Animal’s eye view of the ocean 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 use animal-borne video cameras to explore foraging behaviors of animals in the open ocean. In this episode, we cover: •[00:00] Introduction •[00:46] Taiki Adachi, an ecologist at the National Institute of Polar Research in Japan, observed how elephant seals use their whiskers to locate prey in the dark depths of the ocean •[02:13] Carey Kuhn, an ecologist at the Alaska Fisheries Science Center in Seattle, Washington, explored how the size of prey affected the foraging behavior of northern fur seals. •[03:43] Ryan Logan, an ecologist at California State University Long Beach, recorded a solitary sailfish hunting in the open ocean and estimated its energy expenditures. •[05:05] Simone Videsen, an ecologist at Aarhus University in Denmark, performed a similar analysis of the energetic efficiency of humpback whales. •[06:12] Takuya Maekawa, an engineer at Osaka University in Japan, designed a device to detect and automatically record rare behaviors performed by streaked shearwaters. •[07:56] Final thoughts and conclusion. About Our Guests: Taiki Adachi  Assistant Professor National Institute of Polar Research Carey Kuhn  Researcher Alaska Fisheries Science Center Ryan Logan  Postdoctoral Research Fellow California State University Long Beach Simone Videsen  Postdoctoral Researcher Aarhus University Takuya Maekawa  Associate Professor Osaka University View related content here: https://www.pnas.org/doi/full/10.1073/pnas.2119502119 https://www.frontiersin.org/articles/10.3389/fmars.2022.1015594/full https://www.nature.com/articles/s41598-023-28748-0 https://www.science.org/doi/10.1126/sciadv.ade3889 https://academic.oup.com/pnasnexus/article/3/1/pgad447/7517476 Follow us on Spotify, Apple Podcasts, YouTube, 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

Inequitable wildfire smoke exposure in California 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, Joan Casey shows that some California communities are disproportionately exposed to wildfire air pollution. In this episode, we cover: •[00:00] Introduction •[01:04] Joan Casey, an environmental epidemiologist at the University of Washington, describes recent decades of wildfire in California. •[01:34] Casey describes the environmental equity issues of fine particulate matter (PM2.5) air pollution. •[02:26] Casey describes why she chose to study the equity of wildfire smoke pollution exposure. •[03:01] She explains the results of the study, showing that by one definition of disadvantaged communities, smoke exposure appeared equitable. Another measure, including racial and ethnic identity data, showed inequitable exposure. •[05:26] Casey explores possible reasons for this inequitable exposure. •[06:21] The benefits of improved air monitoring among marginalized communities. •[07:34] Caveats and limitations of the study. •[08:35] Next steps in this line of research. •[09:27] Hopes for policy impacts. •[10:22] Conclusion. About Our Guest: Joan Casey Assistant Professor University of Washington School of Public Health View related content here: https://www.pnas.org/doi/abs/10.1073/pnas.2306729121 Follow us on Spotify, Apple Podcasts, YouTube, 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

Biodiversity and gentrification 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, Mason Fidino explores how gentrification changes biodiversity in urban areas. In this episode, we cover: •[00:00] Introduction •[01:02] Mason Fidino, a quantitative ecologist at the Lincoln Park Zoo in Chicago, defines gentrification and its social impacts. •[01:53] Fidino explains how gentrification changes neighborhoods. •[03:09] Fidino explains why the research focused on medium to large mammals. •[03:40] A description of camera traps and how they collect data. •[05:09] The results, including links between gentrification and biodiversity. •[06:59] The implications of the study for urban planners and urban residents. •[08:23] Caveats and limitations of the study. •[09:50] Conclusion. About Our Guest: Mason Fidino Quantitative Ecologist Lincoln Park Zoo View related content here: https://www.pnas.org/doi/abs/10.1073/pnas.2318596121 Follow us on Spotify, Apple Podcasts, YouTube, 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 PNAS Highlights newsletter

School enrollment during COVID-19 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, Micah Baum describes how public school enrollments in the US changed during the COVID-19 pandemic. In this episode, we cover: • [00:00] Introduction • [00:54] Micah Baum, an economist at the University of Michigan, introduces school districts’ three modes of learning in fall 2020: virtual, in-person, and hybrid. • [01:31] Baum explains the reasons for studying public school enrollment changes between the 2019-2020 school year and the 2020-2021 school year.  • [02:51] Description of the data sources used in the study.  • [03:50] Explanation of the changes in enrollment numbers between the two school years. • [06:00] Explanation of racial differences in enrollment changes. • [06:46] Exploration of what these results suggest about parent choices.  • [08:24] Implications for school funding in future years. • [09:18] Caveats and limitations of the study. • [09:51] Conclusion. About Our Guest: Micah Baum PhD Student University of Michigan View related content here: https://www.pnas.org/doi/full/10.1073/pnas.2307308120 Follow us on Spotify, Apple Podcasts, YouTube, 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

Emotional power of live music 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, Sascha Frühholz describes the emotional power of live music compared to recorded music. In this episode, we cover: • [00:00] Introduction • [00:59] Sascha Frühholz, a cognitive neuroscientist at the University of Oslo, reviews the neuroscience of emotional responses to music. • [02:02] Description of the study hypothesis regarding the difference of responses to recorded and live music. • [02:34] Description of the experimental setup. • [03:15] Description of the music played during the experiment, with examples. • [04:30] Recounting of the results of the study. • [05:05] The differences between responses to recorded and live music. • [05:45] What the listeners knew during and after the experiment. • [06:09] Inclusion of unpleasant music in the experiment, with examples. • [06:49] Description of the listeners’ feelings during the experiment. • [07:14] The musicians’ feelings about the experiment.  • [07:42] Exploration of generalizing the results to other settings. • [08:19] Caveats and limitations of the study. • [09:11] Conclusion. About Our Guest: Sascha Frühholz Professor University of Oslo View related content here: https://www.pnas.org/doi/10.1073/pnas.2316306121 Follow us on Spotify, Apple Podcasts, YouTube, 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

Adapting to poor air quality 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, Rebecca Saari explores potential adaptations needed for worsening air quality due to climate change. In this episode, we cover: • [00:03] Introduction • [00:57] Rebecca Saari, an air quality engineer at the University of Waterloo, describes an air quality alert. • [01:23] Explanation of the hazard of fine particulate matter air pollution. • [02:18] Description of the study’s modeling approach. • [03:14] Description of modeling methods.  • [04:05] Explanation of study results and where air quality alerts may rise due to climate change. • [04:34] Exploration of the social impacts of inequitable distribution of worsening air quality. • [05:24] Description of strategies for mitigating the health risk of poor air quality. • [06:27] Discussion of the costs and benefits of increased time spent indoors to mitigate health risk. • [07:22] Discussion of the role of policy in protecting from air quality hazards. • [08:13] Explanation of the study’s caveats and limitations. • [09:30] Potential impacts of the study. • [10:11] Conclusion About Our Guest: Rebecca Saari Associate Professor  University of Waterloo View related content here: https://www.pnas.org/doi/abs/10.1073/pnas.2215685121 Follow us on Spotify, Apple Podcasts, YouTube 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

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, Christine Pu describes how commonly used measures of poverty don't agree, and why definitions of poverty matter.   In this episode, we cover: · [00:00] Introduction · [00:59] Christine Pu, an interdisciplinary scientist from Stanford University, introduces the importance of definitions of poverty. · [01:40] List of the four commonly used definitions of poverty. · [02:29] The motivation behind the study. · [03:21] Study design and methods. · [04:20] Results of the study and discussion of why poverty measures may not agree. · [05:50] Discussion of how poverty definitions impact efforts to alleviate poverty. · [06:57] How policymakers can approach definition of poverty. · [07:46] Implications and potential impacts of the study. · [08:25] Study caveats and limitations. · [08:54] Conclusion.   About Our Guests: Christine Pu PhD Candidate Stanford University   View related content here: https://www.pnas.org/doi/abs/10.1073/pnas.2316730121   Follow us on Spotify, Apple Podcasts, Google 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 Highlights newsletter

How a small fish makes big sounds 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, Verity Cook from Charité – Berlin University of Medicine explains how a fish 12 millimeters in length produces sounds exceeding 140 decibels. In this episode, we cover: •[00:00] Introduction •[01:37] Can you tell us more about the fish you studied? •[02:26] What are some of the methods you used to characterize the fish’s sound production mechanism? •[03:49] Can you walk us through the process of how these fish produce sound? •[05:02] What are the broader implications of your findings? •[05:53] Conclusion. About Our Guest: Verity Cook PhD Student Charité – Berlin University of Medicine View related content here: https://www.pnas.org/doi/full/10.1073/pnas.2314017121 Follow us on Spotify, Apple Podcasts, Google 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: https://twitter.com/PNASNews Facebook: https://www.facebook.com/PNASNews/ LinkedIn: https://www.linkedin.com/showcase/pnas-news/ YouTube: https://www.youtube.com/pnas-news Sign up the Highlights newsletter: https://mailchi.mp/nas/podcast-highlights

Dinosaur feathers hint at flight history 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, Jingmai O’Connor and Yosef Kiat share insights gleaned from modern birds’ feathers that help understand the evolutionary history of flight in dinosaurs. In this episode, we cover: •[00:00] Introduction •[01:02] Jingmai O’Connor, a vertebrate paleontologist at the Field Museum of Natural History, describes the characteristics of feathers associated with flight. •[02:11] O’Connor gives context and background for previous knowledge of the evolution of flight feathers in dinosaurs. •[03:25] O’Connor describes the sources of fossil specimens for analysis of feather evolution. •[04:29] Yosef Kiat, an ornithologist at the Field Museum of Natural History, tells what he learned about the consistent number of primary feathers in modern birds. He also tells how that number applies to dinosaurs.  •[05:54] O’Connor explains what the symmetry of feathers reveals about a species’ flight ability and history. •[06:29] Kiat applies feather symmetry to explain the flight evolutionary history of Caudipteryx. •[07:05] Kiat summarizes the findings of the study, using feather number and shape to assess the flight abilities of four genera of dinosaurs. •[07:47] Kiat and O’Connor describe the type of potential fossil evidence that could fill in holes in the history of flight evolution in dinosaurs. •[08:42] Kiat and O’Connor explain the study’s caveats and limitations. •[09:44] Conclusion. About Our Guests: Jingmai O’Connor Associate Curator of Fossil Reptiles  Field Museum of Natural History, Chicago, IL Yosef Kiat Postdoctoral Research Fellow Field Museum of Natural History, Chicago, IL View related content here: https://www.pnas.org/doi/10.1073/pnas.2306639121 Follow us on Spotify, Apple Podcasts, Google 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: https://twitter.com/PNASNews Facebook: https://www.facebook.com/PNASNews/ LinkedIn: https://www.linkedin.com/showcase/pnas-news/ YouTube: https://www.youtube.com/pnas-news Sign up the Highlights newsletter: https://mailchi.mp/nas/podcast-highlights

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 the potential impact of anthropogenic disturbances on bee communication. In this episode, we cover: [00:00] Introduction [00:45] Description of the waggle dance of honeybees. [01:59] Maggie Couvillon, an entomologist at Virginia Tech, explains what information researchers can glean from the waggle dance. [03:24] Christoph Grüter, a behavioral ecologist at the University of Bristol, describes what impact climatic changes may have on bee communication. [05:13] Michael Hrncir, a behavioral ecologist at the University of Sao Paulo, recorded the impact of rising air temperatures on foraging in stingless bees. [06:48] Grüter explains how landscape changes and habitat fragmentation might affect bee communication. [08:23] Elli Leadbeater, an ecologist at Royal Holloway University of London, found that dancing honeybees found the foraging environment of central London superior to agricultural land. [09:49] Kris Braman, an entomologist at the University of Georgia, studied how the distribution of land cover at different scales influences bee diversity in Georgia. [11:24] Grüter explains how insecticides may alter bee communication strategies. [12:41] Denise Alves, a behavioral ecologist at the University of Sao Paulo, describes how a fungal pesticide can affect nestmate recognition in stingless bees. [14:23] Adam Dolezal, an entomologist at the University of Illinois Urbana-Champaign, describes how a bee pathogen affects nestmate recognition in honeybees. [15:17] Final thoughts and conclusion. About Our Guests: Maggie CouvillonAssistant ProfessorVirginia Tech Christoph GrüterSenior LecturerUniversity of Bristol Michael HrncirProfessorUniversity of Sao Paulo Elli LeadbeaterProfessorRoyal Holloway University of London Kris BramanDepartment Head and ProfessorUniversity of Georgia Denise AlvesPost-doctoral ResearcherUniversity of Sao Paulo Adam DolezalAssistant ProfessorUniversity of Illinois Urbana-Champaign View related content here: https://royalsocietypublishing.org/doi/10.1098/rsbl.2022.0155 https://www.pnas.org/doi/full/10.1073/pnas.2219031120 https://www.sciencedirect.com/science/article/pii/S0022191020300512 https://besjournals.onlinelibrary.wiley.com/doi/10.1111/1365-2664.14011 https://link.springer.com/article/10.1007/s10841-022-00402-6 https://www.sciencedirect.com/science/article/pii/S0045653521026199 https://www.pnas.org/doi/10.1073/pnas.2002268117 Follow us on Spotify, Apple Podcasts, Google 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: https://twitter.com/PNASNews Facebook: https://www.facebook.com/PNASNews/ LinkedIn: https://www.linkedin.com/showcase/pnas-news/ YouTube: https://www.youtube.com/pnas-news Sign up the Highlights newsletter: https://mailchi.mp/nas/podcast-highlights

Alex Cristia and Elika Bergelson explain the factors influencing speech in children.

Chris Thorogood and Derek Moulton explain how mathematical modeling of carnivorous pitcher plants can lend insights into their evolution.

Allegra Midgette and Nadia Chernyak describe when young children begin to perceive and accept unequal and gendered division of household labor. 

Karen Steel explains a proof of concept for restoring hearing loss in mice. 

Stanley Cohen reflects on the 50-year legacy of a classic PNAS paper on recombinant DNA.

Longqi Yang and Fengqi You discuss the potential reductions in carbon emissions of switching from in person to remote work.

Jeremy Siow, Taylor Damann, and Margit Tavits discuss both historical and modern gender inequality in Europe.

Emmanuel Mignot explains how a variant of an immune system gene might protect some people against neurodegenerative disease.

Cecilia Machado and Douglas Almond discuss the impact of a first child on the career trajectory of mothers.

Laela Sayigh asks whether dolphins use "motherese" when communicating with their calves.

Pascal Polonik and Kate Ricke explain why reducing greenhouse gas emissions does not always improve environmental equity.

Ian Phillips, Rui Zhe Goh, and Chaz Firestone use auditory illusions to explore how people perceive silence.

Cameron Hecht discusses an intervention targeting high school teachers to improve student retention and diversity in STEM fields.

Vanessa Duthé explains how dehorning affects the behavior of black rhinoceroses.

Eric Martínez explains why legal documents are written in hard-to-read language.

Researchers explore trends in the gender gap among internationally mobile scholars.

Mattia Tagliavento talks about the evolutionary transition from dinosaurs to birds using isotopes in Troodon eggshells.

Pengfei Liu shares findings on racial disparities in exposure to the air pollutant nitrogen dioxide.

Chinmay Kalluraya and Matthew Daugherty explain how vertebrates acquired a gene critical for vision from bacteria.

Blair P. Bentley, Lisa Komoroske, and Camila Mazzoni discuss the role genomic elements play in the evolution of sea turtles.

A special edition of Science Sessions delves into the capabilities of robots inspired by plants and animals.

Stanislas Dehaene and Marie Amalric investigate whether short online videos are sufficient to teach mathematics concepts.

Anna Lea Albright and Peter Huybers describe how optical effects consistent with air pollution appear in the paintings of Claude Monet and J.M.W. Turner.

Kristin Winchell explains the genetic basis of anole adaptation to urban environments.

Researchers document animal extinctions in the Ediacaran Period that may have preceded the earliest known mass extinction.

Bo Wang and Chunpeng Xu describe how fossilized katydids provide insight into the role of insect sounds in the Mesozoic.

Tom McGrath describes how the neural network AlphaZero taught itself how to play chess without observing a human game.

Orit Peleg, Golnar Fard and Francisco López Jiménez explain how honeybees overcome geometric constraints to construct honeycombs.

Taylor Hersh explores how patterns of clicks produced by sperm whales suggest the exchange of cultural information between the whales.

Researchers discuss what animal soundscapes can tell us about the health of ecosystems.

Daniel Cusworth discusses combining aircraft-based and satellite-based measurement to identify methane emission point sources.

Syee Weldeab describes what researchers can learn from ancient global warming about the risks posed by ocean floor methane hydrates.

Ling Zhu and David B. Grusky explore intergenerational factors influencing occupational gender segregation in the United States.

Izzy Gainsburg and Veronica Derricks discuss how patient activation can disrupt implicit bias in physician-patient interactions.

Matilda Gibbons, Lars Chittka and Jonathan Birch discuss the possibility that bumblebees may feel pain.

Researchers explore how misinformation spreads and what can be done to stop it.

Lauren Howe and Alia Crum explore the interactions of societal biases with the placebo effect.

Steve Horvath and Elaine Ostrander explain the usefulness of epigenetic clocks in humans and dogs.

Researchers explore how and when humans first arrived in the Americas.

L. Mahadevan, Petur Bryde, and Suraj Shankar explain the otherworldly sounds of the musical saw.

Guido Friebel discusses the lack of gender parity in academic positions in economics.

Christianne Corbett and Robb Willer explore perceptions of electability of female political candidates.

A feature episode explores recent developments and future research directions in treating cystic fibrosis.

Martijn van de Pol reports that approximately half of the changes in the traits of 60 European bird species can be attributed to rising mean temperatures. 

Brenhin Keller and Kalin McDannell explore the origins of a worldwide gap in the geologic record spanning hundreds of millions to billions of years.

Neda Maghbouleh, Ariela Schachter, and René Flores explore the US Census classification of people with Middle Eastern and North African ancestry.

Thema Monroe-White and Cassidy Sugimoto discuss how disparities at the intersection of race and gender affect the expansion of scientific knowledge. 

Researchers explore cutting-edge approaches to coral reef conservation. Image credit: Cody Engelsma (Mote Marine Laboratory, Sarasota, FL).

Researchers explore cutting-edge approaches to coral reef conservation. Image credit: Cody Engelsma (Mote Marine Laboratory, Sarasota, FL).

Ray Block Jr. and John Holbein report that Americans are more likely to respond to an emailed survey request from a sender with a putatively White name than a sender with a putatively Black name. Image credit: iStock/Prostock-Studio.

A collection of research articles explores how tropical ecosystems have borne the brunt of the human impact on the environment. Image credit: Pixabay/Pexels.

A collection of research articles explores how tropical ecosystems have borne the brunt of the human impact on the environment. Image credit: Pixabay/Pexels.

A special episode explores the state of CRISPR use in agriculture. Image credit: Can Stock Photo/molekuul.

A special episode explores the state of CRISPR use in agriculture. Image credit: Can Stock Photo/molekuul.

Rodrigo Cámara-Leret explains the impact of indigenous language extinction on medicinal plant knowledge. Image credit: Pixabay/DEZALB.

Nicolas Taberlet and Nicolas Plihon explore the physical explanation for a fascinating natural phenomenon: the formation of Zen stones on frozen lakes. Image credit: N. Taberlet, N. Plihon. Lab Physique ENS de Lyon and CNRS.

Hessam Azarijafari, Randy Kirchain, and Jeremy Gregory explore how innovations in the concrete industry can reduce greenhouse gas emissions. Image credit: Pexels/Life Of Pix.

Sarah Chambliss discusses racial and ethnic disparities in exposure to air pollutants. Image credit: Pixabay/sueegeneris.

Maggie Wagner and Manuel Kleiner report that the interaction between maize and soil microbes influences hybrid vigor. Image credit: Kayla M. Clouse.

Gaige Kerr discusses racial disparities in atmospheric levels of nitrogen dioxide in the United States.

Stephanie Marciniak, Logan Kistler, and Ed Louis describe an extinct giant lemur.

Mohammad Reza Alizadeh, John T. Abatzoglou, and Mojtaba Sadegh report that forest fires have been advancing upslope across the western United States in recent decades.

Eran Amichai investigates how bats know the speed of sound.

Mike Gil discusses how changes in animal behavior can affect ecosystems.

Brad Greenwood explains how patient–physician racial concordance decreases Black infant mortality.

Vinay Pathak describes when and where HIV sheds its capsid coating while infecting human cells.

Jeannie Lee describes the discovery of self-cleaving ribozymes.

Josh Bongard describes AI-designed, reconfigurable biological organisms made from frog cells.

Jonathon Yuly, David Beratan, and Peng Zhang investigate how electron bifurcation reactions work.

Adam Mastroianni and Daniel Gilbert explore why conversations almost never end when people want them to.

Joe Levy shows how glaciers on Mars can reveal its climate history.

Marianne Alleyne, Aimy Wissa, and Ophelia Bolmin explain how the click beetle amplifies power to pull off its signature jump.

Mara Reed and Michael Manga explore why Yellowstone's Steamboat Geyser resumed erupting in 2018.

Martin Bizzarro tells what zircon crystals reveal about the geological history of Mars.

Aleix Martinez explains why facial expressions often are not accurate indicators of emotion.

Amanda Rodewald, Ivan Rudik, and Catherine Kling talk about the hazards of ozone pollution to birds.

Se-Jin Lee and Emily Germain-Lee explain a way to preserve bone and muscle mass during spaceflight.

David Crowder and Gengping Zhu explain how to predict the spread of the Asian giant hornet.

Brian Fields explores a hypothesis that a supernova may be responsible for a mass extinction.

Eric Horvitz discusses AI’s promises and perils.

Juliana Vianna and Rauri Bowie explain the origin and diversification of penguins.

William Nordhaus explains the economic consequences of Greenland ice sheet melt.

NAS member Dalton Conley explains how the Vietnam War draft lotteries are a natural experiment for studying how military service affects life outcomes.

Clark Larsen describes the costs of urban life a Neolithic city.

Mette Svenning and Alexander Tveit describe a bacterium that can live on gases in the air.

Derek Moulton explains the mathematics behind bivalve shell design.

Eelco Tromer and Jolien van Hooff explain the origins of the kinetochore in eukaryotic cells.

Fabiola Gianotti, Marcia McNutt, and Donna Shalala discuss the past, present, and future of women in STEM.

Francesco Paesani, Thomas Zeuch, and Valeria Molinero discuss the size limits of ice crystals.

Julia Schwab and Steve Brusatte describe how marine reptiles made the evolutionary move from land to sea.

Ellen Welti explains how grasshoppers in a Kansas prairie could be in decline even with abundant grass.

NAS member David Baker describes how to design proteins from scratch and the products of his lab's own protein design efforts

Elli Theobald and Scott Freeman describe the benefits of active learning for underrepresented minority students.

Adam Millard-Ball and Chris Barrington-Leigh explain trends in urban street network design.

NAS member and Nobel laureate David Baltimore describes efforts to enhance T cells' ability to fight cancer and HIV.

Christine Dunham discusses RNA frameshifting and its potential applications in biotechnology.

Henri Weimerskirch describes how albatrosses can help detect illegal fishing boats.

Philipp Heck tells the story of interstellar stardust grains that predate the Solar System.

Baruch Fischhoff, a decision scientist at Carnegie Mellon University, explains the ingredients necessary for effective science communication.

Kerry Sieh recounts the hunt for a meteorite impact crater in Southeast Asia.

Dana Lepofsky describes ancient sustainable clam gardening practices.

Theoretical physicists Hans Briegel and Hendrik Poulsen Nautrup describe an artificial intelligence that can design quantum experiments.

Simon DeDeo and Alexander Barron discuss the rhetoric that shaped the French Revolution.

Cam Braun explains how ocean eddies allow sharks to dive and forage in deep water.

Shara Bailey explains the significance of a three-rooted lower molar in an archaic jaw.

Noel Clark and Tommaso Bellini describe how nucleic acids form double-helical liquid crystals, with implications for the origins of life.

Benjamin de Haas explains individual differences in eye movement patterns.

Eric Boilard explains the role of serotonin and platelets in immune responses.

A collection of research articles explores developments in interfacial transport and mixing, with wide-ranging practical applications.

Jennifer Mandel outlines the evolutionary history of the sunflower family.

Jonathan Lefcheck and Robert Orth discuss nutrient pollution and recovery in the Chesapeake Bay.

Daniel Hodgson explains the physics of chocolate-making.

Chris Field discusses misconceptions about climate change and how humans can adapt to a warming planet.

Noah Diffenbaugh and Marshall Burke discuss how global warming impacts economies and income inequality.  

Margaret McFall-Ngai describes how a symbiont bacterium affects a host cephalopod.

A paleontological site preserves the immediate aftermath of the asteroid impact that may have caused a global mass extinction.

Thor Berger and Per Engzell explore connections between European immigration and present-day economic mobility in the US.

Erin Cech discusses parenting and gender disparities among STEM professionals.

Bettina Schulz Paulsson explains the origin and spread of Europe's megaliths, including Stonehenge.

Daven Henze discusses how air pollution spreads across the globe and what policymakers are doing in response.

Tetsuto Miyashita describes how the hagfish helps define the vertebrate tree of life.

Daniel Wieczynski and Van Savage show how climate affects the diversity of forests.

Jingfang Fan explains what network theory can reveal about climate systems.

Christopher Monroe discusses recent developments in quantum computing.

Alexis Noel and David Hu describe the unusual properties of a cat's tongue.

Blair Hedges discusses the state of Haiti's remaining forests and the consequences to biodiversity.

Chryssa Kouveliotou describes her efforts to compile a detailed X-ray map of the galactic plane.

Heather McKillop explores the Maya salt industry.

Mike Hout explores the persistence of occupational and socioeconomic standing from parent to child in America.

Robert Reed explains genetic controls on butterfly wing colors.

Nick Melosh describes a method for sampling RNA and proteins from cells using nanostraws.

Victoria Orphan and Elizabeth Trembath-Reichert discuss microbial life in the deep subseafloor.

Amaia Arranz-Otaegui describes the discovery of bread that far pre-dates agriculture.

Lauren Schiebelhut describes natural selection following sea star wasting disease.

Rob Voigt and Nicholas Camp examine respectfulness in police officers' interactions with community members.

Jenni Lehtimäki and Stefan Reber explore links between animal exposure in upbringing and immune system function.

Ralph Pudritz and Ben Pearce describe a model of how RNA-based life could have originated on the early Earth.

David Hughes discusses how a parasitic fungus manipulates ant behavior for reproduction.

Rob Knight discusses the role of the human gut microbiota in health and disease.

John Rogers describes soft, wearable electronic devices for health monitoring.

Karina Guziewicz and Artur Cideciyan explain a potential gene therapy approach for macular degeneration.

Bridget Scanlon discusses the use of global hydrologic models for studying changes in water storage worldwide.

Christof Koch describes a large-scale effort to understand how the cerebral cortex functions.

Robert Tjian discusses the role of philanthropy in funding scientific research.

Omar Akbari and Kevin Esvelt discuss a gene editing approach for harmful mosquitoes.

Atul Butte explains how researchers can use existing data to answer biomedical questions.

Polina Lishko discusses the development of unisex contraceptives.

Joseph DeRisi describes the Chan Zuckerberg Biohub, a new privately-funded medical research center in the Bay Area.

Patrick McGovern describes evidence of winemaking in Georgia during the Neolithic period.

Carl Fuldner and Shane DuBay describe how bird feathers preserve records of air pollution.

Vadim Backman describes a technique for high resolution imaging of biological molecules without labels.

Jonathan Sears describes potential treatment strategies for retinopathy of prematurity.

Rita Fior describes how zebrafish can make cancer treatment more efficient.

Sandu Popescu and Jeff Tollaksen explain how a fundamental principle of nature does not hold in quantum mechanics.

Yayoi Obata describes the formation of mammalian egg cells in vitro.

John Spear discusses the legacy of Thomas Gold's "Deep Hot Biosphere" hypothesis.

Russell Graham describes the extinction of woolly mammoths from St. Paul island.

Andrew Murray describes metabolic adaptations of Himalayan Sherpas to low-pressure, low-oxygen conditions at high altitudes.

Fernando Colchero, Roland Rau, and Susan Alberts describe the relationship between lifespan equality and average lifespan.

Rowan Lockwood discusses the sustainability of Native American oyster harvesting in the Chesapeake Bay.

Pelham Keahey describes how differential structured illumination microendoscopy can improve cancer diagnosis.

Entomologist May Berenbaum discusses the effects of agricultural fungicides on honey bee health.

Malcolm MacIver describes how our aquatic ancestors may have become interested in land.

Jeff Schneider explains how self-driving cars use machine learning to learn the rules of the road.

Steven Weinberg describes his experiences writing about science for a general audience.

Steve Elledge discusses how cells sense and respond to damage to their DNA.

Erez Lieberman Aiden discusses a model of how DNA folds to fit inside a cell nucleus.

Researchers Jean-Philippe Vielle-Calzada and Miguel Vallebueno discuss 5,000-year-old partially domesticated maize.

Charles Rice and Robert Landford discuss the future of hepatitis C research without chimpanzees.

Clint Otto discusses the impact of land-use changes on beekeepers in the Dakotas.

George Church, Matthieu Landon, and Michael Napolitano discuss the genetic replacement of arginine codons in E. coli.

Kip Thorne and Rai Weiss describe the detection of gravitational waves with LIGO.

Eileen Crimmins discusses the mortality difference between the sexes and its possible causes.

Kavli Prize winner Eve Marder discusses flexibility and stability in neural circuits.

Joshua Elliott discusses potential impacts of climate change on water availability for irrigation.

Andrea Rinaldo explains how cell phone data can be used to model disease spread.

Amanda Woerman discusses the role of the alpha-synuclein prion in the neurodegenerative disorder multiple system atrophy.

Anne Case and Angus Deaton describe recent changes in mortality trends for white non-Hispanic Americans.

Glaucio Paulino and Evgueni Filipov describe an origami-inspired approach to designing deployable structures and metamaterials.

Mark Jacobson explains the feasability of a 100% wind, water, and solar power grid in the continental United States.

Will Castleman and Cuneyt Berkdemir describe how to mimic rare earth elements using superatom clusters.

Yatrik Shah describes the connection between maternal iron absorption during lactation and neonatal anemia.

Sangeeta Bhatia describes the development of nanoparticles that can aid in detecting cancer and other diseases.

Stanislas Dehaene investigates how certain areas of the brain might be related to mathematical ability.

John Mather of the NASA Goddard Space Flight Center explains why and how the James Webb Space Telescope is being built.

Robyn Lee and Marcel Behr investigate the genomics of endemic tuberculosis in Northern Canada.

Karl Deisseroth explains a method to explore the wiring and structure of the brain.

Anthony James describes how gene drives can be used to spread malaria parasite resistance in mosquitoes.

Anthony Vecchiarelli explains a system of genetic cargo movement within cells that has roots in the work of Alan Turing.

Jintai Lin explains the impact of a global economy on air pollution in China and in the US.

Frank Bates describes how a project related to chewing gum led to materials science discoveries.

Abigail Marsh describes mechanisms of altruistic kidney donors' responsiveness to others' emotions.

Robert Epstein of the American Institute for Behavioral Research describes how search engine rankings can influence voter preferences.

Seth Burgess describes a timeline of events surrounding the end-Permian mass extinction.

Yaara Oren and Tal Pupko describe how bacteria can evolve via transfer of gene regulatory regions.

Noam Sobel explains how a human olfactory fingerprint helps uncover the uniqueness of individuals’ sense of smell.

Rino Rappuoli of GlaxoSmithKline discusses preclinical studies of a vaccine candidate against Staphylococcus aureus.

As AAAS president for 2015, Geraldine Richmond focuses on global scientific engagement.

Susan Fiske describes how intentional acts of harm motivate people to assign blame.

Jef Boeke explains how to safeguard against unauthorized growth of engineered microorganisms.

Lonnie Thompson discusses clues to Earth's ancient climate history that are stored in tropical glacial ice.

Kyle Siler discusses the role of editors as gatekeepers at scientific journals.

Alán Aspuru-Guzik discusses how he uses supercomputing as a "molecular spaceship" to explore chemical space and discover potentially useful new molecules.

Keith Joung and Feng Zhang explain methods for editing sequences of DNA in living cells.

Veronica Vieland discusses a common disconnect between scientists and statisticians in evaluating scientific evidence.

Robin Ali describes efforts to transplant healthy rod and cone cells into afflicted retinas.

Hesham Sadek explains the regenerative capability of newborn mouse hearts.

Ambassador Deborah Birx discusses international efforts in the fight against HIV/AIDS.

Elaine Mardis discusses how next generation sequencing technology is helping the Pan-Cancer Initiative gain a molecular understanding of cancer.

David Schaffer describes how to culture human stem cells in a fully-defined, scalable 3D medium.

Brian Kaspar discusses the role of astrocyte cells in the motor neuron disease ALS.

Frank McCormick discusses a National Cancer Institute-led effort to turn a well-known cancer-causing protein into a viable drug target.

James Collins explains how researchers can rewire bacterial cells and control multiple genes simultaneously within a single cell.

Francesco Pennacchio explains how neonicotinoid insecticides can influence the immune response of honey bees.

Caroline Roullier and colleagues won the 2013 Cozzarelli Prize in Behavioral and Social Sciences for their work on the distribution of sweet potatoes in Oceania.

Yoel Sadovsky and Carolyn Coyne describe the placenta's role in protecting the fetus from infection by viruses.

Tad Patzek explains how natural gas production declines over time in hydrofractured wells.

Mimi Kao and Allison Doupe explore song learning in the male zebra finch.

Erik Petigura and Geoffrey Marcy discuss the number of Earth-like planets that may exist in our galaxy.

James "Jay" McClelland describes a parallel distributed processing approach to understanding human cognition.

Alvin Roth discusses how principles of economics can benefit people who need kidney transplants.

Inés Ibañez-Tallon discusses how nicotine and neurons conspire to hamper efforts to quit smoking.

Inder Verma and colleagues describe how a breast cancer-associated gene might be implicated in brain size control in mammals.

Paul Dunk discusses the chemistry of carbon in space following a supernova.

NAS member Gregory Petsko discusses efforts to assess the US postdoctoral workforce.

Ariena van Bruggen and J. Glenn Morris, Jr. discuss their work on citrus greening, a disease that is threatening the global citrus industry.

C. Thomas Caskey and Amy McGuire discuss whole-genome genetic screening for adult-onset diseases.

James Liao talks about engineering microorganisms to synthesize fuels and chemicals from CO2.

Janet Werker describes how exposure to speech and environmental factors can affect language acquisition by infants.

Neuroscientists John Morrison and Yuko Hara talk about the links between estrogen, mitochondria, and age-related cognitive decline.

David Mills discusses regional differences in microbes found in grape must.

Yi Cui discusses how nanometerials are improving the energy storage capacity of batteries.

Steven Benner discusses the interaction between early humans and alcohol.

Scott Fraser discusses tools to glean a multicolored view of embryonic development.

Deborah Hung talks about identifying new approaches for treating and diagnosing infectious diseases.

Steven Pinker explains the idea of a cognitive niche, which may have facilitated the evolution of human intelligence.

David Laibson describes how behavioral economics can help incentivize positive behaviors.

Harry Klee explains how he is trying to make commercial tomatoes more flavorful.

Nicholas Fisher discusses his recent study investigating the health risks associated with eating seafood contaminated with Fukushima-derived radioactivity.

Nina Mazar discusses her recent study showing that where people sign a form affects how honestly they complete it.

Jeff Lichtman explains the promise and challenges tied to building a mouse connectome.

Matt Sponheimer discusses what our ancient evolutionary ancestors may have eaten.

Andrew Zammit-Mangion, Michael Dewar,Visakan Kadirkamanathan, and Guido Sanguinetti describe their statistical model of conflict dynamics and how they tested it using the WikiLeaks Afghan War Diary.

Janet Braam and E. Wassim Chehab discuss how plants anticipate and defend against insect attacks.

Paloma Gonzalez-Bellido, Hanchuan Peng, and Apostolos Georgopoulos describe their research on how dragonflies catch their prey.

Sean Palecek and Xiaojun Lian describe their efficient method for converting stem cells into heart muscle cells.

Clayton R. Magill and Katherine H. Freeman discuss how water availability and ecosystem changes influenced early human habitats.

Bob MacCallum explores how music can evolve from noise based on listeners' preferences.

Diana Wall discusses how life in the soil may change in a warming world.

Marcelo Jacobs-Lorena describes how he engineered a symbiotic bacterium found in mosquito guts to block the transmission of the malaria parasite.

Julie Segre and Liliana Losada discuss human-microbe interactions in a recording of a PNAS Science Cafe event held in Washington, DC on February 27, 2013.

John Durant talks about the role of science festivals in science literacy.

Bernhard Palsson explains how bacteria can be used as factories to produce sustainable products.

Joel Levine discusses his research on social interaction networks in fruit flies.

Chet Sherwood explores the unique aspects of the human brain's anatomy and function

Thalia Wheatley and Beau Sievers discuss the structural similarities between music and movement.

E. Peter Greenberg explains how antisense RNA help regulate bacterial social interactions.

David Hu describes his research on how mosquitos survive collisions with raindrops, which could help design better flying robots.

Bob MacCallum explores how music can evolve from noise based on listeners' preferences.

Merlin Hanauer and Chase Mendenhall discuss the science of biodiversity, in the second of two recordings of a PNAS Science Cafe event held in Washington, DC on October 17, 2012.

Merlin Hanauer and Chase Mendenhall discuss the science of biodiversity, in the first of two recordings of a PNAS Science Cafe event held in Washington, DC on October 17, 2012.

Fred Alt discusses methods to map human chromosomal reshuffling.

Myra Finkelstein discusses her research showing that California condors are significantly threatened by lead from lead-based ammunition.

Chemical engineer Mark Davis discusses his research on nano-sized cancer therapeutics.

Chemical biologist Allan Conney discusses his research on caffeine's anticancer properties.

Neuroscientist Charles F. Stevens discusses his research on finding the brain's underlying design principles.

Marc Kirschner discusses the goals of systems pharmacology.

Frances Arnold explains how she harnesses the power of evolution to create proteins and organisms with applications in medicine and in alternative energy.

Akiko Iwasaki explains how gut bacteria boost immunity to influenza virus.

Sarkis Mazmanian talks about how gut bacteria interact with the immune system to influence health and disease.

David Walt discusses his research on using fluorescent bacteria to send secret messages.

2011 Nobel Prize winner Bruce Beutler talks about his discovery of the first mammalian innate immune receptors, our first line of defense against the threat of microorganisms.

Medical entomologist Scott O'Neill explains how an intracellular bacterium could help curb the spread of dengue virus.

Cell biologist Ira Mellman discusses cancer immunotherapy at Genentech.

Changhuei Yang and Guoan Zheng talk about their inexpensive, lens-free biomedical imaging device, which could change the way we do microscopy.

Spanish chef Ferran Adrià and physicist David Weitz discuss the science of cooking.

Lora Hooper talks about the complex bacterial ecosystem in our gut and its important role in metabolism and immunity.

Baruch Fischhoff and Dietram Scheufele discuss the need for a scientific approach to the communication of science.

Structural biologist Pamela Björkman explains how engineering improved versions of naturally occurring antibodies against HIV might make them promising therapeutic agents.

Roland Kanaar explains how elevated temperature augments cancer treatment.

Merlin Hanauer discusses the benefits of protected areas.

Cozzarelli Prize winner Jacob Waldbauer reconstructs the history of oxygen on Earth.

Cozzarelli Prize winners Robert Saye and James Sethian introduce a numerical method to track complex motions.

Economist James Smith discusses the effect of childhood mental problems on adult life.

Erica Machlin Cox and Selena Sagan discuss an unusual interaction that protects the hepatitis C virus from our body's defenses.

George Church discusses the potential of synthetic biology.

Erin Hanlon and Jeanne Duffy introduce their research on sleep, in a recording of the PNAS "Science of Sleep" event held in Washington, DC on March 14, 2012.

Robert Langer and Steven Zeitels describe a polymer gel that could help patients regain lost voice.

Developmental biologist Cliff Tabin explains how genes shape the formation of organs.

Can stem cells help cure Type 1 diabetes? Douglas Melton hopes to find out.

Nancy Adler discusses the need for sex-specific scientific reporting and the role it has played in women's health over the last 20 years.

Psychology experts Daniel Pine and Mark Wiederhold answer fear-related questions from the audience, in second of two recordings from PNAS's "The Science of Fear!" event held in Washington, DC on October 12, 2011.

Psychology experts Daniel Pine and Mark Wiederhold introduce their research on fear, in the first of two recordings from PNAS' "The Science of Fear!" event held in Washington, DC on October 12, 2011.

Daniel Nocera discusses how efficient catalysts can help us store solar energy in the same way plants do.

Molecular biologist Stephen Liberles discusses how prey learn to recognize the scent of a predator.

Donald Ingber discusses the "microfabrication" of human biological systems as a means to replace animal testing during drug development.

Inder Verma discusses his new role at PNAS and his future plans for the journal.

Wendy Kellogg discusses her research into social computing and her boots-on-the-ground observations of how mobile phones can impact the developing world.

Stephen Quake discusses rapid DNA sequencing and treating medical patients based on their genomes.

Gregory Abowd discusses the clinical applications of capturing and recording the every day experiences of children with autism spectrum disorder.

George Whitesides discusses an inexpensive and easy-to-use medical diagnostic device that can be used in the developing world.

Jennifer Golbeck discusses the intersection of computer science, sociology, and social networking.

Physicist David Weitz discusses the material properties that make chocolate to-die-for.

Bo Begole discusses ubiquitous computing, behavioral modeling, and smart environments that can anticipate people's information needs.

Secretary of the Smithsonian Institution Wayne Clough discusses his goal to educate the public about the Smithsonian's groundbreaking scientific research projects.

Roger Beachy discusses the role of genetically modified crops in feeding the world's growing population.

Zvonimir Dogic discusses how viruses can be coaxed into forming self-assembling, polymer membranes.

Won-Yong Song and Jiyoung Park discuss the urgent problem of arsenic-tainted rice in Southeast Asia, and genetically engineered rice plants that would be safe to consume and could help remediate arsenic-contaminated groundwater.

Liza Moscovice discusses what her study on baboon behavior reveals about the evolution of cooperation in humans.

Robina Shaheen and Mark Thiemens discuss an oxygen isotope signature that reveals how carbonates on Mars form in the absence of life.

Cheryl Lyn Walker discusses the role of a cellular protein, called ATM, in offsetting oxidative damage.

Benjamin tenOever discusses his team's prize winning discovery that could be the key to developing a universal influenza A vaccine.

NIH Director Dr. Francis Collins discusses "personalized medicine," a novel approach in which doctors diagnose and treat patients using detailed information about each individual.

Susan Stipp discusses her PNAS research article that reveals whether the ash cloud from the 2010 eruption of Iceland's Eyjafjallajökull volcano posed a threat to aircraft, and if the widespread airport closures in Europe were warranted.

Jim Jensen, Executive Director of the Office of Congressional and Government Affairs, a branch of the National Research Council, discusses how scientific research shapes public policy.

Kei Koizumi, Assistant Director for Federal Research and Development at the White House Office of Science and Technology Policy, discusses some aspects of the President's 2012 research budget.

Nate Lewis dicusses the design principles and applications of electronic artificial noses.

Peter Schiller discusses a device that could one day restore sight to the blind by directly stimulating the visual cortex.

PNAS Editor-in-Chief Randy Schekman discusses the journal's new option to publish online-only research articles.

Rutledge Ellis-Behnke discusses his research in nano-healing, a technology that halts bleeding and helps the brain and body to recover from injury and disease.

David Hillis explains how phylogenetics can be used to solve criminal cases involving the intentional transmission of HIV via unprotected sex.

Paul Ekman, the scientist whose research inspired the Fox television drama "Lie to Me," explains that almost everyone can learn to read the facial microexpressions that reveal concealed emotions, but that the technique is no "Pinocchio's nose."

Neil Shubin researches the evolutionary origin of anatomical features. Dr. Shubin's most recent discovery, Tiktaalik roseae, has been dubbed the "missing link" between fish and land animals. Dr. Shubin discusses Tiktaalik and the evolutionary shift from life in water to life on land.

Marcel Salathé researches disease transmission and prevention, at the Penn State University Center for Infectious Disease Dynamics. To investigate how flu-like diseases spread through schools, Dr. Salathé used wireless sensors to measure the number of close-proximity, person-to-person interactions during a typical day at a local high school.

Charles J. Weschler studies the chemistry of indoor pollutants, including airborne particles, volatile organic compounds, and inorganic gases such as ozone. Listen as Dr. Weschler discusses the consequences of indoor pollution at home and in the workplace.

Neil deGrasse Tyson is an astrophysicist, author, host of "NOVA ScienceNOW," and the Frederick P. Rose Director of the Hayden Planetarium. Listen as Dr. Tyson discusses the extraordinary capabilities of the Chandra X-ray Observatory, and the nature of dark matter and dark energy.

Neil deGrasse Tyson is an astrophysicist, author, host of "NOVA ScienceNOW," and the Frederick P. Rose Director of the Hayden Planetarium. Listen as Dr. Tyson discusses the balance between scientific credibility and public exposure, and the pitfalls of challenging Pluto's status as a planet.

Dr. Mae Jemison is a physician and scientist, who on September 12, 1992 aboard the space shuttle Endeavour, became the world's first woman of color to travel into space. Listen as Dr. Jemison discusses race and gender bias in science education, and the importance of public science literacy.

Dr. Nathan Wolfe is the Lorry I. Lokey Visiting Professor in Human Biology at Stanford University and Director of the Global Viral Forecasting Initiative. Listen as Dr. Wolfe discusses malaria and the parasites that cause it, and his research that determined the origin of malignant malaria in humans.

Dr. Lennart Balk discusses the thiamine deficiency syndrome killing European wild birds.

Dr. Mary Immordino-Yang discusses her fMRI study of admiration and compassion.

Dr. Vera Gorbunova discusses the innate cancer immunity of the naked mole rat.

Listen as Dr. Daniel Rugar discusses his 100 million-fold improvement in resolution to conventional magnetic resonance imaging.

Michael Köttgen and Owen Woodward discuss identifying a key gene associated with gout, and the possible therapeutic implications.

John Dore discusses the connection between rising atmospheric carbon dioxide levels and the increasing acidity of Earth's oceans.

Edward C. Holmes is a professor of biology and a Distinguished Senior Scholar in the Eberly College of Science at the Pennsylvania State University. Listen as Dr. Holmes discusses his research on using comparative genomics to study the genetic evolution of RNA viruses.

Alessandro Acquisti is an Associate Professor of Information Technology and Public Policy at the Heinz College at Carnegie Mellon University in Pittsburgh, PA. Listen as Dr. Acquisti discusses his research in the economics of privacy and his 2009 PNAS research article on predicting Social Security numbers.

Maureen Cropper is an economics professor at the University of Maryland and a former lead economist at the World Bank. Listen as Dr. Cropper discusses her research in environmental economics and her 2008 election into the National Academy of Sciences.

James Thomson is best known for his pioneering work that isolated and cultured non-human primate and human embryonic stem cells. Listen as Dr. Thomson discusses his research and the future of stem cells in medical uses ranging from drug discovery, transplantation, and as a basic research tool.

Emily Carter's work merges quantum mechanics, applied mathematics, and solid state physics to create simulations of various molecules and materials. Listen as Dr. Carter discusses her research and her 2008 election to the National Academy of Sciences.

Richard Klein served as editor for the PNAS Special Feature titled "Out of Africa". This collection of articles explores the historical expansion of Homo sapiens from Africa to Eurasia. The Special Feature, along with an editorial by Dr. Klein, will publish in the September 22 issue of PNAS.

Jennifer Lippincott-Schwartz's laboratory at the National Institutes of Health works to characterize the fundamental principles governing protein geography and movement within cells. Dr. Lippincott-Schwartz talks about her work and her recent election to the National Academy of Sciences.

"Decreases in dengue transmission may act to increase the incidence of dengue hemorrhagic fever"

"Cross-modal individual recognition in domestic horses (Equus caballus)."

"Neurons derived from reprogrammed fibroblasts functionally integrate into the fetal brain and improve symptoms of rats with Parkinson's disease"

"The implications of human metabolic network topology for disease comorbidity"

"MicroRNA-directed transcriptional gene silencing in mammalian cells"

"Fluid helium at conditions of giant planetary interiors"

Randy Schekman, the PNAS Editor-in-Chief, discusses the selection process and history of the Cozzarelli Prize. The Cozzarelli Prize is given annually to six outstanding PNAS articles, each representing one of the major disciplines of the National Academy of Sciences.

Fred Gage is a professor in the Laboratory of Genetics at the Salk Institute in La Jolla, CA. In this podcast, Dr. Gage talks about the subtleties involved as researchers explore how to use stem cells to treat conditions such as Parkinson's disease.

Thomas Wellems is the head of the Malaria and Vector Research Unit at the National Institutes of Health. In this episode, he discusses the advances made in the fight against malaria and the problems that still remain.

Bruce Alberts is the former President of the National Academy of Sciences and the current editor-in-chief of Science. In this podcast, Dr. Alberts talks about how he generates ideas for editorials, how Science approaches issues of scientific misconduct, and his opinion on the proliferation of journals worldwide.

PNAS is one of the world's most-cited multidisciplinary scientific journals and has been published by the National Academies since 1915. This podcast, part of the Sounds of Science produced by the National Academies, looks at the history and future of this publication with Ken Fulton, publisher of PNAS.

Pamela J. Fraker was elected to the National Academy of Sciences in 2007. She is known for her investigations of the impact of nutritional deficiencies, particularly of zinc, on immune defense. Her work provided evidence that deficiency in protein--calories causes a decline in antibody and cell mediated responses, which leads to higher rates of infection, poor wound healing, and other adverse impacts in the malnourished and those with chronic disease.

Ran Nathan organized the Movement Ecology Special Feature for PNAS. He is an associate professor and the chair of the department of Evolution, Systematics, and Ecology at the Hebrew University of Jerusalem, in Jerusalem, Israel.

Elected to the National Academy of Sciences in 1990 for her work in the field of Plant Biology, Nina Fedoroff is a pioneer in the molecular aspects of plant transposable elements. Building upon the work of Barbara McClintock, she elucidated the sequence of some of these elements, demonstrated their utility for gene cloning and was instrumental in converting the study of plant transposable elements into one accessible by molecular techniques.

Richard T. Durrett was elected to the National Academy of Sciences in 2007 for his work in applied mathematical sciences. Durrett's research in probability theory concerns problems that arise from ecology and genetics. He has developed mathematical models to study the evolution of microsatellites, impacts of selective sweeps on genetic variation, genome rearrangement, gene duplication, and gene regulation.

C. Owen Lovejoy was elected to the National Academy of Sciences in 2007 for his work in the field of anthropology. Lovejoy overturned traditional models of human origins by integrating biomechanics into biological anthropology, demonstrating that the earliest hominids walked on two legs. He developed novel methods for quantifying sexual dimorphism and revealing the demographics of prehistoric humans.

Albert Libchaber was elected to the National Academy of Sciences in 2007 for his work in physics. Libchaber has made lasting and fundamental contributions to experimental chaos dynamics and its application to biological physics, from elucidating the forces at work when a fish swims through water to defining the minimal conditions necessary for artificial life.

John G. Hildebrand was elected to the National Academy of Sciences in 2007. His work on the functional organization, physiology, and development of the central olfactory system of insects has made him a pioneer in analyzing neural mechanisms underlying chemosensory control of mating behavior and insect--plant interactions. This work has application in disruption of insect mating behavior and herbivory, with practical benefit to human health and welfare.

Understanding the nanoparticle-protein corona using methods to quantify exchange rates and affinities of proteins for nanoparticles.

Targeted delivery of proteins across the blood--brain barrier.

Müller cells are living optical fibers in the vertebrate retina.

Savanna chimpanzees use tools to harvest the underground storage organs of plants.

Faceting ionic shells into icosahedra via electrostatics.

Incorporating plant functional diversity effects in ecosystem service assessments