The edge of galaxy formation III: The effects of warm dark matter on Milky Way satellites and field dwarfs

In this third paper of the series, we investigate the effects of warm dark matter with a particle mass of $m_\mathrm{WDM}=3\,\mathrm{keV}$ on the smallest galaxies in our Universe. We present a sample of 21 hydrodynamical cosmological simulations of dwarf galaxies and 20 simulations of satellite-host galaxy interaction that we performed both in a Cold Dark Matter (CDM) and Warm Dark Matter (WDM) scenario. In the WDM simulations, we observe a higher critical mass for the onset of star formation. Structure growth is delayed in WDM, as a result WDM haloes have a stellar population on average two Gyrs younger than their CDM counterparts. Nevertheless, despite this delayed star formation, CDM and WDM galaxies are both able to reproduce the observed scaling relations for velocity dispersion, stellar mass, size, and metallicity at $z=0$. WDM satellite haloes in a Milky Way mass host are more susceptible to tidal stripping due to their lower concentrations, but their galaxies can even survive longer than the CDM counterparts if they live in a dark matter halo with a steeper central slope. In agreement with our previous CDM satellite study we observe a steepening of the WDM satellites' central dark matter density slope due to stripping. The difference in the average stellar age for satellite galaxies, between CDM and WDM, could be used in the future for disentangling these two models.Comment: 10 pages, 11 figures, accepted for publication on MNRA

E‐cigarette support for smoking cessation: Identifying the effectiveness of intervention components in an on‐line randomized optimization experiment

Aims, Design and Setting The aim of this study was to determine which combination(s) of five e-cigarette-orientated intervention components, delivered on-line, affect smoking cessation. An on-line (UK) balanced five-factor (2 × 2 × 2 × 2 × 2 = 32 intervention combinations) randomized factorial design guided by the multi-phase optimization strategy (MOST) was used. Participants A total of 1214 eligible participants (61% female; 97% white) were recruited via social media. Interventions The five on-line intervention components designed to help smokers switch to exclusive e-cigarette use were: (1) tailored device selection advice; (2) tailored e-liquid nicotine strength advice; (3): tailored e-liquid flavour advice; (4) brief information on relative harms; and (5) text message (SMS) support. Measurements The primary outcome was 4-week self-reported complete abstinence at 12 weeks post-randomization. Primary analyses were intention-to-treat (loss to follow-up recorded as smoking). Logistic regressions modelled the three- and two-way interactions and main effects, explored in that order. Findings In the adjusted model the only significant interaction was a two-way interaction, advice on flavour combined with text message support, which increased the odds of abstinence (odds ratio = 1.55, 95% confidence interval = 1.13–2.14, P = 0.007, Bayes factor = 7.25). There were no main effects of the intervention components. Conclusions Text-message support with tailored advice on flavour is a promising intervention combination for smokers using an e-cigarette in a quit attempt

Mobile Phone Text Messages to Support People to Stop Smoking by Switching to Vaping: Codevelopment, Coproduction, and Initial Testing Study.

SMS text messages are affordable, scalable, and effective smoking cessation interventions. However, there is little research on SMS text message interventions specifically designed to support people who smoke to quit by switching to vaping. Over 3 phases, with vapers and smokers, we codeveloped and coproduced a mobile phone SMS text message program. The coproduction paradigm allowed us to collaborate with researchers and the community to develop a more relevant, acceptable, and equitable SMS text message program. In phase 1, we engaged people who vape via Twitter and received 167 responses to our request to write SMS text messages for people who wish to quit smoking by switching to vaping. We screened, adjusted, refined, and themed the messages, resulting in a set of 95 that were mapped against the Capability, Opportunity, and Motivation-Behavior constructs. In phase 2, we evaluated the 95 messages from phase 1 via a web survey where participants (66/202, 32.7% woman) rated up to 20 messages on 7-point Likert scales on 9 constructs: being understandable, clear, believable, helpful, interesting, inoffensive, positive, and enthusiastic and how happy they would be to receive the messages. In phase 3, we implemented the final set of SMS text messages as part of a larger randomized optimization trial, in which 603 participants (mean age 38.33, SD 12.88 years; n=369, 61.2% woman) received SMS text message support and then rated their usefulness and frequency and provided free-text comments at the 12-week follow-up. For phase 2, means and SDs were calculated for each message across the 9 constructs. Those with means below the neutral anchor of 4 or with unfavorable comments were discussed with vapers and further refined or removed. This resulted in a final set of 78 that were mapped against early, mid-, or late stages of quitting to create an order for the messages. For phase 3, a total of 38.5% (232/603) of the participants provided ratings at the 12-week follow-up. In total, 69.8% (162/232) reported that the SMS text messages had been useful, and a significant association between quit rates and usefulness ratings was found (χ =9.6; P=.002). A content analysis of free-text comments revealed that the 2 most common positive themes were helpful (13/47, 28%) and encouraging (6/47, 13%) and the 2 most common negative themes were too frequent (9/47, 19%) and annoying (4/47, 9%). In this paper, we describe the initial coproduction and codevelopment of a set of SMS text messages to help smokers stop smoking by transitioning to vaping. We encourage researchers to use, further develop, and evaluate the set of SMS text messages and adapt it to target populations and relevant contexts. [Abstract copyright: ©Vassilis Sideropoulos, Eleni Vangeli, Felix Naughton, Sharon Cox, Daniel Frings, Caitlin Notley, Jamie Brown, Catherine Kimber, Lynne Dawkins. Originally published in JMIR Formative Research (https://formative.jmir.org), 27.09.2023.

Tailored interventions to assist smokers to stop smoking using e-cigarettes (TASSE): Study protocol [version 3]

Background: T here is increasing evidence that e-cigarettes (EC) are an effective smoking cessation aid when combined with behavioural support. T here is further evidence for digital tailored interventions as cost effective approaches that can increase smoking cessation rates. Experimental work also suggests the addition of a ‘nicotine fact sheet’ can improve smokers’ risk perceptions related to EC. However, multifaceted approaches to deliver ‘tailored advice’ for smoking cessation combining various key evidenced based components are lacking. T he aim of this study is to use a Multiphase Optimisation Strategy (MOST ) to determine which of five, or a combination thereof, EC-orientated intervention components is associated with self-reported cessation over the previous 4-weeks at 12-week follow-up. Methods/Design: T his online study will utilise a 2x2x2x2x2 factorial design resulting in 32 experimental conditions. T he five intervention components will be: 1: tailored advice on EC device; 2: tailored advice on e-liquid nicotine strength; 3: tailored advice on eliquid flavour; 4: e-cigarette written information; 5: text message support. A sample of N=1184 adult, UK resident smokers will be randomly allocated to one of the 32 conditions, which will be permutations of the 5 components (counter-balanced). T he primary outcome is 4 weeks of self-reported complete abstinence at 12 weeks post randomisation. Secondary outcomes are 7-day point prevalence, 50% reduction in baseline cigarettes smoked per day, time to switch and adherence to recommendation. T he primary analysis will be by intent-to-treat with the assumption that missing equals smoking. Logistic regression will be used to model the five main effects and the ten 2x2 interactions. A number of secondary analyses will also be conducted including models adjusting for demographic and smoking indices and including only those who received the intervention. Discussion: T o date, components that assist quitting by use of EC or other aids have largely been studied in isolation. T his study presents the first attempt to combine evidenced based interventions, using the MOST method, to test which components are associated with quitting. T he findings will be used to inform which components to include and their estimated effect sizes for a definitive randomised controlled trial (RCT ) to examine the efficacy of the intervention compared with usual care (own choice and no support)

Text messages to support e-cigarette use for smoking cessation: a tool for researchers

E-cigarettes are now the most popular quit aid chosen by smokers in England. Mobile phone text messages have been shown to be a useful tool in facilitating smoking cessation attempts by providing behaviour change support. To date, no published examples of text messages exist specifically aimed at smokers attempting to quit with e-cigarettes (vaping). As part of a parent study, we led an online call to vapers asking what advice and information they would give, in the form of a text message, to smokers wishing to quit smoking by vaping. We received 102 initial suggestions. Alongside behaviour change and smoking cessation experts, we checked the messages for readability and scientific accuracy, removed inappropriate messages, refined and edited others, and added additional messages. Messages were also grouped by theme and relevance to the stage of quitting. 95 messages were taken forward for further evaluation by 376 smokers, ex-smokers and vapers. Here we present the full set of 95 messages along with a final set of 78 that were selected and ordered for our parent study by two members of the research team along with four vapers. We encourage engagement with this resource and further validation from researchers interested in smoking cessation with e-cigarettes

High frequency magnetic oscillations of the organic metal θ\theta-(ET)4_4ZnBr4_4(C6_6H4_4Cl2_2) in pulsed magnetic field of up to 81 T

De Haas-van Alphen oscillations of the organic metal $\theta$-(ET)$_4$ZnBr$_4$(C$_6$H$_4$Cl$_2$) are studied in pulsed magnetic fields up to 81 T. The long decay time of the pulse allows determining reliable field-dependent amplitudes of Fourier components with frequencies up to several kiloteslas. The Fourier spectrum is in agreement with the model of a linear chain of coupled orbits. In this model, all the observed frequencies are linear combinations of the frequency linked to the basic orbit $\alpha$ and to the magnetic-breakdown orbit $\beta$.Comment: 6 pages, 4 figure