Pnas Science Sessions

A giant virus associated with oyster aquaculture mortality 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, Curtis Suttle and Kevin Xu Zhong explain how a previously unidentified virus may be connected to mass die-offs of farmed Pacific oysters. In this episode, we cover: • [00:00] Introduction • [01:03] Environmental virologist Curtis Suttle introduces the importance of the Pacific oyster to aquaculture. • [01:42] Suttle describes mass mortality events, including one he witnessed. • [02:42] Environmental microbiologist Kevin Xu Zhong talks about the methods used to identify the Pacific Oyster Nidovirus 1. • [03:53] Zhong describes the notable features of the nido

Swamp lights and bat sight 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 explore two spooky mysteries: the source of will-o'-the-wisps and how bats integrate vision with echolocation. In this episode, we cover: •[00:00] Introduction •[00:58] Richard Zare's background and expertise. •[01:26] Richard, have you ever seen will-o'-the-wisps in the wild? •[01:31] What did we already know about will-o'-the-wisps before your study? •[02:42] How could water droplets ignite methane? •[03:24] Tell us about the methods of your study. How did you explore this phenomenon? •[04:17] What are the broader implications of your findings, beyond just will-o'-the-wisps?

Implications of a mutation in modern humans 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, Xiangchun Ju and Svante Pääbo explore the evolutionary implications of a mutation that separates modern humans from ancestral hominins. In this episode, we cover: •[00:00]  •[01:22] Neurobiologist Xiangchun Ju introduces the enzyme adenylosuccinate lyase, or ADSL, and its role in the synthesis of purine. •[02:09] Evolutionary anthropologist Svante Pääbo talks about the discovery of the A429V mutation, which is present in modern humans but not Neanderthals or Denisovans. •[03:38] Ju and Pääbo talk about the methods to humanize mice in order to study the evolutionary importa

Where primates evolved 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, Jorge Avaria-Llautureo and Chris Venditti explain why the evolution of primates likely occurred in cold, dry climates rather than in tropical forests. In this episode, we cover: •[00:00] Introduction •[00:58] Evolutionary biologist Jorge Avaria-Lautureo explains the prevailing hypothesis that primates evolved in a tropical climate •[02:54] Evolutionary biologist Chris Venditti introduces evidence suggesting a different origin climate. •[03:54] Avaria discusses how the researchers reconstructed the climate of early primate species. •[05:05] Venditti and Avaria explain why it was important to us

Climate change and lake oxygenation 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, Joachim Jansen explains how climate change altered cycles of oxygenation in lakes. In this episode, we cover: •[00:00] Introduction. •[00:56] Limnologist Joachim Jansen introduces us to the cycles of oxygenation in lakes throughout the seasons. •[02:35] He describes previous hypothesis about climate change and lake oxygenation and introduces the methods and datasets of the study.  •[04:59] Jansen introduces the results of the study, including key differences between large and small lakes. •[06:54] He talks about the consequences of deoxygenation.  •[09:03] Jansen explains the cave

The physics of the squash nick shot 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, Roberto Zenit explains the physics behind the unanswerable nick shot in the game of squash. In this episode, we cover: •[00:00] Introduction. •[00:56] Engineer Roberto Zenit introduces the game of squash, including his participation in the sport, and introduces the nick shot. •[02:11] He talks about the background and methods of the study.  •[04:50] Zenit describes the mechanics of a nick shot. •[06:01] He talks about the implications of the study for squash players and for other applications. •[08:52] Zenit recounts the caveats and limitations of the study. •[09:41] Conclusion. A

A pterosaur and its ecosystem at the end of the Triassic 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, Kay Behrensmeyer and Ben Kligman describe what a fossil bone bed in Arizona reveals about a 209-million-year-old pterosaur and its ecosystem. In this episode, we cover: •[00:00] Introduction •[01:01] Paleoecologist Kay Behrensmeyer and paleontologist Ben Kligman describe the discovery of this fossil bone bed. •[03:10] Kligman and Behrensmeyer introduce a previously undescribed pterosaur. •[05:00] They talk about what this specimen says about the ecology and evolution of pterosaurs. •[06:15] Kligman and Behrensmeyer talk about the importance of studying this fo

The postglacial history of the Saimaa ringed seal 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, Jaakko Pohjoismäki, Jukka Jernvall, and Ari Löytynoja discuss the evolutionary history of the Saimaa ringed seal. In this episode, we cover: •[00:00] Introduction •[01:06] Molecular biologist Jaakko Pohjoismäki introduces Lake Saimaa and the Saimaa ringed seal. •[02:30] Zoologist Jukka Jernvall talks about the characteristics of species isolated by glaciation. •[03:27] Evolutionary biologist and bioinformatician Ari Löytynoja explains the genetic and demographic methods of the study. •[04:11] Löytynoja and Jernvall explain why the results were surprising and where th

Managing eastern black rhinoceros populations with genetic studies 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, Barbara Mable and Ronald Mellya show how allowing endangered rhinos to move between populations enhances genetic diversity. In this episode, we cover: •[00:00] Introduction •[01:00] Evolutionary geneticist Barbara Mable explains why is genetic diversity important in managing small, isolated populations of rhinos. •[02:59] Park warden Ronald Mellya describes how his firsthand experience with rhino management led to this study. •[04:52] Mable explains the methods of the study and the contributions of co-author Anubhab Khan. •[06:20] Mable talks about

A reference genome aids efforts to rescue the northern white rhinoceros 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, Franz-Josef Müller explains genomic tools to aid the functionally extinct northern white rhinoceros. In this episode, we cover: •[00:00] Introduction •[01:11] Multidisciplinary scientist Franz-Josef Müller introduces the northern white rhinoceros. •[01:55] He introduces induced pluripotent stem cells and why they’re important in efforts to save the northern white rhinoceros. •[04:20] He talks about the genomic risks of using induced pluripotent stem cells •[05:21] Müller tells the story of how he and his colleagues came together to complete the

Water and the possibility of life on Mars 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 explain what we know about the potential for water and life on Mars and what we might learn from analysis of returned samples. In this episode, we cover: •[00:00] Introduction •[01:04] Mark Thiemens explains the importance of bringing samples from Mars back to Earth. •[02:37] Arya Udry explains the current gaps and limitations in the geological record provided by Martian meteorites. •[03:55] Bruce Jakosky explains what we currently know about the presence and history of water on Mars. •[05:26] Monica Grady explains how analyzing volatile species in Martian sample

Using reinforcement learning to plan for an uncertain climate future 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, Ning Lin talks about how reinforcement learning methods plant to mitigate climate risk despite uncertainty in climate change risk forecasts. In this episode, we cover: •[00:00] Introduction •[1:04] Civil engineer Ning Lin introduces why climate forecast uncertainty complicates risk management planning. •[02:41] Lin explains how reinforcement learning works. •[03:26] She talks about why the team studied risk management for Manhattan. •[04:54] Lin explains the results of the reinforcement learning study. •[05:40] She recounts the results that surpris

Insights in route planning from London taxi drivers 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, Hugo Spiers, Pablo Fernández Velasco, and Eva-Marie Griesbauer share what they learned about human route planning from talking with London taxi drivers. In this episode, we cover: •[00:00] Introduction •[00:59] Cognitive neuroscientist Hugo Spiers reviews previous studies on human route planning. •[01:29] Cognitive scientist and philosopher Pablo Fernández Velasco talks about why they chose to study London taxi drivers. •[01:49] Spiers describes the test that qualifies London taxi drivers. •[02:39] Spiers explains the experimental procedure. •[04:01] A recording of

Individual decision-making and collective animal behavior 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 explore advances in the modeling of collective animal behaviors. In this episode, we cover: •[00:00] Introduction •[00:48] Conor Heins incorporated cognitive processes into a model of collective behavior. •[02:13] Eva Kanso analyzed how confinement influences collective behavior. •[03:41] Andreu Puy considered the role of speed in the leader-follower dynamics of schooling fish. •[04:45] Daniel Kronauer explored how a colony of clonal raider ants collectively responds to rising temperatures. •[06:02] Sonja Friman quantified the energy savings of st

Modeling extreme heat waves 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, Kai Kornhuber explains how and why climate models struggle to reproduce extreme heat wave trends. In this episode, we cover: •[00:00] Introduction •[00:53] Extreme weather climatologist Kai Kornhuber explains why modeling heat waves is important. •[01:38] He talks about how the study modeled hotspots of anomalous heat wave activity. •[03:01] Kornhuber tells where the hotspots are located. •[04:17] He explains how well climate models reproduce these trends. •[06:43] He talks about ways climate modelers can improve model representation of heat waves. •[07:48] Kornhuber describes the caveats

Reconsidering the social cost of carbon 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, Frances Moore presents a re-analysis of how the social costs of carbon emissions are quantified. In this episode, we cover: •[00:00] Introduction •[00:50] Climate economist Frances Moore explains the “social cost of carbon.” •[02:21] She describes the background of the study.  •[03:35] She talks about the methods of the study, which included a survey of experts. •[05:18] Moore presents the results, including underestimation of the social cost of carbon. •[07:02] She talks about the policy implications of the study. •[08:35] Moore discusses the caveats and limitations of the st

How hula hoops stay aloft 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, Olivia Pomerenk reveals the physics of hula hooping. In this episode, we cover: •[00:00] Introduction •[00:49] Applied mathematician Olivia Pomerenk talks about the history of hula hooping. •[01:52] Pomerenk explains the fascinating nature of hula hoop motion as well as her own personal experiences with the children’s toy. •[02:44] She describes the experimental setup with robotic hula hoopers, as well as the mathematical model that arose from experiments. •[04:44] Pomerenk enumerates the forces needed for successful hula hooping.  •[05:51] She explains how body shape affects hula hooping.

Erosion, subsidence, and sea level rise on Arctic coastlines 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, Roger Creel describes how compounding forces could reshape a thawing Arctic coastline. In this episode, we cover: •[00:00] Introduction •[00:57] Sea level geophysicist Roger Creel introduces the importance of subsidence in Arctic coastline erosion.  •[02:04] Creel describes his firsthand experiences seeing how erosion, subsidence, and sea level rise are impacting Alaskan communities. •[03:43] He explains how his model of coastline impacts was constructed. •[05:49] He describes the results of the study. •[06:43] Creel talks about the risks to coastal infras

How brains and AI systems process moving images 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, Hollis Cline describes how neuroscience informed development of an artificial intelligence movie recognition system. In this episode, we cover: •[00:00] Introduction •[00:55] Neuroscientist Hollis Cline introduces the background of the study. •[01:49] Cline talks about the current limitations of artificial intelligence movie recognition. •[02:58] She explains why Xenopus tadpoles were used as subjects in this study. •[03:29] Cline talks about the experimental setup and procedure. •[05:53] She explains the results of tadpole neurological monitoring. •[06:32] Cline adds

Sustainability of plant-based meat alternatives 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 the environmental, health, and economic tradeoffs that limit the potential benefits of plant-based meat alternatives. In this episode, we cover: •[00:00] Introduction •[01:19] Rodolphe Barrangou explains the potential opportunities and challenges for plant-based meat alternatives to help mitigate the environmental impact of meat. •[03:18] Marco Springmann compares plant-based meat and milk alternatives with both animal-sourced foods and unprocessed plant-based foods across multiple metrics. •[05:16] Bill Aimutis highlights the potential environmenta