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Proceedings of the National Academy of Sciences @pnas.org · 1h

A simple #geoengineering approach seems to restore dwindling #Arctic #ice in pilot studies. Could it actually work at a larger scale? In PNAS Front Matter: ow.ly/iwt550ZU1wh #ClimateChange #seawater #clouds #energy

A rapidly warming Arctic has prompted a group of enterprising researchers to consider ways to restore crucial Arctic ice.
Image credit: Science Source/Peter J. Raymond.

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Proceedings of the National Academy of Sciences @pnas.org · 19h

One of the most-viewed PNAS articles in the last week is “A refined phylochronology of the second plague pandemic in Western Eurasia.” Explore the article here: ow.ly/9kYE50ZTHmE For more trending articles, visit ow.ly/If0k50ZTHmF.

Schematic workflow from data generation to the PhIRM and historical contextualization. Icons are modified from Flaticon.com.

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Proceedings of the National Academy of Sciences @pnas.org · 21h

In this issue: Dual-phase gel organization of chromosomes; insect farming and animal manure; and increased air pollution after independent monitoring ended. In PNAS: ow.ly/t24i50ZTHfo

Pictured is a parasitoid wasp (Anastatus formosanus) alongside parasitized stink bug eggs.

Image credit: Haichun Liu.

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Proceedings of the National Academy of Sciences @pnas.org · 23h

When wildfires burn in cities, metals in the smoke, ash, soil, and debris pose a health risk. People living in the footprint of the 2023 Maui fire had 40 times more antimony and 2.2 times more arsenic in their urine than reference levels. In PNAS: ow.ly/AML150ZTyNv

Devastation in Lahaina, Maui, after the August 2023 wildfires.

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Proceedings of the National Academy of Sciences @pnas.org · 01/10/2026

Opinion: “Don’t tax the talent that builds American science.” A #DHS rule could have lasting consequences for #GraduateStudents, #InternationalStudents, and US scientific competitiveness. In PNAS Front Matter: ow.ly/JW8O50ZTzaa #StudentVisa #ScienceEnterprise

Four years is shorter than the median time to a U.S. research doctorate in essentially every science and engineering field. That gap between the rule and the reality puts the pipeline of American science at risk. Image credit: Shutterstock/Charles HHuang.

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Proceedings of the National Academy of Sciences @pnas.org · 01/10/2026

If Florida ends all vaccination mandates for school attendance, as proposed by state officials, Floridians could see a significant number of pediatric deaths within five years, and endemic measles could spread across the United States. In PNAS: ow.ly/ktPF50ZTyvB

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Proceedings of the National Academy of Sciences @pnas.org · 30/09/2026

How can studying illegal markets across sectors strengthen research and public policy? A new PNAS blog explores how a shared scientific framework can reveal commonalities and differences across these markets. Read more: ow.ly/4KR250ZSUGe

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Proceedings of the National Academy of Sciences @pnas.org · 30/09/2026

Fossil fuel subsidies lead to increased emissions, but cancelling them can harm poor people. Shifting funds from fossil fuel producers to low-income consumers via existing social assistance programs can reduce poverty and lower emissions. In PNAS: ow.ly/vCQZ50ZSNpQ

Worker delivering LPG gas cylinders to rural customers in a village in Maharashtra, India

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Proceedings of the National Academy of Sciences @pnas.org · 30/09/2026

From the Science Sessions archive, a reflection on how the COVID-19 pandemic changed public school enrollment. Revisit the research behind enrollment shifts across the United States and their implications for schools and families: ow.ly/Clt550ZSM0Z

Young boy attentively watching a laptop screen while holding a pencil and notebook at a wooden table.

Credit: Pexels/Katerina Holmes

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Proceedings of the National Academy of Sciences @pnas.org · 29/09/2026

As the climate warms, compound drought and heat wave events are becoming more frequent and intense across the contiguous United States. Areas at high risk for such events are disproportionately poor, unhealthy, and rural. In PNAS: ow.ly/nqfA50ZSNx3

Drought-damaged corn and cracked soil.
CREDIT: Bob Nichols/USDA.

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Proceedings of the National Academy of Sciences @pnas.org · 29/09/2026

One of the most-viewed PNAS articles in the last week is “Spatially refined satellite gravimetry captures human signatures in global terrestrial water storage trends.” Explore the article here: ow.ly/ytuh50ZSNBp For more trending articles, visit ow.ly/YSuq50ZSNBo.

A multi-part figure with panels A to I showing bar graphs of results from continental-scale multivariate regression and local bivariate spatial association, used for TWS trend attribution.

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Proceedings of the National Academy of Sciences @pnas.org · 29/09/2026

College students did worse on a test of attention control when what they thought was a gun was present in the laboratory than when a stapler was present. The researchers argue that allowing guns in educational settings may impair cognitive control. In PNAS: ow.ly/bL6k50ZSNh7

Images of participants’ workstation in the gun condition and stapler condition.

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Proceedings of the National Academy of Sciences @pnas.org · 29/09/2026

How close are US schools to environmental hazards? In the latest PNAS Science Sessions episode, researchers examine schools’ proximity to sources of environmental hazards and what these patterns reveal about potential student exposures. Listen now: ow.ly/Vklp50ZSLW2

Chain-link fence with a U.S. EPA Superfund cleanup site sign marking a contaminated area under environmental protection.

Credit: wikimedia/markzvo

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Proceedings of the National Academy of Sciences @pnas.org · 29/09/2026

Carbonaceous chondrite meteorites preserve a chemical record of the early Solar System. A study of three stable isotopes of oxygen in primitive meteorites finds them unchanged from the primordial oxygen reservoirs of the early Solar System. In PNAS: ow.ly/aNwK50ZSkgj

Interior slice of a carbonaceous chondrite meteorite containing organic matter from the early Solar System.
CREDIT: Michail I. Petaev (Harvard University, Cambridge, MA).

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Proceedings of the National Academy of Sciences @pnas.org · 29/09/2026

As the climate warms, droughts and floods may occur in quicker succession. Researchers project more frequent drought–flood transitions across China, with greater risks for lower-income populations. In Science X / Phys.org: ow.ly/op5M50ZSquO In PNAS Nexus: ow.ly/n7hW50ZSquL

Conceptual diagram of drought–flood alternation events and associated impacts.
Image credit: Qi et al.

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Proceedings of the National Academy of Sciences @pnas.org · 29/09/2026

Read highlights in this week’s issue of PNAS: We explore ocean circulation, precipitation, and temperature; examine the derivation of LSD analogs; and analyze the migration of “brain-eating” amoebae. ow.ly/g4HP50ZSl9x

Pictured is a map showing population by race in Baltimore, Maryland, and the surrounding area.
Image credit: Census Dots.

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Proceedings of the National Academy of Sciences @pnas.org · 28/09/2026

Smoking appears to be more deadly in recent decades. A study uncovers the reason for the trend: smokers are, on average, older than they once were, due to cultural changes that have reduced the number of young people taking up the habit. In PNAS Nexus: ow.ly/4HAs50ZSqqz

Close-up of an elderly person smoking. Stock photo.

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Proceedings of the National Academy of Sciences @pnas.org · 28/09/2026

Earlier PNAS research linked US embassy air-quality monitoring to reduced pollution. A new study finds pollution rose after the program was suspended. In NPR: ow.ly/EX4050ZSpUZ In PNAS: 2026: ow.ly/XTOT50ZSpUU 2022: ow.ly/Rcn650ZSpuh

Smog mixed with a thick layer of clouds covers the Metro Manila skyline in the Philippines on August 27.
Image credit: Photo by Melvin James Urubio/NurPhoto/via Getty Images

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Proceedings of the National Academy of Sciences @pnas.org · 28/09/2026

Opinion: As researchers increasingly use AI-generated materials, how well do they reflect the concepts being studied? A PNAS piece examines the “synthetic validity” problem, especially in the #SocialSciences. In PNAS Front Matter: ow.ly/vZUQ50ZSkYY #AI #LLM

Illustration of a person inspecting a ruler with a magnifying glass as others fall from a conveyor belt into a box labeled AI Ruler Co. 144 Rulers Model 10202.
Image credit: Dave Cutler (artist).

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Proceedings of the National Academy of Sciences @pnas.org · 28/09/2026

Reliable electricity can be critical to healthcare. A study in the Democratic Republic of the Congo finds facilities with power ≥22 hours/day have 41% lower mortality than those without sufficient, reliable power. In PNAS: ow.ly/7Als50ZSkwm

Doctors work on a patient under lights. Stock photo.

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Proceedings of the National Academy of Sciences @pnas.org · 26/09/2026

Explore peer-reviewed research in cell biology from Proceedings of the National Academy of Sciences, including intracellular transport and cytoskeletal organization. Discover articles that shed light on development, homeostasis, and the cellular basis of health and disease: ow.ly/4rz150ZRvp2

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Proceedings of the National Academy of Sciences @pnas.org · 26/09/2026

Researchers are testing a simple #geoengineering approach to restore dwindling #Arctic #ice. Could it actually work? Promising early studies face challenges related to scale, funding, and oversight. ow.ly/V42H50ZRv2r #ClimateChange #seawater #clouds #energy

A startup company called Real Ice is experimenting with using flooding pumps to spread seawater on patches of Arctic ice.
Image credit: Real Ice | www.realice.eco.

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Proceedings of the National Academy of Sciences @pnas.org · 26/09/2026

Uranium–lead dating of bronze artifacts from the Shang Dynasty in China reveals the source of their constituent tin: the Great Hinggan Range polymetallic belt in Northeast China. The findings may help reconstruct Bronze Age supply chains. In PNAS: ow.ly/27FY50ZRujm

Small bronze arrowhead excavated at the Yingshuisi site in China.
CREDIT: Zhenfei Sun.

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Proceedings of the National Academy of Sciences @pnas.org · 26/09/2026

In this week’s PNAS Nexus Advance Articles: Deep learning without weight symmetry; cultural proximity and local premiums in collective memory; model distillation for multimodal early-warning systems; and more. ow.ly/WZuF50ZRvzo

Explore the latest Advance Articles from PNAS Nexus! Read now at pnasnexus.org.

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Proceedings of the National Academy of Sciences @pnas.org · 26/09/2026

One of the most-discussed PNAS articles on Reddit last month was “Evolutionary trends in Triceratops from the Hell Creek Formation, Montana.” Explore the article: ow.ly/zwvK50ZRvPm

Potential patterns of HCF Triceratops evolution. (A) Anagenesis, or transformation of a lineage over time. (B) Bifurcation of an anagenetic lineage in which the ancestor becomes pseudoextinct through evolution (sensu ref. 38). (C and D) True cladogenesis implies the coexistence of ancestral and descendant clades for at least a short period. The gray and white asterisks represent potential positions for MOR 3045 and MOR 3027.

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Proceedings of the National Academy of Sciences @pnas.org · 25/09/2026

In a recent PNAS QnAs, plant biologist Gregg Alan Howe discusses how plants coordinate their defenses with nutrient availability. His work helps reveal how plants sustain immune responses when resources are limited. Read more: ow.ly/yM0N50ZRvaB

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Proceedings of the National Academy of Sciences @pnas.org · 25/09/2026

Breastfeeding is important work. A study computes the economic value of breastfeeding in England throughout history, as a share of GDP. Its proportional value has consistently exceeded 0.1% of GDP [AR2.1]and peaked in the year 1540 at 6.58%. In PNAS: ow.ly/ufGl50ZRuce

Etching depicting a woman, wearing a headscarf and breastfeeding a baby; at left there is a basket; at right there is a tree. c. 1782–1803.
CREDIT: © The Trustees of the British Museum. Shared under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) licence.

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Proceedings of the National Academy of Sciences @pnas.org · 25/09/2026

A major question in conservation science is whether species will be able to adapt to climate change by evolving. In the case of black-browed albatrosses, a model predicts that such evolutionary rescue is only likely in a low-emissions scenario. In PNAS: ow.ly/4KyE50ZRuxN

Black-browed albatrosses (Thalassarche melanophris).
CREDIT: Samantha Patrick.

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Proceedings of the National Academy of Sciences @pnas.org · 25/09/2026

Exposure to subtoxic doses of a widely used per- and polyfluoroalkyl substance (PFAS) suppresses innate antiviral immune responses. The study suggests that environmental exposure to PFAS comes with public health risks. In PNAS: ow.ly/knFQ50ZR6jp

Schematic representation of perfluorooctane sulfonate (PFOS) as a negative regulator of antiviral innate immunity through targeting interferon regulatory factor 3 (IRF3) activation.

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Proceedings of the National Academy of Sciences @pnas.org · 25/09/2026

One of the most-viewed PNAS articles in the last week is “Air pollution after the shutdown of US embassy monitoring.” Explore the article here: ow.ly/Fn8450ZR63B For more trending articles, visit ow.ly/h5Rm50ZR63F.

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Proceedings of the National Academy of Sciences @pnas.org · 24/09/2026

In this issue: A new route to predicting nucleation through confined simulations, tooth enamel-inspired fabric architecture, and worldwide trends in water storage. In PNAS: ow.ly/AZwg50ZR5aH

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Proceedings of the National Academy of Sciences @pnas.org · 24/09/2026

A global analysis of food system resilience shows that nations can do much to protect their citizens from undernourishment due to shocks such as climate extremes, conflicts, pandemics, and economic upheaval. In PNAS: ow.ly/sxL050ZR67G

Customers shopping at a market in Lagos, Nigeria.

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Proceedings of the National Academy of Sciences @pnas.org · 24/09/2026

Biology textbook descriptions of #chromosomes may fall short. The cellular structures aren’t composed of carefully folded #DNA, a recent study shows. Instead, they’re dual-phase gels. In PNAS Journal Club: ow.ly/jgBI50ZR52R #IonicHydrogel #histones #protein

The behavior of chromosomes matches that of an ionic hydrogel, which can exist in a decondensed or condensed phase.
Image credit: Shutterstock / CHIARI VFX.

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Proceedings of the National Academy of Sciences @pnas.org · 23/09/2026

One of the most-viewed PNAS Nexus articles in the last week is “Host nucleolin-targeting unique peptide drugs as potent broad-spectrum anti-influenza therapies.” Explore now: ow.ly/Zs9G50ZPTup To submit your own research, visit PNAS Nexus at ow.ly/1tL850ZPTsY.

$Western blot analysis showing distribution of IAV proteins in A549 cell fractions treated with AGM-380d and AGM-380t compounds.$

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Proceedings of the National Academy of Sciences @pnas.org · 23/09/2026

Cocoa farmers could benefit from better forecasts of extreme rainfall events, which modeling shows are an important determinant of cocoa yields for a crop that supports 6 million farmers and brings joy to millions more through chocolate. In PNAS: ow.ly/tgX050ZPSx6

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Proceedings of the National Academy of Sciences @pnas.org · 23/09/2026

One of the most-discussed PNAS articles on Reddit last month was “Value misalignment in X’s feed algorithm is a reflection of value tensions in engagement.” Explore the article: ow.ly/FnpI50ZPSZN

Top: Amplification results for the four middle-level value clusters of Self-transcendence, Openness to change, Conservation, and Self-enhancement. Bottom: A radar plot of amplification results for low-level values using coefficients computed from the preregistered PCA analysis (Materials and Methods).

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Proceedings of the National Academy of Sciences @pnas.org · 22/09/2026

New research from National Academy of Sciences and National Academy of Medicine member Ruslan Medzhitov and colleagues identifies a potential therapeutic target for improving survival during severe influenza infection. In PNAS Nexus: ow.ly/BN3b50ZPSSM

Graphs and lung tissue images comparing influenza infection in mice with and without vanin-1, showing similar antiviral immune responses and lung pathology despite differences in survival.

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Proceedings of the National Academy of Sciences @pnas.org · 22/09/2026

One of the most-viewed PNAS articles in the last week is “Two-dimensional billiards are Turing complete.” Explore the article here: ow.ly/zs8G50ZPTvY For more trending articles, visit ow.ly/YEYv50ZPTvZ.

Billiard dynamics implementing the read–write operation. The blue and red rays correspond to reading a 0 or a 1, respectively.

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Proceedings of the National Academy of Sciences @pnas.org · 22/09/2026

Environmental, social, and governance (ESG) ratings fail to systematically penalize companies for deforestation. Incorporating quantifiable spatial deforestation data—such as data from remote sensing—into assessments could help inform ratings. In PNAS: ow.ly/rW0550ZPSs9

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Proceedings of the National Academy of Sciences @pnas.org · 22/09/2026

From elephants and manatees to fungi and comb jellies, explore the connections across the Tree of Life. Watch LabX Tree of Life series, then dig deeper with related research from the PNAS journals. Watch the series: ow.ly/aJ0b50ZPTjw Explore research: ow.ly/zYeV50ZPT8y

LabX - One leaf. One branch. One enormous. Tree of Life. Explore the Tree Life!

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Proceedings of the National Academy of Sciences @pnas.org · 22/09/2026

Irrigation increases crop yields, which reduces the need for agricultural land and thus the clearing of forests and associated carbon emissions. A study estimates that US irrigation provides an estimated gross GHG benefit of 6.86 Gt CO2e annually. In PNAS: ow.ly/Rura50ZPSuB

Net GHG emissions from irrigation in the United States. Total national impacts by source of emission under the current and zero-irrigation scenarios.

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Proceedings of the National Academy of Sciences @pnas.org · 22/09/2026

Groundwater depletion associated with agriculture may be more severe than previously thought, according to a study that reanalyzes satellite-based gravity measurements to evaluate trends in terrestrial water storage across the globe. In PNAS: ow.ly/mzGg50ZPInS

Global trends in terrestrial water storage from two satellite data sets across 1° equal-area mass concentrations.

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Proceedings of the National Academy of Sciences @pnas.org · 22/09/2026

Less splashback, more science. 🚽🏆 Researchers used fluid physics and differential equations to design a splash-free urinal—work that earned the 2026 Ig Nobel Prize in Physics. In Smithsonian Magazine: ow.ly/pGQN50ZPKsx In PNAS Nexus: ow.ly/jPE350ZPKte

This year's Ig Nobel Award ceremony took place in Zurich, Switzerland.
Image credit: Improbable Research via Facebook

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Proceedings of the National Academy of Sciences @pnas.org · 22/09/2026

Read highlights in this week’s issue of PNAS: We explore peptide structure in Venus-like conditions, analyze heel-strike biomechanics in humans and chimpanzees, and examine bacteria endemic to Antarctic soils. ow.ly/fymh50ZPKev

Pictured are mammalian host cells infected with Trypanosoma cruzi, the parasite that causes Chagas disease, showing parasites in red and nuclei in blue.
Image credit: Bryanna Thomas, Alan Abrams, and Rajiv S. Jumani (Novartis Biomedical Research, Cambridge, MA).

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Proceedings of the National Academy of Sciences @pnas.org · 21/09/2026

A scientific observation was hiding in a 400-year-old painting. 🦇 A 1611 artwork depicts a greater noctule bat carrying a songbird—centuries before modern research documented the behavior.. In Science News: ow.ly/SuTe50ZPK7g In PNAS: ow.ly/kQGi50ZPJPw

This 17th-century work depicts a bat eating a songbird, a behavior scientists only recently confirmed.
Image credit: Jan Brueghel

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Proceedings of the National Academy of Sciences @pnas.org · 21/09/2026

Discover one of the top-performing PNAS Nexus articles on Altmetric over the past three months! “Restoring indigenous trees can help combat malnutrition in Africa” by Vansant et al. scored 34, driven by strong media attention. Read more: ow.ly/8xqV50ZPKhY

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Proceedings of the National Academy of Sciences @pnas.org · 21/09/2026

Studies in Hong Kong during the 2014 unrest and in Israel during a 2014 military escalation show that taking the time to reflect and write essays about threats reduced bias against outsiders—but only for those with multicultural experience. In PNAS Nexus: ow.ly/XH3Z50ZPKmq

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Proceedings of the National Academy of Sciences @pnas.org · 21/09/2026

Explore The Ecology of Segregation in Cities Special Feature to see how redlining and other forms of urban segregation have shaped city ecologies, including studies on tree canopy, flood exposure, biodiversity, and infrastructure resilience. In PNAS: ow.ly/XYYh50ZPHNs

A raised entrance to a subway staircase at the 145th Street Station in Harlem, New York City, designed to keep rain out of the station during extreme weather.

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Proceedings of the National Academy of Sciences @pnas.org · 21/09/2026

#Microplastics seem to be everywhere. But how exactly do they move through water and land? #EarthScientists find ways to track their journey with an eye toward #remediation. In PNAS Front Matter: ow.ly/ZAPB50ZPIQA

Transport models of microplastics, here shown in a drop of seawater, help predict where they’ll build up, a vital tool in tracking and potential cleanup efforts.
Image credit: SINCLAIR STAMMERS / Science Source.

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