Signal and Noise Analysis in TRION -Time-Resolved Integrative Optical Fast Neutron Detector

TRION is a sub-mm spatial resolution fast neutron imaging detector, which employs an integrative optical time-of-flight technique. The detector was developed for fast neutron resonance radiography, a method capable of detecting a broad range of conventional and improvised explosives. In this study we have analyzed in detail, using Monte-Carlo calculations and experimentally determined parameters, all the processes that influence the signal and noise in the TRION detector. In contrast to event-counting detectors where the signal-to-noise ratio is dependent only on the number of detected events (quantum noise), in an energy-integrating detector additional factors, such as the fluctuations in imparted energy, number of photoelectrons, system gain and other factors will contribute to the noise. The excess noise factor (over the quantum noise) due to these processes was 4.3, 2.7, 2.1, 1.9 and 1.9 for incident neutron energies of 2, 4, 7.5, 10 and 14 MeV, respectively. It is shown that, even under ideal light collection conditions, a fast neutron detection system operating in an integrative mode cannot be quantum-noise-limited due to the relatively large variance in the imparted proton energy and the resulting scintillation light distributions.Comment: 18 page

Young people, crime and school exclusion: a case of some surprises

During the 1990s the number of young people being permanently excluded from schools in England and Wales increased dramatically from 2,910 (1990/91) to a peak of 12,700 (1996/97). Coinciding with this rise was a resurgence of the debate centring on lawless and delinquent youth. With the publication of Young People and Crime (Graham and Bowling 1995) and Misspent Youth (Audit Commission 1996) the 'common sense assumption' that exclusion from school inexorably promoted crime received wide support, with the school excludee portrayed as another latter day 'folk devil'. This article explores the link between school exclusion and juvenile crime, and offers some key findings from a research study undertaken with 56 young people who had experience of being excluded from school. Self-report interview questions reveal that whilst 40 of the young people had offended, 90% (36) reported that the onset of their offending commenced prior to their first exclusion. Moreover, 50 (89.2% of the total number of young people in the sample), stated that they were no more likely to offend subsequent to being excluded and 31 (55.4%) stated that they were less likely to offend during their exclusion period. Often, this was because on being excluded, they were 'grounded' by their parents

Desperately seeking a cure: Treatment seeking and appraisal in irritable bowel syndrome

© 2018 The British Psychological Society Objectives: Irritable bowel syndrome (IBS) is common and adversely affects patients' quality of life. Multiple potential treatment options exist for patients (and clinicians) to choose from, with limited evidence to inform treatment selection. The aim was to explore how patients with IBS go about seeking and appraising different treatment modalities, with a view to elucidating the psychological processes involved and identifying opportunities to improve clinical practice. Design: Qualitative study nested within a randomized controlled trial of therapist-delivered and web-based cognitive behavioural therapy versus treatment-as-usual for IBS. Methods: A total of 52 people participated in semi-structured interviews about their prior experiences of treatments for IBS. Transcripts were analysed using inductive thematic analysis. Results: Key themes (desperation for a cure, disappointment at lack of cure, appraising the effects of diverse treatments, and hope for positive effects) clustered around an overarching theme of being trapped within a vicious cycle of hope and despair on treatment seeking. A desperation and willingness drove interviewees to try any treatment modality available that might potentially offer relief. Coming to accept there is no cure for IBS helped interviewees escape the vicious cycle. Treatments were appraised for their effects on symptoms and quality of life while also considering, but rarely prioritizing, other aspects including convenience of the regimen itself, whether it addressed the perceived root causes of IBS, perceived side-effects, and cost. Conclusion: Treatment seeking in IBS can be challenging for patients. Supportive discussions with health care professionals about illness perceptions, treatment beliefs, and goals could improve patients' experiences. Statement of contribution What is already known on this subject? Irritable bowel syndrome (IBS) is a highly prevalent chronic relapsing functional gastrointestinal disorder. Studies show few treatment modalities provide complete symptom relief. IBS is associated with emotional and physical distress, and negatively impacts personal, social, and professional aspects of quality of life. What does this study add? Patients appraise IBS treatments for impact on quality of life and treatment characteristics. Developing acceptance and coping strategies helps escape treatment-seeking vicious cycles of hope and despair. Clinicians could better support patients by discussing their illness perceptions, treatment goals, and values

Questioning policy, youth participation and lifestyle sports

Young people have been identified as a key target group for whom participation in sport and physical activity could have important benefits to health and wellbeing and consequently have been the focus of several government policies to increase participation in the UK. Lifestyle sports represent one such strategy for encouraging and sustaining new engagements in sport and physical activity in youth groups, however, there is at present a lack of understanding of the use of these activities within policy contexts. This paper presents findings from a government initiative which sought to increase participation in sport for young people through provision of facilities for mountain biking in a forest in south-east England. Findings from qualitative research with 40 young people who participated in mountain biking at the case study location highlight the importance of non-traditional sports as a means to experience the natural environments through forms of consumption which are healthy, active and appeal to their identities. In addition, however, the paper raises questions over the accessibility of schemes for some individuals and social groups, and the ability to incorporate sports which are inherently participant-led into state-managed schemes. Lifestyle sports such as mountain biking involve distinct forms of participation which present a challenge for policy-makers who seek to create and maintain sustainable communities of youth participants

famoz : a software for parentage analysis using dominant, codominant and uniparentally inherited markers

Abstract FAMOZ (an acronym for father/mother) is a software useful in reconstructing parentage for dominant, codominant and uniparentally inherited markers. It is written in C and TclTk languages and is available for Unix, Linux and Windows systems at http://www.pierroton.inra.fr/ genetics/labo/Software/Famoz/index.html. Parameters and assumptions used in the calculations are few and simple. Exclusion and identity probabilities, log-likelihoods of any genetic relationship, potential father and parent or parent pair, half-and full-sibship are calculated based on real or simulated data. Error rates for genotypic mistyping can be introduced. Simulations can be done to build statistical tests for parentage assignment

A Toy Model for Testing Finite Element Methods to Simulate Extreme-Mass-Ratio Binary Systems

Extreme mass ratio binary systems, binaries involving stellar mass objects orbiting massive black holes, are considered to be a primary source of gravitational radiation to be detected by the space-based interferometer LISA. The numerical modelling of these binary systems is extremely challenging because the scales involved expand over several orders of magnitude. One needs to handle large wavelength scales comparable to the size of the massive black hole and, at the same time, to resolve the scales in the vicinity of the small companion where radiation reaction effects play a crucial role. Adaptive finite element methods, in which quantitative control of errors is achieved automatically by finite element mesh adaptivity based on posteriori error estimation, are a natural choice that has great potential for achieving the high level of adaptivity required in these simulations. To demonstrate this, we present the results of simulations of a toy model, consisting of a point-like source orbiting a black hole under the action of a scalar gravitational field.Comment: 29 pages, 37 figures. RevTeX 4.0. Minor changes to match the published versio

Verification of micro-scale photogrammetry for smooth three-dimensional object measurement

By using sub-millimetre laser speckle pattern projection we show that photogrammetry systems are able to measure smooth three-dimensional objects with surface height deviations less than 1 μm. The projection of laser speckle patterns allows correspondences on the surface of smooth spheres to be found, and as a result, verification artefacts with low surface height deviations were measured. A combination of VDI/VDE and ISO standards were also utilised to provide a complete verification method, and determine the quality parameters for the system under test. Using the proposed method applied to a photogrammetry system, a 5 mm radius sphere was measured with an expanded uncertainty of 8.5 μm for sizing errors, and 16.6 μm for form errors with a 95 % confidence interval. Sphere spacing lengths between 6 mm and 10 mm were also measured by the photogrammetry system, and were found to have expanded uncertainties of around 20 μm with a 95 % confidence interval