The mathematical research of William Parry FRS

In this article we survey the mathematical research of the late William (Bill) Parry, FRS

Zenithal bistability in a nematic liquid crystal device with a monostable surface condition

The ground-state director configurations in a grating-aligned, zenithally bistable nematic device are calculated in two dimensions using a Q tensor approach. The director profiles generated are well described by a one-dimensional variation of the director across the width of the device, with the distorted region near the grating replaced by an effective surface anchoring energy. This work shows that device bistability can in fact be achieved by using a monostable surface term in the one-dimensional model. This implies that is should be possible to construct a device showing zenithal bistability without the need for a micropatterned surface

Regulating DC link voltage fluctuations on a grid connected wave power system using energy storage

The fluctuating nature of power generated from waves combined with the weak nature of the network, makes the connection of arrays of wave energy converters (WECs) to the network a challenge. This paper investigates the research questions raised by the proposed development of a wave farm using coastal WECs, where the spatial layout of the WECs is restricted and cannot be used to damp the fluctuations in generated power. The concept of using energy storage on a common DC link to compensate for the fluctuations in real power, and ensure that the power quality on a weak, rural distribution network is not compromised, will also be discussed

A feasibility study of signed consent for the collection of patient identifiable information for a national paediatric clinical audit database

Objectives: To investigate the feasibility of obtaining signed consent for submission of patient identifiable data to a national clinical audit database and to identify factors influencing the consent process and its success. Design: Feasibility study. Setting: Seven paediatric intensive care units in England. Participants: Parents/guardians of patients, or patients aged 12-16 years old, approached consecutively over three months for signed consent for submission of patient identifiable data to the national clinical audit database the Paediatric Intensive Care Audit Network (PICANet). Main outcome measures: The numbers and proportions of admissions for which signed consent was given, refused, or not obtained (form not returned or form partially completed but not signed), by age, sex, level of deprivation, ethnicity (South Asian or not), paediatric index of mortality score, length of hospital stay (days in paediatric intensive care). Results: One unit did not start and one did not fully implement the protocol, so analysis excluded these two units. Consent was obtained for 182 of 422 admissions (43%) (range by unit 9% to 84%). Most (101/182; 55%) consents were taken by staff nurses. One refusal (0.2%) was received. Consent rates were significantly better for children who were more severely ill on admission and for hospital stays of six days or more, and significantly poorer for children aged 10-14 years. Long hospital stays and children aged 10-14 years remained significant in a stepwise regression model of the factors that were significant in the univariate model. Conclusion: Systematically obtaining individual signed consent for sharing patient identifiable information with an externally located clinical audit database is difficult. Obtaining such consent is unlikely to be successful unless additional resources are specifically allocated to training, staff time, and administrative support

Differential attainment and recruitment to Intensive Care Medicine training in the UK, 2018–2020

Background Differences exist among doctors in examination performance, clinical and academic career progression, and prevalence of performance assessment by professional regulatory bodies. Some of these differences have been reported in relation to individual characteristics. The purpose of this study is to establish whether any specific individual characteristics are associated with performance in selection for entry into specialty training in Intensive Care in the United Kingdom. Methods We evaluated data of 509 candidates from the national recruitment rounds of 2018/19 and 2019/20. The outcome evaluated was “success at interview". Variables reaching statistical significance at univariate logistic regression analysis were fed in the multivariable analysis to identify independent predictors of success, with additional exploratory analyses performed, where indicated. Results The candidates’ median age was 31.5 (interquartile range, IQR 30–33.7) years, 324 (63.7%) were male, 256 (50.3%) not married/in civil partnership, 6 (1.2%) pregnant. The majority (316, 62.1%) were White British, 99 (19.5%) of Asian background, other ethnicities represented less than 20% of the sample. Of the 509 candidates, 155 (30.5%) were Atheist, 140 (27.5%) Christian; most were heterosexual (440, 86.4%); 432 (84.9%) reported no disability, while 4 (0.8%) had a minor and 1 (0.2%) had a major disability; 432 (84.9%) candidates held a UK medical degree; 77 (15.1%) a non-UK degree. At univariate logistic regression analysis (LRA) multiple factors were found to be associated with a lower likelihood of success, the strongest being an international medical graduate (IMG, holding a non-UK medical degree); others were increasing age, male gender, being married, Asian or mixed ethnicity, specific religious beliefs (Buddhism, Islam and Hinduism). After feeding all factors significant at univariate analysis, the only two retained as independent predictors at multivariable regression were Asian ethnicity and holding a non-UK degree. Asian UK graduates success rate was 92.7%, comparable to the national average of 92.3%, the Asian IMGs success rate was significantly lower, at 45.5%. Conclusions As the imbalances seen within the candidates of Asian background are explained by considering the country of primary medical training, the variations in performance is likely to reflect differences in training systems and understanding of the UK NHS

Clinical effectiveness and cost-effectiveness of supported mindfulness-based cognitive therapy self-help compared with supported cognitive behavioral therapy self-help for adults experiencing depression: The low-intensity guided help through mindfulness (LIGHTMind) randomized clinical trial

Importance Depression is prevalent. Treatment guidelines recommend practitioner-supported cognitive behavioral therapy self-help (CBT-SH) for mild to moderate depression in adults; however, dropout rates are high. Alternative approaches are required. Objective To determine if practitioner-supported mindfulness-based cognitive therapy self-help (MBCT-SH) is superior to practitioner-supported CBT-SH at reducing depressive symptom severity at 16 weeks postrandomization among patients with mild to moderate depression and secondarily to examine if practitioner-supported MBCT-SH is cost-effective compared with practitioner-supported CBT-SH. Design, Setting, and Participants This was an assessor- and participant-blinded superiority randomized clinical trial with 1:1 automated online allocation stratified by center and depression severity comparing practitioner-supported MBCT-SH with practitioner-supported CBT-SH for adults experiencing mild to moderate depression. Recruitment took place between November 24, 2017, and January 31, 2020. The study took place in 10 publicly funded psychological therapy services in England (Improving Access to Psychological Therapies [IAPT]). A total of 600 clients attending IAPT services were assessed for eligibility, and 410 were enrolled. Participants met diagnostic criteria for mild to moderate depression. Data were analyzed from January to October 2021. Interventions Participants received a copy of either an MBCT-SH or CBT-SH workbook and were offered 6 support sessions with a trained practitioner. Main Outcomes and Measures The preregistered primary outcome was Patient Health Questionnaire (PHQ-9) score at 16 weeks postrandomization. The primary analysis was intention-to-treat with treatment arms masked. Results Of 410 randomized participants, 255 (62.2%) were female, and the median (IQR) age was 32 (25-45) years. At 16 weeks postrandomization, practitioner-supported MBCT-SH (n = 204; mean [SD] PHQ-9 score, 7.2 [4.8]) led to significantly greater reductions in depression symptom severity compared with practitioner-supported CBT-SH (n = 206; mean [SD] PHQ-9 score, 8.6 [5.5]), with a between-group difference of −1.5 PHQ-9 points (95% CI, −2.6 to −0.4; P = .009; d = −0.36). The probability of MBCT-SH being cost-effective compared with CBT-SH exceeded 95%. However, although between-group effects on secondary outcomes were in the hypothesized direction, they were mostly nonsignificant. Three serious adverse events were reported, all deemed not study related. Conclusions and Relevance In this randomized clinical trial, practitioner-supported MBCT-SH was superior to standard recommended treatment (ie, practitioner-supported CBT-SH) for mild to moderate depression in terms of both clinical effectiveness and cost-effectiveness. Findings suggest that MBCT-SH for mild to moderate depression should be routinely offered to adults in primary care services. Trial Registration isrctn.org Identifier: ISRCTN1349575

Optical waveguide characterization of a tristable antiferroelectric liquid crystal cell

Copyright © 2004 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Journal of Applied Physics 95 (2004) and may be found at http://link.aip.org/link/?JAPIAU/95/2246/1The optical convergent-beam waveguide technique has been used to characterize a homogeneously aligned 3 µm cell containing a liquid crystal in the antiferroelectric phase. The director structure has been quantified with the cell at 0 V and at ±50 V dc, and three distinct states have been observed. From the optical data collected, it is found that the material forms a tilted-bookshelf ferroelectric structure in the presence of a suitable voltage, and the characteristic alternating (anticlinic) structure of the antiferroelectric phase when the cell is short-circuited. The biaxiality of the antiferroelectric state has been measured, and (approximately) uniaxial refractive indices, the cone angle, and layer tilt have been determined for the ferroelectric state

Low-intensity guided help through mindfulness (LIGHTMIND): study protocol for a randomised controlled trial comparing supported mindfulness-based cognitive therapy self-help to supported cognitive behavioural therapy self-help for adults experiencing depression

Background: Depression has serious personal, family and economic consequences. It is estimated that it will cost £12.15 billion to the economy each year in England by 2026. Improving Access to Psychological Therapies (IAPT) is the National Health Service talking therapies service in England for adults experiencing anxiety or depression. Over 1 million people are referred to IAPT every year, over half experiencing depression. Where symptoms of depression are mild/moderate, people are typically offered Cognitive Behavioural Therapy (CBT) self-help supported by a psychological wellbeing practitioner (PWP). The problem is that over half of people who complete treatment for depression in IAPT remain depressed despite receiving National Institute of Health and Care Excellent (NICE) recommended treatment. Furthermore, less than half of IAPT service users complete treatment. This study seeks to investigate the effectiveness of an alternative to CBT self-help. Mindfulness-based cognitive therapy differs from CBT in focus, approach and practice and may be more effective with a higher number of treatment completions. Methods/Design: This is a definitive randomised controlled trial comparing supported mindfulness-based cognitive therapy self-help (MBCT-SH) with supported cognitive behavioural therapy self-help (CBT-SH) for adults experiencing mild/moderate depression being treated in IAPT services. Four hundred and ten participants experiencing mild/moderate depression will be recruited from IAPT services and randomised to receive either an MBCT-based self-help workbook or a CBT-based self-help workbook. Participants will be asked to complete their workbook within 16 weeks, with six support sessions with a PWP. The primary outcome is depression symptom severity upon treatment completion. Secondary outcomes are treatment completion rates and measures of generalized anxiety, wellbeing, functioning and mindfulness. An exploratory non-inferiority analysis will be conducted in the event the primary hypothesis is not supported. A semi-structured interview with participants will guide understanding of change processes. Discussion: If the findings from this randomised controlled trial demonstrate that MBCT-SH is more effective than CBT-SH for adults experiencing depression, this will provide evidence for policy makers and lead to changes to clinical practice in IAPT services, leading to greater choice of self-help treatment options and better outcomes for service users. If the exploratory non-inferiority analysis is conducted and this indicates non-inferiority of MBCT-SH in comparison to CBT-SH this will also be of interest to policy makers when seeking to increase service user choice of self-help treatment options for depression. Trial registration: Current Controlled Trial registration number ISRCTN 13495752. Registered on 31 August 2017 (www.isrctn.com/ISRCTN13495752). Protocol Version: Version 1 (18 January 2020) Recruitment Status: Recruiting: participants are currently being recruited and enrolled Date first participant randomised: 24 November 2017 Trial Sponsor: Sussex Partnership NHS Foundation Trust ([email protected]

Low-Intensity Guided Help Through Mindfulness (LIGHTMIND): study protocol for a randomised controlled trial comparing supported mindfulness-based cognitive therapy self-help to supported cognitive behavioural therapy self-help for adults experiencing depression

Background Depression has serious personal, family and economic consequences. It is estimated that it will cost £12.15 billion to the economy each year in England by 2026. Improving access to psychological therapies (IAPT) is the National Health Service talking therapies service in England for adults experiencing anxiety or depression. Over 1 million people are referred to IAPT every year, over half experiencing depression. Where symptoms of depression are mild to moderate, people are typically offered cognitive behavioural therapy (CBT) self-help (CBT-SH) supported by a psychological well-being practitioner. The problem is that over half of people who complete treatment for depression in IAPT remain depressed despite receiving National Institute of Health and Care Excellent recommended treatment. Furthermore, less than half of IAPT service users complete treatment. This study seeks to investigate the effectiveness of an alternative to CBT-SH. Mindfulness-based cognitive therapy (MBCT) differs from CBT in focus, approach and practice, and may be more effective with a higher number of treatment completions. Methods/design This is a definitive randomised controlled trial comparing supported MBCT self-help (MBCT-SH) with CBT-SH for adults experiencing mild to moderate depression being treated in IAPT services. We will recruit 410 participants experiencing mild to moderate depression from IAPT services and randomise these to receive either an MBCT-based self-help workbook or a CBT-based self-help workbook. Participants will be asked to complete their workbook within 16 weeks, with six support sessions with a psychological well-being practitioner. The primary outcome is depression symptom severity on treatment completion. Secondary outcomes are treatment completion rates and measures of generalized anxiety, well-being, functioning and mindfulness. An exploratory non-inferiority analysis will be conducted in the event the primary hypothesis is not supported. A semi-structured interview with participants will guide understanding of change processes. Discussion If the findings from this randomised controlled trial demonstrate that MBCT-SH is more effective than CBT-SH for adults experiencing depression, this will provide evidence for policy makers and lead to changes to clinical practice in IAPT services, leading to greater choice of self-help treatment options and better outcomes for service users. If the exploratory non-inferiority analysis is conducted and this indicates non-inferiority of MBCT-SH in comparison to CBT-SH this will also be of interest to policy makers when seeking to increase service user choice of self-help treatment options for depression. Trial registration Current Controlled Trial registration number: ISRCTN 13495752. Registered on 31 August 2017 (www.isrctn.com/ISRCTN13495752)