It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Friday, June 06, 2025
First-ever airborne toxin detected in Western Hemisphere
Once in a while, scientific research resembles detective work. Researchers head into the field with a hypothesis and high hopes of finding specific results, but sometimes, there’s a twist in the story that requires a deeper dive into the data.
That was the case for the University of Colorado Boulder researchers who led a field campaign in an agricultural region of Oklahoma. Using a high-tech instrument to measure how aerosol particles form and grow in the atmosphere, they stumbled upon something unexpected: the first-ever airborne measurements of Medium Chain Chlorinated Paraffins (MCCPs), a kind of toxic organic pollutant, in the Western Hemisphere. Their results published today in ACS Environmental Au.
“It's very exciting as a scientist to find something unexpected like this that we weren't looking for,” said Daniel Katz, CU Boulder chemistry PhD student and lead author of the study. “We're starting to learn more about this toxic, organic pollutant that we know is out there, and which we need to understand better.”
MCCPs are currently under consideration for regulation by the Stockholm Convention, a global treaty to protect human health from long-standing and widespread chemicals. While the toxic pollutants have been measured in Antarctica and Asia, researchers haven’t been sure how to document them in the Western Hemisphere’s atmosphere until now.
MCCPs are used in fluids for metal working and in the construction of PVC and textiles. They are often found in wastewater and as a result, can end up in biosolid fertilizer, also called sewage sludge, which is created when liquid is removed from wastewater in a treatment plant. In Oklahoma, researchers suspect the MCCPs they identified came from biosolid fertilizer in the fields near where they set up their instrument.
“When sewage sludges are spread across the fields, those toxic compounds could be released into the air,” Katz said. “We can't show directly that that's happening, but we think it's a reasonable way that they could be winding up in the air. Sewage sludge fertilizers have been shown to release similar compounds.”
MCCPs little cousins, Short Chain Chlorinated Paraffins (SCCPs), are currently regulated by the Stockholm Convention, and since 2009, by the EPA here in the United States. Regulation came after studies found the toxic pollutants, which travel far and last a long time in the atmosphere, were harmful to human health. But researchers hypothesize that the regulation of SCCPs may have increased MCCPs in the environment.
“We always have these unintended consequences of regulation, where you regulate something, and then there's still a need for the products that those were in,” said Ellie Browne, CU Boulder chemistry professor, CIRES Fellow, and co-author of the study. “So they get replaced by something.”
Measurement of aerosols led to a new and surprising discovery
Using a nitrate chemical ionization mass spectrometer, which allows scientists to identify chemical compounds in the air, the team measured air at the agricultural site 24 hours a day for one month. As Katz cataloged the data, he documented the different isotopic patterns in the compounds. The compounds measured by the team had distinct patterns, and he noticed new patterns that he immediately identified as different from the known chemical compounds. With some additional research, he identified them as chlorinated paraffins found in MCCPs.
Katz says the makeup of MCCPs are similar to PFAS, long-lasting toxic chemicals that break down slowly over time. Known as “forever chemicals,” their presence in soils recently led the Oklahoma Senate to ban biosolid fertilizer.
Now that researchers know how to measure MCCPs, the next step might be to measure the pollutants at different times throughout the year to understand how levels change each season. Many unknowns surrounding MCCPs remain, and there’s much more to learn about their environmental impacts.
“We identified them, but we still don’t know exactly what they do when they are in the atmosphere, and they need to be investigated further,” Katz said. “I think it's important that we continue to have governmental agencies that are capable of evaluating the science and regulating these chemicals as necessary for public health and safety.”
New laboratory earthquake model links real contact area to earthquake dynamics, opening a new pathway for earthquake prediction and early warning systems
Researchers have developed a laboratory earthquake model that connects the microscopic real contact area between fault surfaces to the possibility of earthquake occurrences. Published in the Proceedings of the National Academy of Sciences, this breakthrough demonstrates the connection between microscopic friction and earthquakes, offering new insights into earthquake mechanics and potential prediction.
“We’ve essentially opened a window into the heart of earthquake mechanics,” said Sylvain Barbot, associate professor of earth sciences at the USC Dornsife College of Letters, Arts and Sciences and principal investigator of the study. “By watching how the real contact area between fault surfaces evolves during the earthquake cycle, we can now explain both the slow buildup of stress in faults and the rapid rupture that follows. Down the road, this could lead to new approaches for monitoring and predicting earthquake nucleation at early stages.”
For decades, scientists have relied on empirical “rate-and-state” friction laws to model earthquakes — mathematical descriptions that work well but don’t explain the underlying physical mechanisms. “Our model reveals what’s actually happening at the fault interface during an earthquake cycle.”
Barbot says the discovery is a deceptively simple concept: “When two rough surfaces slide against each other, they only make contact at minuscule, isolated junctions covering a fraction of the total surface area.” This “real area of contact” — invisible to the eye but measurable through optical techniques — turns out to be the key state variable that controls earthquake behavior.
Laboratory earthquakes: Lighting earthquakes in real time
The study utilizes transparent acrylic materials that allowed the researchers to literally watch earthquake ruptures unfold in real time. Using high-speed cameras and optical measurements, the team tracked how LED light transmission changed as contact junctions formed, grew and were destroyed during laboratory earthquakes.
“We can literally watch the contact area evolve as ruptures propagate,” Barbot said. “During fast ruptures, we see approximately 30% of the contact area disappear in milliseconds — a dramatic weakening that drives the earthquake.”
The laboratory results revealed a previously hidden relationship: The empirical “state variable” used in standard earthquake models for decades represents the real area of contact between fault surfaces. This discovery provides the first physical interpretation of a mathematical concept that has been central to earthquake science since the 1970s.
From simulation to prediction
The researchers analyzed 26 different simulated earthquake scenarios and found that the relationship between rupture speed and fracture energy follows the predictions of linear elastic fracture mechanics. The team’s computer simulations successfully reproduced both slow and fast laboratory earthquakes, matching not only the rupture speeds and stress drops but also the amount of light transmitted across the fault interface during ruptures.
As contact areas change during the earthquake cycle, they affect multiple measurable properties including electrical conductivity, hydraulic permeability and seismic wave transmission. Since the real area of contact affects multiple physical properties of fault zones, continuous monitoring of these proxies during earthquake cycles could provide new insights into fault behavior.
The implications extend far beyond academic understanding and laboratory experiments. The research suggests that monitoring the physical state of fault contacts could provide new tools for earthquake short-term systems and potentially for reliable earthquake prediction using the electric conductivity of the fault.
“If we can monitor these properties continuously on natural faults, we might detect the early stages of earthquake nucleation,” Barbot explained. “This could lead to new approaches for monitoring earthquake nucleation at early stages, well before seismic waves are radiated.”
Looking ahead
The researchers plan to scale up their findings outside controlled laboratory conditions. Barbot explained: The study’s model provides the physical foundation for understanding how fault properties evolve during seismic cycles.
“Imagine a future where we can detect subtle changes in fault conditions before an earthquake strikes,” Barbot said. “That’s the long-term potential of this work.”
About the study: In addition to Barbot, Baoning Wu, formerly at USC and now at the University of California, San Diego, authored the study.
The study was supported by National Science Foundation award number EAR-1848192 and the Statewide California Earthquake Center proposal number 22105.
A new study from UCLA Health shows that the 2021 expanded Child Tax Credit helped prevent energy insecurity among middle-class families with children but provided no measurable benefit to the lowest-income households. Researchers found that when the credit expired, middle-class families experienced a significant increase in their inability to pay energy bills, while the poorest families saw no change, suggesting they hadn't benefited from the policy in the first place.
Why it matters
Energy insecurity—the inability to adequately meet basic heating, cooling, and energy needs—affects one in three U.S. households and poses serious health risks for families with children. The problem leads to dangerous coping mechanisms like unsafe space heaters that cause fires, impossible "heat or eat" choices between energy bills and other necessities, and increased parental stress that affects both adults and children. With energy costs rising and extreme weather becoming more frequent, finding effective policies to address energy insecurity is increasingly urgent. This study provides crucial evidence about how tax policy can be used to tackle this growing public health challenge.
What the study did
Researchers analyzed nationally representative survey data from 2021-2022, comparing what happened to energy insecurity when the expanded Child Tax Credit expired. They used a difference-in-differences approach, comparing changes in energy insecurity between households eligible for the credit (those with children) and ineligible households, during versus after the credit's expiration. The team also conducted separate analyses for different income groups, categorized by their percentage of the federal poverty level, to understand how benefits varied across economic strata.
What they found
There was a 4% relative increase, equivalent to approximately 308,560 families who could no longer pay their energy bills when the expanded Child Tax Credit expired. This effect was concentrated among middle-class families: households earning 200-400% and 400-600% of the federal poverty level experienced significant increases in energy insecurity after losing the credit. No differences were seen in the lowest-income groups (under 200% of federal poverty level), suggesting these families received no measurable energy security benefit from the expanded credit. The findings were specific to bill-paying ability and families having to choose between paying for energy and other basic needs like food or medicine. Effects may have been limited to middle income families because these families often have incomes just slightly over the cutoff (known as the “benefit cliff”) to receive other benefit programs, like the Supplemental Nutrition Assistance Program (SNAP) or the Low Income Home Energy Assistance Program (LIHEAP), even though they might need help with their food or electric bills. Researchers also found that lower income families have more competing needs to cover, and therefore are spending more of the child tax credit on other necessities like food or debt, leaving little left over to pay energy bills.
What's next
The differential impacts by income level raises a critical concern regarding middle class families needing assistance to meet their basic needs, as well as questions about how to design tax credits and other policies to effectively reach families in poverty. Researchers suggest that future studies should explore whether larger credit amounts might be needed to meaningfully impact the lowest-income households. The findings also highlight the need for continued research on energy insecurity as a public health issue, particularly in the setting of extreme weather events and increased energy demands and costs.
From the experts
"This study shows that the expanded Child Tax Credit provided meaningful benefits to middle class families struggling to pay their energy bills, but that the poorest families are being left out," said Dr. Cecile Yama, lead author of the study and physician at UCLA. "The fact that middle-class families saw reduced energy insecurity when they had the credit, but the poorest families didn't, tells us two things: middle class families need this financial support to survive, and our poorest families may need even more."
Drs. Cecile Yama and Jordan M. Rook from the National Clinician Scholars Program at UCLA; Drs. Lauren E. Wisk, Rebecca Dudovitz and David P. Eisenman; and Kathryn M. Leifheit all from the David Geffen School of Medicine at UCLA; and Dr. Diana Hernández from Columbia University's Mailman School of Public Health.
Funding and Disclosures
The authors have no conflicts of interest relevant to this article to disclose.
Victoria Glynn’s illustrations show the complex relationships between the coral animal, and the algae and bacteria that live with the coral. Taken together, this is called the coral holobiont. To understand resilience—how easily corals recover or respond to changes in their environment— it helps to be able to imagine all the different organisms that may play a role.
When Victoria Glynn came to Panama to study the effects of extreme ocean temperatures on coral reefs at the Smithsonian Tropical Research Institute (STRI) as a pre-doctoral fellow in professor Rowan Barrett’s lab at McGill University, she drew corals to explain her work to kids. Now, her illustrations help broader audiences reach an “Ah ha!” moment as she explains how corals from more variable ocean environments may be better equipped to survive rising ocean temperatures than corals from more stable environments—in a paper published in Current Biology.
Ask someone to draw a coral and they might draw a lump or a deer-antler shape, maybe with some fish or shells to illustrate its sea-floor setting. But Victoria’s drawings are much more intricate…because corals consist of the coral animal and its skeleton; the symbiotic algae, for energy capture; and a host of tiny bacteria…its microbiome--like we have in our guts, responsible for a lot of other functions. Scientists call this the coral holobiont, from the Greek for ‘the whole living thing’.
"Most people know that our gut microbiome plays a major role in our health, depending on our diet and the microbes we have. In many ways, corals are not so different," Victoria, now a post-doctoral associate at the University of Vermont, explains. "Their survival is intricately tied to their microbiomes. When I explain how corals stay healthy as their environment changes, I hope my drawings help people see just how complex they really are, and why it’s crucial to consider all the organisms involved: the coral animal, their symbiotic algae and the bacterial microbiome."
To survive, coral and their algae maintain a tight relationship, but when ocean water gets too hot, the algae often jump ship, leaving just the white coral skeleton behind, a phenomenon called coral bleaching.
Victoria did her doctoral work in Panama as part of the Rohr Reef Resilience Project led by Sean Connolly, STRI staff scientist. STRI’s location gives researchers easy access to the Tropical Eastern Pacific, an area of ocean extending from Ecuador’s Galapagos Islands north to Costa Rica’s Cocos Islands. This is a perfect natural laboratory for learning how corals respond to temperature extremes.
Project scientists take advantage of the frigid ocean currents that come to the surface in the Gulf of Panama to ask if corals growing there are more resilient to temperature extremes than corals in other places where temperatures are not so extreme, and why. In this study, they asked three big questions: How do high ocean temperatures affect the relationship between the coral animal and its algal partner? And what about its bacterial microbiome? And do these relationships explain how some corals are better able to survive at high temperatures?
The group sampled cauliflower corals (Pocillopora spp.) in the Gulf of Panama (where there are yearly temperature fluctuations) and in the Gulf of Chiriquí (nearby but with more stable year-round temperatures) and then ran an experiment to see what happens when they turn up the heat.
“We exposed corals to rapid heat stress in tanks on the yacht and, as the temperature climbed, we took samples so we could extract the DNA of the corals,their algae, and bacteria,” said Victoria. “This way, we gained insights into the relationships between the corals and the different members of their microbiome as the temperature rose.”
The corals themselves: Genetically, the corals from the two sites were similar, indicating that they must disperse easily along the coast, mixing different populations; but the few genetic differences between corals at the two sites may be important. The authors think that there could be differential selection on genes previously associated with the ability to resist thermal stress, with more ability to resist stress in the corals from the more variable Gulf of Panama.
The algae: The dynamics for the algae surprised them. In earlier experiments, at high temperatures, corals shifted to a different genus of algae that was more heat tolerant, but in this experiment, some corals kept their original algal partner.
The bacteria: The bacterial microbiome from corals at both sites was disrupted by higher temperatures, rapidly entering a disease-like state. But compared to previous studies on Australia’s Great Barrier Reef, the corals from the Gulf of Panama had less stable microbiomes at high temperatures.
The Australian experiments lasted longer—from weeks to months—and corals experienced temperatures ~4-5°C above their mean monthly maximum temperature, which can be thought of as the average hottest temperatures experienced. In the Panama experiment, which were less than 24 hours long, corals were exposed 10.5°C above their mean monthly maximum temperatures, and the microbes associated with the corals changed to a more diseased state at around 7.5°C above the hottest average temperatures.
To disrupt the relationship between corals and their bacteria, it took higher temperatures that the temperatures it took to stress out the coral animal itself, suggesting that for the Pocillopora corals in Panama, it’s more likely that a coral will die at high temperatures even before its microbiome is severely affected.
Overall:At the highest temperatures, the corals collected from the Gulf of Panama, where temperatures are more variable, handled the heat better. But corals from the stable-temperature environment struggled when they were heated.
The team’s findings support the idea that the Tropical Eastern Pacific’s naturally variable environments may contribute to these corals’ enhanced ability to withstand heat. This may explain why these reefs were able to bounce back after the catastrophic 1982 El Niño Southern Oscillation event.
“Coral reefs cover just 0.1% of Earth's surface but they support around 25% of all marine life. Reefs also provide critical services to more than a billion people globally, through fisheries, tourism, coastal protection, and cultural significance. As ocean temperatures continue to rise, coral reefs are increasingly under threat,” said Victoria. “Understanding what makes some corals more resilient to warming oceans will be essential for guiding conservation efforts, protecting coastal communities, and safeguarding biodiversity. When we think about these complex organisms, we need to get away from two-partner thinking and view them as an integrated whole,” said Victoria, “my artwork helps me do that, and also lets me share my love for the beauty of nature, and my passion for conserving the underwater world.”
Funding for the CBASS experiment was provided by the Mark and Rachel Rohr Foundation. Additional support was provided to lead author Victoria Glynn through a Fulbright U.S. Scholar Grant and a Vanier Canada Graduate Scholarship, which supported the molecular work, data analysis, and manuscript preparation. Further support came from the Smithsonian Tropical Research Institute, NSERC, and others.
About the Smithsonian Tropical Research Institute
Headquartered in Panama City, Panama, STRI is a unit of the Smithsonian Institution whose mission is to understand tropical biodiversity and its importance to human welfare, trains students to conduct research in the tropics and promotes conservation by increasing public awareness of the beauty and importance of tropical ecosystems. Watch STRI’s video and visit the institute on its website and on Facebook, X and Instagram for updates.
Victoria Glynn’s illustrations show the complex relationships between the coral animal, and the algae and bacteria that live with the coral. Taken together, this is called the coral holobiont. To understand resilience—how easily corals recover or respond to changes in their environment— it helps to be able to imagine all the different organisms that may play a role.
University of Otago – Ōtākou Whakaihu Waka scientists have discovered that it takes mere minutes for a species of sex-changing fish to develop dominant behaviour after a change in the pecking order.
The new study led by the Department of Anatomy and published on Proceedings of the Royal Society B, examines the New Zealand spotty, or paketi, a fish that can change from female to male during adulthood in response to a change in social hierarchy.
It found that the sex change process begins almost immediately when a dominant spotty is removed from a group.
Lead author Haylee Quertermous, a PhD Candidate in the Department of Anatomy, says although the full sex change process takes weeks, it only takes minutes for a second-ranked fish to take advantage of the power vacuum and assert dominant behaviours.
“The aggressive behaviours (called ‘rushes’) involved the dominant fish swimming rapidly towards subordinate individuals,” she says.
“Sometimes the dominant fish will make physical contact with the subordinates, including taking bites at them, usually around their tail and fins. These aggressive behaviors are usually accompanied by the subordinate quickly swimming away (‘escaping’) from the dominant fish.”
While she expected to be able to see behavior changes within an hour of removing the dominant fish, she was surprised by just how rapid the change could be.
“In many of the tanks, second-ranked fish increased their aggression within just a few minutes after removal of the dominant fish.”
She cautions the dominant behaviour that accompanies a female to male sex change in spotties does not indicate a change from typically ‘female’ to ‘male’ behaviour, as other sex-changing fish species such as clownfish for example, change from male to more dominant female fish.
The researchers observed that spotties form linear dominance hierarchies based on size, with larger individuals dominating smaller ones.
They sought to determine which fish in the hierarchy were more likely to change sex when the opportunity arose.
Results show dominant, larger fish are more likely to change sex, and when social hierarchies are disrupted, less dominant fish can quickly change their behavior to seize new opportunities.
The study also delved into the neural mechanisms underlying spotties’ social interactions, finding that the social decision-making network in the fish brain is highly involved in establishing dominance.
Fish that attained dominant positions showed significant differences in this network compared to fish of all other ranks.
Dr Kaj Kamstra, who led the neurobiological aspects of the research, says the findings provide valuable insights into the complex interplay between social behavior and neural processes in these fish.
“They also highlight the importance of social context in shaping individual behavior, shedding light on the evolution of social behavior and the flexibility of brain mechanisms in adapting to changing social environments.
“The research has broader implications for understanding social dynamics in other species, even humans.”
The findings can be applied to other species of sex-changing fish where social dominance appears to be the most common trigger for sex change, and could prove beneficial for aquaculture and open water fisheries, with many commercial valuable fisheries dependent on fishes that change sex, for example, New Zealand’s blue cod.
Journal
Proceedings of the Royal Society B Biological Sciences
June 5, 2025 – A new study in Scientific Reports reveals the hidden pain of fish during slaughter and offers practical solutions to improve their welfare. Focusing on rainbow trout, the research quantifies pain in air asphyxia—a common slaughter method—using the innovative Welfare Footprint Framework (WFF). With up to 2.2 trillion wild and 171 billion farmed fish killed annually, the findings highlight an opportunity for welfare reforms on a massive scale.
The study shows rainbow trout endure an average of 10 minutes of intense pain during air asphyxia, with estimates ranging from 2 to 22 minutes depending on factors like fish size and water temperature. This translates to approximately 24 minutes of pain per kilogram of fish. These estimates are based on a comprehensive review of existing research to assess the intensity and duration of pain and distress experienced by the fish.
Crucially, the study also assesses the cost-effectiveness of interventions. If implemented properly, electrical stunning could avert 60 to 1,200 minutes of moderate to extreme pain for every U.S. dollar of capital cost. Percussive stunning offers high welfare potential as well, though challenges remain in achieving consistency in commercial settings. The study also notes that pre-slaughter practices such as crowding and transport – often overlooked – are likely to even cause greater cumulative suffering than the slaughter itself.
At the heart of this study is the Welfare Footprint Framework (WFF), developed by the Center for Welfare Metrics, a novel method that quantifies animal welfare by estimating the total time animals spend in various states of suffering or well-being. By assigning time-based values to subjective experiences, the WFF allows for direct comparisons between different animal welfare interventions, much like environmental footprints or health impact assessments in human contexts, in familiar terms that anyone can understand.
Dr. Wladimir Alonso, who conceptualized the method, explains, "The Welfare Footprint Framework provides a rigorous and transparent evidence-based approach to measuring animal welfare, and enables informed decisions about where to allocate resources for the greatest impact."
This study’s results could help shape regulatory discussions, improve certification standards, and guide welfare investments that deliver the greatest benefit per dollar spent.
Publication: Schuck-Paim et al. (2025). Quantifying the welfare impact of air asphyxia in rainbow trout slaughter for policy and practice. Scientific Reports. DOI: 10.1038/s41598-025-04272-1
For more information: media@welfarefootprint.org.
The Welfare Footprint Framework is freely available for research and policy use at welfarefootprint.org.
