On quasi-linear reaction diffusion systems arising from compartmental SEIR models.

The global existence and boundedness of solutions to quasi-linear reaction-diffusion systems are investigated. The system arises from compartmental models describing the spread of infectious diseases proposed in Viguerie et al. (Appl Math Lett 111:106617, 2021); Viguerie et al. (Comput Mech 66(5):1131-1152, 2020), where the diffusion rate is assumed to depend on the total population, leading to quasilinear diffusion with possible degeneracy. The mathematical analysis of this model has been addressed recently in Auricchio et al. (Math Methods Appl Sci 46:12529-12548, 2023) where it was essentially assumed that all sub-populations diffuse at the same rate, which yields a positive lower bound of the total population, thus removing the degeneracy. In this work, we remove this assumption completely and show the global existence and boundedness of solutions by exploiting a recently developed L p -energy method. Our approach is applicable to a larger class of systems and is sufficiently robust to allow model variants and different boundary conditions.

Fifteen-minute consultation: Recognition of sickle cell crises in the paediatric emergency department.

Children with sickle cell disease can develop life-threatening and painful crises that require prompt assessment and efficient management by healthcare professionals in the emergency or acute care setting. Due to migration patterns and improved survival rates in high-prevalence countries, there is an increased tendency to encounter these patients across the UK. These factors warrant regular revisions in sickle cell crisis management, along with education for medical personnel and patients to improve clinical care and patient management. The focus of this article is on the initial assessment and management of acute paediatric sickle cell complications in the emergency setting. Specific case studies, including acute pain crises, trauma, splenic sequestration, aplastic crises, acute chest syndrome, infection, avascular necrosis, osteomyelitis and stroke, are discussed. Due to the current COVID-19 pandemic, we have also reviewed specific concerns around this patient group.

Fifteen-minute consultation: Drowning in children.

Drowning is a significant cause of childhood morbidity and mortality globally. The underlying mechanisms vary with child development and most are modifiable to public health promotion strategies. This article serves to highlight some of the specific considerations for the clinical management of drowning in children, both prehospital and by the in-hospital paediatric resuscitation team. This includes changes to standard advanced paediatric life support in the presence of hypothermia.

Fifteen-minute consultation: How to be the paediatrician at a trauma call.

The management of paediatric trauma patients can be complex, involving a coordinated multidisciplinary approach. Paediatricians form an integral part of the trauma team and are often tasked with managing circulation. In this article, we will discuss the assessment of catastrophic haemorrhage and 'circulation' through the viewpoint of a paediatrician via a case discussion. This will include initial investigations and management, noting the time critical nature in identifying and stopping catastrophic haemorrhage. The discussion will comment on how to address hypovolaemic shock and touch on the role of imaging.

How Medical Tourism Enables Preferential Access to Care: Four Patterns from the Canadian Context.

Medical tourism is the practice of traveling across international borders with the intention of accessing medical care, paid for out-of-pocket. This practice has implications for preferential access to medical care for Canadians both through inbound and outbound medical tourism. In this paper, we identify four patterns of medical tourism with implications for preferential access to care by Canadians: (1) Inbound medical tourism to Canada's public hospitals; (2) Inbound medical tourism to a First Nations reserve; (3) Canadian patients opting to go abroad for medical tourism; and (4) Canadian patients traveling abroad with a Canadian surgeon. These patterns of medical tourism affect preferential access to health care by Canadians by circumventing domestic regulation of care, creating jurisdictional tensions over the provision of health care, and undermining solidarity with the Canadian health system.

Simple finite element methods for approximating predator-prey dynamics in two dimensions using MATLAB.

We describe simple finite element schemes for approximating spatially extended predator-prey dynamics with the Holling type II functional response and logistic growth of the prey. The finite element schemes generalize 'Scheme 1' in the paper by Garvie (Bull Math Biol 69(3):931-956, 2007). We present user-friendly, open-source MATLAB code for implementing the finite element methods on arbitrary-shaped two-dimensional domains with Dirichlet, Neumann, Robin, mixed Robin-Neumann, mixed Dirichlet-Neumann, and Periodic boundary conditions. Users can download, edit, and run the codes from http://www.uoguelph.ca/~mgarvie/ . In addition to discussing the well posedness of the model equations, the results of numerical experiments are presented and demonstrate the crucial role that habitat shape, initial data, and the boundary conditions play in determining the spatiotemporal dynamics of predator-prey interactions. As most previous works on this problem have focussed on square domains with standard boundary conditions, our paper makes a significant contribution to the area.

Smartphone use for Paediatric Calculations in Emergencies (SPaCE).

BACKGROUND: The preparation for critically ill children involves calculating drug and fluid volumes using the commonly taught WETFLAG (weight, energy, endotracheal tube, fluids, lorazepam, adrenaline, glucose) acronym. While smartphone applications (apps) are increasingly used for these calculations in clinical practice, limited studies have explored their accuracy and safety. AIM: To assess the accuracy of three calculation methods for paediatric emergency drug doses and fluid volumes: a smartphone app, reference charts and traditional calculation methods. The secondary aims were to investigate the effect on the time taken and self-reported stress levels. METHODS: A convenience sample of healthcare professionals from four hospitals contributed. Participants calculated drug and fluid doses for fictional patients using the three different methods. The method and case order were randomised centrally. The study recorded the number of errors made during the calculations, healthcare professionals' self-reported stress levels on a scale of 0 (no stress) to 10 (maximum stress) and the time taken for each case. The app was developed at the direct request of the study team. RESULTS: Ninety-six participants calculated values for six fictional cases, resulting in 576 calculations. Traditional calculation methods showed a statistically significant higher rate of error compared with the use of a smartphone app or reference charts (mean=1, 0, 0, respectively). The smartphone app outperformed both traditional calculation methods and reference charts for time taken and user-reported stress levels. CONCLUSIONS: Traditional methods of 'WETFLAG' drug and fluid calculations are associated with a statistically significant increased risk of error compared with the use of reference charts or smartphone app. The smartphone app proved significantly faster and less stressful to use compared with traditional calculation methods or reference charts.

Development of a rapid enzyme immunoassay for the detection of retinol-binding protein.

BACKGROUND: Retinol-binding protein (RBP) was chosen as a surrogate marker for retinol because of the close correspondence between retinol and RBP. OBJECTIVE: To meet the need for rapid, cost-effective determination of vitamin A status in populations, a quantitative enzyme immunoassay (EIA) for detection of RBP was developed. DESIGN: The resulting RBP EIA, a competitive assay, uses RBP adsorbed to microtest strip wells to compete with RBP in serum. The assay takes approximately 40 min. RESULTS: With a reference panel of sera, test accuracy was found to be within 4% of expected values through the calibrated range of 0.48-1.92 micro mol RBP/L (10-40 micro g RBP/mL). Intraassay and interassay variability averaged 6.7% and 8.9%, respectively. Specificity testing showed no interference from other serum proteins, prealbumin, rheumatoid factor, bilirubin, estrogen, or C-reactive protein. The RBP EIA provided linear results between 0.43 and 1.80 micro mol RBP/L (9 and 38 micro g RBP/mL). Preliminary laboratory evaluations indicated that the RBP EIA correlates well with radial immunodiffusion for RBP and with HPLC for retinol, the current reference standard. A field evaluation in a population at risk for vitamin A deficiency (VAD) resulted in close correlation between RBP EIA measures and retinol measures by HPLC (R(2) = 0.82). CONCLUSIONS: The RBP EIA is as reliable in estimating VAD as is HPLC retinol. After successful validations, the test should enable public health authorities to rapidly monitor VAD and track vitamin A status in populations.