PNAS Science Sessions

Getting to the root of the rhizosphere Science Sessions are brief conversations with cutting-edge researchers, National Academy members, and policymakers as they discuss topics relevant to today's scientific community. Learn the behind-the-scenes story of work published in the Proceedings of the National Academy of Sciences (PNAS), plus a broad range of scientific news about discoveries that affect the world around us. In this episode, researchers describe methods for illuminating interactions between plants and microbes in the rhizosphere. In this episode, we cover: •[00:00] Introduction •[00:35] Molly Hanlon describes a relatively inexpensive technique for rapidly imaging plant anatomy along the root axis. •[01:47] Oumeng Zhang explains a microscopy technique for imaging 3D microbial interactions with improved speed and reduced phototoxicity compared to traditional methods. •[03:07] Reinaldo Alcalde describes the results of his and Oumeng's approach. •[04:08] Victoria Orphan used synthetic cryolite to create a transparent, soil-like scaffold, allowing belowground microbial processes to be visualized. •[05:31] Final thoughts and conclusion. About Our Guests: Molly Hanlon  Senior Research Scientist Donald Danforth Plant Science Center Oumeng Zhang Assistant Professor Texas A&M University Reinaldo Alcalde Senior Postdoctoral Scholar California Institute of Technology Victoria Orphan James Irvine Professor of Environmental Science and Geobiology California Institute of Technology View related content here: https://www.sciencedirect.com/science/article/pii/S2643651525001566 https://www.pnas.org/doi/10.1073/pnas.2403122121 https://academic.oup.com/pnasnexus/article/4/5/pgaf118/8114130 Follow us on Spotify, Apple Podcasts, or wherever you get your podcasts for more captivating discussions on scientific breakthroughs! Visit Science Sessions on PNAS.org: https://www.pnas.org/about/science-sessions-podcast  Follow PNAS: Twitter/X Facebook LinkedIn YouTube Sign up the PNAS Highlights newsletter

Economic costs of measles outbreaks Science Sessions are brief conversations with cutting-edge researchers, National Academy members, and policymakers as they discuss topics relevant to today's scientific community. Learn the behind-the-scenes story of work published in the Proceedings of the National Academy of Sciences (PNAS), plus a broad range of scientific news about discoveries that affect the world around us. In this episode, Alison Galvani explains the costs of waning measles vaccination rates. In this episode, we cover: •[00:00] Introduction. •[01:12] Epidemiologist Alison Galvani introduces the MMR vaccine and describes its efficacy. •[02:23] Galvani recounts the changes in MMR vaccination rates in recent years. •[03:56] She describes how the researchers modeled the economic impacts of measles outbreaks. •[05:49] Galvani talks about what the economic impacts look like in everyday life. •[06:39] She talks about the findings regarding the costs of measles outbreaks in 2025. •[07:06] Galvani enumerates the costs of a percentage decrease in vaccination rates. •[08:06] She lists the takeaways from the study, including the disproportionate societal effects of a small decrease in vaccination rates. •[08:58] She lists the caveats and limitations of the study. •[10:13] Conclusion. About Our Guest: Alison Galvani Director, Center of Infectious Disease Modeling and Analysis  Yale School of Public Health View related content here: https://www.pnas.org/doi/abs/10.1073/pnas.2605971123 Follow us on Spotify, Apple Podcasts, or wherever you get your podcasts for more captivating discussions on scientific breakthroughs! Visit Science Sessions on PNAS.org: https://www.pnas.org/about/science-sessions-podcast  Follow PNAS: Twitter/X Facebook LinkedIn YouTube Sign up for the PNAS Highlights newsletter

Evidence of early plate tectonics Science Sessions are brief conversations with cutting-edge researchers, National Academy members, and policymakers as they discuss topics relevant to today's scientific community. Learn the behind-the-scenes story of work published in the Proceedings of the National Academy of Sciences (PNAS), plus a broad range of scientific news about discoveries that affect the world around us. In this episode, Brad Peters explores what we can learn from the journey of sediments from the early Earth through the rock cycle. In this episode, we cover: •[00:00] Introduction. •[01:04] Geochemist Brad Peters tells us about the Marquesas Archipelago and why is it a place of interest for geologists. •[02:42] He recounts evidence suggesting that one component of the Marquesas lavas was recycled sediment from the early Earth. •[04:59] Peters walks us through the likely journey of this sediment from its origins to its eruption on the Marquesas Archipelago. •[06:24] He explains what this lava tells us about the tectonic processes that were active four billion years ago. •[07:43] Peters summarizes how this result is different than what we previously thought about the inception of plate tectonics. •[08:19] He talks about what the results mean for the story of the early Earth. •[09:13] He lists the caveats and limitations of the study. •[10:09] Conclusion. About Our Guest: Brad Peters Postdoctoral researcher ETH Zurich View related content here: https://www.pnas.org/doi/abs/10.1073/pnas.2500506123 Follow us on Spotify, Apple Podcasts, or wherever you get your podcasts for more captivating discussions on scientific breakthroughs! Visit Science Sessions on PNAS.org: https://www.pnas.org/about/science-sessions-podcast  Follow PNAS: Twitter/X Facebook LinkedIn YouTube Sign up for the PNAS Highlights newsletter

Domestication of wheat Science Sessions are brief conversations with cutting-edge researchers, National Academy members, and policymakers as they discuss topics relevant to today's scientific community. Learn the behind-the-scenes story of work published in the Proceedings of the National Academy of Sciences (PNAS), plus a broad range of scientific news about discoveries that affect the world around us. In this episode, David Lordkipanidze recounts archaeological findings from Georgia expanding the history of bread wheat. In this episode, we cover: •[00:00] Introduction. •[00:51] Archaeologist and paleobotanist David Lordkipanidze tells about the archaeological sites where wheat samples were found. •[02:53] He talks about methods for identifying plant grains among archeological artifacts. •[04:49] Lordkipanidze explains the significance of finding bread wheat and goat grass grains together. •[06:45] He talks about how the findings change the origin story of bread wheat. •[08:28] He lists the caveats and limitations of the study. •[09:24] Conclusion. About Our Guest: David Lordkipanidze Director Georgia National Museum View related content here: https://www.pnas.org/doi/10.1073/pnas.2537697123 Follow us on Spotify, Apple Podcasts, or wherever you get your podcasts for more captivating discussions on scientific breakthroughs! Visit Science Sessions on PNAS.org: https://www.pnas.org/about/science-sessions-podcast  Follow PNAS: Twitter/X Facebook LinkedIn YouTube Sign up for the PNAS Highlights newsletter

Using AI to predict the weather Science Sessions are brief conversations with cutting-edge researchers, National Academy members, and policymakers as they discuss topics relevant to today's scientific community. Learn the behind-the-scenes story of work published in the Proceedings of the National Academy of Sciences (PNAS), plus a broad range of scientific news about discoveries that affect the world around us. In this episode, researchers discuss advances in AI-enabled weather forecasting. In this episode, we cover: •[00:00] Introduction •[01:12] Jeffrey Shrader explains what 48 expert forecasters had to say about how weather predictions might further improve through 2100, including the potential role of AI. •[03:43] Ignacio Lopez-Gomez explains how he used generative AI to downscale large-scale earth system models into finer-scale regional climate projections. •[05:35] Xiaofeng Li explains how he used a machine learning model to forecast whether tropical cyclones will rapidly intensify. •[07:40] Hui Su explains what nowcasting is and how her deep diffusion model works. •[09:52] Pedram Hassanzadeh explains what grey swans are and why they may be challenging for AI to predict. •[10:47] Qiang Sun explains how he and his colleagues tested the ability of AI to predict gray swans. •[12:28] Final thoughts and conclusion. About Our Guests: Jeffrey Shrader Associate Professor of International and Public Affairs Columbia University Ignacio Lopez-Gomez Research Scientist Google Xiaofeng Li Research Scientist Institute of Oceanology, Chinese Academy of Sciences Hui Su Chair Professor Hong Kong University of Science and Technology Pedram Hassanzadeh Associate Professor University of Chicago Qiang Sun Research Scientist University of Chicago View related content here: https://www.pnas.org/doi/full/10.1073/pnas.2523372123 https://www.pnas.org/doi/full/10.1073/pnas.2420288122 https://www.pnas.org/doi/full/10.1073/pnas.2415501122 https://www.pnas.org/doi/full/10.1073/pnas.2517520122 https://www.pnas.org/doi/full/10.1073/pnas.2420914122 Follow us on Spotify, Apple Podcasts, or wherever you get your podcasts for more captivating discussions on scientific breakthroughs! Visit Science Sessions on PNAS.org: https://www.pnas.org/about/science-sessions-podcast  Follow PNAS: Twitter/X Facebook LinkedIn YouTube Sign up the PNAS Highlights newsletter