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Experimental protocol for phase 1 of the APARC QUOCA (QUasibiennial oscillation and Ozone Chemistry interactions in the Atmosphere) working group
No full textThe quasi-biennial oscillation (QBO) is the main mode of variability in the tropical stratosphere, influencing the predictability of other regions in the atmosphere through its teleconnections to the stratospheric polar vortices and coupling to surface tropical and extratropical variability. However, climate and forecasting models consistently underestimate QBO amplitudes in the lower stratosphere, likely contributing to their failure to simulate these teleconnections. One underexplored contributor to model biases is missing representation of ozone-radiative feedbacks, which enhance temperature variability in the lower stratosphere, particularly at periods at and greater than the QBO (>28 months). While previous studies suggest that ozone-radiative feedbacks can impact QBO periods, amplitudes and the associated secondary circulation in the lower stratosphere, the reported impacts differ widely among models and are hard to interpret due to differences in methodology. To this end, here we propose a coordinated experimental protocol – held joint between the Atmospheric Processes and their Role in Climate (APARC) Quasi-Biennial Oscillation Initiative (QBOi) and Chemistry Climate Modeling Initiative (CCMI) activities – which is aimed at assessing the coupling between stratospheric ozone, temperature and the circulation. We use the proposed experiments to define the ozone feedback on the QBO in both present-day and idealized (abrupt quadrupling of carbon dioxide) climates. While primary focus is on the QBO, the proposed protocol also enables analysis of other aspects of ozone-radiative-dynamical coupling in the atmosphere, including impacts on the Brewer-Dobson Circulation and tropospheric eddy-driven jet responses to future climate change. Here we document the scientific rationale and design of the QUOCA Phase 1 experiments, summarize the data request, and give a brief overview of participating models. Preliminary results using the NASA Goddard Institute for Space Studies E2-2 climate model are used to illustrate sensitivities to certain methodological choices
Practice Theory and the Biosocial : Microbes, Matter, Milieu
No full textUsing recent developments in social theory, this book offers questions about how bacteria, viruses, microscopic materials and societies develop in tandem. The examples discussed – from urban infrastructures to the medieval plague and from antibiotic resistance to epigenetics –develop an account of how previous and present arrangements make some futures more likely than others and how unequal patterns of exposure and entanglement arise. This book aims to demonstrate the relevance of social and practice theories by overcoming classic distinctions between the very small and the very large, between agency and structure, and between nature and culture
The evolution of chemical risk in a Chinese river catchment exposed to untreated wastewater
Get PDFThe risks posed by chemicals released with domestic wastewater can be reduced by treating wastewater prior to its release; but in developing countries such as China, many of its settlements lack the infrastructure to treat its domestic wastewater. Improving our understanding of the risk posed by these chemicals in catchments that are partially served by sewage treatment works would enable this risk to be better managed. The spatially explicit chemical risk assessment model, Geo-referenced Regional Exposure Assessment Tool for European Rivers (GREAT-ER), was used to determine how chemical risk varies across the East River catchment, South-East China, in response to the construction of new sewage treatment works and to population change between 2010 through 2020. We evaluated the risks from two naturally occurring estrogens, estrone and 17β-estradiol, as well as two personal care product ingredients, triclosan and triclocarban. Model predictions suggest that initially, chemical concentrations decrease substantially because of the rapid construction of new sewage treatment works throughout the catchment, but as the rate of construction slowed and population continued to increase, chemical risk increased, with concentrations for most chemicals increasing to levels greater than in 2010. We then explored the potential impact of treating 100% of domestic wastewater within the catchment, which we estimated would sufficiently reduce chemical risk for triclocarban and estrone. Subsequently, to try and reduce the risk posed by triclosan, we theoretically reduced the usage of triclosan until concentrations were reduced to levels below the predicted no effect concentration. The results from this analysis suggested that triclosan usage would need to be reduced by approximately 90% to reach safe concentrations in the East River catchment
Can we enhance neurorehabilitation through regional implementation of group-based telerehabilitation? : A mixed-methods evaluation of NeuroRehabilitation OnLine (NROL)
Get PDFObjectives: To determine whether neurorehabilitation can be enhanced through regional implementation of group-based telerehabilitation, we implemented the NeuroRehabilitation OnLine (NROL) innovation regionally and evaluated scale-up from a systems perspective. Design: Observational, exploratory service evaluation using a mixed-methods convergent parallel design. Setting: Stroke and neurological rehabilitation services from four organisations across a regional healthcare system in the UK. Participants: Therapy staff from community-based services and patients with a stroke or neurological condition receiving active community rehabilitation including NROL from April 2022 to March 2024. Intervention: A regional multidisciplinary group-based neurological telerehabilitation innovation (NROL). Outcome measures: Selected Proctor’s implementation outcomes, to establish system-level adoption, acceptability and sustainability of the regional NROL innovation. Results: NROL was adopted by all intended organisations and continues as part of usual care with participation growing. It was acceptable to therapy staff and patients across the region, well-used, valued and supported increased therapy provision. For sustainability, staffing and travel efficiencies were identified through effective collaborative regional systems working. The importance of continued wide stakeholder engagement, robust evaluation and alignment was highlighted. Conclusions: NROL was successfully embedded into real-world practice at a system level and enhanced neurorehabilitation. Looking forward, longer-term sustainment of this innovation will require a compelling business case and value proposition for decision-makers, addressing economic, equality and operational efficiency considerations
Critical Undersea Infrastructures : A Framework to Address Threats in a Post-Physical Context
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Board diversity as strategic choice and why it should matter to SMEs
Get PDFPurpose: Diversity in boards has gained attention as a reflection of societal imbalances. The purpose of this paper is to investigate the impact of diversity in terms of both gender and nationality in management boards of small and medium-sized enterprises (SMEs) on firm performance from an upper echelons perspective. The authors also examine how board-specific characteristics influence the structural makeup of boards in gender and nationality diversity terms. Design/methodology/approach: The authors focus on the UK because of its individualistic society and flexible labour market and assess 309 SMEs in the manufacturing industry over 2009–2019. A 3-stage least squares (3SLS) estimator is used to analyse the data, the Shannon index to measure board diversity, return on assets as proxy for firm performance, and owner-manager presence, board member age and tenure are the board-specific characteristics of primary interest. Findings: Both gender and nationality diversity contribute to firm performance and represent distinct upper echelon characteristics that change the cognitive and psychological dynamics of boards. Firms with larger boards do not perform better, but diverse boards reduce the narrowing view of CEOs. Yet the presence of owner-managers, despite their performance-enhancing contribution, holds firms back from benefitting from diversity as a strategic choice. Originality/value: This study extends the upper echelons theory to include board diversity as an important aspect that should become more central in upper echelon thinking when understanding firm performance. The authors’ findings suggest that theoretical developments in search of understanding firm behaviour must proceed by accounting for diversity and not simply focusing on decision-making styles
Threshold displacement energies of oxygen in YBa2Cu3O7 : A multi-physics analysis
No full textNeutron bombardment of high temperature superconducting (HTS) magnets may compromise the integrity of the magnetic confinement in future fusion reactors. The amount of damage produced by a single neutron can be predicted from the threshold displacement energies (TDE) of the constituent ions in the HTS materials, such as the Rare Earth Cuperates. Therefore, in this work a multiphysics simulation approach is adopted to determine the threshold displacement energies for oxygen in YBa2Cu3O7. Classical molecular dynamics (MD) simulations are employed to determine statistically representative TDEs for all four oxygen sites and these results are validated using Born-Oppenheimer MD employing forces derived from Density Functional Theory (DFT). The simulations were performed at the operational temperature (25 K) and the temperature of existing neutron irradiation studies (360 K) enabling a discussion about the relevance of this data. Overall, these findings enhance our understanding of radiation-induced damage in HTS materials and provide data that can be incorporated into higher order models offering critical insights into shielding design and magnet longevity
The Qualitative Exploration of Experiences of Suicide Attempts and the Nature of Memories of Attempts
No full textThis thesis explores the individuals experience of a suicide attempt, containing four sections: a literature review, research paper, critical appraisal and ethics section. In Section One, the literature review presents a meta-ethnography to increase our understanding of how individuals experience both in the moment of and post-attempt. A systematic search of five databases was conducted which identified 36 papers that met inclusion criteria. The meta-synthesis resulted in four key themes: (1) ordering chaos, (2) more pain than before, (3) the need to try and stay alive, and (4) the need for meaningful relationships. These findings highlight a challenging process a person goes through following a suicide attempt. Clinical implications include suicide awareness training for care staff to reduce stigma. In Section Two, empirical research is presented which aimed to explore the nature of momentary memories of suicide attempts in men in mid-life, with a focus on if they are experienced as traumatic and how that may impact future risk. Four men (40-64 years) participated and underwent a two-week daily diary period followed by individual semi structured interviews. Interview data was analysed using reflexive thematic analysis which generated four themes: (1) memories forcing entry and being pushed back; (2) vivid nowness: like the back of my hand; (3) guilt and conflict resurface; and (4) recognising a positive change in mindset. Findings convey that memories can be experienced as traumatic and result in associated difficult emotions. Yet memories can also evoke helpful reflection on progress since the attempt. Implications include utilising psychological interventions to support people to accept memories, implement grounding techniques and increase coping. In Section Three, a critical appraisal summarises key findings across the systematic literature review and the empirical paper as well as highlighting key reflections that can inform future research with this population
Electrochemical pre-treatment of aluminum alloy in environmentally friendly medium : Parameter optimization and bonding strengthening mechanism
Get PDFThe electrochemical treatment of adhesive surfaces in neutral salt solutions is a promising novel method for improving the bonding performance of aluminum alloys. However, the mechanism through which this treatment improves interfacial bonding strength remains poorly understood. This study systematically investigates the relationship among electrochemical parameters, microstructure, property evolution, and the bonding strength of thin-walled aluminum adhesive joints. Multi-scale characterization techniques were employed to elucidate the strengthening mechanism from the perspectives of chemical bonding and mechanical interlocking. The results demonstrated that a current density of 0.8 A·cm−2 applied for 100 s increased the bonding strength by 170% compared to untreated joints. Furthermore, the effect of electrochemical treatment, sandblasting, and grinding on the surface characteristics and bonding properties was compared. XPS and FTIR analyses revealed that the electrochemical treatment significantly increased the surface density of hydroxyl groups, which promoted the opening of epoxy rings and the subsequent formation of covalent bonds. This finding confirms the critical role of chemical bonding in enhancing interfacial strength. Eventually, a qualitative model was developed to illustrate the mechanism by which electrochemical treatment enhances the adhesive performance of aluminum alloy joints. These insights are valuable for exploring the potential application of electrochemical treatment to thin-walled, lightweight alloy components