PNAS Science Sessions

Tracking whales with acoustic sensing

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, Martin Landrø describes how to track whale movements with undersea fiber optic cables.

In this episode, we cover: •[00:00] Introduction. •[01:01] Underwater acoustician Martin Landrø explains why it's important to track whale movement, and why it's difficult. •[01:45] Landrø explains the methods used to detect whales previously. •[03:01] He introduces distributed acoustic sensing. •[04:14] Landrø tells the story of how they used distributed acoustic sensing to detect whale movement. •[06:11] He talks about the results and what the method was able to detect. •[07:30] He explores possibilities for using this method in the future. •[08:38] He lists the caveats and limitations of the study. •[09:25] Conclusion.

About Our Guest:

Martin Landrø Professor Norwegian University of Science and Technology

View related content here: https://www.pnas.org/doi/full/10.1073/pnas.2603077123

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Schools' proximities to hazardous materials sites

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, Matthew Kraft maps the proximities of schools to hazardous materials sites.

In this episode, we cover: •[00:00] Introduction. •[00:59] Education and economics researcher Matthew Kraft recounts the background of the study. •[02:11] He introduces the hazardous waste sites included in the study. •[03:50] Kraft talks about what surprised him about mapping results. •[05:08] He lists the risks these sites might pose to the millions of children and thousands of employees at these schools. •[06:09] Kraft lists the groups of students disproportionately potentially exposed to hazardous waste sites. •[07:00] He talks about the takeaways for policymakers. •[08:03] He lists the caveats and limitations of the study. •[10:21] Conclusion.

About Our Guest:

Matthew Kraft Professor Brown University

View related content here: https://www.pnas.org/doi/abs/10.1073/pnas.2605971123

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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

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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

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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

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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

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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!

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Cryopreservation of brain tissue structures

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, Alexander German explains how to cryopreserve brain tissue through vitrification.

In this episode, we cover: •[00:00] Introduction. •[01:14] Physician-scientist Alexander German introduces the problems with traditional cryopreservation methods. •[02:22] German explains why we cryopreserve tissue. •[03:23] He tells about vitrification and why it's different than traditional cryopreservation. •[04:13] German explains why osmotic stress is a concern in cryopreservation. •[04:51] He talks about how the protocol minimizes damage to brain structures and tissues. •[06:26] He recounts the tests they performed to evaluate the preservation and function of the vitrified tissues. •[07:03] German describes the usefulness of vitrification. •[08:48] He lists the caveats and limitations of the study. •[10:03] Conclusion.

About Our Guest:

Alexander German Resident Universität Erlangen-Nürnberg

View related content here: https://www.pnas.org/doi/full/10.1073/pnas.2516848123

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The lost forests of Doggerland

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, Robin Allaby explores the paleoecology of the submerged area known as Doggerland.

In this episode, we cover: •[00:00] Introduction. •[01:10] Evolutionary biologist Robin Allaby introduces the location of Doggerland and history of its exploration. •[02:58] He introduces sedimentary DNA, including how it can be used to reconstruct paleoecology. •[03:43] Allaby describes the methods of the study. •[05:18] He introduces the primary findings about the plant and animal life of Doggerland. •[06:14] He describes the surprising find of Pterocarya in Doggerland. •[08:07] Allaby discusses the habitability of Doggerland for Mesolithic societies. •[09:38] He lists the caveats and limitations of the study. •[10:13] Conclusion.

About Our Guest:

Robin Allaby Professor University of Warwick

View related content here: https://www.pnas.org/doi/full/10.1073/pnas.2508402123

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Generative AI and scientific journals

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, Yi Bu explores how generative AI has changed academic publishing.

In this episode, we cover: •[00:00] Introduction. •[00:50] Computational social scientist Yi Bu tells about the policies academic journals have introduced to address generative AI. •[02:17] Bu describes the dataset he analyzed and his findings regarding journals' policies. •[04:07] He answers the question: Did journal policies have any effect on AI usage? •[05:39] Bu talks about how the rate of AI disclosure compares with estimates of probable AI use. •[06:53] He explains the takeaway for journal editors and the scientific community at large. •[07:27] He lists the caveats and limitations of the study. •[10:11] Conclusion.

About Our Guest:

Yi Bu Assistant Professor Peking University

View related content here: https://www.pnas.org/doi/abs/10.1073/pnas.2526734123

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Visit Science Sessions on PNAS.org: https://www.pnas.org/about/science-sessions-podcast

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