Speaker: Matthew Johnston
Why does a virus take over a population while a cellular signal flickers out and dies? In epidemiology, the answer lies in R₀—the “basic reproduction number” that determines whether a disease sparks an epidemic or fizzles out. While R₀ is a staple of public health, its mathematical foundations have surprising applications in the microscopic world of biochemistry. This talk explores how the same tools used to track COVID-19 or the flu can be applied to the complex networks inside our own cells. By using the “next generation matrix method,” we can predict when biochemical systems—such as those governing signal transduction or gene regulation—will sustain a robust signal or gracefully shut down.