Increased risk of HIV and other drug-related harms associated with injecting in public places: national bio-behavioural survey of people who inject drugs

Background: Whilst injecting drugs in public places is considered a proxy for high risk behaviour among people who inject drugs (PWID), studies quantifying its relationship with multiple drug-related harms are lacking and none have examined this in the context of an ongoing HIV outbreak (located in Glasgow, Scotland). We aimed to: 1) estimate the prevalence of public injecting in Scotland and associated risk factors; and 2) estimate the association between public injecting and HIV, current HCV, overdose, and skin and soft tissue infections (SSTI). Methods: Cross-sectional, bio-behavioural survey (including dried blood spot testing to determine HIV and HCV infection) of 1469 current PWID (injected in last 6 months) recruited by independent interviewers from 139 harm reduction services across Scotland during 2017–18. Primary outcomes were: injecting in a public place (yes/no); HIV infection; current HCV infection; self-reported overdose in the last year (yes/no) and SSTI the last year (yes/no). Multi-variable logistic regression was used to determine factors associated with public injecting and to estimate the association between public injecting and drug-related harms (HIV, current HCV, overdose and SSTI). Results: Prevalence of public injecting was 16% overall in Scotland and 47% in Glasgow city centre. Factors associated with increased odds of public injecting were: recruitment in Glasgow city centre (aOR=5.45, 95% CI 3.48–8.54, p<0.001), homelessness (aOR=3.68, 95% CI 2.61–5.19, p<0.001), high alcohol consumption (aOR=2.42, 95% CI 1.69–3.44, p<0.001), high injection frequency (≥4 per day) (aOR=3.16, 95% CI 1.93–5.18, p<0.001) and cocaine injecting (aOR=1.46, 95% CI 1.00 to 2.13, p = 0.046). Odds were lower for those receiving opiate substitution therapy (OST) (aOR=0.37, 95% CI 0.24 to 0.56, p<0.001) and older age (per year increase) (aOR=0.97, 95% CI 0.95 to 0.99, p = 0.013). Public injecting was associated with an increased risk of HIV infection (aOR=2.11, 95% CI 1.13–3.92, p = 0.019), current HCV infection (aOR=1.49, 95% CI 1.01–2.19, p = 0.043), overdose (aOR=1.59, 95% CI 1.27–2.01, p<0.001) and SSTI (aOR=1.42, 95% CI 1.17–1.73, p<0.001). Conclusions: These findings highlight the need to address the additional harms observed among people who inject in public places and provide evidence to inform proposals in the UK and elsewhere to introduce facilities that offer safer drug consumption environments

High willingness to use drug consumption rooms among people who inject drugs in Scotland: findings from a national bio-behavioural survey among people who inject drugs

Background To address rising drug-related harms (including significant transmission of HIV) among people who inject drugs (PWID) in Glasgow, officials have proposed the introduction of the UK's first drug consumption room (DCR) in Glasgow city centre. Using a nationally representative sample, this study aimed to determine willingness to use a DCR among PWID nationally, in Glasgow city centre (the proposed DCR location), other Scottish city centres (excluding Glasgow) and the rest of Scotland (excluding city centres). Methods Bio-behavioural survey, of 1469 current PWID (injected in last 6 months) across Scotland during 2017-18. Willingness to use DCRs was examined by drug-related risk behaviours and harms overall in Scotland, and then stratified by Glasgow city centre (n = 219), other Scottish city centres (n = 226) and the rest of Scotland (n = 1024). Results The majority of PWID overall in Scotland (75%) were willing to use a DCR; willingness was higher among those recruited in Glasgow city centre (83%) and other Scottish city centres (83%), compared to the rest of Scotland (72%) (p < 0.001). Willingness was greater among PWID who reported (compared to those who did not report) injecting heroin (76%, p = 0.002), cocaine injecting (79%, p = 0.014), homelessness (86%, p < 0.001), public injecting (87%, p < 0.001) and an overdose (80%, p = 0.026). Willingness was found to be associated with a cumulative multiple risk variable: increased from 66% among those with a score of zero to 85% with a score of at least three (p < 0.001). Conclusions The vast majority of PWID at greatest risk of drug-related harm in Glasgow and elsewhere in Scotland would be willing to use a DCR, supporting proposals for the introduction of DCRs nationally

SubHaloes going Notts: The SubHalo-Finder Comparison Project

We present a detailed comparison of the substructure properties of a single Milky Way sized dark matter halo from the Aquarius suite at five different resolutions, as identified by a variety of different (sub-)halo finders for simulations of cosmic structure formation. These finders span a wide range of techniques and methodologies to extract and quantify substructures within a larger non-homogeneous background density (e.g. a host halo). This includes real-space, phase-space, velocity-space and time- space based finders, as well as finders employing a Voronoi tessellation, friends-of-friends techniques, or refined meshes as the starting point for locating substructure.A common post-processing pipeline was used to uniformly analyse the particle lists provided by each finder. We extract quantitative and comparable measures for the subhaloes, primarily focusing on mass and the peak of the rotation curve for this particular study. We find that all of the finders agree extremely well on the presence and location of substructure and even for properties relating to the inner part part of the subhalo (e.g. the maximum value of the rotation curve). For properties that rely on particles near the outer edge of the subhalo the agreement is at around the 20 per cent level. We find that basic properties (mass, maximum circular velocity) of a subhalo can be reliably recovered if the subhalo contains more than 100 particles although its presence can be reliably inferred for a lower particle number limit of 20. We finally note that the logarithmic slope of the subhalo cumulative number count is remarkably consistent and <1 for all the finders that reached high resolution. If correct, this would indicate that the larger and more massive, respectively, substructures are the most dynamically interesting and that higher levels of the (sub-)subhalo hierarchy become progressively less important.Comment: 16 pages, 7 figures, 2 tables, Accepted for MNRA

In vivo fluorescence lifetime imaging of macrophage intracellular metabolism during wound responses in zebrafish

The function of macrophages in vitro is linked to their metabolic rewiring. However, macrophage metabolism remains poorly characterized in situ. Here, we used two-photon intensity and lifetime imaging of autofluorescent metabolic coenzymes, nicotinamide adenine dinucleotide (phosphate) (NAD(P)H) and flavin adenine dinucleotide (FAD), to assess the metabolism of macrophages in the wound microenvironment. Inhibiting glycolysis reduced NAD(P)H mean lifetime and made the intracellular redox state of macrophages more oxidized, as indicated by reduced optical redox ratio. We found that TNFα+ macrophages had lower NAD(P)H mean lifetime and were more oxidized compared to TNFα− macrophages. Both infection and thermal injury induced a macrophage population with a more oxidized redox state in wounded tissues. Kinetic analysis detected temporal changes in the optical redox ratio during tissue repair, revealing a shift toward a more reduced redox state over time. Metformin reduced TNFα+ wound macrophages, made intracellular redox state more reduced and improved tissue repair. By contrast, depletion of STAT6 increased TNFα+ wound macrophages, made redox state more oxidized and impaired regeneration. Our findings suggest that autofluorescence of NAD(P)H and FAD is sensitive to dynamic changes in intracellular metabolism in tissues and can be used to probe the temporal and spatial regulation of macrophage metabolism during tissue damage and repair

Advances in Space Radiation Shielding Codes

Early space radiation shield code development relied on Monte Carlo methods and made important contributions to the space program. Monte Carlo methods have resorted to restricted one-dimensional problems leading to imperfect representation of appropriate boundary conditions. Even so, intensive computational requirements resulted and shield evaluation was made near the end of the design process. Resolving shielding issues usually had a negative impact on the design. Improved spacecraft shield design requires early entry of radiation constraints into the design process to maximize performance and minimize costs. As a result, we have been investigating high-speed computational procedures to allow shield analysis from the preliminary concept to the final design. For the last few decades, we have pursued deterministic solutions of the Boltzmann equation allowing field mapping within the International Space Station (ISS) in tens of minutes using standard Finite Element Method (FEM) geometry common to engineering design methods. A single ray trace in such geometry requires 14 milliseconds and limits application of Monte Carlo methods to such engineering models. A potential means of improving the Monte Carlo efficiency in coupling to spacecraft geometry is given

The characteristics of people who inject drugs in the United Kingdom: changes in age, duration, and incidence of injecting, 1980–2019, using evidence from repeated cross-sectional surveys

Abstract Background and aims Mortality and drug treatment data suggest that the median age of people who inject drugs is increasing. We aimed to describe changes in the characteristics of people injecting drugs in the United Kingdom (UK). Design Repeat cross-sectional surveys and modelling. Setting Low-threshold services in the United Kingdom such as needle and syringe programmes. Participants A total of 79 900 people who recently injected psychoactive drugs in the United Kingdom, recruited as part of the Unlinked Anonymous Monitoring Survey (England, Wales, Northern Ireland, 1990–2019) and Needle Exchange Surveillance Initiative (Scotland, 2008–2019). Measurements Age of people currently injecting, age at first injection, duration of injecting (each 1990–2019) and estimates of new people who started injecting (1980–2019). Findings In England, Wales and Northern Ireland between 1990 and 2019, the median age of people injecting increased from 27 (interquartile range [IQR], 24–31) to 40 (IQR, 34–46); median age at first injection increased from 22 (IQR, 19–25) to 33 (IQR, 28–39); and median years of injecting increased from 7 (IQR, 3–11) to 18 (IQR, 9–23). Values in Scotland and England were similar after 2008. The estimated number that started injecting annually in England increased from 5470 (95% prediction interval [PrI] 3120-6940) in 1980 to a peak of 10 270 (95% PrI, 8980-12 780) in 1998, and then decreased to 2420 (95% PrI, 1320-5580) in 2019. The number in Scotland followed a similar pattern, increasing from 1220 (95% PrI, 740–2430) in 1980 to a peak of 3080 (95% PrI, 2160–3350) in 1998, then decreased to a 270 (95% PrI, 130–600) in 2018. The timing of the peak differed between regions, with earlier peaks in London and the North West of England. Conclusions In the United Kingdom, large cohorts started injecting psychoactive drugs in the 1980s and 1990s and many still inject today. Relatively few people started in more recent years. This has led to changes in the population injecting drugs, including an older average age and longer injecting histories