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Path integral spin dynamics with exchange and external field
No full textIn this work, we propose a path-integral-inspired formalism for computing the quantum thermal expectation values of spin systems subject to magnetic fields that can be time dependent and can accommodate the presence of Heisenberg exchange interactions between the spins. This is done by deriving an effective magnetic field from the quantum partition function of the system to use in classical atomistic spin dynamics simulations and generalizes the formalism presented in our previous work [Phys. Rev. Res. 5, 043075 (2023)]. In special cases where the effective field can be computed exactly, we compare our results with exact/numerical diagonalization methods for both ferromagnetic and antiferromagnetic coupling. We show that our method works well across a large temperature range and can reproduce quantum expectation values for antiferromagnetic coupling, which is usually not possible with classical models
The Cost-Effectiveness of Collagenase Injection versus Limited Fasciectomy for Moderate Dupuytren’s Contracture:An Economic Evaluation of the DISC Trial and a Decision Analytical Model
No full textObjectives: To compare the cost-effectiveness of collagenase injection (collagenase) and limited fasciectomy (LF) surgery in treating moderate Dupuytren’s contracture (DC) in the UK over different time horizons. Methods: An incremental cost-effectiveness analysis was conducted alongside a multicentre, pragmatic, parallel randomised controlled trial (DISC), to determine the short-term cost-effectiveness of collagenase compared to LF. A Markov decision analytic model was developed to assess long-term cost-effectiveness. Results: Collagenase was associated with significantly lower cost and insignificantly lower Quality-adjusted life year (QALY) gain compared to LF at one year. The probability of collagenase being cost-effective was over 99% at willingness-to-pay thresholds of £20,000–£30,000 per QALY. At two years, collagenase was both significantly less costly and less effective compared to LF, and LF became cost-effective above a threshold of £25,488. There was a high level of uncertainty surrounding the 2-year results. Over a lifetime horizon, collagenase generated a cost saving of £2,968 per patient, but was associated with a mean QALY loss of -0.484. The probability of collagenase being cost-effective dropped to 22% and 16% at £20,000–£30,000 per QALY, respectively. Conclusions: Collagenase was less costly and less effective than LF in treating DC. The cost-effectiveness of collagenase compared to LF was time-dependent. Collagenase was highly cost-effective one-year post-treatment, but the probability of collagenase being cost-effective declined over time. The Markov model suggested that LF is more cost-effective over a lifetime horizon. These findings emphasise the importance of longer follow-up when comparing surgical and nonsurgical interventions to fully capture overall costs and benefits. Keywords: Dupuytren’s contracture, Collagenase clostridium histolyticum, limited fasciectomy, cost-effectiveness, Markov mode
Exploring how an e-cigarette intervention influenced tobacco smoking behaviour in people accessing homelessness services: Findings from the SCeTCH trial process evaluation
No full textBackground Smoking prevalence among people experiencing homelessness is high. This study explored the factors which influenced potential smoking abstinence among participants receiving an e-cigarette (EC) intervention within the Smoking Cessation Trial in Centres for Homelessness (SCeTCH) across Great Britian. Methods Using the Capability Opportunity Motivation – Behaviour (COM-B) model, hypothesised and emerging mediators were explored quantitatively via measures in baseline and follow-up questionnaires (n=239) and qualitatively via interviews with homelessness centre staff (n=16) and participants (n=31) who received an EC starter pack and 4-week e-liquid supply. We purposively sampled 8 centres for interviews, representing varied regions and participant vaping/smoking and sociodemographic status. Quantitative measures were analysed descriptively. Qualitative data were analysed thematically. Data from the two approaches were mapped onto the COM-B for combined analysis and reporting. Results After receiving the intervention, participants demonstrated high capability to use EC and appreciation of EC for harm reduction. Some participants reported dissatisfaction with vaping. Opportunity for behaviour change was strengthened by perceived acceptability to vape and social support beyond the centre but hindered by a smoking culture and perceived lack of staff support. Motivation was enhanced by EC efficacy belief, pride from cutting down, and financial benefits of vaping, but negatively impacted by challenging personal circumstances. Conclusion For people accessing homelessness support centres, smoking abstinence remains challenging. More intensive support and a variety of approaches to support smoking cessation, particularly those which address the psychosocial factors which hinder smoking abstinence, may be required. Future research should focus on how this can be achieved
Consumers as regulators of global value chains’ conduct? A consumer-inclusive framework of change
No full textInadequate conduct of global value chains (GVCs) has given rise to serious concerns by academics and policymakers but efforts to improve it have made minimal progress, jeopardizing global wealth distribution and accentuating inequality. In the work, we advance a novel analytical framework for addressing this concern, underpinned by the trust of including the consumers as an important constituency that could bring about the desired change. Blending insights of governmentality, social movements, and ethical consumerism theories with those of ethical conduct in GVCs and combining them with lessons of a comparative analysis of ethical conduct in the coffee and fashion GVCs, we develop a framework for change that is driven by consumer agency and their power to ‘regulate’ global brands’ conduct via their consumption behavior. We identify a range of private- and public-sector constituencies that could mobilize the consumers towards this end and explicate the mechanisms to bring about this outcome. This framework supplements the top-down approach proposed by extant research with a bottom-up, grassroots approach. In doing this, it directs the debate regarding GVC conduct to new directions based on a different logic. The framework guides policy intervention by extending the role of governments from that of regulators of global brands to facilitators of consumers’ mobilization and societal change
A meta-ethnography of women’s intimate and sexual experiences across the menopause continuum
No full textWomen’s intimate and sexual experiences during midlife are shaped by complex biopsychosocial factors, warranting focused attention in research and clinical practice. A hormonal shift in the menopause transition period may cause symptoms such as vaginal dryness, thinned mucosa, and painful intercourse. Other symptoms include decreased libido, and difficulty achieving orgasm during sexual activity. With more women reaching midlife, there is more need to understand how physiology and psychology impact their intimate relationships and overall health. The purpose of this review was to explore published qualitative studies on women’s sexual experiences including function, satisfaction, and challenges during midlife and the menopause continuum. A meta-ethnographic approach was conducted to synthesize all relevant qualitative studies. We searched on the Web of Science, Scopus, and CINAHL for studies published between 2010 and September 2024. Of 1,361 studies identified, 53 studies encompassing diverse cultural contexts met the inclusion criteria and were synthesized. Three main themes were identified: physical symptoms and cultural influences on sexuality during menopause and midlife; emotional, psychological, and relational responses to sexual and bodily changes, including shifts in self-perception, body image, emotional well-being, and relationship dynamics; and adapting to sexual changes during the midlife and menopause transition. The review highlights that biological changes alone are insufficient to fully understand midlife and menopausal women’s sexual experiences, emphasizing the need for a biopsychosocial approach to provide holistic care. Greater attention should be given to midlife women’s sexual health and well-being by raising awareness and encouraging open discussions about menopause and sexual changes. Healthcare professionals play a critical role in recognizing the psychological impacts of these changes and facilitating conversations to help women feel comfortable discussing sensitive topics. The review highlights the need for future research to explore women’s experiences of menopause and sexual health and well-being across diverse cultural contexts, with particular attention to non-Western countries where such perspectives remain underrepresented
Dynamics of proximity-induced magnetism at cobalt/molecular interfaces
No full textInterfacing ferromagnetic metals with organic molecules is a versatile strategy to control key parameters in magnetic and spintronic technologies. Hybridization between the metal’s surface d orbitals and molecular p orbitals profoundly alters both the interfacial molecular layer and adjacent metal interface atomic layers, causing substantial changes in the magnetic properties of metal/molecule heterostructures. While magnetic modifications within the metallic layer are relatively well understood, the interfacial magnetism remains elusive. Using ultrafast time-resolved magneto-optical spectroscopy, we investigate the magnetic dynamics in such heterostructures and identify a distinct interfacial magnetic component that appears universal across various cobalt/molecule combinations. Our findings reveal a highly anisotropic magnetic layer localized at the interface, which has remained undetected in static measurements. This interfacial layer likely originates from strong chemical modifications in the cobalt surface induced by chemisorbed molecules. These results underscore the crucial role of molecular chemisorption in shaping interfacial magnetic properties, offering further opportunities for tuning functionalities in molecule-based spintronic devices
Confidence intervals for adaptive trial designs II: case study and practical guidance
No full textIn adaptive clinical trials, the conventional confidence interval (CI) for a treatment effect is prone to undesirable properties such as undercoverage and potential inconsistency with the final hypothesis testing decision. Accordingly, as is stated in recent regulatory guidance on adaptive designs, there is the need for caution in the interpretation of CIs constructed during and after an adaptive clinical trial. However, it may be unclear which of the available CIs in the literature are preferable. This paper is the second in a two-part series that explores CIs for adaptive trials. Part I provided a methodological review of approaches to construct CIs for adaptive designs. In this paper (Part II), we present an extended case study based around a two-stage group sequential trial, including a comprehensive simulation study of the proposed CIs for this setting. This facilitates an expanded description of considerations around what makes for an effective CI procedure following an adaptive trial. We show that the CIs can have notably different properties. Finally, we propose a set of guidelines for researchers around the choice of CIs and the reporting of CIs following an adaptive design
Surrogate-assisted optimization of roll-to-roll slot die coating
No full textRoll-to-roll slot die coating is a key wet processing technique, where achieving a specific thickness with minimal variability is crucial. However, the numerous input parameters make optimization complex. Despite its advanced applications, computer-aided optimization remains underutilized, leaving potential performance improvements untapped. Due to the lack of accurate first-principle models, machine learning offers a promising approach. This study employs Radial Basis Function Neural Networks as surrogate models trained on experimental data to optimize roll-to-roll slot die coating. These models predict coating thickness and uniformity with mean absolute errors below 11.5 %. Key process parameters are identified, with shim thickness and substrate velocity having the greatest impact on coating uniformity, while coating gap played a lesser role. An evolutionary optimization approach identified new operating parameters, leading to improved coating properties. Experimentally, these optimized conditions achieved the five lowest recorded uniformity values and increased the hyper-volume fraction from 0.68 to 0.84. Some prediction inconsistencies were observed, likely due to the high sensitivity of lab-scale equipment, which is expected to improve at an industrial scale. This work paves the way for wider adoption of machine learning and accurate metrology in slot die coating
