PNAS Science Sessions

How python hearts grow and shrink 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, Leslie Leinwand, of the University of Colorado in Boulder, and Claudia Crocini, of Charité – Berlin University of Medicine in Germany, describe how the hearts of constricting pythons change size after meals. In this episode, we cover: •[00:00] Introduction •[01:19] What is the natural context for cardiac hypertrophy in constricting pythons? •[02:48] What were the mechanisms involved in this process that you identified? •[05:27] What did you discover about the mechanisms of heart size regression in these snakes? •[07:24] What are the next steps in this line of research? •[08:21] Conclusion. About Our Guest: Leslie Leinwand Professor University of Colorado Claudia Crocini Junior Research Group Leader Charité – Berlin University Medicine View related content here: https://www.pnas.org/doi/full/10.1073/pnas.2322726121 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 Highlights newsletter

How people travel to racially different neighborhoods 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, Mario Small talks about patterns of people's travel to neighborhoods racially different than their home neighborhood. In this episode, we cover: •[00:00] Introduction •[00:59] Sociologist Mario Small describes how everyday travel can temper residential segregation. •[01:57] Small talks about how their study tracked peoples’ movements and defined travel beyond a person’s racial comfort zone. •[03:48] Small explains the study’s results. •[06:08] He explores why some destinations take people to racially similar neighborhoods and some take people to racially different neighborhoods. •[07:15] Small shows how “15-minute cities” might inadvertently reinforce residential segregation. •[08:21] He lists the caveats and limitations of the study. •[10:34] Conclusion. About Our Guest: Mario Small Quetelet Professor of Social Science Columbia University View related content here: https://www.pnas.org/doi/10.1073/pnas.2401661121 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 Highlights newsletter

How pathogen stowaways traversed the oceans 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, Jamie Lloyd-Smith and Elizabeth Blackmore describe how they modeled the epidemiology of pathogens on ocean voyages. In this episode, we cover: •[00:00] Introduction •[01:04] Integrative scientist Jamie Lloyd-Smith and disease ecologist Elizabeth Blackmore describe how they came to study the epidemiology of ocean travel. •[03:21] Blackmore and Lloyd-Smith explain why they focused on three pathogens: influenza, measles, and smallpox. •[04:13] Lloyd-Smith explains the results of the disease model, with pathogen biology, passenger number, and journey length factoring into the duration of shipboard outbreaks. •[05:05] Blackmore details the additional insights provided by newspaper records of ship arrivals in 1850s San Francisco. •[06:57] Lloyd-Smith and Blackmore talk about the caveats and limitations of the study. •[08:02] Blackmore and Lloyd-Smith explore potential next steps. •[09:47] Conclusion. About Our Guests: Jamie Lloyd-Smith Professor University of California, Los Angeles Elizabeth Blackmore Doctoral student Yale University View related content here: https://www.pnas.org/doi/10.1073/pnas.2400425121 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 Highlights newsletter

Why “Tornado Alley” is unique to North America 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, Funing Li and Dan Chavas explain why North America produces many tornadoes each year and South America does not. In this episode, we cover: •[00:00] Introduction •[01:01] Weather and climate scientist Funing Li talks about the frequency of tornadoes within and outside of the United States. •[01:25] Li explains the geography of severe thunderstorm hotspots in North and South America. •[02:46] Weather and climate scientist Dan Chavas and Li describe how they became interested in the effect of surface geography on tornadoes. •[05:13] Li and Chavas explain their modeling approach. •[07:23] Li and Chavas talk about why surface roughness is important for tornado formation. •[08:14] Chavas and Li describe the implications of the study, including effects of climate change and insights into paleoclimate. •[09:43] Caveats and limitations of the study. •[10:26] Conclusion. About Our Guests: Funing Li Postdoctoral associate Massachusetts Institute of Technology Dan Chavas Associate professor Purdue University View related content here: https://www.pnas.org/doi/10.1073/pnas.2315425121 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

Creating culturally inclusive school environments 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, Stephanie Fryberg, Hazel Markus, and Laura Brady explore how to create culturally inclusive environments in schools. In this episode, we cover: •[00:00] Introduction •[01:00] Social cultural psychologist Stephanie Fryberg introduces the value of culturally inclusive learning environments. •[01:43] Social cultural psychologist Hazel Markus talks about how disparities can arise from a lack of cultural belonging. •[02:25] Markus introduces the predominant cultural model that creates challenges for some students. •[03:18] Social cultural psychologist Laura Brady explains an alternate interdependence model. •[4:01] Brady talks about the school leaders involved in the study. •[4:34] Fryberg outlines the professional development intervention. •[5:44] Fryberg and Markus share examples of teacher responses. •[6:26] Brady talks about how teacher practices and student attitudes changed. •[7:44] Brady lists the caveats and limitations of the study. •[8:31]Markus and Fryberg share takeaways from the study. •[9:43] Conclusion. About Our Guests: Stephanie Fryberg Professor of social and cultural psychology, Director of Research for the Indigenous Social Action and Equity Center Northwestern University Hazel Markus  Professor of social and cultural psychology, co-director of Stanford Spark Stanford University Laura Brady Senior researcher  American Institutes for Research View related content here: https://www.pnas.org/doi/full/10.1073/pnas.2322872121 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

How redlining affects biodiversity 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, Cesar Estien explores the legacy of mid-20th century redlining through the biodiversity of disadvantaged neighborhoods. In this episode, we cover: •[00:00] Introduction •[1:04] Cesar Estien, an urban ecologist at the University of Washington, describes the practice of redlining. •[2:50] He tells how a study of redlining and environmental quality led to a study of animal diversity. •[3:33] Estien describes why the study cities of San Francisco, Oakland, Los Angeles, and San Diego were chosen for the study. •[4:25] He explains the difference between species richness and community composition. •[5:31] He reports the study findings regarding species richness and community composition in redlined and greenlined neighborhoods. •[6:55] Estien talks about the lasting legacy of racial injustice on the ecology of cities. •[7:52] He explains why equitable access to biodiversity matters. •[9:04] Caveats and limitations of the study. •[10:09] Conclusion. About Our Guest: Cesar Estien Ph.D. Candidate University of California, Berkeley View related content here: https://www.pnas.org/doi/full/10.1073/pnas.2321441121 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

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