The Conversation Weekly

Carolyn Holmes, an assistant professor of political science at the University of Tennessee, discusses the intriguing connections between white nationalist movements in South Africa and the United States. She reveals how Donald Trump's focus on South Africa's white Afrikaners influences US refugee policy, exploring historical roots dating back to a 1930s sociological study. Carolyn also examines the cyclical nature of racial narratives, the role of media in shaping perceptions of violence, and critiques the political implications of prioritizing Afrikaners in refugee applications.

Ian Barr, a leading virologist and Deputy Director at the WHO Collaborating Centre for Reference and Research on Influenza, reveals the intricate process behind flu vaccine strain selection. He shares insights on how 40 scientists meet biannually to decide which strains to target, the role of hemispheric interactions in flu patterns, and how emerging variants complicate decisions. Barr also discusses the future of vaccines, including advancements in mRNA technology, and addresses the rise of vaccine hesitancy post-COVID.

In this insightful discussion, Laura Wilcox, a meteorologist from the University of Reading, reveals how China transformed its air quality from smog-filled to clean skies, particularly ahead of the 2008 Olympics. She explains the immediate policy actions taken, like vehicle regulation and coal reduction, leading to a significant drop in pollution levels. However, Laura also highlights a surprising twist: cleaner air means reduced cooling aerosols, potentially accelerating global warming. The talk explores the health benefits of cleaner air while addressing the broader climate implications.

Nadir Jeevanjee, a physical scientist at NOAA's Geophysical Fluid Dynamics Laboratory, shares insights on the history of climate models. He highlights Syukuro Manabe's groundbreaking work and his 1967 predictions about CO2-induced warming. Jeevanjee explains how early models accurately forecasted phenomena like polar amplification and stratospheric cooling. He also discusses the alarming threats to climate data collection due to recent funding cuts, emphasizing the importance of these foundational models in today's climate science and discussions.

Robert Muggah, founder of the Igarapé Institute and a researcher at Princeton's Brazil LAB, dives into the deep-rooted issue of organized crime in Brazil. He explains how groups like the Commando Vermelho have expanded from prisons into various sectors like mining and fintech. Muggah discusses the recent violent police raid in Rio, its political implications, and the public's mixed reactions. He also suggests that heavy-handed tactics often exacerbate the problem and emphasizes the need for community-focused policing and financial strategies to combat crime effectively.

Penelope Geng, an associate professor of English at Macalester College, dives into 16th-century fears surrounding witches and demons. She recounts James VI's terrifying royal journey and his witchcraft fears, prompting him to write ‘Daemonologie.’ Explore the clash between Protestantism and ghostly beliefs, and how this shaped societal views on supernatural entities. Geng also discusses the lingering impact of these beliefs in modern culture, contrasting the fear of demons with the nostalgia for ghosts.

Larisa Yarovaya, Director of the Centre for Digital Finance at the University of Southampton, dives into the world of corporate cryptocurrency. She discusses how MicroStrategy's bold Bitcoin purchases sparked a trend among public companies, holding over $114 billion in Bitcoin. Yarovaya highlights the risks of volatility and liquidity that come with this strategy, warns of potentially overcrowded treasury markets, and emphasizes the need for cautious engagement with crypto. She also sheds light on why institutions are turning to stablecoins for stability.

As one of the birthplaces of the industrial revolution, the River Mersey in northern England is no stranger to pollution flowing into its waters. Now it's got a new problem: monitoring shows the amount of forever chemicals, also known as PFAS, entering the Mersey catchment area is among some of the highest in the world.In this episode we speak to water scientist Patrick Byrne at Liverpool John Moores University in the UK about why so many per- and polyfluoroalkyl substances (PFAS), are still making it into our rivers, many from sources that are lying hidden. Identifying these sources of pollution, can help prioritise how to clean them up. This episode was produced by Mend Mariwany, Katie Flood and Gemma Ware. Sound design and mixing by Michelle Macklem and theme music by Neeta Sarl. Read the full credits for this episode and sign up here for a free daily newsletter from The Conversation.If you like the show, please consider donating to The Conversation, an independent, not-for-profit news organisation.You can be exposed to PFAS through food, water, even swimming in lakes – new maps show how risk from ‘forever chemicals’ variesAustralia has banned 3 ‘forever chemicals’ – but Europe wants to ban all 14,000 as a precautionHow I tracked the biggest hidden sources of forever chemical pollution in UK rivers – new study

Back in the 1980s, when Shimon Sakaguchi was a young researcher in immunology, he found it difficult to get his research funded. Now, his pioneering work which explains how our immune system knows when and what to attack, has won him a Nobel prize.Sakaguchi, along with American researchers Mary Brunkow and Fred Ramsdell, were jointly awarded the 2025 Nobel prize in physiology or medicine for the work on regulatory T-cells, known as T-regs for short, a special class of immune cells which prevent our immune system from attacking our own body.In this episode Sakaguchi tells The Conversation about his journey of discovery and the potential treatments it could unlock.This episode was produced by Mend Mariwany, Katie Flood and Gemma Ware. Sound design and mixing by Michelle Macklem and theme music by Neeta Sarl. Read the full credits for this episode and sign up here for a free daily newsletter from The Conversation.If you like the show, please consider donating to The Conversation, an independent, not-for-profit news organisation.Metal-organic frameworks: Nobel-winning tiny ‘sponge crystals’ with an astonishing amount of inner spaceNobel physics prize awarded for pioneering experiments that paved the way for quantum computersHow does your immune system stay balanced? A Nobel Prize-winning answerNobel medicine prize: how a hidden army in your body keeps you alive – and could help treat cancer

As Donald Trump gives oxygen to unproven theories about what might be behind a recent rise in autism cases, experts repeatedly point to the changing nature of how autism is diagnosed and viewed.A key moment in the history of autism diagnosis was the publication in 1994 of a new version of the Diagnostic and Statistical Manual of Mental Disorders. It's a reference book of psychiatric conditions and how to diagnose them, used by psychiatrists and psychologists around the world. In this episode, Andrew Whitehouse, a professor of autism research at the University of Western Australia, explains why this shift in autism diagnosis happened in the 1990s, what impact it had, and what it's meant for the support autistic people get. This episode was produced by Katie Flood, Mend Mariwany and Gemma Ware. Sound design and mixing by Michelle Macklem and theme music by Neeta Sarl. Read the full credits for this episode and sign up here for a free daily newsletter from The Conversation.If you like the show, please consider donating to The Conversation, an independent, not-for-profit news organisation.