Path integration mediated systematic search: A Bayesian model

The systematic search behaviour is a backup system that increases the chances of desert ants finding their nest entrance after foraging when the path integrator has failed to guide them home accurately enough. Here we present a mathematical model of the systematic search that is based on extensive behavioural studies in North African desert ants . Cataglyphis fortis. First, a simple search heuristic utilising Bayesian inference and a probability density function is developed. This model, which optimises the short-term nest detection probability, is then compared to three simpler search heuristics and to recorded search patterns of . Cataglyphis ants. To compare the different searches a method to quantify search efficiency is established as well as an estimate of the error rate in the ants' path integrator. We demonstrate that the Bayesian search heuristic is able to automatically adapt to increasing levels of positional uncertainty to produce broader search patterns, just as desert ants do, and that it outperforms the three other search heuristics tested. The searches produced by it are also arguably the most similar in appearance to the ant's searches

A Cross-sectional Questionnaire Study to Gather the Teaching Preferences and Expectations of UK Undergraduate Medical Students For Culinary Medicine Learning

Aim: To determine undergraduate medical students’ teaching preferences and expectations for Culinary Medicine (CM) learning with a view to informing development of a CM course at a UK medical school. Setting: A single, urban UK medical school. Participants :180 undergraduate medical students. Study design: A cross-sectional questionnaire study collecting quantitative and qualitative (free-text) data. Methods and outcome measures: An online questionnaire consisting of 16 questions of various styles (Likert-type, multiple choice and free-text). Quantitative analysis of multiple choice and Likert-type scale questions was conducted. Qualitative thematic analysis was used to analyse the free-text responses and identify themes. Results: Three core themes related to students’ understanding of CM were identified: (1) ‘CM Learning’: students’ perceived relevance of CM knowledge, perceived relevance of CM to healthcare and their expectations for teaching; (2) ‘The Relationship between Food and Health’: links between diet, social factors and health; and (3) ‘Evidence-based Medicine’: students’ perceptions about scientific principles underlying CM. Quantitative analysis revealed that, although 83% of students felt that learning CM is important for their future clinical practice, 56% felt unable to take a dietary history. 73% of students were dissatisfied with the quality, and 78% were dissatisfied with the quantity, of existing medical school teaching understood to be relevant to CM. Topics that students would like to be taught on a CM course included weight management and portion control. Students felt that problem-based style learning would be the most appropriate method for delivering CM teaching. Conclusions: This study revealed that medical students felt their dietary counsulting skills could be improved with further clinically relevant teaching in the undergraduate medical curriculum. Students’ preferences for CM learning have been taken into consideration in the development of a CM course for fifth-year undergraduate students at a UK medical school, which is delivered during their General Practice placement

The domestic and gendered context for retirement

Against a global backdrop of population and workforce ageing, successive UK governments have encouraged people to work longer and delay retirement. Debates focus mainly on factors affecting individuals’ decisions on when and how to retire. We argue that a fuller understanding of retirement can be achieved by recognizing the ways in which individuals’ expectations and behaviours reflect a complicated, dynamic set of interactions between domestic environments and gender roles, often established over a long time period, and more temporally proximate factors. Using a qualitative data set, we explore how the timing, nature and meaning of retirement and retirement planning are played out in specific domestic contexts. We conclude that future research and policies surrounding retirement need to: focus on the household, not the individual; consider retirement as an often messy and disrupted process and not a discrete event; and understand that retirement may mean very different things for women and for men

Accuracy of clinical predictions of prognosis at the end-of-life: evidence from routinely collected data in urgent care records

BACKGROUND: The accuracy of prognostication has important implications for patients, families, and health services since it may be linked to clinical decision-making, patient experience and outcomes and resource allocation. Study aim is to evaluate the accuracy of temporal predictions of survival in patients with cancer, dementia, heart, or respiratory disease. METHODS: Accuracy of clinical prediction was evaluated using retrospective, observational cohort study of 98,187 individuals with a Coordinate My Care record, the Electronic Palliative Care Coordination System serving London, 2010-2020. The survival times of patients were summarised using median and interquartile ranges. Kaplan Meier survival curves were created to describe and compare survival across prognostic categories and disease trajectories. The extent of agreement between estimated and actual prognosis was quantified using linear weighted Kappa statistic. RESULTS: Overall, 3% were predicted to live "days"; 13% "weeks"; 28% "months"; and 56% "year/years". The agreement between estimated and actual prognosis using linear weighted Kappa statistic was highest for patients with dementia/frailty (0.75) and cancer (0.73). Clinicians' estimates were able to discriminate (log-rank p < 0.001) between groups of patients with differing survival prospects. Across all disease groups, the accuracy of survival estimates was high for patients who were likely to live for fewer than 14 days (74% accuracy) or for more than one year (83% accuracy), but less accurate at predicting survival of "weeks" or "months" (32% accuracy). CONCLUSION: Clinicians are good at identifying individuals who will die imminently and those who will live for much longer. The accuracy of prognostication for these time frames differs across major disease categories, but remains acceptable even in non-cancer patients, including patients with dementia. Advance Care Planning and timely access to palliative care based on individual patient needs may be beneficial for those where there is significant prognostic uncertainty; those who are neither imminently dying nor expected to live for "years"

Prediction of RCF Damage on Underground Metro Lines

London Underground (LUL) is one of the largest metro networks in the world and carried nearly 1.5 billion passengers in 2015. This increasing passenger demand leads to higher axle loads and shorter headways in the railway operations. However, this has a detrimental impact on the damage generated at the wheel-rail interface. In spite of the advances in rolling stock and track engineering, new developments in material manufacturing methods and rail inspection technology, cracking in rails still remains a major concern for infrastructure managers in terms of safety and maintenance costs. In this study, field data from two metro lines on the LUL network was analysed to identify the distribution and severity of the different damage types. Detailed vehicle dynamics route simulations were conducted for the lines and the calculated wheel-rail forces were investigated to assess the applicability current models for the prediction of rail damage on metro lines. These models include the Whole Life Rail Model (WLRM), previously developed for Great Britain (GB) main line tracks, and Shakedown theory. The influence of key factors such as curve radius, different friction conditions, track irregularities and wheel-rail profiles on the wheel-rail contact interface have been evaluated and compared with outputs from simulations on mainline routes. The study found that the contact patch energy (Tγ) and the interaction between wear and RCF in rails were highly influenced by the characteristics of metro tracks. It was also shown that both the Tγ and Shakedown methods can provide successful prediction of damage susceptibility of rails. However, in order to increase the accuracy of damage predictions and to ascertain the severity of different damage types, the duty conditions which are observed by the rail and the changes in contact conditions resulting from the successive vehicle passes should be considered in the modelling

Palliative care for cirrhosis: a UK survey of health professionals' perceptions, current practice and future needs

Objective: To determine the knowledge and practice patterns of a UK cohort of relevant healthcare professionals (HCPs) about delivering palliative care in cirrhosis, and to inform priorities for future research. / Design: An on-line questionnaire survey with closed and open responses. / Setting: HCPs identified from the mailing list of special interest groups in hepatology and gastroenterology (liver), general practice and specialist palliative care (SPC) across the UK. / Results: Of the 6181 potential contacts identified, 517 HCPs responded. Most believed a role exists for SPC in caring for people with cirrhosis, but many SPC HCPs felt ill prepared to provide good care to those facing death. Further training was needed in managing liver-related symptoms, symptom control and end of life issues. All HCP groups wished to increase community provision of palliative care support, but many general practitioners felt unable to manage advanced cirrhosis in the community. There were differences in the optimal trigger for SPC referral with liver HCPs less likely to refer at symptom deterioration. Prognostication, symptom management and service configuration were key areas identified for future research. / Conclusions: All who responded acknowledged the role of SPC in caring for those dying with cirrhosis and need for further training to improve confidence and enable joint working between SPC, general practice and liver teams. Low response rates make it difficult to generalise these findings, which require further validation

CoMPASs: IOn programme (Care Of Memory Problems in Advanced Stages of dementia: Improving Our Knowledge): protocol for a mixed methods study

Approximately 700 000 people in the UK have dementia, rising to 1.2 million by 2050; one-third of people aged over 65 will die with dementia. Good end-of-life care is often neglected, and detailed UK-based research on symptom burden and needs is lacking. Our project examines these issues from multiple perspectives using a rigorous and innovative design, collecting data which will inform the development of pragmatic interventions to improve care