We investigate the consequences of periodic, on–off glucose infusion on the glucose–insulin regulatory system based on a system-level mathematical model with two explicit time delays. Studying the effects of such infusion protocols is mathematically challenging yet a promising direction for probing the system response to infusion. We pay special attention to the interplay of periodic infusion with intermediate-time-scale, ultradian oscillations that arise as a result of the physiological response of glucose uptake and back-release into the bloodstream. By using numerical solvers and numerical continuation software, we investigate the response of the model to different infusion patterns, explore how these patterns affect the overall levels of glucose and insulin, and how this can lead to entrainment. By doing so, we provide a road-map of system responses that can potentially help identify new, less-invasive, test strategies for detecting abnormal responses to glucose uptake without falling into lockstep with the infusion pattern.

The RDA for dietary protein is likely insufficient for individuals with cystic fibrosis (CF). This study sought to characterise protein intake and diet quality in adults with cystic fibrosis (awCF), before and after elexacaftor/tezacaftor/ivacaftor (ETI) therapy, compared with healthy controls. Dietary intake was assessed by diet diary in awCF at baseline (BL, n 40) and at follow-up > 3 months post ETI therapy (follow-up (FUP), n 40) and in age-matched healthy controls (CON, n 80) free from known disease at a single time point. Protein intake dose and daily distribution, protein quality, protein source and overall diet quality were calculated for each participant. Both CON (1·39 (sd 0·47) g·kg–1·day–1) and CF (BL: 1·44 (sd 0·52) g·kg–1·day–1, FUP: 1·12 (sd 0·32) g·kg–1·day–1) had a higher mean daily protein intake than the protein RDA of 0·75g·kg–1·day–1. There was a significant reduction in daily protein intake in the CF group at FUP (P = 0·0003, d = 0·73), with levels below the alternative suggested dietary intake of ≥ 1·2 g·kg–1·day–1. There were no sex differences or noticeable effects on protein quality or source following the commencement of ETI therapy when compared with CON (all P > 0·05), although overall diet quality decreased between time points (P = 0·027, d = 0·57). The observed reduction in daily protein intake in the present cohort emphasises the importance of ensuring appropriate dietary protein intake to promote healthy ageing in adults with CF. More research is needed to evidence base dietary protein requirements in this at-risk population.

An expanding scholarship on interracial intimacy in colonial contexts has generally focused on cases of administrative disputes or judicial conflicts that brought “mixed couples,” “mixed-race families,” or “métis” to the attention of colonial authorities. But what of the lives and experiences of those who did not contest their legal status, remaining under the administrative radar and thus virtually invisible in the archives of the colonial state? This article tackles these issues in the context of the French colony of New Caledonia by analyzing the trajectory of a household established out of official sight, made up of a French settler, a Kanak woman, and their descendants. The goal here is to understand what this phenomenon of relative social invisibility reveals about the scope and limits of colonial domination “at ground level.” Combining ethnographic fieldwork and archival research, the article traces the conditions under which this family configuration was able to emerge and then endure for over fifty years. It finally disappeared after the death of the French settler, when each of the wider family groups—European and Kanak—to varying degrees sought to efface this awkward past within their respective social worlds.

This study provides a comprehensive analysis of the snow and avalanche climate of the Chic-Chocs region of the Gaspé Peninsula, located in the northeastern Appalachians of eastern Canada. The data revealed two major components of the snow and avalanche climate: a cold snow cover combined with a maritime influence causing melt/ice layers through rain-on-snow events. The CRCM6-SNOWPACK model chain was good at representing the seasonal mean of climatic indicators, snow grain type and an avalanche problem type that well represented the investigated snow and avalanche climate of the study region. The global comparison shows that the snow and avalanche climate is different from other areas in western North America, but similar to Mount Washington (New Hampshire, USA) and central Japan. We show a clustering based solely on avalanche problem types, which showed that the onset date of wet snow problems divided most of the winters into three clusters. We compare these clusters with the French Alps and show some similarities, moving away from a traditional snow and avalanche climate description. The paper concludes that the use of advanced snow cover modeling combined with avalanche problem type characterization represents a suitable method to improve our understanding and classification of snow and avalanche climates for avalanche related problems, ultimately contributing to improved forecasting and risk management in similar regions.

In this study, we tackle the challenge of inferring the initial conditions of a Rayleigh–Taylor mixing zone for modelling purposes by analysing zero-dimensional (0-D) turbulent quantities measured at an unspecified time. This approach assesses the extent to which 0-D observations retain the memory of the flow, evaluating their effectiveness in determining initial conditions and, consequently, in predicting the flow’s evolution. To this end, we generated a comprehensive dataset of direct numerical simulations, focusing on miscible fluids with low density contrasts. The initial interface deformations in these simulations are characterised by an annular spectrum parametrised by four non-dimensional numbers. To study the sensitivity of 0-D turbulent quantities to initial perturbation distributions, we developed a surrogate model using a physics-informed neural network (PINN). This model enables computation of the Sobol indices for the turbulent quantities, disentangling the effects of the initial parameters on the growth of the mixing layer. Within a Bayesian framework, we employ a Markov chain Monte Carlo (MCMC) method to determine the posterior distributions of initial conditions and time, given various state variables. This analysis sheds light on inertial and diffusive trajectories, as well as the progressive loss of initial conditions memory during the transition to turbulence. Furthermore, it identifies which turbulent quantities serve as better predictors of Rayleigh–Taylor mixing zone dynamics by more effectively retaining the memory of the flow. By inferring initial conditions and forward propagating the maximum a posteriori (MAP) estimate, we propose a strategy for modelling the Rayleigh–Taylor transition to turbulence.

Objectives/Goals: Manual skin assessment in chronic graft-versus-host disease (cGVHD) can be time consuming and inconsistent (>20% affected area) even for experts. Building on previous work we explore methods to use unmarked photos to train artificial intelligence (AI) models, aiming to improve performance by expanding and diversifying the training data without additional burden on experts. Methods/Study Population: Common to many medical imaging projects, we have a small number of expert-marked patient photos (N = 36, n = 360), and many unmarked photos (N = 337, n = 25,842). Dark skin (Fitzpatrick type 4+) is underrepresented in both sets; 11% of patients in the marked set and 9% in the unmarked set. In addition, a set of 20 expert-marked photos from 20 patients were withheld from training to assess model performance, with 20% dark skin type. Our gold standard markings were manual contours around affected skin by a trained expert. Three AI training methods were tested. Our established baseline uses only the small number of marked photos (supervised method). The semi-supervised method uses a mix of marked and unmarked photos with human feedback. The self-supervised method uses only unmarked photos without any human feedback. Results/Anticipated Results: We evaluated performance by comparing predicted skin areas with expert markings. The error was given by the absolute difference between the percentage areas marked by the AI model and expert, where lower is better. Across all test patients, the median error was 19% (interquartile range 6 – 34) for the supervised method and 10% (5 – 23) for the semi-supervised method, which incorporated unmarked photos from 83 patients. On dark skin types, the median error was 36% (18 – 62) for supervised and 28% (14 – 52) for semi-supervised, compared to a median error on light skin of 18% (5 – 26) for supervised and 7% (4 – 17) for semi-supervised. Self-supervised, using all 337 unmarked patients, is expected to further improve performance and consistency due to increased data diversity. Full results will be presented at the meeting. Discussion/Significance of Impact: By automating skin assessment for cGVHD, AI could improve accuracy and consistency compared to manual methods. If translated to clinical use, this would ease clinical burden and scale to large patient cohorts. Future work will focus on ensuring equitable performance across all skin types, providing fair and accurate assessments for every patient.

Geriatric (old age) psychiatry faces growing challenges amid Europe’s ageing population. This editorial emphasises the need for specialised training, mentorship and subspecialty recognition to attract young psychiatrists. By addressing structural gaps and fostering innovation, the field offers a rewarding career in enhancing older adults’ mental healthcare and quality of life.

The intuition that knowledge requires the satisfaction of some sort of anti-luck condition is widely shared. I examine the claim that modal robustness is sufficient for satisfying this condition: for a true belief to be non-luckily true, it is sufficient that this belief is safe and sensitive. I argue that this claim is false by arguing that, at least when it comes to beliefs in necessary truths, satisfying the anti-luck condition requires satisfying a non-modal condition. I also advance a plausible candidate for this condition and argue for the implausibility of mathematical Platonism on this basis.

There is a growing focus on understanding the complexity of dietary patterns and how they relate to health and other factors. Approaches that have not traditionally been applied to characterise dietary patterns, such as latent class analysis and machine learning algorithms, may offer opportunities to characterise dietary patterns in greater depth than previously considered. However, there has not been a formal examination of how this wide range of approaches has been applied to characterise dietary patterns. This scoping review synthesised literature from 2005 to 2022 applying methods not traditionally used to characterise dietary patterns, referred to as novel methods. MEDLINE, CINAHL and Scopus were searched using keywords including latent class analysis, machine learning and least absolute shrinkage and selection operator. Of 5274 records identified, 24 met the inclusion criteria. Twelve of twenty-four articles were published since 2020. Studies were conducted across seventeen countries. Nine studies used approaches with applications in machine learning, such as classification models, neural networks and probabilistic graphical models, to identify dietary patterns. The remaining studies applied methods such as latent class analysis, mutual information and treelet transform. Fourteen studies assessed associations between dietary patterns characterised using novel methods and health outcomes, including cancer, cardiovascular disease and asthma. There was wide variation in the methods applied to characterise dietary patterns and in how these methods were described. The extension of reporting guidelines and quality appraisal tools relevant to nutrition research to consider specific features of novel methods may facilitate consistent reporting and enable synthesis to inform policies and programs.

Cumulative exposure to anticholinergic and sedative medications has been associated with worsening physical function in older adults. We evaluated the feasibility of measuring physical function using wearable devices and explored the impact of reducing the anticholinergic and sedative medication burden in a pilot study of community-dwelling adults aged 60 years and older. Evaluations included the 10-meter walk test (10MWT), the Short Physical Performance Battery (SPPB), and the mini-BESTest. Two participants/month were recruited in one clinic in 2022. The five participants had a median age of 67, a median DBI of 1.7, and four were female. The feasibility analysis showed that the 10MWT and SPPB tests were completed on 12/12, and the mini-BESTest on 11/12. An exploratory analysis showed clinically meaningful improvements in gait speed (mean +0.18 m/s) and SPPB (mean +2.2 points). We showed the feasibility of measuring physical function by wearable devices during deprescribing of anticholinergic and sedative medications.

The diet proposed by the EAT-Lancet Commission has faced criticism concerning its affordability. This study aimed to investigate the cost associated with a greater alignment to the EAT-Lancet reference diet in the province of Québec, Canada. The dietary habits of 1147 French-speaking adults were assessed using repeated web-based 24-h recall data collected between 2015 and 2017 in the cross-sectional PRÉDicteurs Individuels, Sociaux et Environnementaux (PREDISE) study. Diet costs were calculated using a Nielsen food price database. Usual dietary intakes and diet costs were estimated using the National Cancer Institute’s multivariate Markov Chain Monte Carlo method. Adherence to the EAT-Lancet diet was assessed using the EAT-Lancet dietary index (EAT-I). Associations between diet costs and EAT-I scores were evaluated using linear regression models with restricted cubic splines. After adjustment for energy intake, a higher EAT-I score (75th v. 25th percentiles) was associated with a 1·0 $CAD increase in daily diet costs (95 % CI, 0·7, 1·3). This increase in diet costs was mostly driven by the following component scores of the EAT-I (75th v. 25th percentiles, higher scores reflecting greater adherence): vegetables (1·6 $CAD/d, 95 % CI: 1·2, 2·1), free sugars (1·6 $CAD/d, 95 % CI: 1·3, 1·9), fish and plant-based proteins (1·4 $CAD/d, 95 % CI: 1·0, 1·8), fruits (0·9 $CAD/d, 95 % CI: 0·4, 1·3) and whole grains (0·4 $CAD/d, 95 % CI: 0·0, 0·8). Inversely, a greater score for the poultry and eggs component was associated with reduced diet costs (–1·2 $CAD/d, 95 % CI: −1·7, −0·7). This study suggests that adhering to the EAT-Lancet diet may be associated with an increase in diet costs in the province of Québec.