Impact of initial COVID-19 restrictions on psychiatry presentations to the emergency department of a large academic teaching hospital

Objectives: To determine if the initial COVID-19 societal restrictions, introduced in Ireland in March 2020, impacted on the number and nature of psychiatry presentations to the emergency department (ED) of a large academic teaching hospital.Methods: We examined anonymised clinical data of psychiatry presentations to the ED during the initial 8-week period of COVID-19 restrictions. Data from corresponding 8-week periods in 2018 and 2019 were also extracted for comparison.Results: Psychiatry presentations to ED reduced by 21% during the COVID-19 restrictions, from 24/week to 19/week when compared with corresponding periods in 2018/2019 (Poisson's Rate Test estimate of difference -5.2/week, 95% CI 1.3-9.1, p = 0.012). Numbers attending for out-of-hours assessment remained unchanged (81 v. 80), but numbers seeking assessment during normal hours decreased (71 v. 114). We observed increased presentations from the Conclusions: Rates of emergency presentation with mental illness reduced during the initial COVID-19 restrictions. This may represent an unmet burden of mental health needs. Younger people may be experiencing greater distress and mental illness during the current crisis. More people sought help for anxiety disorders during the COVID-19 restrictions compared with corresponding data from 2018 and 2019.</p

Agent-based model of angiogenesis simulates capillary sprout initiation in multicellular networks

Many biological processes are controlled by both deterministic and stochastic influences. However, efforts to model these systems often rely on either purely stochastic or purely rule-based methods. To better understand the balance between stochasticity and determinism in biological processes a computational approach that incorporates both influences may afford additional insight into underlying biological mechanisms that give rise to emergent system properties. We apply a combined approach to the simulation and study of angiogenesis, the growth of new blood vessels from existing networks. This complex multicellular process begins with selection of an initiating endothelial cell, or tip cell, which sprouts from the parent vessels in response to stimulation by exogenous cues. We have constructed an agent-based model of sprouting angiogenesis to evaluate endothelial cell sprout initiation frequency and location, and we have experimentally validated it using high-resolution time-lapse confocal microscopy. ABM simulations were then compared to a Monte Carlo model, revealing that purely stochastic simulations could not generate sprout locations as accurately as the rule-informed agent-based model. These findings support the use of rule-based approaches for modeling the complex mechanisms underlying sprouting angiogenesis over purely stochastic methods