Exact Bayesian curve fitting and signal segmentation.

We consider regression models where the underlying functional relationship between the response and the explanatory variable is modeled as independent linear regressions on disjoint segments. We present an algorithm for perfect simulation from the posterior distribution of such a model, even allowing for an unknown number of segments and an unknown model order for the linear regressions within each segment. The algorithm is simple, can scale well to large data sets, and avoids the problem of diagnosing convergence that is present with Monte Carlo Markov Chain (MCMC) approaches to this problem. We demonstrate our algorithm on standard denoising problems, on a piecewise constant AR model, and on a speech segmentation problem

Matrix Models and D-branes in Twistor String Theory

We construct two matrix models from twistor string theory: one by dimensional reduction onto a rational curve and another one by introducing noncommutative coordinates on the fibres of the supertwistor space P^(3|4)->CP^1. We comment on the interpretation of our matrix models in terms of topological D-branes and relate them to a recently proposed string field theory. By extending one of the models, we can carry over all the ingredients of the super ADHM construction to a D-brane configuration in the supertwistor space P^(3|4). Eventually, we present the analogue picture for the (super) Nahm construction.Comment: 1+37 pages, reference added, JHEP style, published versio

A generation apart? Youth and political participation in Britain

Conventional wisdom holds that young people in Britain are alienated from politics, with some claiming that this reflects a wider crisis of legitimacy that should be met by initiatives to increase citizenship. This article addresses these areas, presenting both panel survey and focus group data from first-time voters. It concludes that, contrary to the findings from many predominantly quantitative studies of political participation, young people are interested in political matters, and do support the democratic process. However they feel a sense of anti-climax having voted for the first time, and are critical of those who have been elected to positions of political power. If they are a generation apart, this is less to do with apathy, and more to do with their engaged scepticism about ‘formal’ politics in Britain

Standardizing and Scaling up Quality Adolescent Friendly Health Services in Tanzania.

Adolescents in Tanzania require health services that respond to their sexual and reproductive health - and other - needs and are delivered in a friendly and nonjudgemental manner. Systematizing and expanding the reach of quality adolescent friendly health service provision is part of the Tanzanian Ministry of Health and Social Welfare's (MOHSW) multi-component strategy to promote and safeguard the health of adolescents. We set out to identify the progress made by the MOHSW in achieving the objective it had set in its National Adolescent Health and Development Strategy: 2002-2006, to systematize and extend the reach of Adolescent Friendly Health Services (AFHS) in the country. We reviewed plans and reports from the MOHSW and journal articles on AFHS. This was supplemented with several of the authors' experiences of working to make health services in Tanzania adolescent friendly. The MOHSW identified four key problems with what was being done to make health services adolescent friendly in the country - firstly, it was not fully aware of the various efforts under way; secondly, there was no standardized definition of AFHS; thirdly, it had received reports that the quality of the AFHS being provided by some organizations was poor; and fourthly, only small numbers of adolescents were being reached by the efforts that were under way. The MOHSW responded to these problems by mapping existing services, developing a standardized definition of AFHS, charting out what needed to be done to improve their quality and expand their coverage, and integrating AFHS within wider policy and strategy documents and programmatic measurement instruments. It has also taken important preparatory steps to stimulate and support implementation. The MOHSW is aware that the focus of the effort must now shift from the national to the regional, council and local levels. The onus is on regional and council health management teams as well as health facility managers to take the steps needed to ensure that all adolescents in the country obtain the sexual and reproductive health (SRH) services they need, delivered in a friendly and non-judgemental manner. But they cannot do this without substantial and ongoing support

Friendship activities of adults with intellectual disability in supported accommodation in northern England

Background Despite there being considerable evidence to suggest that friendships are central to health and well-being, relatively little attention had been paid to the friendships of people with intellectual disabilities. Methods Friendship activities involving people with and without intellectual disabilities were measured over the preceding month in a sample of 1542 adults with intellectual disabilities receiving supported accommodation in nine geographical localities in Northern England. Results The results of the study indicate: (1) low levels of friendship activities among people with intellectual disabilities in supported accommodation; (2) people with intellectual disabilities are more likely to be involved in activities with friends who also have intel lectual disabilities than with friends who do not have intellectual disabilities; (3) most friendship activities take place in the public domain rather than in more private settings (e.g. at home); (4) the setting in which a person lives is a more significant determinant of the form and content of activities with their friends than the characteristics of participants. Conclusions Further attention needs to be given to research and practice initiatives aimed at increasing the levels of friendship activities of people with intellectual disabilities

Why do health workers in rural Tanzania prefer public sector employment?

Severe shortages of qualified health workers and geographical imbalances in the workforce in many low-income countries require the national health sector management to closely monitor and address issues related to the distribution of health workers across various types of health facilities. This article discusses health workers' preferences for workplace and their perceptions and experiences of the differences in working conditions in the public health sector versus the church-run health facilities in Tanzania. The broader aim is to generate knowledge that can add to debates on health sector management in low-income contexts. The study has a qualitative study design to elicit in-depth information on health workers' preferences for workplace. The data comprise ten focus group discussions (FGDs) and 29 in-depth interviews (IDIs) with auxiliary staff, nursing staff, clinicians and administrators in the public health sector and in a large church-run hospital in a rural district in Tanzania. The study has an ethnographic backdrop based on earlier long-term fieldwork in Tanzania. The study found a clear preference for public sector employment. This was associated with health worker rights and access to various benefits offered to health workers in government service, particularly the favourable pension schemes providing economic security in old age. Health workers acknowledged that church-run hospitals generally were better equipped and provided better quality patient care, but these concerns tended to be outweighed by the financial assets of public sector employment. In addition to the sector specific differences, family concerns emerged as important in decisions on workplace. The preference for public sector employment among health workers shown in this study seems to be associated primarily with the favourable pension scheme. The overall shortage of health workers and the distribution between health facilities is a challenge in a resource constrained health system where church-run health facilities are vital in the provision of health care in rural areas and where patients tend to prefer these services. In order to ensure equity in distribution of qualified health workers in Tanzania, a national regulation and legislation of the pension schemes is required

The American Association for the Surgery of Trauma renal injury grading scale: Implications of the 2018 revisions for injury reclassification and predicting bleeding interventions.

BackgroundIn 2018, the American Association for the Surgery of Trauma (AAST) published revisions to the renal injury grading system to reflect the increased reliance on computed tomography scans and non-operative management of high-grade renal trauma (HGRT). We aimed to evaluate how these revisions will change the grading of HGRT and if it outperforms the original 1989 grading in predicting bleeding control interventions.MethodsData on HGRT were collected from 14 Level-1 trauma centers from 2014 to 2017. Patients with initial computed tomography scans were included. Two radiologists reviewed the scans to regrade the injuries according to the 1989 and 2018 AAST grading systems. Descriptive statistics were used to assess grade reclassifications. Mixed-effect multivariable logistic regression was used to measure the predictive ability of each grading system. The areas under the curves were compared.ResultsOf the 322 injuries included, 27.0% were upgraded, 3.4% were downgraded, and 69.5% remained unchanged. Of the injuries graded as III or lower using the 1989 AAST, 33.5% were upgraded to grade IV using the 2018 AAST. Of the grade V injuries, 58.8% were downgraded using the 2018 AAST. There was no statistically significant difference in the overall areas under the curves between the 2018 and 1989 AAST grading system for predicting bleeding interventions (0.72 vs. 0.68, p = 0.34).ConclusionAbout one third of the injuries previously classified as grade III will be upgraded to grade IV using the 2018 AAST, which adds to the heterogeneity of grade IV injuries. Although the 2018 AAST grading provides more anatomic details on injury patterns and includes important radiologic findings, it did not outperform the 1989 AAST grading in predicting bleeding interventions.Level of evidencePrognostic and Epidemiological Study, level III

Suono e Spettacolo. Athanasius Kircher, un percorso nelle Immagini sonore.

The Society of Jesus made great propaganda efforts throughout the seventeenth century and chose the images and the play as a privileged means to communicate and persuade. Athanasius Kircher, a key figure of the seventeenth century, he decided to dominate the wild nature of sound through Phonurgia Nova, which includes a gallery of powerful symbolic images for Baroque aesthetics. The essay, through the grant of the images from the Library of the Department of Mathematics "Guido Castelnuovo" Sapienza University of Rome, aims to understand, through the pictures offered by Kircher, the sound phenomenon and the spectacle that this produces. In Phonurgia Nova a process of dramatization sound effects takes place, often through machines and "visions" applied to the theatrical reality, as experimental and astonishing environment beloved in baroque. Kircher illustrates the sound through explanatory figures, so to dominate the sound through the eyes. Sound is seen, admired and represented: its spectacle not only takes place through the implementation of sound machines or the "wonders" applied to the theater, but even through images, creating create a sense of wonder in in the erudite person of the seventeenth century

Alternating Kinetics of Annihilating Random Walks Near a Free Interface

The kinetics of annihilating random walks in one dimension, with the half-line x>0 initially filled, is investigated. The survival probability of the nth particle from the interface exhibits power-law decay, S_n(t)~t^{-alpha_n}, with alpha_n approximately equal to 0.225 for n=1 and all odd values of n; for all n even, a faster decay with alpha_n approximately equal to 0.865 is observed. From consideration of the eventual survival probability in a finite cluster of particles, the rigorous bound alpha_1<1/4 is derived, while a heuristic argument gives alpha_1 approximately equal to 3 sqrt{3}/8 = 0.2067.... Numerically, this latter value appears to be a stringent lower bound for alpha_1. The average position of the first particle moves to the right approximately as 1.7 t^{1/2}, with a relatively sharp and asymmetric probability distribution.Comment: 6 pages, RevTeX, 5 eps figures include