Atypical and novel presentations of Coronavirus Disease 2019: a case series of three children.

Typical presentations of Coronavirus Disease 2019 (Covid-19) including respiratory symptoms (cough, respiratory distress and hypoxia), fever and dyspnoea are considered main symptoms in adults, but atypical presentation in children could be a diagnostic challenge. We report three children whose initial presentation was gastrointestinal, and in whom Covid-19 infection was found, concluding that cases of acute appendicitis, mesenteric adenitis and flank tenderness may mask an infection with this virus, and should therefore be investigated.

A computational psychiatry approach identifies how alpha-2A noradrenergic agonist Guanfacine affects feature-based reinforcement learning in the macaque.

Noradrenaline is believed to support cognitive flexibility through the alpha 2A noradrenergic receptor (a2A-NAR) acting in prefrontal cortex. Enhanced flexibility has been inferred from improved working memory with the a2A-NA agonist Guanfacine. But it has been unclear whether Guanfacine improves specific attention and learning mechanisms beyond working memory, and whether the drug effects can be formalized computationally to allow single subject predictions. We tested and confirmed these suggestions in a case study with a healthy nonhuman primate performing a feature-based reversal learning task evaluating performance using Bayesian and Reinforcement learning models. In an initial dose-testing phase we found a Guanfacine dose that increased performance accuracy, decreased distractibility and improved learning. In a second experimental phase using only that dose we examined the faster feature-based reversal learning with Guanfacine with single-subject computational modeling. Parameter estimation suggested that improved learning is not accounted for by varying a single reinforcement learning mechanism, but by changing the set of parameter values to higher learning rates and stronger suppression of non-chosen over chosen feature information. These findings provide an important starting point for developing nonhuman primate models to discern the synaptic mechanisms of attention and learning functions within the context of a computational neuropsychiatry framework.

Association between mandatory seatbelt laws and road traffic injuries in Iran.

This study investigated the efficacy of mandatory seatbelt legislation on traffic injuries and intensity of road traffic injuries (RTIs). We carried out a before- after interventional study. Data regarding road traffic accidents and injuries one year before and one and two years after the implementation of mandatory seatbelt legislation were obtained from the traffic police database. Traffic accident mortality was 13.0% of all RTIs during the year prior to implementation. This decreased to 9.7% and 11.4% during the first and second years after implementation, respectively (p < 0.001). The mortality rate was not consistent for seatbelt use since there was a slight increase in the mortality rate in second year after implementation of mandatory seatbelt use although this level was lower than the pre- implementation rate. Our findings suggest mandatory seatbelt use reduces the intensity of RTIs and reduces the crude number of RTIs.