraction of births with enhanced number of new mutations can negatively influence the whole population.Comment: 10 pages including 6 figures; draf

How can we resolve Lewontin's Paradox?

We discuss the genetic, demographic, and selective forces that are likely to be at play in restricting observed levels of DNA sequence variation in natural populations to a much smaller range of values than would be expected from the distribution of census population sizes alone—Lewontin’s Paradox. While several processes that have previously been strongly emphasized must be involved, including the effects of direct selection and genetic hitchhiking, it seems unlikely that they are sufficient to explain this observation without contributions from other factors. We highlight a potentially important role for the less-appreciated contribution of population size change; specifically, the likelihood that many species and populations may be quite far from reaching the relatively high equilibrium diversity values that would be expected given their current census sizes

Therapeutic radiographers' perceptions of the barriers and enablers to effective smoking cessation support

Introduction: Tobacco smoking during and post radiotherapy is associated with increased treatment toxicity and increased cancer related mortality. Routine delivery of smoking cessation advice is inconsistent in practice. This study identifies the key barriers and facilitators to the provision of effective smoking cessation conversations in radiotherapy practice. Methods: A baseline questionnaire (n ¼ 43) was used to identify current practice, barriers and facilitators to smoking cessation in radiotherapy and to inform a topic guide for follow up focus groups (n ¼ 5). Ethical approval was obtained through the 4 NHS trusts and the Health Research Authority. Focus group transcription was coded by two researchers. Results: Therapeutic Radiographers initiate health behaviour conversations with patients; there are a number of factors that facilitate the likelihood of a health behaviour conversation; indication that a patient smokes anatomical site and presence of acute effects. Key barriers to smoking cessation provision include; lack of training, limited knowledge, limitations as a result of poor clinical infrastructure, local culture and perceptions that patients do not prioritise smoking cessation during treatment. Conclusion: Therapeutic Radiographers have the motivation to provide smoking cessation advice, however they require further training to develop knowledge and skills in relation to benefits of smoking cessation and cessation strategies. Therapeutic Radiographers also expect that patients will respond negatively to smoking cessation advice, and that this might be damaging to the therapeutic relationship. Departmental culture and trust infrastructure can also significantly inhibit the provision of smoking cessation in radiotherapy practice and further support to implement NICE guidance is required

'If I had a family, there is no way that I could afford to work here': juggling paid and unpaid care work in social services

Drawing on three case studies in each of Australia, New Zealand and Scotland, this article explores how care workers employed in the social services sector negotiate their unpaid care responsibilities in the context of lean work organization and low pay. For younger workers, the unrelenting demands of service provision and low pay made any long-term commitment to working in social services unrealistic, while many female workers experienced significant stress as they bent their unpaid care responsibilities to the demands of their paid work. However, male workers, less likely to have primary caring responsibilities, appeared less troubled by the prioritizing of paid over unpaid care work and less likely to self-exploit for the job. At the same time, there is a widespread acceptance across different national and organizational contexts that the work/family juggle is a personal responsibility rather than a structural problem caused by the demands of underfunded and overstretched organizations