O Canada, land of opportunity, champion of human rights, cradle of diversity….This is how our national story so often goes. Today in The Conversation Canada, filmmaker and assistant professor at OCAD University, Min Sook Lee, profiles the migrant farm workers who are bravely poking holes in that myth. Sharing their stories in the documentary film, Migrant Voices, she explains how they reveal “unfree” lives as “mail-order servants” in a “supremacist” nation. Al Jazeera’s Witness will screen the film for free throughout May.

We all know that heading out for a run is healthier than an evening in front of the TV. But do you know your opioids from your endocannabinoids? In the run-up to Canada’s Mental Health Week, our regular contributor Scott Lear of Simon Fraser University takes a deep dive into the science of exercise. Just two and a half hours of physical activity per week can reduce your risk of depression by one fifth, says Lear. It can also boost your memory, self-esteem and brain function. He will tell you how.

Leadership and painting may not seem like the most obvious of bedfellows, and yet Moura Quayle of the University of British Columbia weaves them together strategically. Leaders with a design mindset 'paint' the way forward, she writes, "with colourful, wide brushes…."

Finally, another regular contributor, Michael J. Armstrong, takes us back to May 1942, when the Second World War was expanding across the Pacific. He uses mathematical models to assess whether the Battle of the Coral Sea, the first navy carrier-versus-carrier battle in history, could have had a different outcome, perhaps even shortening the Pacific war.