Spacetime and orbits of bumpy black holes

Our universe contains a great number of extremely compact and massive objects which are generally accepted to be black holes. Precise observations of orbital motion near candidate black holes have the potential to determine if they have the spacetime structure that general relativity demands. As a means of formulating measurements to test the black hole nature of these objects, Collins and Hughes introduced "bumpy black holes": objects that are almost, but not quite, general relativity's black holes. The spacetimes of these objects have multipoles that deviate slightly from the black hole solution, reducing to black holes when the deviation is zero. In this paper, we extend this work in two ways. First, we show how to introduce bumps which are smoother and lead to better behaved orbits than those in the original presentation. Second, we show how to make bumpy Kerr black holes -- objects which reduce to the Kerr solution when the deviation goes to zero. This greatly extends the astrophysical applicability of bumpy black holes. Using Hamilton-Jacobi techniques, we show how a spacetime's bumps are imprinted on orbital frequencies, and thus can be determined by measurements which coherently track a small orbiting body's orbital phase. We find that weak-field orbits of bumpy black holes are modified exactly as expected from a Newtonian analysis of a body with a prescribed multipolar structure, reproducing well-known results from the celestial mechanics literature. The impact of bumps on strong-field orbits is especially strong, suggesting that this framework will allow observations to set robust limits on the extent to which a spacetime's multipoles deviate from the black hole expectation.Comment: 24 pages, 3 figures, accepted to Phys. Rev. D. This version corrects some typos and incorporates suggested edit

Evaluating the responsiveness of the Warwick Edinburgh Mental Well-Being Scale (WEMWBS) : group and individual level analysis

Background: Mental well-being now features prominently in UK and international health policy. However, progress has been hampered by lack of valid measures that are responsive to change. The objective of this study was to evaluate the responsiveness of the Warwick Edinburgh Mental Well-being Scale (WEMWBS) at both the individual and group level. Methods: Secondary analysis of twelve different interventional studies undertaken in different populations using WEMWBS as an outcome measure. Standardised response mean (SRM), probability of change statistic (P̂) and standard error of measurement (SEM) were used to evaluate whether WEMWBS detected statistically important changes at the group and individual level, respectively. Results: Mean change in WEMWBS score ranged from −0.6 to 10.6. SRM ranged from −0.10 (95% CI: -0.35, 0.15) to 1.35 (95% CI: 1.06, 1.64). In 9/12 studies the lower limit of the 95% CI for P̂ was greater than 0.5, denoting responsiveness. SEM ranged from 2.4 to 3.1 units, and at the threshold 2.77 SEM, WEMWBS detected important improvement in at least 12.8% to 45.7% of participants (lower limit of 95% CI>5.0%). Conclusions: WEMWBS is responsive to changes occurring in a wide range of mental health interventions undertaken in different populations. It offers a secure base for research and development in this rapidly evolving field. Further research using external criteria of change is warranted

The Non-homogeneous Poisson Process for Fast Radio Burst Rates

This paper presents the non-homogeneous Poisson process (NHPP) for modeling the rate of fast radio bursts (FRBs) and other infrequently observed astronomical events. The NHPP, well-known in statistics, can model changes in the rate as a function of both astronomical features and the details of an observing campaign. This is particularly helpful for rare events like FRBs because the NHPP can combine information across surveys, making the most of all available information. The goal of the paper is two-fold. First, it is intended to be a tutorial on the use of the NHPP. Second, we build an NHPP model that incorporates beam patterns and a power law flux distribution for the rate of FRBs. Using information from 12 surveys including 15 detections, we find an all-sky FRB rate of 586.88 events per sky per day above a flux of 1 Jy (95\% CI: 271.86, 923.72) and a flux power-law index of 0.91 (95\% CI: 0.57, 1.25). Our rate is lower than other published rates, but consistent with the rate given in Champion et al. 2016.Comment: 19 pages, 2 figure

Gyroscopes orbiting black holes: A frequency-domain approach to precession and spin-curvature coupling for spinning bodies on generic Kerr orbits

A small body orbiting a black hole follows a trajectory that, at leading order, is a geodesic of the black hole spacetime. Much effort has gone into computing "self-force" corrections to this motion, arising from the small body's own contributions to the system's spacetime. Another correction to the motion arises from coupling of the small body's spin to the black hole's spacetime curvature. Spin-curvature coupling drives a precession of the small body, and introduces a "force" (relative to the geodesic) which shifts the small body's worldline. These effects scale with the small body's spin at leading order. In this paper, we show that the equations which govern spin-curvature coupling can be analyzed with a frequency-domain decomposition, at least to leading order in the small body's spin. We show how to compute the frequency of precession along generic orbits, and how to describe the small body's precession and motion in the frequency domain. We illustrate this approach with a number of examples. This approach is likely to be useful for understanding spin coupling effects in the extreme mass ratio limit, and may provide insight into modeling spin effects in the strong field for nonextreme mass ratios.National Science Foundation (U.S.) (Grant PHY-1403261

Writing the unreadable untext: a collaborative autoethnography of #rhizo14

No abstract available

Barnardo’s ReachOut: final evaluation report March 2019

ReachOut is a preventative child sexual exploitation (CSE) project established in 2016 under a partnership funding agreement between Barnardo’s, the KPMG Foundation, Department for Education, Communities and Local Government and Rotherham Metropolitan Borough Council (RMBC). An independent evaluation was commissioned from the University of Bedfordshire with DMSS Research both to evaluate the impact of the project and to provide ongoing learning and feedback. A diverse staff team was recruited from a range of professional backgrounds including criminal justice, social work and youth work. There have been three main strands of work undertaken by ReachOut in order to achieve its aims: •Outreach work to raise awareness and provide support to children and young people in their communities  •Healthy relationship education in schools and other settings •Direct support for children and young people identified as at risk of CSE. These have operated at three levels of prevention: universal, including outreach at community events across Rotherham, helping to convey the message  that CSE is relevant to everyone; primary prevention, including education work in schools reaching over 2000 children and young people; targeted prevention with groups and communities identified as potentially more vulnerable to CSE as well as direct work with around 300 individual children and young people. Over the course of the three years, evaluators have carried out interviews with ReachOut staff and managers and representatives from external agencies; observed sessions of delivery; interviewed samples of young people and parents; analysed feedback questionnaires from school students and staff; reviewed project monitoring and samples of case records

Perpetration of Image-Based Sexual Abuse: Extent, Nature and Correlates in a Multi-Country Sample

This study examined Image-Based Sexual Abuse (IBSA) victimisation in the United Kingdom, Australia, and New Zealand (n = 6,109). Findings showed that 37.7% (n=2,306) of respondents had at least one IBSA victimisation experience since age 16. Logistic regression analyses further identified that demographic characteristics (age, sexuality, disability/assistance), attitudes towards IBSA, and experiential variables (including online behaviours) were each predictors of IBSA victimisation. Though gender did not explain overall extent, the relational contexts and impacts of IBSA remained gendered in particular ways. Implications of the study are discussed with respect to conceptualising gendered violence and future research

Thank you to all our manuscript reviewers in 2015

The editors of Hereditary Cancer in Clinical Practice would like to thank all our reviewers who have contributed to the journal in 2015. Without the participation of skilful reviewers, no academic journal could succeed, and we are grateful to the committed individuals who have given their time and expertise to the peer review of manuscripts for Hereditary Cancer in Clinical Practice. We look forward to your continued support in 2016