Research

Modelling and data analysis are necessary to support decisions and advocacy efforts. Models are the formalisms that translate data into quantities that answer questions. I develop models to fit to data, to estimate key parameters, and to resolve unknown, implicit, critical assumptions. I develop theory that demonstrates the power of mechanistic mathematical models in data analysis. I am also developing resources to help experts in adjacent disciplines learn about the power of modelling.

Population dynamics

My research is in population biology, mathematical modelling, evolutionary epidemiology, species range shifts, infectious diseases and public health.

My group’s past work has added in physiology and temperature dependence to describe seasonal population dynamics and species ranges shifts in response to climate warming. We have integrated dispersal, movement, and genetic diversity into models to describe spatial dynamics and trait evolution. Our work has been applied to salmon parasites, tiny clams, rabies, drug resistance in hospitals, SARS-CoV-2, bumblebees, wolves, moths, and butterflies.

Our work during the pandemic

Population biology is a field that has contributed substantially to our knowledge of how infectious diseases spread. Our modelling work during the COVID-19 pandemic began with a technical report that was included in witness testimony when travel measures implemented under the public health emergency were challenged in provincial court. This work was subsequently peer-reviewed, published, and cited in a World Health Organization report for the Western Pacific Region. We would make many more contributions to the pandemic response including a thorough retrospective analysis of the travel measures implemented in Newfoundland and Labrador during the pandemic (Mohammadi et al. 2025).

Our peer-reviewed and published contributions include:

Understanding the pandemic in Newfoundland and Labrador

To support pandemic decision-making in Newfoundland and Labrador (and more generally to advance the scientific evidence base to support jurisdictions that implement within-country travel measures and/or an elimination strategy)

During the COVID-19 pandemic I was quoted in the British Medical Journal, the New York Times, the Globe and Mail, and local media such as NTV, the Canadian Broadcasting Corporation, and The Telegram. I appeared in a Fields Institute Panel. I was lead organizer for the AARMS-EIDM Summer School in Modelling Infectious Diseases.

I am a member of the Canadian small jurisdictions working group, a group that advances modelling frameworks to support public health in small jurisdictions.

Publications

For my publications, see Google Scholar.

When financially possible, our publications are open access. If you can’t access a publication, please email me. Below are links to publications that may be more difficult to access. You might also search MedRxiv and BioRxiv for author-typeset copies of the publications.