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Biological definitions, causality, and reductionism in psychiatry
Get PDFThe main focus of this thesis is the project of biological psychiatry to classify psychiatric conditions, such as schizophrenia and depression, on the basis of biological features—as opposed to psychological and behavioural features, which constitute the basis for their current classification. Written as a collection of independent papers, this thesis mainly deals with three issues related to said project.
The first issue is the following: classifying medical conditions on the basis of biology requires individual conditions to be defined in terms of a biological factor—asthma is, for instance, defined in terms of inflammation of the airways. The standard view is that individual psychiatric conditions are to be defined in terms of their (hypothesised) “single, clear” biological causes. However, critics of biological psychiatry rely on current evidence to point out these conditions are caused, instead, by a variety of biological, psychological, and social factors. This causal heterogeneity is thought by critics to preclude the development of psychiatric definitions based on biology. I argue (roughly speaking) that biological definitions could be achieved for those conditions notwithstanding causal heterogeneity.
The second issue is the following: biological psychiatry’s search for biological definitions has been deemed to be biologically reductionist. Biological reductionism, however, is nowadays standardly refused. Hence, if the search for psychiatric biological definitions is committed to reductionism, it could be construed as a search for a prima facie defective understanding of psychiatric illness, namely, a biologically reductionist understanding which is nowadays standardly rejected. Also, if the search in question is committed to reductionism, then this search is subject to criticisms that have been advanced against reductionism. Nevertheless, I will argue that the quest for psychiatric biological definitions does not involve a commitment to reductionism, and thus it does not prompt a biologically reductionist understanding in psychiatry. Consequently, complaints against reductionism do not apply to said quest.
Finally, the third issue is the following: critics remark that the above quest allows the possibility that psychiatric conditions are given purely biological definitions. These are definitions according to which a patient has the relevant condition if and only they have certain biological features—regardless of whether they have symptoms or not. Hence, purely biological definitions allow the existence of asymptomatic cases of the condition in question, and of symptomatic patients who do not to have the condition. Critics believe that if psychiatric conditions were given purely biological definitions, those definitions would not pick out the very same conditions that are currently defined in terms of symptoms. I argue, to the contrary, that those definitions would, in fact, pick out the conditions that are currently defined in terms of symptoms.
Two complementary issues will also be addressed. One of them concerns how to best understand current medical classification; the other concerns what exactly distinguishes biological from non-biological approaches to psychiatric illness. If my arguments are correct, the quest of biological psychiatry for biological definitions overcomes the three difficulties mentioned above
Microdosing classic psychedelic substances for obsessive-compulsive experiences: an Interpretative Phenomenological Analysis
Get PDFIntroduction. After decades of research paucity, the therapeutic effects of psychedelics have recently started to be explored again. Obsessive-Compulsive Disorder (OCD) is a serious mental health condition which affects millions of people globally. Previous literature investigating psychedelics’ influence on OCD is promising but scarce, with literature focusing on microdosing psychedelics for OCD even more limited.
Aims. This research aimed to develop an understanding of how people make sense of microdosing psychedelics in an attempt to help with their experiences of obsessions and compulsions.
Methods. Eight semi-structured interviews were conducted, utilising an Interpretative Phenomenological Analysis (IPA) approach. Given the topic area's illegal nature in many countries, prioritising participants' anonymity and defining obsessive-compulsive experiences are thoroughly considered.
Results. This study constructed three overarching themes: 1. The powerful nature of obsessive-compulsive experiences; 2. Microdosing psychedelics was perceived to ease obsessions and compulsions; and 3. Positioning microdosing psychedelics within other therapeutic contexts.
Discussion. Participants suggested that microdosing psychedelics reduced their obsessive-compulsive experiences and broader anxiety, which linked with previous literature suggesting similar outcomes. Strengths of this study include the data collection method and the author’s commitment to using reflective group spaces during the analysis stage. Limitations of this study are presented, including reflections on why this study may have attracted participants with more positive than challenging experiences of microdosing psychedelics for obsessions and compulsions. Multiple suggestions for future research linked to the findings of this study are presented
Opportunities for enhancing unintentional injury prevention in children aged under five years in Muscat, Oman: A mixed methods study
Get PDFChild law in Oman stresses the child’s right to safety and health, and the Ministry of Health provides a sophisticated child health promotion programme. However, there is a relatively high rate of unintentional injuries among children under five years of age. There is currently limited information about Omani caregivers’ awareness and practice of injury prevention and health promotion concerning child safety.
Aim: To explore the needs, challenges, and opportunities to enhance parents/caregivers’ awareness and practice concerning unintentional child injury prevention at home in Muscat, Oman.
Methods: Phase one was a systematic review to identify effective health education methods for injury prevention and their effectiveness in caregiver knowledge, skills, and attitudes. The second phase was a convergent parallel mixed methods design in two parts underpinned by the socioecological model (SEM). A survey was developed to explore Omani caregivers’ practice of child safety and the influencing factors with responses analysed descriptively. Semi-structured interviews were conducted with doctors and nurses working in primary healthcare centres in Muscat with data analysed using framework analysis based on the SEM. Quantitative and qualitative analysis was conducted separately with integration as the final step.
Findings: Complex multilevel factors influence caregiver awareness and child safety practices in Oman. There is a lack of caregiver knowledge concerning the benefits of some safety equipment, and some have a negative perception of the preventability of injury. Socio-economic factors such as big families, low income, and multiple caregivers are associated with inadequate supervision. Most caregivers had not participated in child safety education or parenting programmes.
Primary healthcare provides opportunities to integrate child safety within child health programmes, including regular visits to health centres. However, there are several challenges to the effective implementation of health education, including limited resources, time constraints and workload. Additional challenges relate to socio-economic status, neighbourhood safety, and willingness to attend health education sessions.
Conclusion: Caregiver safety education needs improvement. Ideally education will be tailored to account for different family and community contexts. Opportunistic delivery of safety information can be provided in waiting areas of primary health settings. Structured sessions should be delivered during appointments in health centres supplemented by online courses with interactive features through social media and webpages. Collaboration with other governmental sectors is necessary to empower working mothers and implement and enforce safety measures effectively
Motor adaptations to movement-evoked low back pain
Get PDFLow back pain (LBP) is a main cause of disability worldwide, resulting in a significant socio-economic burden on society. In some people with LBP, the main mechanism of pain is nociceptive, and symptoms are increased by mechanical stimuli. By changing mechanical stresses applied to lumbar structures, movement and physical activity can exacerbate LBP, a phenomenon known as movement-evoked pain (MEP). Given the relationship between LBP and movement for many people, research has focused on how they influence each other with evidence supporting that people with LBP move differently. However, findings are often contradictory due to clinical heterogeneity. For this reason, experimental pain models have been used to better understand the effects of pain in the lumbar region on movement. Despite being clinically relevant, the investigation of MEP and its effect on motor adaptations remains underexplored in both experimental and clinical LBP. Understanding how movement-evoked LBP affects movement is essential as it could help to partially explain the clinical heterogeneity and mechanisms underpinning motor adaptations to pain, ultimately facilitating more personalised interventions for people with LBP. The primary aim of this thesis was to investigate how movement-evoked LBP affects how people move. Additionally, this thesis aimed to determine if such motor adaptations are specific to the direction of the pain provocative movement, and if they represent a purposeful strategy to reduce pain in accordance with contemporary theory on motor adaptation to pain. The first study within this thesis was a systematic review which supported the causal effect of pain experimentally induced in the lumbar region on motor adaptations, specifically revealing a reduction of the range of motion of the lumbar spine, reduced activation of deep trunk muscles, and task-dependent increased or decreased activation of superficial lumbar muscles. The systematic review revealed that the investigation of the effects of MEP was limited, as one study out of twenty-six used an experimental model where pain was modulated by movement. The second study of this thesis investigated the effects of MEP experimentally induced in the lumbar region in association to either lumbar flexion or extension. This revealed that MEP is a main determinant of motor adaptations to experimental pain since a reduction of lumbar movement was only observed in the pain-provoking direction. Also, participants who showed larger reductions of lumbar range of motion also reported lower pain intensity, supporting the notion that motor adaptations to experimental pain represent a purposeful strategy to reduce pain. The third study investigated motor adaptations to movement-evoked LBP in people with clinical LBP. Kinematic differences were specific to what trunk movement was pain provocative, with larger lumbar flexion and smaller knee and hip flexion seen for people reporting higher pain intensity during forward bending. Overall, this thesis showed that clinical and experimental pain in the lumbar region changes movement, and that the pain provocative direction is a main determinant of the observed motor adaptations. These results also confirm that motor adaptations are purposeful strategies to reduce pain. Pain directionality may explain some of that heterogeneity of motor adaptations observed in people with clinical and experimental LBP, and it may offer new insights for the development of personalised and more effective interventions for people with clinical LBP
Exploring the impact of mood on higher-level cognitive functions
Get PDFThis thesis contains one volume consisting of five chapters and is submitted by Bryony Fenton for the Clinical Psychology Doctorate. The first chapter comprises a meta-analysis reviewing the executive function performance of children and adolescents with current depression, relative to healthy controls. The key finding in this review was that executive function was significantly worse in children and adolescents with depression. This effect was present for both overall executive function and the three investigated executive functioning subdomains (inhibition, working memory and shifting), with working memory showing the most significant impairment. Methodological limitations were considered, highlighting the need for more rigorous and robust research in the field. Clinical implications related to the assessment, formulation and intervention of childhood/adolescent depression were also explored.
The second chapter details an empirical research project investigating the effect of happiness on the theory of mind ability of 3-4 1⁄2-year-old children. Consistent with research focused on adults, it was found that children induced to feel happiness were more likely to make errors on a classic false belief task than children induced to feel neutral in mood. This paper offers support for happiness in children increasing reliance on more easily accessible egocentric knowledge, when mental state reasoning. However, it is recognised that additional research is required to explore this topic further, with potential avenues discussed.
The third and fourth chapters contain press releases for both the meta-analysis and the empirical research paper respectively, for the purpose of public dissemination
Ecological restoration as Indigenous environmental justice: A case study of the Upper Great Lakes Métis in Sudbury, Ontario
Get PDFIndigenous peoples have long-standing relationships with the lands and waters in their communities and can, therefore, be disproportionately affected by the environmental impacts of resource extraction and industrial development. As such, ecological restoration offers social and environmental implications that have the potential to transform communities and promote Indigenous environmental justice. This thesis examines the relationship between ecological restoration and Indigenous environmental justice, specifically focusing on the Upper Great Lakes Métis in Sudbury, Ontario.
Sudbury has a long history of mining and industrial development that has led to severe environmental degradation. However, the implementation of a successful ‘re-greening programme’ over the last four decades has remarkably restored components of Sudbury’s damaged landscapes. Despite the success of the scientifically-based restoration programme, there has been no research on how the Métis living in Sudbury perceive its processes and goals. This study seeks to fill this gap by exploring how the Métis perceive their environment and how they can contribute to restorative environmental work in the region.
Using a mixed-methods approach, this study uncovers local perspectives on ecological restoration and environmental justice whilst drawing upon environmental justice frameworks, decolonising principles, and Two-Eyed Seeing. Through the use of ethnography with Métis participants and restoration professionals, the study uncovers local concerns regarding well-being and the environment. The study finds that the Upper Great Lakes Métis prefer a restoration approach incorporating Indigenous and Western scientific knowledge, underscoring the importance of Two-Eyed Seeing. This finding emphasises that acceptance of ecological restoration projects requires recognition of locally-valued forms of environmental justice. As seen in the literature, forms of justice may vary by Indigenous community. Thus, if restoration processes and outcomes are to incorporate Indigenous ways of knowing, pan-Indigenous approaches should be eschewed in favour of accommodating multiple understandings of well-being.
This study contributes to Indigenous scholarship on ecological restoration and environmental justice, underscoring the importance of recognising the power dynamics between various social groups, including governments, industry, the scientific community, and other Indigenous peoples. It also highlights the need to confront these dynamics to promote Indigenous environmental justice, a concept that varies by community
‘Yes, we get food… but you see we are still foodless’: everyday experiences of food for women and young people in the asylum system as epistemic injustice
No full textThis thesis adopts a participatory approach to understanding the everyday experiences of food for women, children and young people navigating the asylum system living in the West Midlands, United Kingdom (UK). The research is set within a socio-political backdrop of a hostile environment, increasing charitable food aid provision and the ‘cost of living’ crisis in the UK. Whilst cumulating issues around accessing consistent, nutritious foods are observed across the UK population, it is disproportionately impacting people in the asylum system, and this remains under researched. This research develops a novel theoretical approach by using a framework that combines concepts of epistemic injustice, food sovereignty and necropolitics to unpack how and why women, children and young people in the asylum system are not heard in relation to their everyday experiences of food. By centring the focus on race, the thesis addresses a lacuna within existing research in social policy; there has largely been an omission in critiquing the racialisation of social security regimes.
There were 128 women, children and young people that participated in this research. The participatory research methods evolved during the research period, they include: ethnographic research, creative methods, PhotoVoice, semi-structured interviews and a ‘Bring and Share’ event. This research provides a series of key findings around the role of food in everyday life. The women, children and young people reveal that they struggled to access culturally appropriate, fresh food from formal charitable food aid or dispersed accommodation spaces. The women and young people introduce new ways of understanding this, through describing how “food makes me happy” or a lack of suitable food leaves the women feeling “empty”. They highlight that navigating formal charitable food aid spaces was fraught with inconsistent treatment, mapping onto existing ideas around ‘deserving’ or ‘underserving’ dichotomies, but also important discussions around race. The women highlight the extent of their resistance against the hostile environment, experienced at a macro state level and through micro replications of hostility, experienced in formal charitable food aid spaces. They describe sharing food, friendship and developing community gardens. The women critique the provision of housing in the West Midlands and highlight the specific challenges this presents in relation to food, ranging from insanitary conditions to the inability to access cooking facilities. This research calls for greater recognition of the racism and oppression, silencing and dismissal experienced by women, children and young people in relation to food. As outlined by a coresearcher, the fundamental argument of this thesis is: “yes, we get food… but you see, we are still foodless”
Accelerating structure discovery for functional materials
Get PDFDiscovering new functional materials and furthering understanding of known functional materials benefits from computational structure searching approaches that can identify the ground state structure for a particular system. To this end, using both density-functional theory (DFT) and machine learning (ML) models, I have searched for the structures of new materials with potential applications as electrodes for alkali-ion batteries and as single-photon emitters (SPEs).
To search for new Li-Ni-S ternary electrodes with a high gravimmetric charge capacity, I have taken a random structure searching approach. Initial searches were performed with an ab initio model, but the process was accelerated by three orders of magnitude by switching to a machine learning model. Over 150,000 structures were generated and while no ternary compounds were identified on the convex hull, new polymorphs of NiS and NiS were discovered that are lower in formation energy than the structures reported experimentally and on the Materials Project.
Ab initio random structure searching (AIRSS) was also applied to search for point defects responsible for single photon emission in monolayer hBN. Previous studies of hBN as an SPE have focused on only a limited range of intrinsic defects. In this work I have generated over 5000 intrinsic and extrinsic defects and calculated their defect formation energies. Numerous new low energy defects were discovered that have not previously been considered as SPE sources. The optical absorption and emission spectra of these defects can now be modelled so that they can be compared to experiment in hopes of identifying defects that give rise to desirable optical phenomena.
K-intercalated graphite (KGIC) is a potential anode material for K-ion batteries and its electrochemical synthesis can be observed unobtrusively through Raman spectroscopy. To better our understanding of the relationship between the structure and the Raman spectra, I have modelled Raman spectra for stages 1-5 KGIC within the conventional Rüdorff- Hofmann (RH) model and a range of candidate cells within the Daumas-Hérold (DH) model, which were generated with a bespoke machine-learning driven algorithm. DH-type cells were energetically accessible at room temperature but the modelled Raman spectra showed poor correlation with experiment. I conclude that the RH model is more consistent with experimentally observed KGICs, but the material may contain DH-type defects in small quantities.
In addition, two Na-niobates with potential electrode applications, layered NaNbO and NaNbO, were recently synthesised. To verify the structures of these compounds, I have modelled their Na NMR spectra. In the case of NaNb7O18, the positions of the Na ions were unknown and so I have modelled the spectra of a range of candidate cells. The total energy of these candidate cells differed by less than 3.3 meV / atom, suggesting that the Na ions are disorderly distributed between several sites throughout the structure. The modelled Na NMR spectrum of layered NaNbO shows exceptional correlation with the experimental spectrum, suggesting a strong match between the candidate structure and the synthesised material. The modelled Na NMR spectrum of NaNbO contained three peaks which correlate well with peaks in the experimental spectrum. The modelled spectra did not reproduce the fourth peak, which has been attributed to a NaNb3O8 impurity. The model cells of NaNbO therefore also seem to be consistent with the experimental sample
Development and calibration of 3-hydroxy fatty acid-based palaeoclimatic proxies in pedogenic and lacustrine environments
Get PDFTerrestrial environments are where the majority of climate change impacts will affect human societies, and the Intergovernmental Panel on Climate Change (IPCC) have called for high-resolution palaeoclimatic data to improve future temperature predictions in (often arid) regions with uncertainty in hydroclimatic regime, such as the Southwestern U.S. Environmental proxies derived from organic biomarkers are important tools for reconstruction of past climatic conditions, however their development and application between terrestrial environments is complex due to environmental heterogeneity. C-C 3-OH FAs are bacterial lipids investigated as a novel palaeoclimate biomarker group in recent years in soils, lake and marine sediments. However proxy-MAAT relationships are highly variable between regional soil transects, and studies of lacustrine 3-OH FA distributions are limited. This thesis aims to investigate environmental drivers of 3-OH FA variability in pedogenic and lacustrine environments at a regional scale, to assess the performance of RAN as a temperature proxy in soils that span moisture and pH gradients, and compare 3-OH FA temperature proxy development and performance between and within soils and lakes, to improve regional calibration of terrestrial 3-OH FA-based environmental proxies for robust applicability.
In Chapter 3, relationships between 3-OH FA temperature and pH proxies (RAN, RAN, and RIAN) and contemporary environmental conditions are assessed in soils from the East Coast and Southwestern U.S., and the 3-OH FA distributions of these soils investigated for novel environmental proxy development. 3-OH FA proxy performance was compared with brGDGT-based MBT and CBT for the soils. pH and MAP are first-order drivers of 3-OH FA variability in U.S. soils, best described by the novel pH proxy -log(RIN). We find RAN is the primary 3-OH FA temperature response in U.S. soils with pH<7.2, which may be associated with pH and moisture stress invoked on 3-OH FA bacterial soils in arid environments. In Chapter 4, relationships between 3-OH FA temperature proxies (RIN and RAN are investigated in 26 lake sediments from the SW U.S. and compared with existing data from Chinese lake sediments and the SW U.S. soils. 3-OH FA proxy performance was compared with brGDGT-based MBT’. [(-C + a-C + a-C) / n-C] is the 3-OH FA response to MAAT in U.S. lake sediments and is most responsive to TMAM, differing from the MAAT responses of RIN in Chinese lakes and RANS in SW soils. Different 3-OH FA temperature proxies are viable within and between lacustrine and pedogenic environments, suggesting that lacustrine temperature calibrations from 3-OH FAs have a regional calibre at present. In Chapter 5, the potential to streamline 3-OH FA extraction from environmental samples is investigated by testing a low temperature long duration (70 °C, 14 hrs; 'Low n' Slow') acid hydrolysis method on 3-OH FA recovery and proxy data from re-extracted SW U.S. lake sediments and soils. The Low n' Slow method is successful at streamlining the laboratory procedure for 3-OH FA extraction and extracting 3-OH FAs, but raises implications for palaeoclimatic interpretations from 3-OH FAs extracted by different hydrolysis temperatures. In Chapter 6, the Low n' Slow method is applied to a 105 yr lacustrine sequence from Esthwaite Water (UK). 3-OH FA proxies are able to track environmental conditions at a sub-decadal resolution, however most proxies have a unique and contradicting response to temperature, which is potentially related to a history of nutrient enrichment at Eshwaite Water.
This thesis reveals important insights into the environmental drivers of 3-OH FA production in lacustrine and pedogenic environments, and produces regional lake and soil 3-OH FA-based proxy calibrations applicable to the U.S. The proxies likely represent both homeoviscous adaptation of bacterial membranes to ambient environmental conditions and bacterial community changes. There is much more to learn about 3-OH FA variability in response to environmental conditions, particularly in lacustrine environments, and we recommend a global-scale investigation of 3-OH FAs in lakes across different environmental gradients in future studies
Propagation effects within an Extended Optical Amplifier and their impact on the Spatial Distribution of squeezing: towards Quantum Imaging
Get PDFA continuous laser beam can be viewed as a stream of photons travelling through space. Assuming the generation of each photon is a random and independent process, and they do not interact with each other, they display Poissonian statistics. This leads to random intensity fluctuations on the beam, often referred to as shot noise; this is a limiting factor in many light-based measurements, in particular in imaging.
A technique known as squeezing can be used to reduce this intensity noise at the expense of increasing phase noise, adhering to Heisenberg’s uncertainty principle. Recently, ways of producing squeezed light have been studied extensively. One method, four wave mixing (4WM) in an atomic vapour, has been shown to produce twin beams with a correlated intensity statistics, by acting as a multi-spatial-mode optical parametric amplifier (MSM OPA). Therefore, the intensity difference between the coupled modes is squeezed. Squeezing occurs in multiple spatial modes within the beams, so even localised regions of them are correlated in intensity.
Previously, the focus has been on determining the minimum size of these correlated regions, the coherence area. However, there have been significant challenges in deducing this, which is believed to be due to propagation effects between the coupled modes as they travel through the extended optical parametric amplifier. This leads to the correlated regions not being in an expected place in each beam. As such, the focus of this thesis largely concerns the identifying and untangling this phenomena. Further, a new scheme, SAI, is proposed that aims to compensate for these propagation effects in a fully optical way
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