Error-Related Negativity and Feedback-Related Negativity on a Reinforcement Learning Task

Event-related potentials play a significant role in error processing and attentional processes. Specifically, event-related negativity (ERN), feedback-related negativity (FRN), and the P300 are related to performance monitoring. The current study examined these components in relation to subjective probability, or confidence, regarding response accuracy on a complicated learning task. Results indicated that confidence ratings were not associated with any changes in ERN, FRN, or P300 amplitude. P300 amplitude did not vary according to participants’ subjective probabilities. ERN amplitude and FRN amplitude did not change throughout the task as participants learned. Future studies should consider the relationship between ERN and FRN using a learning task that is less difficult than the one employed in this study

Recent Central American and low latitude climate variability revealed using speleothem-based rainfall proxy records from southern Belize

Comprehensive assessment of recent tropical climate variability is essential in order to understand the full spatial expression of climate change in the context of long term climate variability. This requires highly resolved and precisely dated tropical proxy records which include the critical transition from the pre-industrial to industrial eras. Speleothem provide highly-resolved and well preserved climate signals and are particularly valuable in tropics where few alternative high resolution records are available. This thesis presents a comprehensive study of recent Central American and low latitude climate variability through assessment of two highly resolved speleothem stable isotope based rainfall proxy records from Yok Balum Cave, southern Belize. The YOK-G stalagmite δ13C record has a bi-monthly resolution and robust chronology permitting the inference of palaeo-seasonality as well as intra annual rainfall variations over the last 453 years. The record strongly suggests that volcanic aerosol injections into the Northern Hemisphere atmosphere result in southward Intertropical Convergence Zone (ITCZ) repositioning, and firmly implicate anthropogenic aerosol emissions as having caused 20th Century rainfall reductions in the northern tropics. The YOK-I stalagmite δ13C record provides a bi-annually resolved correlate records of North Atlantic Oscillation for the last 2000 years. Links between high latitude explosive volcanism and repositioning of the ITCZ are further investigated with emphasis on the subsequent impact of observed North Atlantic Oscillation (NAO) phases. High latitude eruptions are compellingly linked to negative NAO circulatory patterns in the North Atlantic thereby providing new insight into atmospheric mechanics of the North Atlantic. Cave monitoring data provides essential background information on cave environmental variables which could modify climate signals preserved within speleothem carbonate, precluding or complicating interpretations. Using remote monitoring techniques the cave ventilation dynamics and hydrology at Yok Balum are characterised, thereby helping to put the speleothem geochemical data discussed into correct environmental context

Microstructural evolution of environmental barrier coatings in high-temperature steam

Environmental Barrier Coatings (EBCs) are required for use of SiC-based composites in hot sections of gas turbine engines. The primary function of EBCs is to limit the interaction of SiC with steam in the combustion environment. Due to the additional constraints of thermal expansion match and chemical compatibility with the SiC substrate, state-of-the art EBCs are typically fabricated from complex silicates. These silicates typically have sufficiently high silica activities that they also react with the steam by the following generic reaction. Please click Additional Files below to see the full abstract

Design of ultra-high temperature ceramics for oxidation resistance

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Sit-to-Stand Symmetry in Individuals with Hip Pathology

Why study hip fracture? • Hip fractures occur in approximately 300,000 individuals over 65 years of age and is on the rise • 53.3% of those who fall, fall again • 50% loss of function in involved lower extremity post fracture • 25% increased mortality rate 1 year post hip fracture An asymmetry in force production has been found to exist between fractured/non- fractured sides during a sit-to-stand task post hip fracture, despite having adequate capacity to perform the task symmetrically. Houck 2011 found the asymmetry is a result of weakness in the fractured lower extremity. Briere 2013 found the asymmetry is a result of motor control dysfunction in the nervous system rather than a pure strength deficit. An explanation for these errors could be that patients rated their perceived effort distribution rather than their force/weight distribution through their lower extremities during a functional sit to stand task

Ocean processes at the Antarctic continental slope

The Antarctic continental shelves and slopes occupy relatively small areas, but, nevertheless, are important for global climate, biogeochemical cycling and ecosystem functioning. Processes of water mass transformation through sea ice formation/melting and ocean-atmosphere interaction are key to the formation of deep and bottom waters as well as determining the heat flux beneath ice shelves. Climate models, however, struggle to capture these physical processes and are unable to reproduce water mass properties of the region. Dynamics at the continental slope are key for correctly modelling climate, yet their small spatial scale presents challenges both for ocean modelling and for observational studies. Cross-slope exchange processes are also vital for the flux of nutrients such as iron from the continental shelf into the mixed layer of the Southern Ocean. An © 2014 The Authors

How should activity guidelines for young people be operationalised?

Background: If guidelines regarding recommended activity levels for young people are to be meaningful and comparable, it should be clear how they are operationalised. It is usually open to interpretation whether young people are required to meet activity and screen time targets (1) all days of the week, (2) on most days of the week, (3) on average across all days, or (4) whether compliance should be understood as the probability that a randomly selected young person meets the guidelines on a randomly selected day. This paper studies this question using data drawn from the Australian Health of Young Victorians study.Methods: The subjects for this study were 885 13–19 year olds who recalled four days of activities using a computerised use-of-time instrument, the Multimedia Activity Recall for Children and Adolescents (MARCA). Daily minutes of moderate-to-vigorous physical activity (MVPA) and screen time were calculated. The prevalence of compliance to Australian guidelines (≥ 60 min/day of MVPA and ≤ 120 min/day of screen time outside of school hours) was calculated using the four methods.Results: The four methods resulted in significantly different prevalence estimates for compliance to the MVPA guideline (20–68%), screen guideline (12–42%) and both guidelines (2–26%). Furthermore, different individuals were identified as compliant by the different methods.Conclusion: Clarification of how compliance to guidelines should be operationalised would assist in comparisons between studies, and in consistency in determining correlates of compliance

Two Jobs in One Day : Exploring the Dynamics of Personal Assistance Relationships in the Workplace

Disabled people are under-represented and can experience discrimination in the workplace in the UK and globally. The employment of a Workplace Personal Assistant (WPA) is an option for disabled people who require assistance to undertake their job role. The WPA role is designed to increase the accessibility of the workplace via personalised and self-directed assistance, yet is little known or understood. The dynamics of these assistance relationships are explored from analysis of interviews with disabled people, their WPAs and representatives of the organisations in which they work. Disabled people who use a WPA undertake two jobs in one day - their substantive role and the management of their WPA. Understanding these dual roles, and recognising the subtle skills required and additional labour undertaken, can help to challenge the ableist assumptions which shape the workplace and help open up the workplace for disabled people who require a WPA

Partnerships between deaf people and hearing dogs (PEDRO) : Effectiveness and Cost-Effectiveness of Receiving a Hearing Dog on Mental Well-Being and Health in People With Hearing Loss: Protocol for a Randomized Controlled Trial

Background People with hearing loss, particularly those who lose their hearing in adulthood, are at increased risk of social isolation, mental health difficulties, unemployment, loss of independence, risk of accidents, and impaired quality of life. In the United Kingdom (UK), a single third sector organisation provides hearing dogs, a specific type of assistance dog trained to provide sound support to people with hearing loss. These dogs may also deliver numerous psychosocial benefits to recipients. This has not previously been fully investigated. Objective To evaluate the impact of a hearing dog partnership on the lives of individuals with severe or profound hearing loss. Methods and Analysis A two-arm, randomised controlled trial conducted within the UK, with 162 hearing dog applicants, aged 18 years and over. Participants will be randomised 1:1 using a matched-pairs design to receive a hearing dog sooner than usual (intervention arm – Arm B) or to receive a hearing dog within the usual timeframe (comparator arm – Arm A). In the effectiveness analysis, the primary outcome is a comparison of mental wellbeing six-months after Arm B have received a hearing dog (Arm A: not yet received hearing dog), measured using the Short Warwick Edinburgh Mental Wellbeing Scale. Secondary outcome measures include the PHQ-9, GAD-7 and WSAS. An economic evaluation will assess cost-effectiveness including health-related quality-adjusted life years using the EQ-5D-5L and social-care-related-quality-adjusted life-years. Participants will be followed up for up to two years. A nested qualitative study will investigate the impacts of having a hearing dog and how these impacts come about. Results The study was funded by the National Institute for Health Research’s School for Social Care Research. Recruitment commenced in March 2017 and is now complete. 165 participants were randomised. Data collection will continue until January 2020. Results will be published in peer-reviewed journals and at conferences. A summary of the findings will be made available to participants. Ethical approval was received from the University of York’s Department of Social Policy and Social Work Research Ethics Committee (reference SPSW/S/17/1). Conclusions The findings from this study will provide, for the first time, strong and reliable evidence on the impact of having a hearing dog on people’s lives in terms of their quality of life, well-being and mental health. Trial registration The trial has been retrospectively registered International Standard Randomised Controlled Trial Number (ISRCTN) 36452009; https://doi.org/10.1186/ISRCTN36452009. Trial status: Ongoing