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In-situ environmental transmission electron microscopy on nickel-based nanostructures
No full textThis thesis explores the synthesis, phase transformations, and structural development of nickel-based nanoparticles (Ni-based NPs) using ex-situ and in-situ environmental transmission electron microscopy (ETEM).
The study starts with exploring the transformation of carbamide and ammonia into NiO nanoparticles (NPs). We focus on the mechanism of this transformation via nickel hydroxide intermediates, β-Ni(OH)2 and Ni3(OH)4(NO3)2, which are achieved through thermal annealing. The ex-situ thermal decomposition of these intermediates resulted in NiO NPs with distinct shapes, sizes, and surface properties. NiO obtained by the carbamide route forms nanorods with polar {111}c facets with a bandgap of 3.7 eV. NiO obtained by the ammonia route forms flower-like 3D nanostructures with neutral {002} facets and a lower bandgap of 3.2 eV, associated with an increased number of surface states due to their three times smaller size compared to NiO obtained by the carbamide route. Both sets of NPs are Ni-deficient.
Next, we study these phase transformation mechanisms by utilising the electron beam as a driving force. In-situ (E)TEM was employed to observe the real-time transformation of the intermediates, β-Ni(OH)2 and Ni3(OH)4(NO3)2, under electron beam irradiation, as well as in an annealing and O₂ environment. In both cases, the transformation proceeded via β-NiOOH intermediates to NiO, with 3D flower-like morphology preserved in both cases. In-situ annealing at 350–400 °C formed <3 nm NiO particles retained the original structure, in comparison to ex-situ treatments that led to distinct NiO NPs morphologies.
Next, we focused on NiO NPs obtained by physical ultra-high vacuum methods. MBE-grown Ni ultrathin films were transformed to Ni NPs under annealing in H2 atmosphere and vacuum, resulting in Ni NPs with varied morphologies. Ni NPs oxidation was performed in a 1 Pa background of O2, H2O, and H2O + CO2. O2 background resulted in the formation of spherical NiO NPs; H2O background yielded single-crystal NiO NPs, faceted predominantly by {111} surfaces, while CO2 + H2O mixtures produced polycrystalline NiO NPs, with irregular shape.
Finally, we studied the reduction and oxidation of core-shell Ni/NiO NPs. We follow this process dynamically using in-situ ETEM, which includes shell grains coalescence and changes in crystallinity. The oxidation of pristine Ni NPs results in core-shell formation of Ni/NiO, which follows the Cabrera-Mott and logistic models of self-limited oxide formation.
The findings in this work support the rational design of Ni-based nanostuctures with potential use in catalysis
Examining the Physical Environment and Social Determinants on Sleep
Get PDFPoor sleep affects people all over the world and it could impact both physical and mental health. Therefore, understanding the reasons that impacts sleep could highlight ways of how to improve it.
Literature review: The quality of the physical environment could impact health. But little was known about how the physical environment impacted sleep in the long-term. In three databases, 21 cohort and experimental papers were found that assessed this. Fourteen of these papers showed that more noise, air pollution, and negative neighbourhood surroundings, such as crime and disorder, had a negative impact on sleep. Meanwhile, more green spaces, better neighbourhood design and steps taken to reduce noise was linked to better sleep. But there was no link between walkability and sleep. Also, a small number of papers found no links to sleep or that more air pollution was linked to better sleep, probably because they used different approaches to gather information from participants. Still, this suggested that improving the physical environment might lead to better sleep.
Empirical study: Social determinants, meaning social, economic and environmental factors, could impact sleep because they could influence the conditions people live in and access to resources. To understand this better, this study looked at how poor sleep was linked with social determinants and mental health difficulties in 2513 people. This showed that having support and higher age was linked to better sleep. While difficulties with paying for necessities, being female, financially secure, and having a minority sexual orientation was linked to worse sleep, possibly because of stress. Poor sleep also impacted the connection between worse mental health and these factors too, but ethnicity and declared religion was not linked to sleep or mental health. This pointed out that making improvements in society might improve sleep and therefore also mental health
Hoarding Disorder: Executive Functioning and Treatment Acceptability
No full textObjectives. Hoarding disorder (HD) incurs significant disability and disease burden, but psychological interventions for HD have difficulty engaging and retaining adult patients in treatment. This systematic review and meta-analysis synthesized evidence around acceptability in HD intervention literature, extracted key themes and conducted a proportional meta-analysis of treatment refusal and dropout rates.
Methods. PubMed, PsycInfo, SCOPUS and ProQuest were searched in April 2025 for quantitative and qualitative research exploring psychological interventions for adult HD patients. Sekhon et al.’s (2017) acceptability framework was used to narratively synthesize study findings. Pooled treatment refusal and dropout rates were synthesised using proportional meta-analysis and benchmarked against other diagnoses.
Results. Fifty-four studies were included (n=2027 of 13 different psychological interventions). The treatment refusal rate (k=27) was 13.43% (95% CI[8.10-19.67]) and treatment dropout rate (k=48) was 14.93% (95% CI [10.73-19.58]). Participants reported high anxiety about interventions, but actual experiences were generally positive with few adverse effects. Interventions were less acceptable on domains of self-efficacy and perceived effectiveness (e.g. adherence, maintenance of gains). S, and significant flexibility and effort was required to reduce ongoing intervention burden. Treatment refusal and dropout for HD benchmarks as equivalent in the main to other disorders.
Conclusion. HD treatments have refusal and dropout rates similar to interventions for other conditions. Many barriers prevent HD populations from accessing interventions, with some groups underrepresented in both treatments and research. Universal definitions of treatment refusal and dropout and further research into lived experiences of treatment are required.
Objectives. Hoarding disorder (HD) is conceptualised to be associated with deficits in executive functioning, but little research has explored the specific role of clutter in this relationship. This study aimed to a) develop an ecologically valid hoarding environment in virtual reality (VR) and b) test the impact of exposure to excessive clutter compared to no clutter in this environment on participants completing tasks of attention.
Design. A within-subject counterbalanced repeated measures design was used to identify differences in attention performance in cluttered and uncluttered VR environments.
Methods. Healthy community participants (N=44) spent time in cluttered and uncluttered VR houses completing two continuous performance tasks (X-CPT and AX-CPT) within each home environment. Environment and task order were randomised. Participants rated experienced realism, sense of presence and subjective distress in both environments. Repeated-measures multivariate analysis of variance tested the effects for clutter and relevant covariates.
Results. VR environments were realistic and immersive and participants experienced significantly greater distress in the cluttered environment. There were slower mean reaction times and more omission errors in the cluttered home. Differences in commission errors and sustained attention were non-significant. Increased distress in the cluttered home predicted greater deterioration in X-CPT reaction time and omission errors.
Conclusions. Exposure to clutter is detrimental to attention (particularly selective attention and response initiation) and may contribute to HD information processing deficits. Responses to clutter appear heterogeneous and distress influences attentional ability in cluttered environments. VR offers a valid and immersive means of better understanding the mechanisms of HD
Bits and bytes: A sociological exploration of the meanings ascribed to music in the age of the digitally compressed file format
No full textThis thesis examines the meanings that individuals ascribe to music disseminated via digitally compressed audio files (e.g. MP3, Ogg Vorbis, AAC). Digitally compressed music is ubiquitous in the West. However, there is little sociological analysis concerning listeners’ engagement with these files. In particular, the subjects’ meaning-making processes have received little attention in sociological analysis. Existing accounts (see Sterne, 2012) afford too much weight to the object (i.e. technology), whilst neglecting the role of the subject (i.e. individuals). This lacuna requires further investigation, especially if we are to understand experience as playing a central part in people’s everyday interaction with digital music.
My thesis adopts a Weberian (Weber, 2012 [1914]) framework and situates meaning
ascription at the heart of experience. I conducted an inquiry into how such music is received and interpreted by listeners. Rather than deriving meaning directly from the object, it is important to explore how people discuss their relationships with digitally compressed music and the meaning people ascribe to it in their everyday lives. To explore these relationships in more detail, I argue that we ought to consider the aesthetic, social and political dimensions of digitally compressed technology. Doing so enables us to understand how musical experience is linked to multiple facets of everyday life.
I deployed qualitative methods to build rich understandings of social action through conducting four online album listening parties and online follow-up focus groups involving a total of 36 participants. I organised, participated in and observed four online album listening parties, using these as stimuli to provoke further discussions regarding music’s dissemination and the listeners’ experience. I conducted seven focus groups following these parties and used them to collect data on participants’ discussions of their everyday encounters with digitally compressed music. My data was organised and coded electronically on NVIVO, and analysis was conducted thematically. The substantive contributions of this thesis are presented in three chapters.
Chapter 4 explores the role of sound quality in my participants’ reception and interpretation of music disseminated from digitally compressed audio files. The meanings they ascribe to sound quality are complex and multifarious, and whilst participants valued good sound quality, they frequently struggled to understand what I meant by digitally compressed audio and instead discussed meaning in relation to a different perspective of the debates surrounding analogue versus digital technology. Overall, I found that, whilst participants valued good sound quality, they often attributed this to the equipment rather than the format.
Chapter 5 frames listening as a practice and explores the ways in which my participants
engage with music through the lens of attention and distraction. They reported that mostly they were doing something else whilst listening. My analysis focuses primarily on two activities: music listening during work and listening during studying. My participants’ accounts allowed me to examine how music enables them to ‘get into action’ (De Nora, 2000). But whilst the format enables them to go about their daily activities with relative ease, it also creates problematic conditions, ultimately functioning in the interest of capitalist production.
In chapter 6, I argue that notions related to the ‘possession’ of my participants’ music libraries and how they attributed ‘control’ were important for how they ascribed meaning to digitally compressed music. People’s interpretation of music was often related to the tangible properties of formats. They were fond of physical artefacts due to the physical relationship that they had with them. Regarding control, my analysis focuses primarily on my participants’ critique of, and adherence to, corporate power in the current climate of music streaming. I found that their consumption of digitised music was characterised by both elation and frustration.
Overall, this thesis contributes towards a deeper sociological understanding of the social and cultural significance of digitally compressed music. I challenge technologically deterministic accounts of digital music consumption, demonstrating that meaning is not inherent in the format itself, but rather emerges from individuals’ lived experiences and social practices. In so doing, I demonstrate that we ought to emphasise the agency of the listener in actively shaping their musical experiences
Mechanisms of the anti-ageing effect of Dietary Restriction in Drosophila: insights from nutritional supplementation and comparative experiments
No full textEcochaotics in Contemporary Literature: from Tom Stoppard’s Arcadia (1993) to Richard McGuire’s Here (2014)
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Dispute and Interpersonal Violence in Languedoc, 1680-1720: Identity, Community, and Authority
Get PDFThis thesis examines the social landscape of early modern Languedoc through the lens of interpersonal violence. This period has been central to ideas of decreasing interpersonal violence in France, in tandem with the expansion of Louis XIVs state. This study contributes to the dismantling of such determinist theories of modernity through its examination of the records of the parlement of Toulouse, Languedoc’s highest appellate court. The parlement’s criminal dossiers, the sacs à procès, exhibit a significant increase in rates of physical interpersonal violence between 1680 and 1720. This study examines a sample of two hundred of these cases, and in doing so reveals the diverse ways in which the monarchy’s fiscal and political policies in the final decades of Louis XIVs reign disrupted social cohesion in communities throughout the province.
Crucially, this study approaches such incidents from the perspective of the disputants. Where state and institutional histories of early modern France underscore the punitive nature of the law, this thesis builds on developments in the fields of legal anthropology and sociology to ask how recourse to the law featured alongside the use of violence in Languedocians’ disputing strategies. In its assessment of the roles of women, the clergy, the petty nobility and the notability in incidents of violence, the chapters in this thesis grapple with themes of authority, identity, and community. They assess the ways in which individuals managed anxieties and tensions concerning their position and their influence within their communities. Ultimately, the study evidences the concomitant roles of violence and the laws in disputing strategies. But where scholars have previously argued that these mechanisms of social control were used for the restoration of peaceable relations, this study evidences litigants’ use of the courts as a forum for the continuation and escalation, rather than the resolution, of their enmities
CRISPR Interference Screening and Pharmacological Targeting of Sodium Channels in Triple-Negative Breast Cancer Cells
No full textHypoxia is linked with more invasive forms of breast cancer, particularly triple negative breast cancer (TNBC). Elevated intratumoural sodium (Na+) level in patients correlates with disease severity and Na+ reduction predicts treatment response. Our in vivo data, using 23Na+ MRI, suggest that the majority of this Na+ is intracellular, implicating specific Na+ channels and transporters in its accumulation and regulation in the tumour microenvironment. While hypoxia has been shown to upregulate various Na+ channels, their combined involvement in hypoxia-driven breast cancer progression remains unclear.
Here, we performed the first systematic screen to identify Na⁺ channels which support TNBC proliferation under hypoxia. Using a targeted CRISPR interference (CRISPRi) screen with a dCas9-KRAB transcriptional repression system, we repressed 181 Na+ channel and transporter genes in two TNBC cell lines, MDA-MB-231 and MDA-MB-468, cultured under normoxic or hypoxic conditions for 7 days. The screen identified hypoxia-specific depletion of guide RNAs (gRNAs) targeting SCN5A (Nav1.5), SLC10A5, SLC38A5, and SLC34A2 in MDA-MB-231 cells, and GRIN3A, SLC22A12, and SLC34A3 in MDA-MB-468 cells. FXYD5 was also exclusively depleted under hypoxia in both cell lines.
To evaluate the therapeutic potential, we tested the Nav1.5 channel as a target in TNBC cells using propafenone, a clinically approved antiarrhythmic drug not previously studied in the cancer context. Electrophysiological analysis confirmed that propafenone (100 µM) significantly inhibited Na+ currents in MDA-MB-231 cells.
Our findings highlight multiple Na+ transporters involved in TNBC proliferation under hypoxia, with SCN5A/Nav1.5 as a promising therapeutic target in hypoxic TNBC. These results support the potential repurposing of existing Na+ channel-targeting drugs to inhibit hypoxic TNBC progression
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