Exploring internal child sex trafficking networks using social network analysis

This article explores the potential of social network analysis as a tool in supporting the investigation of internal child sex trafficking in the UK. In doing so, it uses only data, software, and training already available to UK police. Data from two major operations are analysed using in-built centrality metrics, designed to measure a network’s overarching structural properties and identify particularly powerful individuals. This work addresses victim networks alongside offender networks. The insights generated by SNA inform ideas for targeted interventions based on the principles of Situational Crime Prevention. These harm-reduction initiatives go beyond traditional enforcement to cover prevention, disruption, prosecution, etc. This article ends by discussing how SNA can be applied and further developed by frontline policing, strategic policing, prosecution, and policy and research

A Striking Confluence Between Theory and Observations of High-Mass X-ray Binary Pulsars

We analyse the most powerful X-ray outbursts from neutron stars in ten Magellanic high-mass X-ray binaries and three pulsating ultraluminous X-ray sources. Most of the outbursts rise to $L_{max}$ which is about the level of the Eddington luminosity, while the rest and more powerful outbursts also appear to recognize that limit when their emissions are assumed to be anisotropic and beamed toward our direction. We use the measurements of pulsar spin periods $P_S$ and their derivatives $\dot{P_S}$ to calculate the X-ray luminosities $L_p$ in their faintest accreting ("propeller") states. In four cases with unknown $\dot{P_S}$, we use the lowest observed X-ray luminosities, which only adds to the heterogeneity of the sample. Then we calculate the ratios $L_p/L_{max}$ and we obtain an outstanding confluence of theory and observations from which we conclude that work done on both fronts is accurate and the results are trustworthy: sources known to reside on the lowest Magellanic propeller line are all located on/near that line, whereas other sources jump higher and reach higher-lying propeller lines. These jumps can be interpreted in only one way, higher-lying pulsars have stronger surface magnetic fields in agreement with empirical results in which $\dot{P_S}$ and $L_p$ values were not used.Comment: Added LMC X-4 and commented on the cyclotron absorption line of SMC X-2. 4 pages, 1 figure, 2 tables, submitted to MNRAS

Engineering a safer society

Evidence based policing continues to be an important area of discussion among police organisations across the world, and parallels are often drawn with medicine as a means to describe how a profession can be enhanced through a commitment to evidence based techniques. The use of the medical analogy in policing does not have everybody convinced, however, and there are those who argue that rather than molecules, bacteria and disease, we are dealing with the complexity of human behaviour, meaning simple cause and effect may always be difficult to establish. In this Research Focus Professors Nick Tilley and Gloria Laycock of the Jill Dando Institute at University College London extend this thinking and suggest that a better professional parallel might be drawn with engineering. Arguing that a process of evidence based trial and error might be more effective in policing than the experimental testing of narrow hypotheses, Professors Tilley and Laycock provide an important and thought provoking addition to the ongoing evidence based policing debate

Competition in UK Electricity markets

This article includes information relating to competition in the UK electricity market, formerly published as part of UK Energy Sector Indicators. The article examines the two parts of the industry where there is competition for provision: generation and sales. For both markets, the article describes the number of companies operating, and the market concentrations. The Herfindahl-Hirschman measure (see explanation at the end of this article) is used to provide the market concentration as it provides extra emphasis on the contribution of participants with the largest shares. For electricity sales, this article covers the major suppliers1 surveyed by BEIS comprising approximately 96% of the market

The Great Pretenders Among the ULX Class

The recent discoveries of pulsed X-ray emission from three ultraluminous X-ray (ULX) sources have finally enabled us to recognize a subclass within the ULX class: the great pretenders, neutron stars (NSs) that appear to emit X-ray radiation at isotropic luminosities $L_X = 7\times 10^{39}$~erg~s$^{-1}-1\times 10^{41}$~erg~s$^{-1}$ only because their emissions are strongly beamed toward our direction and our sight lines are offset by only a few degrees from their magnetic-dipole axes. The three known pretenders appear to be stronger emitters than the presumed black holes of the ULX class, such as Holmberg II \& IX X-1, IC10 X-1, and NGC300 X-1. For these three NSs, we have adopted a single reasonable assumption, that their brightest observed outbursts unfold at the Eddington rate, and we have calculated both their propeller states and their surface magnetic-field magnitudes. We find that the results are not at all different from those recently obtained for the Magellanic Be/X-ray pulsars: the three NSs reveal modest magnetic fields of about 0.3-0.4~TG and beamed propeller-line X-ray luminosities of $\sim 10^{36-37}$~erg~s$^{-1}$, substantially below the Eddington limit.Comment: To appear in Research in Astronomy and Astrophysic

What caused the decline in child arrests in England and Wales: the Howard League’s programme or something else?

There has been a steep decline in child arrests in recent years. The Howard League report Child Arrests in England and Wales 2017 attributes this to a Howard League programme of work with police. We show the decline in arrests began well before that programme of work, and conclude the report's claims are unfounded. However, there is strong evidence that the decline in arrests is due to the long-term fall in child offending rates, probably caused by security improvements. While we are sympathetic to the aims of the Howard League, if security is having such positive effects in terms of safer communities and fewer children being processed through the criminal justice system, then it should command wide support

Right method, right price: the economic value and associated risks of experimentation

Objectives To consider the important contribution to crime reduction policy and practice made by research in experimental criminology; possible future research priorities and their methodological implications bearing in mind the cost and associated risks of research. Method Discussion of the concepts necessary to inform policy and practice leads to a consideration of the appropriate methodology for primary research. On the basis of this discussion, three case studies are considered as exemplars of the argument being developed. Results The authors argue that experimental criminology has been important in demonstrating the impact of certain types of place-based or people-based interventions. Nevertheless, the promised economic benefits are often predicated on interventions being proven effective in a particular geography or environment, on pre-existing levels of investment in the criminal justice system and on the presumed mechanism through which the initiative achieves its effect. As such, these ‘confounding factors’ need to be well researched and reported at the level of an individual experiment. Conclusions Experimental criminology has made an important contribution to policy and practice, but could increase its relevance and impact by adopting evaluation methods which expose the risks of getting the wrong answer and demonstrate the extent to which risks, and therefore costs, might be reduced through strong study design and reporting

Optical studies of two LMC X-ray transients : RX J0544.1-7100 and RX J0520.5-6932

We report observations which confirm the identities of the optical counterpart to the transient sources RX J0544.1-7100 and RX J0520.5-6932. The counterparts are suggested to be a B-type stars. Optical data from the observations carried out at ESO and SAAO, together with results from the OGLE data base, are presented. In addition, X-ray data from the RXTE all-sky monitor are investigated for long term periodicities. A strong suggestion for a binary period of 24.4d is seen in RX J0520.5-6932 from the OGLE data.Comment: 6 pages, 7 figure