The Efficacy of 3 Bleaching Methods on Stained Polymer-Based CAD/CAM Materials

Introduction and aims: This study aimed to investigate the efficacy of 3 bleaching methods on stained polymer-based CAD/CAM blocks in terms of surface roughness, hardness stability, discolouration reduction and susceptibility to re-staining following bleaching. Methods: Two-mm-thick slabs (N = 128) were prepared from CeraSmart (CS), Grandio Blocs (GB), Vita Enamic (VE), and direct resin composite GrandioSO (RC). Coffee-stained specimens (n = 8) were subdivided into bleaching (BL) groups: in-office bleaching (OB), home bleaching (HB), whitening mouthwash (MW), and a control group with 14-day storage in water (CL). Measurements of roughness (Ra), Vickers hardness (HV), and colour parameters (ΔE00, ΔL*, Δb*) were taken before and after BL. Then, all the bleached specimens were re-stained to determine their stain susceptibility. Repeated measures of ANOVA, Pearson's χ2 test, and multiple post hoc tests were performed (α = 0.05). Results: HB was more effective in whitening in terms of achieving minimal residual colour (-0.87 to 0.7) and greater resistance to re-staining (0.41 to 0.89). MW resulted in an increased lightness (ΔL*) of all materials (1.96 - 2.30). However, MW increased the roughness of VE (0.8 µm) and RC (0.4 µm), compared to their baseline measurements (0.057 µm and 0.087 µm, respectively, p = 0.003). All the BL treatments resulted in a greater hardness reduction (14.4% to 18.1%) in the RC than in the other materials. Conclusion: The investigated polymer-based materials and modes of bleaching treatment influenced the bleaching efficacy. For CAD/CAM blocks, in-office bleaching and whitening mouthwash reduced the discolouration but adversely affected their roughness and hardness compared to home bleaching. Home bleaching proved to be the least susceptible to re-staining. Clinical relevance: Knowing how a specific bleaching product affects the colour, roughness and hardness and consequent susceptibility to staining of 4 studied polymer-based materials that represent pre-existing restorations would impact the consideration of bleaching treatment

Messaging with appeal to intrinsic or relational values shows potential to shift demand for wildlife as pets

Overharvesting of wildlife for trade is a key driver of biodiversity loss. Messaging that is aligned with people's values could play a significant role in reducing this impact through behaviour change. Using an online survey, we sought to gauge the willingness among bird hobbyists, breeders, and song contestants to change their bird‐keeping behaviours, and to identify barriers to such change. We then evaluated the persuasiveness of various messages that potentially align with people's values (e.g. addressing conservation, cultural and health considerations), each framed as positive or negative, and with outcomes involving a move to commercially bred birds or cessation of purchasing wild‐caught birds. We identified a degree of plasticity in behaviour, with most respondents perceiving the keeping of wild‐caught birds to be a conservation problem, and a majority claiming they would attempt to breed birds in the future. However, while most respondents acknowledged the illegality of both buying and catching wild birds, they also recognised that most birds in markets are wild‐caught because they are easier and cheaper to source than captive‐bred birds. Messages about the damage done by over‐exploitation to wild bird populations, to the future of bird‐keeping itself, and about the benefits of keeping captive‐bred over wild‐caught birds, were most effective. Messages about generational, legal and especially health concerns appeared to gain little traction. The persuasiveness of these messages varied little across bird‐keeping groups, but age‐ and user‐groups differed in their most trusted sources of information and the media they consulted. Our results suggest that appealing to people's concern over the intrinsic value of wildlife or the relational value of cultural heritage might be more effective at shifting demand for wildlife products than more instrumental or utilitarian considerations. Effective messaging should focus on the negative impacts of over‐exploitation on Indonesia's wildlife and/or national heritage, and on the positive aspects of sustainable captive‐bred alternatives, and be transmitted via multiple media, including local and faith leaders (choice varying geographically), to maximise outreach to the diverse bird‐keeping community. Read the free Plain Language Summary for this article on the Journal blog

The Enactment of Cinematographic Techniques and Aesthetics of Perspective and Proximity in Musical Composition

This research is situated in the field of practice-based research in music composition. The research methodology was to select visuals of existing film material, analyze the technical and aesthetic content of stills or short sequences, and develop a range of strategies for enacting components of the visuals in compositional materials, techniques, and formal structures. Working principally with the shot composition and cinematographic and editing techniques and aesthetics of perspective and proximity in the chosen film extracts, key arising compositional areas included variation forms, the subversion of registral hierarchies, and haptic timbres. The literature review offers a wider context for the composition portfolio, examining film theory and analysis relevant to the research and providing an aesthetic survey of pertinent existing musical works. The first films worked with were Dreyer’s The Passion of Joan of Arc (1927) and Dulac’s La Souriante Madame Beudet (1922). Matilda Mroz’s Temporality and Film Analysis (2012) provided insights into two short scenes in Antonioni’s 1960 film L’Avventura, which formed the basis of the following compositional case studies. A methodology emerged that combined the compositional strategies generated by engagement with the film and film text materials with practical experimentation on instruments composed for, either by the composer or through workshops with instrumentalists. The result of the research is a coherent portfolio of instrumental and electroacoustic pieces, each composition arising from a filmic starting point. Central to the research methodology was an iterative process of reflecting on the questions arising from the research: these explorations form the basis of the critical commentary

Events, turns, and critical junctures: unpacking the temporality of supporter rights and democracy in English football

The future of professional men’s football in England stands at a critical juncture. In the wake of a global pandemic, the national game has been beset by volatility and upheaval. In April 2021, six of the most storied clubs in England announced they would be joining a new breakaway European Super League (ESL). These proposals triggered vehement opposition from fan movements, catalysing the intervention of the UK government who established a fan-led review of football governance (FLR) to consult fans on future regulatory reform and the security and safety of supporters at major events. Emerging out of these exogenous shocks and endogenous change, the governance of English football is set to be radically transformed via the establishment of a new regulatory regime. In this article, we employ eventful sociology and historical institutionalism to operationalise the concept of critical juncture and apply this through an analysis of two temporal periods (1985-1990) and (2020-2024). In doing so, we show how the current ‘regulatory turn’ is interdependently linked to prior historical transformative events, namely the Heysel and Hillsborough stadium disasters and the subsequent neoliberal transformation of English football across the last four decades. Incorporating a more nuanced understanding of change and continuity in the governance of English football, we argue that new regulatory frameworks, despite their transformative potential, may continue to exhibit institutional legacies of the existing regime and prevailing political economy

Reconfigurable Intelligent Surface-Assisted Aerial Nonterrestrial Networks: An Intelligent Synergy With Deep Reinforcement Learning

Reconfigurable intelligent surface (RIS)-assisted aerial non-terrestrial networks (NTNs) offer a promising paradigm for enhancing wireless communications in the era of 6G and beyond. By integrating RIS with aerial platforms such as unmanned aerial vehicles (UAVs) and high-altitude platforms (HAPs), these networks can intelligently control signal propagation, extending coverage, improving capacity, and enhancing link reliability. This article explores the application of deep reinforcement learning (DRL) as a powerful tool for optimizing RIS-assisted aerial NTNs. We focus on hybrid proximal policy optimization (H-PPO), a robust DRL algorithm well-suited for handling the complex, hybrid action spaces inherent in these networks. Through a case study of an aerial RIS (ARIS)-aided coordinated multi-point non-orthogonal multiple access (CoMPNOMA) network, we demonstrate how H-PPO can effectively optimize the system and maximize the sum rate while adhering to system constraints. Finally, we discuss key challenges and promising research directions for DRL-powered RIS-assisted aerial NTNs, highlighting their potential to transform nextgeneration wireless networks

Synthetic cathinones: an updated harms assessment

ACMD has written an updated harms assessment describing the use and harms of synthetic cathinones following a government commission

Men’s experiences of a personalised, appearance-based, facial-morphing, safer drinking intervention

Risky alcohol consumption behaviours remain commonplace, representing a major threat to health and safety, and are especially evidenced by young university students. Consequently, new interventions targeting this high-risk group are required. The current study investigated young male university students’ experiences of a personalised, appearance-based, facial morphing, safer drinking intervention. Twenty-five male student participants were recruited, aged 18–34 years. Inductive thematic analysis of data gathered whilst participants were immersed in the intervention, and thereby exposed to alcohol-aged images of their own faces, produced four primary themes: alcohol as a threat to appearance and health, motivations to protect appearance, motivational aspects of the intervention, and proposed improvements and applications. The results of the current study suggested that participants expressed intentions towards healthier consumption/maintenance of already non-risky intake, supporting the potential of the facial-morphing appearance-based approach to address risky alcohol consumption, even in high-risk groups

Cultural Heritage in Chinese Digital Games

Digital games history has been dominated by Japan, North America, and Europe, both as major producers and consumers of games. However, China is now by far the largest digital games market on the planet, both in terms of player numbers and expenditure. This exceptional growth is naturally reflected in the local production of games, which, despite their large numbers and player base, are only now having more resonance in the West. This paper examines what role Chinese cultural heritage plays in the characterization of its games, as well as the similarities and differences with the Western and Japanese traditions of game arts and development, both from a ludological and aesthetic point of view, with a focus on the role-playing genre

Boundary objects at play in the world's greenest football club

Due to the increase of environmental and societal pressures, organizations are gradually moving away from merely reducing their detrimental effects and heading toward making positive impacts. One sizeable sector of economic activity that is frequently overlooked is that of sport, with football being the largest sector in terms of economic value, fan base and global cultural influence. It is only relatively recently that outliers in the football industry have transitioned from being purely profit-motivated to being both socially and environmentally aware. This transition is challenging because it is being undertaken within the often aggressive masculine environment, as well as having deep-seated socio-historical origins that are found not only within the individual clubs, but also throughout the sport as a whole. One such football club is Forest Green Rovers, which appears to have navigated this journey successfully. However, the research has not yet been able to establish how this has been achieved. This study addresses this research gap by undertaking a four-year examination of the social and environmental initiatives of Forest Green Rovers. This lower league ‘club on the hill’ is globally recognized for its novel approaches and solutions. Through examination of the various Boundary Objects that aid in uniting disparate social groups to effect considerable changes to the ‘match day experience’ and to stakeholders’ consumption behaviors, it explains how their pragmatic, syntactic and semantic functions combine to create an accepted suite of socially and environmentally beneficial initiatives

The IOC and Olympic Law: Scoping the Regulatory Space of the IOC

This chapter explores a specific and often under-explored area of transnational sports law: Olympic law. It begins by defining the parameters of the Olympic legal framework and distinguishing between the origins and functions of lex Olympica and Olympic law by identifying the key foundational documents at the heart of both regulatory systems. Having established their separate purposes, the chapter explores how both sources of law operate as governance structures for the legal regulation of the Olympic Games in two specific fields. First, it will examine the restrictions imposed on athletes’ ability to exploit their participation in the Olympics for their own commercial benefit and the wider legality of Rule 40 of the Olympic Charter. Secondly, it will interrogate the International Olympic Committee’s commitment to protect, respect and provide remedies for the abuse of human rights at the Olympic Games by examining the impact of Rules 40.2 and 50.2 of the Olympic Charter. It will conclude that the importance of the Olympic legal framework is in its ability to act as a template for sports governance, but that it is not yet providing the leadership that the Olympic Movement should be expecting of it