Investigation of the structure and phase transitions in the novel A-site substituted perovskite series (Na1-xKx)0.5Bi0.5TiO

An extensive study of the crystal structure and phase transitions in Na0.5Bi0.5TiO3 has been carried out using neutron/x-ray powder, and single-crystal x-ray, diffraction techniques. This has been complemented with optical and Raman studies. The sequence of phase transitions from the high-temperature prototypic cubic structure (above 813 K), to one of tetragonal (673-773 K) and then rhombohedral structure (5-528 K) has been established in Na0.5Bi0.5TiO3. Coexisting tetragonal/cubic (773-813 K) and rhombohedral/tetragonal (528-673 K) phases have also been observed. Rietveld refinements have revealed the rhombohedral phase, space group Ric, exhibits an antiphase, a-a-a- oxygen octahedra tilt system, with parallel cation displacements. The tetragonal phase, space group P4bm, possesses an unusual combination of in-phase, a0a0c+ oxygen octahedra tilts and antiparallel cation displacements along the polar axis. This structure type is unprecedented amongst the perovskites. A high-pressure study using synchrotron and neutron diffraction has revealed the ambient pressure rhombohedral structure undergoes a phase transition to an orthorhombic structure with Pnma symmetry and the a-b+a- oxygen octahedra tilt system together with antiparallel A-cation ordering along [010]. The pure rhombohedral structure persists up to 8 kbar; between 10-19.4 kbar a rhombohedral/orthorhombic coexistence region was observed and above 26.2 kbar the purely orthorhombic phase was seen. Structural variations as a function of temperature, pressure and doping across the (Na1-xKx)0.5Bi0.5TiO3 series are also presented. With increasing potassium doping across this series, phase transitions from the rhombohedral structure with octahedral tilting to a non-tilted rhombohedral structure (space group, Ram) and then to a tetragonal structure (space group P4mm) was observed. A basic phase diagram for this series has been assembled outlining phase boundaries across the series and as a function of temperature. In this study, the optimum conditions used for the fabrication of powders, ceramics and single crystals of the perovskite compound Na0.5Bi0.5TiO3 and the solid solution across the (Na1-xKx)0.5Bi0.5TiO3 series have been established. A detailed analysis of this A-site substituted distorted perovskite compound is made with structural variations, cation displacements and octahedral distortions for the different phases being reported. The A-site substituted compounds are thoroughly discussed in the context of modem perovskite science

THE POLITICS OF KANT’S AESTHETICS: HANNAH ARENDT, JACQUES RANCIÈRE, AND THE TRANSFORMATION OF COMMON SENSE

This thesis focuses on the political significance of Kant’s aesthetics, as it is taken up in the political thought o f Hannah Arendt and Jacques Rancière. While both Arendt and Rancière model their notions of political community on Kant’s notion of sensus communis, or aesthetic common sense, I point to important differences in their respective appropriations of Kant. Whereas Arendt draws out of Kant’s work on aesthetic judgment a politics of adherence to common sense (consensus), Rancière looks to Kant’s concepts of disinterest and disconnection to develop a politics of “dissensus”, aimed at reconfiguring common sense along more egalitarian lines. I argue that Rancière’s ability to account, not just for the aesthetic partitioning of communities, but also for their radical transformation or re­ partitioning through dissensus, makes him better able than Arendt to account for the introduction o f political subjects rendered invisible and audible by historically cemented forms of common sense

A framework for the adoption and diffusion of Personal Learning Environments in commercial organisations: an exploratory study in the learning and development sector in the UK

This study presents an exploratory approach to identify the main factors of Personal Learning Environment (PLE) adoption and diffusion within commercial organisations. Utilising an inductive investigative approach via the use of Grounded Theory methodology, relevant adoption factors were identified and their resulting influence during various stages of the innovation diffusion process were proposed. Data was collected using semi-structured interviews followed by systematic analysis using a three-staged coding process. The results revealed 10 factors affecting the adoption of PLEs influencing the innovation diffusion process at various stages. Informed by the Technology Acceptance Model and Innovation Diffusion Theory, the proposed model could have important implications for key decision makers within commercial organisations, while adopting, rejecting and assimilating new technological innovations (e.g. PLE) for learning delivery

The Jew as dangerous other in early Italian cinema, 1910-1914

My thesis examines imagery of the Jew in four Italian silent fils: Il mercante di Venezia (Gerolamo Lo Savio, 1910), L'Inferno (Francesco Bertolini, Adolfo Padovan, Giuseppe de Liuoro, 1922) Quo Vadis? (Enrico Guazzoni, 1913) and Cabiria (Giovanni Pastrone, 1914). The thesis deconstructs this filmic imagery and traces its history back to medieval and Renaissance representations of the Jew. This process reveals connections between traditional anti-Jewish ideologies and the moving images of early Italian cinema. In so doing, my thesis demonstrates that there is a powerful relationship between the socio-political and relifious discourses that were in circulation before the First World War in Italy and the presence of anti-Semitic stereotyping in these films. It also argues that the image of the Jew in all of these filmic case studies functiones as a representation of the radical dangerous Other that threatens the unity of the citizenry of the nationstate of the Kingdom of Italy and the cohesion of the Liberal Italian society at a key time of new nation building

Efficient "black-box" multigrid solvers for convection-dominated problems

The main objective of this project is to develop a "black-box" multigrid preconditioner for the iterative solution of finite element discretisations of the convection-diffusion equation with dominant convection. This equation can be considered a stand alone scalar problem or as part of a more complex system of partial differential equations, such as the Navier-Stokes equations. The project will focus on the stand alone scalar problem. Multigrid is considered an optimal preconditioner for scalar elliptic problems. This strategy can also be used for convection-diffusion problems, however an appropriate robust smoother needs to be developed to achieve mesh-independent convergence. The focus of the thesis is on the development of such a smoother. In this context a novel smoother is developed referred to as truncated incomplete factorisation (tILU) smoother. In terms of computational complexity and memory requirements, the smoother is considerably less expensive than the standard ILU(0) smoother. At the same time, it exhibits the same robustness as ILU(0) with respect to the problem and discretisation parameters. The new smoother significantly outperforms the standard damped Jacobi smoother and is a competitor to the Gauss-Seidel smoother (and in a number of important cases tILU outperforms the Gauss-Seidel smoother). The new smoother depends on a single parameter (the truncation ratio). The project obtains a default value for this parameter and demonstrated the robust performance of the smoother on a broad range of problems. Therefore, the new smoothing method can be regarded as "black-box". Furthermore, the new smoother does not require any particular ordering of the nodes, which is a prerequisite for many robust smoothers developed for convection-dominated convection-diffusion problems. To test the effectiveness of the preconditioning methodology, we consider a number of model problems (in both 2D and 3D) including uniform and complex (recirculating) convection fields discretised by uniform, stretched and adaptively refined grids. The new multigrid preconditioner within block preconditioning of the Navier-Stokes equations was also tested. The numerical results gained during the investigation confirm that tILU is a scalable, robust smoother for both geometric and algebraic multigrid. Also, comprehensive tests show that the tILU smoother is a competitive method.EThOS - Electronic Theses Online ServiceEPSRCGBUnited Kingdo

Clinical effectiveness and cost-effectiveness of cognitive behavioural therapy as an adjunct to pharmacotherapy for treatment-resistant depression in primary care: the CoBalT randomised controlled trial

Background: Only one-third of patients with depression respond fully to treatment with antidepressant medication. However, there is little robust evidence to guide the management of those whose symptoms are 'treatment resistant'.<p></p> Objective: The CoBalT trial examined the clinical effectiveness and cost-effectiveness of cognitive behavioural therapy (CBT) as an adjunct to usual care (including pharmacotherapy) for primary care patients with treatment-resistant depression (TRD) compared with usual care alone.<p></p> Design: Pragmatic, multicentre individually randomised controlled trial with follow-up at 3, 6, 9 and 12 months. A subset took part in a qualitative study investigating views and experiences of CBT, reasons for completing/not completing therapy, and usual care for TRD.<p></p> Setting: General practices in Bristol, Exeter and Glasgow, and surrounding areas.<p></p> Participants: Patients aged 18-75 years who had TRD [on antidepressants for 6 weeks, had adhered to medication, Beck Depression Inventory, 2nd version (BDI-II) score of 14 and fulfilled the International Classification of Diseases and Related Health Problems, Tenth edition criteria for depression]. Individuals were excluded who (1) had bipolar disorder/psychosis or major alcohol/substance abuse problems; (2) were unable to complete the questionnaires; or (3) were pregnant, as were those currently receiving CBT/other psychotherapy/secondary care for depression, or who had received CBT in the past 3 years.<p></p> Interventions: Participants were randomised, using a computer-generated code, to usual care or CBT (12-18 sessions) in addition to usual care.<p></p> Main outcome measures: The primary outcome was 'response', defined as 50% reduction in depressive symptoms (BDI-II score) at 6 months compared with baseline. Secondary outcomes included BDI-II score as a continuous variable, remission of symptoms (BDI-II score of < 10), quality of life, anxiety and antidepressant use at 6 and 12 months. Data on health and social care use, personal costs, and time off work were collected at 6 and 12 months. Costs from these three perspectives were reported using a cost-consequence analysis. A cost-utility analysis compared health and social care costs with quality adjusted life-years.<p></p> Results: A total of 469 patients were randomised (intervention: n = 234; usual care: n = 235), with 422 participants (90%) and 396 (84%) followed up at 6 and 12 months. Ninety-five participants (46.1%) in the intervention group met criteria for 'response' at 6 months compared with 46 (21.6%) in the usual-care group {odds ratio [OR] 3.26 [95% confidence interval (CI) 2.10 to 5.06], p < 0.001}. In repeated measures analyses using data from 6 and 12 months, the OR for 'response' was 2.89 (95% CI 2.03 to 4.10, p < 0.001) and for a secondary 'remission' outcome (BDI-II score of < 10) 2.74 (95% CI 1.82 to 4.13, p < 0.001). The mean cost of CBT per participant was £910, the incremental health and social care cost £850, the incremental QALY gain 0.057 and incremental cost-effectiveness ratio £14,911. Forty participants were interviewed. Patients described CBT as challenging but helping them to manage their depression; listed social, emotional and practical reasons for not completing treatment; and described usual care as mainly taking medication.<p></p> Conclusions: Among patients who have not responded to antidepressants, augmenting usual care with CBT is effective in reducing depressive symptoms, and these effects, including outcomes reflecting remission, are maintained over 12 months. The intervention was cost-effective based on the National Institute for Health and Care Excellence threshold. Patients may experience CBT as difficult but effective. Further research should evaluate long-term effectiveness, as this would have major implications for the recommended treatment of depression.<p></p&gt

Custom fitted compression garments enhance recovery from muscle damage in rugby players

PURPOSE: To evaluate the effects of custom fitted compression garments (CG) on recovery from muscle damage in rugby players. METHODS: Forty-five players were tested for lower body strength, power, and indices of muscle-damage before completing a damaging protocol (20 x 20 m sprints with 5 m deceleration, 100 drop-jumps). Players were randomly assigned to wear either custom fitted (CF, n = 13), or standard sized CG (SSG, n = 16), or to received sham ultrasound therapy (CON, n = 16) immediately post-exercise. Players were re-tested immediately, then after 24 h and 48 h. RESULTS: Strength recovery was significantly different between groups (F = 2.7, p = 0.02), with only CF recovering to baseline values by 48 h (p = 0.973). Time x condition effects were also apparent for creatine kinase activity (χ = 30.4, p < 0.001) and mid-thigh girth (F = 3.7, p = 0.005), with faster recovery apparent in CF compared to both CON and SSG (p < 0.05). CONCLUSIONS: Custom fitted CG improved strength recovery and indices of muscle damage in rugby players, compared to controls and standard sized garments. PRACTICAL APPLICATIONS: Athletes and coaches would be advised to use appropriately fitted CG to enhance strength recovery following damaging exercise

A Population-Based Cohort Study Examining the Incidence and Impact of Psychotic Experiences From Childhood to Adulthood, and Prediction of Psychotic Disorder.

OBJECTIVE: The authors investigated the incidence, course, and outcome of psychotic experiences from childhood through early adulthood in the general population and examined prediction of psychotic disorder. METHODS: This was a population-based cohort study using the semistructured Psychosis-Like Symptoms Interview at ages 12, 18, and 24 (N=7,900 with any data). Incidence rates were estimated using flexible parametric modeling, and positive predictive values (PPVs), sensitivity, specificity, and area under the curve were estimated for prediction. RESULTS: The incidence rate of psychotic experiences increased between ages 13 and 24, peaking during late adolescence. Of 3,866 participants interviewed at age 24, 313 (8.1%, 95% CI=7.2, 9.0) had a definite psychotic experience since age 12. A total of 109 individuals (2.8%) met criteria for a psychotic disorder up to age 24, of whom 70% had sought professional help. Prediction of current psychotic disorder at age 24 (N=47, 1.2%), by both self-report and interviewer-rated measures of psychotic experiences at age 18 (PPVs, 2.9% and 10.0%, respectively), was improved by incorporating information on frequency and distress (PPVs, 13.3% and 20.0%, respectively), although sensitivities were low. The PPV of an at-risk mental state at age 18 predicting incident disorder at ages 18-24 was 21.1% (95% CI=6.1, 45.6) (sensitivity, 14.3%, 95% CI=4.0, 32.7). CONCLUSIONS: The study results show a peak in incidence of psychotic experiences during late adolescence as well as an unmet need for care in young people with psychotic disorders. Because of the low sensitivity, targeting individuals in non-help-seeking samples based only on more severe symptom cutoff thresholds will likely have little impact on population levels of first-episode psychosis.The UK Medical Research Council and Wellcome (Grant ref: 102215/2/13/2) and the University of Bristol provide core support for ALSPAC. This study was funded by the Medical Research Council (MRC) Grant MR/M006727/1. The following authors acknowledge support: S.Z by the NIHR Biomedical Research Centre (BRC) at University Hospitals Bristol NHS Foundation Trust and the University of Bristol; A.S.D and G.H by the NIHR BRC at University College London Hospital; P.B.J. by the NIHR CLAHRC East of England, NIHR PGfAR RP-PG-0616-20003 (TYPPEX) and the Wellcome Trust Neuroscience in Psychiatry Network (095844/Z/11/Z); PCF by the Wellcome Trust (206368/Z/17/Z) and the Bernard Wolfe health Neuroscience Fund; M.C. by a European Research Council Consolidator Award (iHEAR 724809). The views expressed in this publication are those of the author(s) and not necessarily those of the NHS, the National Institute for Health Research or the Department of Health and Social Car