Kinetic Monte Carlo simulations of oscillatory shape evolution for electromigration-driven islands

The shape evolution of two-dimensional islands under electromigration-driven periphery diffusion is studied by kinetic Monte Carlo (KMC) simulations and continuum theory. The energetics of the KMC model is adapted to the Cu(100) surface, and the continuum model is matched to the KMC model by a suitably parametrized choice of the orientation-dependent step stiffness and step atom mobility. At 700 K shape oscillations predicted by continuum theory are quantitatively verified by the KMC simulations, while at 500 K qualitative differences between the two modeling approaches are found.Comment: 7 pages, 6 figure

Do safeguarding concerns deter young people’s access to condoms? Issues about integrating sexual health services online

Condoms have been distributed freely, and regionally across England, since the ‘Teenage Pregnancy Strategy’ (Social Inclusion Unit, 1999) which highlighted England as having one of the highest rates of unplanned teenage conceptions in Western Europe. With the aim of making more accessible contraception and sex safer resources and protecting against infections, young people can obtain free condoms through selected registration and distribution points (Evans, 2005; Hadley and Evans, 2013). In 2003, England and Wales founded the National Chlamydia Screening Programme (NCSP) in response to high levels of Chlamydia trachomatis found in young people aged between 15 – 24 years (DH, 2012). Key messages for young people in the prevention of Chlamydia infection are: - Consistently use condoms during vaginal, anal or oral sex - Don’t share sex toys without washing them between use or covering with a fresh condom - Consistently use latex dams for cunnilingus (oral sex on a female) and oroanal sex (rimming) (NHS, 2013

Coping with Poorly Understood Domains: the Example of Internet Trust

The notion of trust, as required for secure operations over the Internet, is important for ascertaining the source of received messages. How can we measure the degree of trust in authenticating the source? Knowledge in the domain is not established, so knowledge engineering becomes knowledge generation rather than mere acquisition. Special techniques are required, and special features of KBS software become more important than in conventional domains. This paper generalizes from experience with Internet trust to discuss some techniques and software features that are important for poorly understood domains

“Active” and “Passive” Coach Pathways: Elite Athletes’ Entry Routes Into High-Performance Coaching Roles

This study sought to analyse the lived experiences of so-called “fast-tracked” coaches from men’s association football and rugby union by seeking to understand how these individuals prepared for and then transitioned into a post-athletic coaching career. Semi-structured interviews were conducted with 13 male coaches. All participants were former elite athletes and had followed a fast-tracked pathway into their current post-athletic coaching roles. Participants were based in England and had retired from an athletic career within 12 months of being interviewed. Two general categories of “active” and “passive” coach pathways were identified for the career trajectory. Active coaches purposefully prepared for a coaching career during their athletic careers, whereas passive coaches did not. Passive coaches’ decisions to become a coach were often reactive and made after retiring from a competitive athletic career. Results indicate that only the career trajectory of passive coaches reflects a fast-track pathway. None of the active or passive coaches negotiated any formalised recruitment processes into their first post-athletic coaching roles. The suggestion is that prejudicial recruitment practices are enacted by senior club management which creates a homogenous coaching workforce. This furthers the need for greater governance of high-performance coach recruitment within England for these sports

Operator Product Expansion for Exclusive Decays: B^+ ->Ds^+ e+e- and B^+ -> Ds^{*+} e+e-

The decays $B^+\to D_{s,d}^+e^+e^-$ and $B^+\to D_{s,d}^{*+}e^+e^-$ proceed through a weak and an electromagnetic interaction. This is a typical ``long distance'' process, usually difficult to compute systematically. We propose that over a large fraction of phase space a combination of an operator product and heavy quark expansions effectively turns this process into one in which the weak and electromagnetic interactions occur through a local operator. Moreover, we use heavy quark spin symmetry to relate all the local operators that appear in leading order of the operator expansion to two basic ones. We use this operator expansion to estimate the decay rates for $B^+\to D_{s,d}^{(*)+}e^+e^-$.Comment: 4 pages, 1 figure, Latex, published version in PR

Achieving the WHO/UNAIDS antiretroviral treatment 3 by 5 goal: what will it cost?

The "3 by 5" goal to have 3 million people in low and middle income countries on antiretroviral therapy (ART) by the end of 2005 is ambitious. Estimates of the necessary resources are needed to facilitate resource mobilisation and rapid channelling of funds to where they are required. We estimated the financial costs needed to implement treatment protocols, by use of country-specific estimates for 34 countries that account for 90% of the need for ART in resource-poor settings. We first estimated the number of people needing ART and supporting programmes for each country. We then estimated the cost per patient for each programme by country to derive total costs. We estimate that between US5.1 billion dollars and US5.9 billion dollars will be needed by the end of 2005 to provide ART, support programmes, and cover country-level administrative and logistic costs for 3 by 5

Seeing with sound? Exploring different characteristics of a visual-to-auditory sensory substitution device

Sensory substitution devices convert live visual images into auditory signals, for example with a web camera (to record the images), a computer (to perform the conversion) and headphones (to listen to the sounds). In a series of three experiments, the performance of one such device (‘The vOICe’) was assessed under various conditions on blindfolded sighted participants. The main task that we used involved identifying and locating objects placed on a table by holding a webcam (like a flashlight) or wearing it on the head (like a miner’s light). Identifying objects on a table was easier with a hand-held device, but locating the objects was easier with a head-mounted device. Brightness converted into loudness was less effective than the reverse contrast (dark being loud), suggesting that performance under these conditions (natural indoor lighting, novice users) is related more to the properties of the auditory signal (ie the amount of noise in it) than the cross-modal association between loudness and brightness. Individual differences in musical memory (detecting pitch changes in two sequences of notes) was related to the time taken to identify or recognise objects, but individual differences in self-reported vividness of visual imagery did not reliably predict performance across the experiments. In general, the results suggest that the auditory characteristics of the device may be more important for initial learning than visual associations

Ola Bratteli and his diagrams

This article discusses the life and work of Professor Ola Bratteli (1946--2015). Family, fellow students, his advisor, colleagues and coworkers review aspects of his life and his outstanding mathematical accomplishments.Comment: 18 pages, 15 figure

The intermediate evolution phase in case of truncated selection

Using methods of statistical physics, we present rigorous theoretical calculations of Eigen's quasispecies theory with the truncated fitness landscape which dramatically limits the available sequence space of a reproducing quasispecies. Depending on the mutation rates, we observe three phases, a selective one, an intermediate one with some residual order and a completely randomized phase. Our results are applicable for the general case of fitness landscape.Comment: 8 page