The role of posttraumatic stress disorder in explaining the psychosocial outcome of subarachnoid haemorrhage patients and their informal carers in both the short- and long-term

Surviving subarachnoid haemorrhage (SAH) patients' experience significantly reduced health-related quality of life (HRQoL) in both the short- and long-term, as well as mysterious symptoms of fatigue and sleep dysfunction. Patients’ family members and friends - who often act as their informal carers - can also experience psychosocial disability. The cause for these poor outcomes remains unknown. Traditional explanations focusing on the neurological sequelae associated with SAH or the characteristics of the illness are not satisfactory; nor are attempts to explain family members' difficulties on the basis of carer burden. The hypothesis which is tested in this thesis is that post-traumatic stress disorder (PTSD) may be abnormally high in both the SAH patient and 'significant other' (SO) population and that this may explain their outcomes. SAH patients are known to be at risk of suffering from PTSD, but it is unknown if this explains their outcome. In terms of patients' SOs, they are known to experience psychiatric symptoms and I suggest these could be caused by their development of PTSD, but this has never been examined. In Part One (Chapter 2-5), I focus on patients' outcomes. Before examining my PTSD hypothesis, I present a meta-analysis (Chapter 2) I conducted of studies which have tried to explain patients' outcome using neurological factors. I conducted the meta-analysis as a tendency for prior studies to be underpowered and use unreliable statistics could have meant that the actual importance of traditional factors was obscured. The results of my meta-analysis however did not support this possibility and instead showed traditional neurological variables did not explain patients' outcome. With this in mind, I then present a longitudinal study (Chapter 5) in which I examined one of the largest prospective series of SAH patients to establish PTS D's explanative importance. Using regression analyses, this study showed PTSD was the best predictor for patients' mental HRQoL - the domain most persistently impaired. It also helped predict patients' physical HRQoL. Moreover, PTSD was linked to sleep problems and may therefore cause fatigue. Crucially, to establish the cause of PTSD, logistic regression was performed. This showed that maladaptive stress coping strategies were the best predictor for PTSD development. In Part Two of the thesis (Chapter 6), I present my longitudinal study of one of the largest prospective samples of SOs. All SOs were assessed with a diagnostic PTSD measure and coping skills were assessed. An elevated incidence of PTSD was found in both the short- and long-term. Although SOs' PTSD did not impinge on the recovery of the SAH patients being cared for, given that it is important to ensure SOs continue caring, regression results are presented which show the cause of SOs' PTSD was (at least in the short- term) due to the use of maladaptive coping strategies. The overarching conclusion is that the elevated incidence of PTSD in SAH patients and SOs helps explain why they experience psychosocial disability. In the final part of the thesis (Chapter 8) the clinical and theoretical implications of this conclusion are considered, such as that teaching patients and their SOs more effective coping skills might prevent PTSD and psychosocial disability

Non-linear electrodynamics : a classical view of the quantum vacuum

Non-linear electrodynamics represents an extension to Maxwell electrodynamics which can describe a range of effects related to high-field physics. We give an overview of recent work looking at various aspects of such theories

Twisted Electromagnetic Modes and Sagnac Ring-Lasers

A new approximation scheme, designed to solve the covariant Maxwell equations inside a rotating hollow slender conducting cavity (modelling a ring-laser), is constructed. It is shown that for well-defined conditions there exist TE and TM modes with respect to the longitudinal axis of the cavity. A twisted mode spectrum is found to depend on the integrated Frenet torsion of the cavity and this in turn may affect the Sagnac beat frequency induced by a non-zero rotation of the cavity. The analysis is motivated by attempts to use ring-lasers to measure terrestrial gravito-magnetism or the Lense-Thirring effect produced by the rotation of the Earth.Comment: LaTeX 31 pages, 3 Figure

On the energy-momentum of light : an all optical view of the Abraham-Minkowski controversy

The energy-momentum of light in a medium is known to have two conflicting descriptions, due to Abraham and Minkowski. In non-linear electrodynamics, a strong field can cause the vacuum to behave analogously to a dielectric material. We investigate the Abraham-Minkowski controversy in this context, and show that for non-linear electrodynamics in vacuum, the Minkowski description is the most natural

Should we stop saying "epileptic"? A comparison of the effect of the terms "epileptic" and "person with epilepsy"

AbstractObjectiveThe advantages and disadvantages of using “epileptic” as a noun to describe someone with epilepsy have long been debated. Recent high-profile recommendations have stated that the term should not be used, including in English, as it perpetuates stigma. This decision was largely informed by a Brazilian Global Campaign Against Epilepsy study that reported experimental evidence indicating that, with students, the label evokes more negative attitudes than “person with epilepsy”. The generalizability of this effect to different countries/cultures, and thus the justification for the recommendations, has never been tested.MethodsWe replicated the Brazilian study in the UK, in English, while also addressing methodological limitations. It was powered to detect the effects reported by the Brazilian study, with 234 students completing a survey regarding epilepsy attitudes. Half were randomized to Group 1 and half to Group 2. In Group 1, patients were referred to as “people/person with epilepsy” within the attitudinal measures, while in Group 2 they were referred to as “epileptic/s”. Measures included translations of the questions used in the Brazilian study and the Attitudes and Beliefs about Living with Epilepsy scale. Participants' epilepsy familiarity and knowledge were also assessed.ResultsThe two groups were comparable in characteristics. A comparison of their responses to the attitude measures revealed no statistically significant or meaningful differences.ConclusionsIn this English replication, the word “epileptic” did not provoke more negative attitudes. This suggests that the effect reported by the Brazilian study might be culturally dependent. Methodological limitations to that study might also be relevant. Our results have implications for the global debate about how negative attitudes towards epilepsy might be addressed. Simply not saying “epileptic” may not promote the positive attitudes towards epilepsy that had been expected. To know how to best refer to those with epilepsy, evidence on the preferences of those actually living with epilepsy is needed

Adaptation without natural selection

Document is itself an extended abstract

Diastereodivergent Synthesis of Cyclopentyl Boronic Esters Bearing Contiguous Fully Substituted Stereocenters

The synthesis of molecules bearing two or more contiguous, quaternary stereocenters is challenging, owing to the difficulty in controlling stereochemistry whilst simultaneously constructing a sterically congested motif. Herein, we report the electrophile‐induced ring contractive 1,2‐metallate rearrangement of 6‐membered cyclic alkenyl boronate complexes for the synthesis of cyclopentyl boronic esters bearing two contiguous, fully substituted stereocenters with high levels of stereocontrol. Remarkably, simple variation of the reaction solvent enabled their diastereodivergent construction with facile access to complementary diastereomeric pairs. The utility of our methodology is demonstrated in the asymmetric total synthesis of (+)‐herbertene‐1,14‐diol

Effect of Greyscale/Print Density on the Properties of High Speed Sintered Nylon 12

High Speed Sintering is an Additive Manufacturing process that creates parts by sintering using inkjet and infra-red lamp technology, rather than the laser systems employed in Laser Sintering. This research investigated the effects of altering the dosage of ink (greyscale/print density) on the properties of parts produced. A clear pattern emerges that shows a ‘sweet spot’ for correct dosage of ink to maximise properties. The work also shows that greyscale allows considerable control of part density that could lead to substantial reductions in part mass beyond those that may be achieved by conventional design optimisation approaches employed today.Mechanical Engineerin

If you can't be with the one you love, love the one you're with: How individual habituation of agent interactions improves global utility

Simple distributed strategies that modify the behaviour of selfish individuals in a manner that enhances cooperation or global efficiency have proved difficult to identify. We consider a network of selfish agents who each optimise their individual utilities by coordinating (or anti-coordinating) with their neighbours, to maximise the pay-offs from randomly weighted pair-wise games. In general, agents will opt for the behaviour that is the best compromise (for them) of the many conflicting constraints created by their neighbours, but the attractors of the system as a whole will not maximise total utility. We then consider agents that act as 'creatures of habit' by increasing their preference to coordinate (anti-coordinate) with whichever neighbours they are coordinated (anti-coordinated) with at the present moment. These preferences change slowly while the system is repeatedly perturbed such that it settles to many different local attractors. We find that under these conditions, with each perturbation there is a progressively higher chance of the system settling to a configuration with high total utility. Eventually, only one attractor remains, and that attractor is very likely to maximise (or almost maximise) global utility. This counterintutitve result can be understood using theory from computational neuroscience; we show that this simple form of habituation is equivalent to Hebbian learning, and the improved optimisation of global utility that is observed results from wellknown generalisation capabilities of associative memory acting at the network scale. This causes the system of selfish agents, each acting individually but habitually, to collectively identify configurations that maximise total utility