Jaynes' MaxEnt, Steady State Flow Systems and the Maximum Entropy Production Principle

Jaynes' maximum entropy (MaxEnt) principle was recently used to give a conditional, local derivation of the ``maximum entropy production'' (MEP) principle, which states that a flow system with fixed flow(s) or gradient(s) will converge to a steady state of maximum production of thermodynamic entropy (R.K. Niven, Phys. Rev. E, in press). The analysis provides a steady state analog of the MaxEnt formulation of equilibrium thermodynamics, applicable to many complex flow systems at steady state. The present study examines the classification of physical systems, with emphasis on the choice of constraints in MaxEnt. The discussion clarifies the distinction between equilibrium, fluid flow, source/sink, flow/reactive and other systems, leading into an appraisal of the application of MaxEnt to steady state flow and reactive systems.Comment: 6 pages; paper for MaxEnt0

Understanding the mental health of doctoral researchers: a mixed methods systematic review with meta-analysis and meta-synthesis.

Data from studies with undergraduate and postgraduate taught students suggest that they are at an increased risk of having mental health problems, compared to the general population. By contrast, the literature on doctoral researchers (DRs) is far more disparate and unclear. There is a need to bring together current findings and identify what questions still need to be answered. We conducted a mixed methods systematic review to summarise the research on doctoral researchers' (DRs) mental health. Our search revealed 52 articles that were included in this review. The results of our meta-analysis found that DRs reported significantly higher stress levels compared with population norm data. Using meta-analyses and meta-synthesis techniques, we found the risk factors with the strongest evidence base were isolation and identifying as female. Social support, viewing the PhD as a process, a positive student-supervisor relationship and engaging in self-care were the most well-established protective factors. We have identified a critical need for researchers to better coordinate data collection to aid future reviews and allow for clinically meaningful conclusions to be drawn. PROSPERO registration CRD42018092867

Walking on sunshine:Scoping review of the evidence for walking and mental health

Background/objectivesWalking has well-established positive relationships with, and effects on, physical health. In contrast, while poor mental health contributes substantially to global health burden, an overview of the benefits from walking has not previously been published. We aimed to scope the literature and present what is known, and highlight what is not known, about walking and mental health.MethodsDesign: Scoping review.Data sources: Ovid (Medline), ProQuest, Web of Science.Screening and reporting: 13 014 records were identified and screened by a team of researchers. Included full texts were analysed and reported according to mental health outcome.ResultsFor the 8 mental health outcomes (identified a priori), there were a total of 5 systematic reviews and 50 individual papers included. Depression had the most evidence and existing systematic reviews were reported. Evidence for anxiety, psychological stress, psychological well-being, subjective well-being and social isolation and loneliness varied in volume and effectiveness, but no harmful effects were identified. There were no studies for walking and resilience. The setting and context of walking seems to be important variables.ConclusionThe evidence base that suggests walking benefits mental health is growing, but remains fragmented and incomplete for some important outcomes. Policy and national guidelines should promote the known mental health benefits of increased walking and future research should directly address the gaps we have identified.</jats:sec

Understanding the quality of life experiences of older or frail adults following a new dens fracture: non-surgical management in a hard collar versus early removal of collar

Introduction: In the UK, fractures of the cervical dens process in older and/or frail patients are usually managed non-surgically in a hard collar. However, hard collars can lead to complications and this management approach is now being questioned, with growing interest in maximising patients’ short-term quality-of-life. It is vital that patient’s perspectives are considered, yet there is a dearth of literature examining the aspect. To help inform wider decision-making about use of collar/no collar management of dens fractures in older/frail people, we explored older/frail people’s experience of the two management approaches and how they affected their perceived quality-of-life. Methods: We interviewed older and/or frail adults with a recent dens fracture (aged ≥65 years or with a clinical frailty score of ≥5) or their caregiver. Participants were recruited from both arms of a clinical trial comparing management using a hard collar for 12 weeks (SM) with early removal of the collar (ERC) and were interviewed following randomisation and again, 12-16 weeks later. Data were analysed using a framework approach. Results: Both participant groups (SM/ERC) reported substantial, negative QoL experiences, with the fall itself, and lack of access to care services and information being frequent major contributory factors. Many negative experiences cut across both participant groups, including pain, fatigue, diminished autonomy and reduced involvement in personally meaningful activities. However, we identified some subtle, yet discernible, ways in which using SM/ERC reinforced or alleviated (negative) QoL impacts, with the perceived benefits/burdens to using SM/ERC varying between different individuals.Conclusion: Study findings can be used to support informed decision-making about SM/ERC management of dens fractures in older/frail patients.Patient or Public Contribution: Public and patient involvement (PPI) contributors were involved in the study design, development of interview topic guides and interpretation of study findings. <br/

“When I Go There, I Feel Like I Can Be Myself.” Exploring Programme Theory within the Wave Project Surf Therapy Intervention

Mental health issues in young people are a priority for health and social care. Surf therapy is an innovative intervention that may help address this health burden globally. While increasing evidence demonstrates the effectiveness of surf therapy, there has been limited exploration as to how it achieves its outcomes. Such theoretical exploration is important for service optimisation, monitoring and proliferation. This research aimed to adopt, for the first time, a rigorous grounded theory approach to explore underlying programme theory within the Wave Project surf therapy intervention. Participants (n = 22, 14 males and 8 females; mean age = 14 years, SD = 3.5, range 8–23) were interviewed about their intervention experiences. Data were analysed through constant comparative analysis and memo writing. Two core categories reflected mediators by which surf therapy may achieve its outcomes: “Self-Selected Pacing and Progression While Surfing” and “Creation of Emotional and Physical Safe Space at Beach”. Three antecedent (linking known inputs to core categories) and three consequent categories (linking core categories to associated outputs) were also identified. These demonstrate theorised pathways from known inputs to associated outcomes within the intervention. These important findings provide plausible evidence on how to optimise the Wave Project’s delivery in tackling mental health burden

The evolution of handedness: why are ant colonies left- and right-handed?

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