Blunting the Spike: the CV Minimum Period

The standard picture of CV secular evolution predicts a spike in the CV distribution near the observed short-period cutoff P_0 ~ 78 min, which is not observed. We show that an intrinsic spread in minimum (`bounce') periods P_b resulting from a genuine difference in some parameter controlling the evolution can remove the spike without smearing the sharpness of the cutoff. The most probable second parameter is different admixtures of magnetic stellar wind braking (at up to 5 times the GR rate) in a small tail of systems, perhaps implying that the donor magnetic field strength at formation is a second parameter specifying CV evolution. We suggest that magnetic braking resumes below the gap with a wide range, being well below the GR rate in most CVs, but significantly above it in a small tail.Comment: 5 pages, 4 figures; accepted for publication in MNRA

Role of the community matron in advance care planning and ‘do not attempt CPR’ decision-making: a qualitative study

The community matron (CM) is often the key worker caring for patients with chronic, life-limiting, long-term conditions, but these patients are not always recognised as palliative cases. This study explored the experiences of CMs with regard to advance care planning (ACP) and ‘do not attempt cardiopulmonary resuscitation’ (DNACPR) decision-making to understand whether or not they felt adequately prepared for this aspect of their role, and why. Qualitative data were generated from six CMs using a broad interpretive phenomenological approach. Face-to-face recorded interviews were analysed using template analysis. The study found that although participants faced complex ethical situations around ACP and DNACPR almost on a daily basis, none had received any formal training despite the emphasis on training in national and local guidelines. Participants often struggled to get their patients accepted on to the Gold Standards Framework. The research found variability and complexity of cases to be the main barriers to clear identification of the palliative phase

Proof of Luck: an Efficient Blockchain Consensus Protocol

In the paper, we present designs for multiple blockchain consensus primitives and a novel blockchain system, all based on the use of trusted execution environments (TEEs), such as Intel SGX-enabled CPUs. First, we show how using TEEs for existing proof of work schemes can make mining equitably distributed by preventing the use of ASICs. Next, we extend the design with proof of time and proof of ownership consensus primitives to make mining energy- and time-efficient. Further improving on these designs, we present a blockchain using a proof of luck consensus protocol. Our proof of luck blockchain uses a TEE platform's random number generation to choose a consensus leader, which offers low-latency transaction validation, deterministic confirmation time, negligible energy consumption, and equitably distributed mining. Lastly, we discuss a potential protection against up to a constant number of compromised TEEs.Comment: SysTEX '16, December 12-16, 2016, Trento, Ital

The Host Galaxy of GRB 060505: Host ISM Properties

We investigate the ISM environment of GRB 060505. Using optical emission-line diagnostic ratios, we compare the ISM properties of the GRB 060505 host region with the hosts of unambiguous long- and short-duration GRBs. We show that the metallicity, ionization state, and star formation rate of the GRB 060505 environment are more consistent with short-duration GRBs than with long-duration GRBs. We compare the metallicity and star formation rates of the GRB 060505 region with four other star-forming regions within the GRB 060505 host galaxy. We find no significant change in metallicity or star formation rate between the GRB 060505 region and the other four host regions. Our results are consistent with a compact-object-merger progenitor for GRB 060505.Comment: 7 pages, two figures; accepted for publication in ApJ

“We could end up in a lot of trouble” Teachers’ communications with young children about mental health

Purpose – Stigma towards people with mental health problems is a significant problem and appears trenchant despite recent anti-stigma campaigns. Attitudes develop in young children, and may be stronger and less malleable in adolescence. Early intervention may be important for mental health education and stigma prevention. Theory, evidence and practical considerations suggest that teachers’ involvement is key. By exploring communication about mental health between teachers and young children, it will be possible to elaborate how stigma develops and may be ameliorated. This study explored teachers’ accounts of this communication and the factors that influence it. Methodology – Semi-structured interviews with fifteen primary school teachers were transcribed and analysed using a grounded theory approach. Findings – Discussions about mental health were largely absent from the classroom, due to teachers’ anxiety. Teachers felt the need to protect children from exposure to people with mental health problems and even from information about the topic, believed they lacked the necessary expertise, worried that such discussions were outside their remit, and were anxious about parents’ reactions. Originality/Value – This was the first study to interview teachers on this topic and suggests that a significant opportunity to address stigma is being missed. Teachers’ silence may reinforce that mental health problems are taboo, and prevent children from developing knowledge and a language to talk about mental health. The inclusion of teachers in early mental health education is more sustainable and could promote more inclusive attitudes, especially if supported by educational policy and curriculum. Keywords - school, young children, teachers, mental health education, stigma prevention, policy, grounded theory Article Classification – Research Pape

Controlling the crystal polymorph by exploiting the time dependence of nucleation rates

Most substances can crystallise into two or more different crystal lattices, called polymorphs. Despite this, there are no systems in which we can quantitatively predict the probability of one competing polymorph forming, instead of the other. We address this problem using large scale (hundreds of events) studies of the competing nucleation of the alpha and gamma polymorphs of glycine. In situ Raman spectroscopy is used to identify the polymorph of each crystal. We find that the nucleation kinetics of the two polymorphs is very different. Nucleation of the alpha polymorph starts off slowly but accelerates, while nucleation of the gamma polymorph starts off fast but then slows. We exploit this difference to increase the purity with which we obtain the gamma polymorph by a factor of ten. The statistics of the nucleation of crystals is analogous to that of human mortality, and using a result from medical statistics we show that conventional nucleation data can say nothing about what, if any, are the correlations between competing nucleation processes. Thus we can show that, with data of our form, it is impossible to disentangle the competing nucleation processes. We also find that the growth rate and the shape of a crystal depends on when it nucleated. This is new evidence that nucleation and growth are linked.Comment: 8 pages, plus 17 pages of supplementary materia

Rationale for windshield glass system specification requirements for shuttle orbiter

A preliminary procurement specification for the space shuttle orbiter windshield pane, and some of the design considerations and rationale leading to its development are presented. The windshield designer is given the necessary methods and procedures for assuring glass pane structural integrity by proof test. These methods and procedures are fully developed for annealed and thermally tempered aluminosilicate, borosilicate, and soda lime glass and for annealed fused silica. Application of the method to chemically tempered glass is considered. Other considerations are vision requirements, protection against bird impact, hail, frost, rain, and meteoroids. The functional requirements of the windshield system during landing, ferrying, boost, space flight, and entry are included