Selective sweeps in SARS-CoV-2 variant competition.

The main mathematical result in this paper is that change of variables in the ordinary differential equation (ODE) for the competition of two infections in a Susceptible-Infected-Removed (SIR) model shows that the fraction of cases due to the new variant satisfies the logistic differential equation, which models selective sweeps. Fitting the logistic to data from the Global Initiative on Sharing All Influenza Data (GISAID) shows that this correctly predicts the rapid turnover from one dominant variant to another. In addition, our fitting gives sensible estimates of the increase in infectivity.

Cardiovascular and sympathetic responses and reflex changes elicited by MDMA.

The recreational use of 3,4-methylenedioxymethamphetamine (MDMA) has increased as have the number of clinical reports linking MDMA use with cardiovascular toxicity. Nonetheless, the cardiovascular and sympathetic nerve responses elicited by MDMA have not been well characterized. The purpose of this study was to characterize the mean arterial pressure (MAP), heart rate (HR), and renal sympathetic nerve responses elicited by the acute administration of MDMA and to determine whether neurotoxic doses of MDMA change cardiovascular and/or cardiovascular reflex function.