Kink instability of flux ropes in partially-ionised plasmas

This is the author accepted manuscript.Data availability: The data that support the findings of this study are available from the corresponding author upon reasonable request. The (PIP) code is available at the following url: https://github.com/AstroSnow/PIP. Details of the code and equations are available in Hillier et al. (2016).In the solar atmosphere, flux ropes are subject to current driven instabilities that are crucial in driving plasma eruptions, ejections and heating. A typical ideal magnetohydrodynamics (MHD) instability developing in flux ropes is the helical kink, which twists the flux rope axis. The growth of this instability can trigger magnetic reconnection, which can explain the formation of chromospheric jets and spicules, but its development has never been investigated in a partially-ionised plasma (PIP). Here we study the kink instability in PIP to understand how it develops in the solar chromosphere, where it is affected by charge-neutral interactions. Partial ionisation speeds up the onset of the non-linear phase of the instability, as the plasma of the isolated plasma is smaller than the total plasma of the bulk. The distribution of the released magnetic energy changes in fully and partially-ionised plasmas, with a larger increase of internal energy associated to the PIP cases. The temperature in PIP increases faster also due to heating terms from the two-fluid dynamics. PIP effects trigger the kink instability on shorter time scales, which is reflected in a more explosive chromospheric flux rope dynamics. These results are crucial to understand the dynamics of small-scale chromospheric structures – mini-filament eruptions – that this far have been largely neglected but could significantly contribute to chromospheric heating and jet formation.NASAScience and Technology Facilities Council (STFC

More-than-food: Diplomats, practitioners, and animal feeding in the zoo. A historical and sociological investigation into the change over time of zoo feeding and nutrition.

In the 1930s chimpanzees at Edinburgh Zoo were allowed to smoke and drink alcohol, at Dublin Zoo the animals’ received drops of Guinness as part of the daily diet. As greater understanding of zoo animals has progressed and anthropomorphic ideals have subsided through conservation movements the zoo animals’ diet has changed significantly within the last 80 to 100 years. Arguably it has changed more in the last 40 years than at any other time in modern zoo history. How and why decisions and changes of the zoo animal diet have been enacted is not as clear as knowing that diets changed. Individual zoos, zoo associations, and government policy has impacted and affected zoo animal diets. Zoo feeding is acutely traditional and has focused historically on ensuring the animals life is maintained. However the move to conservation goals and aims of modern progressive zoos has seen a shift in thinking from maintaining captive animal lives to ensuring they flourish within their artificial captive environment. This thesis aims to provide a voice to those involved in feeding zoo animals. Analysis of historic scientific literature from the late 20th century through to interviews with global leaders in zoo nutrition, zoo veterinarians, and expert zookeepers, the thesis provides a voice to the science of zoo animal nutrition and the art of practical zoo feeding. It highlights the differences in practices of zoo professionals and how care of zoo animals is enacted within the zoo through feeding.Wellcome Trus

Petrogenesis of alkaline rocks and the lithospheric mantle evolution of the Kaapvaal Craton, southern Africa

Alkaline mafic-ultramafic igneous rocks are known across the Kaapvaal Craton of southern Africa, forming in pulses from the Mesoproterozoic to the Cenozoic. These rocks, formed from the low-degree partial melting of diverse upper mantle domains, are intrinsically linked to the global processes responsible for reorganisation of continental plates (the supercontinent cycle). In this thesis, the effects of the supercontinental cycle and the evolution of the Kaapvaal Craton are probed through analyses of a major swarm of carbonate-rich olivine-bearing cratonic lamproites from the Western Limb of the Bushveld Complex (the Western Bushveld lamproites), and a minor cluster of alkaline lamprophyres near Pretoria (the Greenview lamprophyres). 40Ar/39Ar phlogopite dating of the Western Bushveld lamproites reveals a genetic association between the 146–137 Ma dykes and the disaggregation of Gondwana throughout the Mesozoic. Intra-continental rifts propagated between East and West Gondwana triggering low-degree melting of the Kaapvaal subcontinental lithospheric mantle (SCLM), channelling melt into the crust through ancient cratonic lineaments. Combined investigations on the petrology, bulk-rock geochemistry, mineral chemistry, and radiogenic (Sr-Nd-Hf) isotope compositions of the lamproites place constraints on magma petrogenesis and the nature of their source. A period of ancient subduction was key to the development of the lamproite source, whereby slab-derived fluids metasomatised the Kaapvaal cratonic keel, producing isotopically distinct SCLM metasomes. After a considerable period of isolation from the convecting mantle, low-degree partial melting of this source formed the diverse, but universally incompatible element- and isotopically-enriched, lamproite primary melts. Metasomatic enrichment of the SCLM was key in producing the (relatively) elevated platinum-group element (PGE) concentrations of the Western Bushveld lamproites. The introduction of volatile-rich and highly fusible PGE-bearing assemblages into the SCLM allowed for efficient transfer of PGE-rich materials into ascending lamproite melt(s). In contrast, the PGE concentrations of the Greenview lamprophyres primarily reflect melting of sulfide in an asthenospheric source. The diverse petrogeneses and PGE systematics of differing alkaline mafic-ultramafic igneous rocks highlights the importance of a SCLM metasomatised by fluids of subduction origin in promoting highly siderophile element mobility

Adapting to life in metal polluted rivers: implications for conservation, genetic diversity and fisheries management in the brown trout (Salmo trutta)

During an era of unprecedented biodiversity loss, conservation ecology seeks to understand the drivers of declines, scale of impact and how to best mitigate and minimise ongoing threats to biodiversity. Within this field there is increasing awareness of the importance of understanding population genetics, as this can reveal the realised impact of stressors on diversity, how evolution responds to shape populations and their ability to adapt. Due to a long industrial history, the landscapes and ecosystems of the British Isles are amongst the most heavily influenced by anthropogenic impact in the world. This includes a once globally important mining industry which now leaves a legacy of minewater pollution which is acutely toxic to much freshwater life. Despite this, trout appear to persist within many metal impacted systems, with prior work suggesting a small number of impacted populations are genetically distinct and exhibit tolerance mechanisms to survive. In this thesis, the interactions of minewater pollution across the British Isles on the population genetics of phylogeographically divergent populations are examined. The development of a SNP assay is detailed, with this used to understand the scale of neutral genetic diversity and structure across 1,236 individuals representing 71 sampled populations from metal-impacted regions. Demographic history modelling is applied to understand the most credible scenarios to explain the observed genetic structure. I utilise newly developed low-coverage whole genome sequencing methodologies to investigate the scale of parallel adaptation, as well as examining individual adaptations within populations. Lastly, I examine the influence of minewater pollution in shaping the larger structure and diversity of the trout genome. The results demonstrate that metal-impacted trout are genetically distinct from nearby relatively non metal impacted populations, have reduced genetic diversity and these patterns are most credibly explained by recent metal-driven divergence. I demonstrate genomic regions of parallel adaptation to minewater that are more prevalent in geographically proximate populations than those with similar mixtures of metals, and novel adaptations within individual populations. We see that the genomes of individuals from impacted populations have large structural changes and high levels of transposon content, with structural variation driving functional changes in candidate genes for adaptation. These results demonstrate the ability of trout to adapt to highly stressful environments, emphasise the importance of gene flow in maintaining population viability and give insight into the mechanisms of evolution within wild populations in complex systems

Ingestion of a variety of non-animal-derived dietary protein sources results in diverse postprandial plasma amino acid responses which differ between young and older adults.

Data availability: Data described in the manuscript may be made available upon request, pending application.Whole-body tissue protein turnover is regulated, in part, by the postprandial rise in plasma amino acid concentrations, although minimal data exist on the amino acid response following non-animal-derived protein consumption. We hypothesised that the ingestion of novel plant- and algae-derived dietary protein sources would elicit divergent plasma amino acid responses when compared with vegan- and animal-derived control proteins. Twelve healthy young (male [m]/female [f]: 6/6; age: 22±1 y) and 10 healthy older (m/f: 5/5; age: 69±2 y) adults participated in a randomised, double-blind, crossover trial. During each visit, volunteers consumed 30 g protein from milk, mycoprotein, pea, lupin, spirulina or chlorella. Repeated arterialised venous blood samples were collected at baseline and over a 5 h postprandial period to assess circulating amino acid, glucose, and insulin concentrations. Protein ingestion increased plasma total and essential amino acid concentrations (P0.05). Postprandial total and essential amino acid availabilities were highest for pea, spirulina and mycoprotein, and lowest for chlorella (all P0.05). The ingestion of a variety of novel non-animal-derived dietary protein sources elicits divergent plasma amino acid responses, which are further modulated by age

Dynamic interactions of fish skin microbiomes with their aquatic environments and the impacts of antibiotic exposures in aquaculture

Aquaculture is a crucial food sector to meet food demands for the growing human population. Finfish culture in earthen aquaculture ponds is the most dominant form of production globally, largely occurring in Asian countries. Antibiotics are widely used in an attempt to combat disease, which is one of the greatest threats to the production and expansion of aquaculture. This antibiotic (mis)use brings human and environmental concerns, but often with little regulatory monitoring. Limited research has been conducted to understand the complex microbial interactions within earthen aquaculture ponds, particularly the microbes harboured at the fish skin mucosal surface which are critical for the support of fish health and disease resilience. This work focuses on the widely farmed finfish tilapia and utilises high-throughput sequencing approaches to reveal the dynamic interface between fish skin microbiomes and their aquatic environment; knowledge which is then applied to assess the impact of antibiotic exposures in aquaculture. Field assessments of aquaculture ponds in Malawi highlight the inherent variability of tilapia skin microbiomes, with the aquatic environment shown to be an integral determinant by explaining 50% of divergence in microbial community compositions. The majority of microbial taxa are shared between the microbiomes of pond water and tilapia skin, but they are assembled in different compositions and conserved taxa of the tilapia skin are evident. These conserved taxa were studied to assess their response to an antibiotic exposure of Nile tilapia (Oreochromis niloticus) in an experimental outdoor earthen aquaculture pond system in Bangladesh. Here, important commensals, such as Cetobacterium, and putative pathobionts, such as Aeromonas, were transiently depleted and enriched, respectively, in the tilapia skin microbiome in response to antibiotic exposure. Alpha diversity was also reduced, suggesting antibiotics allow a subset of taxa to become more dominant in this community. However, a more general disruption to tilapia skin microbiome compositions was not apparent. Instead, microbiome plasticity in response to temporally fluctuating environmental conditions was a more influential determinant. The functionality of the tilapia skin and pond water microbial communities were also impacted by antibiotic exposure through the transient selection of antimicrobial resistance genes, specifically tetA, tetE, tetA(58) and tetB(P), conferring resistance to the target antibiotic oxytetracycline. There was no evidence to suggest this experimental antibiotic exposure impacted the mobilisation of antimicrobial resistance genes, however, the aquaculture pond environment was found to harbour a diverse resistome, highlighting the potential risks posed by sustained antibiotic misusage. Overall, this work suggests a short-term therapeutic dose of oxytetracycline presents limited risks to fish health and for the development and dissemination of antimicrobial resistance. Collectively, the work presented in this thesis identifies the intricate and dynamic relationship of the fish skin microbiome with the pond environment for tilapia grown in earthen ponds. The variations identified in microbiome responses to stressors, such as antibiotics, highlight the impact of environmental conditions and host factors as key determinants of these microbiomes. A deeper comprehension of these microbial systems and their interplay with the aquatic environment will be critical to optimise aquaculture conditions and mitigate the impacts of disease, paving the way for a sustainable expansion of aquaculture production.Centre for Environment, Fisheries and Aquaculture Scienc

Persistent pain management in prison: an exploration of current practice and patient needs, and facilitators and barriers to intervention engagement

This is the author accepted manuscriptPersistent pain is a complex long-term condition (LTC) characterised by biological, psychological, and social features. It has a significant impact on the physical and emotional function of individual patients and is associated with a lower quality of life, detrimentally effecting families, communities, and wider society. Pain that continues for longer than 12 weeks is termed chronic or ‘persistent’ and affects between 18% to 51% of the world population. Pain is defined by the International Association for the Study of Pain (IASP) as: “An unpleasant sensory and emotional experience associated with actual or potential tissue damage.” Persistent pain was acknowledged as a primary health condition in 2021,5 following the World Health Organisation’s (2019) updated chronic pain guidelines,6 which recognised the condition as pain that persists for more than 3 to 6 months. Studies have demonstrated that an inverse relationship exists between persistent pain and socioeconomic status, with higher prevalence rates seen in poorer areas. These social determinants are likely to be the same circumstances that the prison population comes from. England and Wales has a prison population of 85,851, most of whom are from lower socioeconomic backgrounds and typically (53%) aged between 30 and 50. Higher levels of poor health exist in the prison community in the UK and across Europe, compared with the general population. In addition, the Prison Reform Trust estimates that 50% of all people entering prison have a drug problem.10 The intersection of coexisting persistent pain and opioid use disorder (OUD) poses problems for the prison system due to the diversion of medication and safety concerns.National Institute for Health and Care Research (NIHR

Novice Arabic language Teachers’ Perceptions of their Preparation Programmes and their First Years of Practising Teaching in Saudi Arabia

This study explores Arabic language teachers’ perceptions concerning their preparation programmes and their first years of teaching experience in the Kingdom of Saudi Arabia. The study is informed by the interpretive paradigm due to its exploratory nature. A mixed-method sequential design was utilised to collect the data. Quantitative and qualitative approaches were applied consecutively, with more emphasis on the qualitative strand. The study utilised reflective essays and one-to-one semi-structured interviews in the qualitative stage, in addition to an online questionnaire in the quantitative stage. Thematic analysis was conducted for qualitative data and descriptive statistics for the quantitative data. The analysis of both sets of data culminated in the emergence of two main themes: teachers’ perceptions of their preparation programmes and of their novice teaching experiences. The findings highlighted the issue of the admission system, the focus on the theoretical aspect, the neglect of the practical aspect, and the lack of focus on pedagogical content knowledge within these programmes. The findings also highlighted the challenges teachers encountered during the first years of the teaching profession and linked these challenges to their knowledge and preparation. The study concluded by proposing recommendations for the educational authorities and policymakers in Saudi teachers' education programmes

Do government performance signals affect citizen satisfaction?

This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record Previous studies have confirmed the causal effect of performance information on citizen satisfaction, but they were primarily conducted in survey experimental settings that featured hypothetical and abstract scenarios and primed respondents to look at certain aspects of performance information. Whether the causal effects hold in the real world, which is a much more complex information environment, is questionable. We address the gaps by employing a regression discontinuity design to identify the impact of public schools’ performance grades on parents’ satisfaction with teachers and overall education in New York City. We find that performance signals have independent and lasting effects on citizens’ satisfaction. However, the effects are nonlinear, depending on the levels of performance signals. Parents’ responses are muted at the A/B performance grade cutoff, but their satisfaction increases significantly at the B/C and C/D cutoffs if their schools earn relatively higher grades

The dementia-nature-inclusivity nexus and the needs of people living with dementia

This is the author accepted manuscriptData Availability: Qualitative data will be deposited with ESDS Qualidata within 3 months of study completion. On project completion, selected data will be deposited with the University’s Institutional Repository, Open Research Exeter (ORE)Understanding how to improve the physical and cognitive accessibility of visitor economy businesses and organisations wanting to offer nature-based outdoor pursuits for people with dementia is key to supporting their inclusion and agency. The aim of this qualitative study was to understand the experiences, needs and preferences of people with dementia participating in nature-based outdoor pursuits in their leisure time. Semi-structured interviews were conducted with 15 people with dementia and 15 family members and subjected to thematic analysis. Four themes related to inclusion for people with dementia and their family members reflected diversity in individual needs and preferences for engaging with nature-based outdoor pursuits, their own adaptations to maintain access including accommodating risk, how cognitive and physical accessibility can be supported by businesses, and which practical and psychosocial barriers prevent inclusion. Learning from people with dementia and their family members has helped bridge the gap to their inclusion in nature based outdoor pursuits. Their insights will inform the development of such pursuits by businesses and organisations as well as future work into risk decision-makingEconomic and Social Research Council (ESRC