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)
Sunday, May 04, 2025
PSU study gauges public's willingness on microplastic interventions
Laundry is a major source of microplastic pollution into the environment, and in-line washing machine filters are one potential solution for preventing fibers from entering waterways. But how likely would people be willing to pay for them?
Portland State researchers surveyed a sample of registered voters and environmental interest groups in Oregon to gauge respondents' general knowledge and concerns surrounding microplastics, as well as their willingness to pay for high-efficiency washing machine filters. The researchers hope the study can provide greater insights for policymakers. Currently, Oregon Senate Bill 526 is under committee consideration, which would require new clothes washers sold in the state to have a microfiber filtration system by 2030.
Findings show that less than a quarter of all 664 respondents would be willing to pay full price for a high-efficiency external filter, indicating the need for filters to be included in point of sale purchases rather than after the fact. A limited-scale early adopter program may be a feasible transitional implementation option. Up to 20% more people support filter adoption on their existing washing machines if part of the cost were covered by a government subsidy.
“Washing machines are a major source of microfibers and microplastics entering our wastewater systems and ultimately our waterways," said Elise Granek, study co-author and a professor of environmental science and management at PSU. "Mandating washing machine filters at the point of sale has been identified as a tool to significantly reduce this source of microplastics entering aquatic environments.”
Still, the researchers say the filters are not a full solution on their own and policymakers must continue to give attention to source reduction, investment in plastic alternatives and improved industry regulations.
The study was published in the journal Microplastics and Nanoplastics. Authors include Amanda Gannon, a graduate of PSU's master's in environmental management program; Elise Granek and Max Nielsen-Pincus, professors of environmental science and management at PSU; and Luke Harkins, chief of staff for Oregon Rep. David Gomberg.
Neurons in the ventral visual cortical pathway help our brains make visual sense of the world. A new study finds that these neurons adapt moment to moment to the input they receive. The findings could lead to potential insights on cognitive disorders such as autism spectrum disorder.
Credit: Laboratory of Neurobiology at The Rockefeller University.
Our brains begin to create internal representations of the world around us from the first moment we open our eyes. We perceptually assemble components of scenes into recognizable objects thanks to neurons in the visual cortex.
This process occurs along the ventral visual cortical pathway, which extends from the primary visual cortex at the back of the brain to the temporal lobes. It’s long been thought that specific neurons along this pathway handle specific types of information depending on where they are located, and that the dominant flow of visual information is feedforward, up a hierarchy of visual cortical areas. Although the reverse direction of cortical connections, often referred to as feedback, has long been known to exist, its functional role has been little understood.
Ongoing research from the lab of Rockefeller University’s Charles D. Gilbert is revealing an important role for feedback along the visual pathway. As his team demonstrates in a paper recently published in PNAS, this countercurrent stream carries so-called “top down” information across cortical areas that is informed by our prior encounters with an object. One consequence of this flow is that neurons in this pathway aren’t fixed in their responsiveness but can adapt moment to moment to the information they’re receiving.
“Even at the first stages of object perception, the neurons are sensitive to much more complex visual stimuli than had previously been believed, and that capability is informed by feedback from higher cortical areas,” says Gilbert, head of the Laboratory of Neurobiology.
A different flow
Gilbert’s lab has investigated fundamental aspects of how information is represented in the brain for many years, primarily by studying the circuitry underlying visual perception and perceptual learning in the visual cortex.
“The classical view of this pathway proposes that neurons at its beginning can only perceive simple information such as a line segment, and that complexity increases the farther up the hierarchy you go until you reach the neurons that will only respond to a specific level of complexity,” he says.
Previous findings from his lab indicate that this view may be incorrect. His group has, for example, found that the visual cortex is capable of altering its functional properties and circuitry, a quality known as plasticity. And in work done with his Rockefeller colleague (and Nobel Prize winner) Torsten N. Wiesel, Gilbert discovered long-range horizontal connections along cortical circuits, which enable neurons to link bits of information over much larger areas of the visual field than had been thought. He’s also documented that neurons can switch their inputs between those that are task relevant and those that are task irrelevant, underscoring the dexterity of their functional properties.
“For the current study, we were trying to establish that these capabilities are part of our normal process of object recognition,” he says.
Seeing is understanding
Gilbert’s lab spent several years studying a pair of macaques that had been trained in object recognition using images of a variety of objects the animals may or may not have had familiarity with, such as fruits, vegetables, tools, and machines. As the animals learned to recognize these objects, the researchers monitored their brain activity using fMRI to identify which regions responded to the visual stimuli. (This method was pioneered by Gilbert’s Rockefeller colleague Winrich Freiwald, who has used it to identify regions of the brain that are responsive to faces.)
They then implanted electrode arrays, which enabled them to record the activity of individual nerve cells as the animals were shown images of the objects they’d been trained to recognize. Sometimes they were shown the full object, and other times a partial or tightly cropped image. Then they were shown a variety of different visual stimuli and indicated whether they found a match to the original object or not.
“These are called delayed match-to-sample tasks because there is a delay between when they see an object cue and when they are shown a second object or object component, to which they are trained to report whether the second image corresponds to the initial cue,” Gilbert says. “While they’re looking through all the visual stimuli to find a match, they have to use their working memory to keep in mind the original image.”
Adaptive processing
The researchers found that over a range of visual targets, a single neuron may be more responsive to one target, and with another cue, they’ll be more responsive to a different target.
“We learned these neurons are adaptive processors that change on a moment-to-moment basis, taking on different functions that are appropriate for the immediate behavioral context,” Gilbert says.
They also demonstrated that the neurons found at the beginning of the pathway, thought to be limited to responding to simple visual information, were not actually so constrained in their abilities.
“These neurons are sensitive to much more complex visual stimuli than had previously been believed,” he says. “There doesn’t seem to be as large of a difference in terms of the degree of complexity represented in the early cortical areas relative to the higher cortical areas as previously thought.”
These findings bolster what Gilbert believes is a novel view of cortical processing: that adult neurons do not have fixed functional properties but are instead dynamically tuned, changing their specificities with varying sensory experience.
Observation of cortical activity also revealed a potential functional role of reciprocal feedback connections in object recognition, where the flow of information from higher cortical areas to these lower ones contributes to their dynamic capabilities.
“We discovered that these so-called ‘top-down’ feedback connections convey information from areas of the visual cortex that represent previously stored information about the nature and identity of objects, which is acquired through experience and behavioral context,” he says. “In a sense, the higher-order cortical areas send an instruction to the lower areas to perform a particular calculation, and the return signal—the feedforward signal—is the result of that calculation. These interactions are likely to be operating continually as we recognize an object and, more broadly speaking, make visual sense of our surroundings.”
Autism research applications
The findings are part of an increasing recognition of the importance and prevalence of feedback information flow in the visual cortex—and perhaps far beyond.
“I would argue that top-down interactions are central to all brain functions, including other senses, motor control, and higher order cognitive functions, so understanding the cellular and circuit basis for these interactions could expand our understanding of the mechanisms underlying brain disorders,” Gilbert says.
To that end, his lab is beginning to investigate animal models of autism both at the behavioral and the imaging level. Will Snyder, a research specialist in Gilbert’s lab, will study perceptual differences between autism-model mice and their wild-type littermates. In conjunction, the lab will observe large neuronal populations in the animals’ brains as they engage in natural behaviors using the highly advanced neuroimaging technologies in the Elizabeth R. Miller Brain Observatory, an interdisciplinary research center located on Rockefeller’s campus.
“Our goal is to see if we can identify any perceptual differences between these two groups and the operation of cortical circuits that may underly these differences,” Gilbert says.
The disappearance of sea ice in polar regions due to global warming not only increases the amount of light entering the ocean, but also changes its color. These changes have far-reaching consequences for photosynthetic organisms such as ice algae and phytoplankton. That is the conclusion of new research published in Nature Communications, led by marine biologists Monika Soja-Woźniak and Jef Huisman from the Institute for Biodiversity and Ecosystem Dynamics (IBED) at the University of Amsterdam.
The international research team, which also included physical chemist Sander Woutersen (HIMS/UvA) and collaborators from the Netherlands and Denmark, investigated how the loss of sea ice alters the underwater light environment. Sea ice and seawater differ fundamentally in how they transmit light. Sea ice strongly scatters light and reflects much of it, while allowing only a small amount to penetrate. Yet, this limited amount of light still contains almost the full range of visible wavelengths. In contrast, seawater absorbs red and green light, while blue light penetrates deep into the water column. This is what gives the ocean its blue color.
Molecular vibrations of water
Another key difference between ice and liquid water lies in the role of molecular vibrations. In liquid water, H₂O molecules are free to move and vibrate, which leads to the formation of distinct absorption bands at specific wavelengths. These bands selectively remove portions of the light spectrum, creating gaps in the light available for photosynthesis.
Previous research by Maayke Stomp and Prof. Huisman demonstrated that these molecular absorption features create ‘spectral niches’—distinct sets of wavelengths available for photosynthetic organisms. Phytoplankton and cyanobacteria have evolved a diversity of pigments tuned to the different spectral niches, shaping their global distribution across oceans, coastal waters, and lakes.
In ice, however, water molecules are locked into a rigid crystal lattice. This fixed structure suppresses their ability for molecular vibrations and thereby alters their absorption features. As a consequence, ice lacks the absorption bands of liquid water, and hence a broader spectrum of light is preserved under sea ice. This fundamental difference plays a key role in the spectral shift that occurs as sea ice melts.
Ecological implications
As sea ice disappears and gives way to open water, the underwater light environment shifts from a broad spectrum of colors to a narrower, blue-dominated spectrum. This spectral change is crucial for photosynthesis.
“The photosynthetic pigments of algae living under sea ice are adapted to make optimal use of the wide range of colors present in the little amount of light passing through ice and snow,” says lead author Monika Soja-Woźniak. “When the ice melts, these organisms suddenly find themselves in a blue-dominated environment, which provides a lesser fit for their pigments.”
Using optical models and spectral measurements, the researchers showed that this shift in light color not only alters photosynthetic performance, but may also lead to changes in species composition. Algal species specialized in blue light may gain a strong competitive advantage in comparison to ice algae.
According to Prof. Huisman, these changes can have cascading ecological effects. “Photosynthetic algae form the foundation of the Arctic food web. Changes in their productivity or species composition can ripple upward to affect fish, seabirds, and marine mammals. Moreover, photosynthesis plays an important role in natural CO2 uptake by the ocean.”
The study highlights that climate change in the polar regions does more than melt ice—it causes fundamental shifts in key processes such as light transmission and energy flow in marine ecosystems.
The results underscore the importance of incorporating light spectra and photosynthesis more explicitly in climate models and ocean forecasts, especially in polar regions where environmental change is accelerating at an unprecedented rate.
Publication data:
Soja-Woźniak M, Holtrop T, Woutersen S, van der Woerd HJ, Lund-Hansen LC & Huisman J. 2025. Loss of sea ice alters light spectra for aquatic photosynthesis. Nature Communications 16: 4059.
This photograph taken by an International Space Station astronaut shows a bright meteor from the Perseid meteor shower in Earth’s atmosphere. The brightest meteors are known as fireballs, or bolides
Every year, Earth gets a bit bigger. Thousands of metric tons of space dust fall from the sky, while about 50 tons per year of meteorites crash land somewhere on the surface. Since the 1960s, space junk has also occasionally returned to Earth, falling from a hazy sphere of trash encircling the planet. Remnants of rockets, tools lost by space-walking astronauts, defunct satellites, and more fly through lower Earth orbit, reaching speeds of 18,000 miles per hour. When any item—whether space rock or space junk—enters the atmosphere, scientists try to track its path to estimate where it will land. Will the item in question plunk straight down, or will it fly along at an angle before skittering to a halt? In a news tudy to be presented at the General Assembly of the European Geosciences Union next week, Elizabeth Silber, a scientist at Sandia National Laboratories, will consider how infrasound sensors—instruments that detect sounds at lower frequencies than humans can hear—listen for bolides. Bolides are the bright flashes and booms from large meteoroids breaking apart high in the sky. These events release huge amounts of energy, creating shock waves that travel as infrasound signals across thousands of kilometers. But here’s the challenge: bolides aren’t like explosions that happen in one place. They are moving, generating sound along their path as they travel through the sky. This movement matters, especially for meteoroids and space debris that enter shallow angles. In those cases, different infrasound stations might pick up signals coming from different directions, making it harder to pinpoint the source.
Motivated by this problem, Silber used a network of infrasound sensors around the world maintained by the Comprehensive Test Ban Treaty Organization (CTBTO), an organization tasked with listening for illicit explosions. These instruments also record anything else that claps or booms, from thunder to supersonic aircraft. Using signals specifically from bolides, Silber isolated the purely geometric component for her analysis. She found that if a bolide enters Earth’s atmosphere at a relatively steep angle— greater than 60°—analysis of the infrasound signal gets the trajectory right. But when it comes more horizontally, the uncertainty increases.
“Infrasound from a bolide is more like a sonic boom stretched across the sky than a single bang,” Silber says. "You must account for the fact that the sound is being generated along the flight path.”
And so, this study highlights a critical need: to consider the trajectory of an object when interpreting infrasound data. Infrasound instruments are indispensable for planetary defense, according to Silber, and the findings are relevant to Earth-bound space junk. If you don’t know where something is going, then you have a hard time preparing for it. If you’d like to learn more, don’t miss the full PICO presentation on Friday, 02 May at 11:28-11:30 CEST at PICO spot 5. If you’re interested in scientific applications of data collected by the International Monitoring System managed by the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), check out the full SM8.5 PICO session on Friday, 02 May, starting at 10:45 CEST. PICO sessions are given in hybrid format supported by a zoom meeting.
Dr. Silber will be attending virtually, and would be happy to answer questions via email Caption: This photograph taken by an International Space Station astronaut shows a bright meteor from the Perseid meteor shower in Earth’s atmosphere. The brightest meteors are known as fireballs, or bolides. Credit: NASA Note to the media When reporting on this story, please mention the EGU General Assembly 2025, which is taking place from 27 April– 02 May 2025. This paper will be presented in full [Session SSP1.2] at EGU25 on Fri, 02 May, 10:45–12:30 (CEST) PICO spot 5. If reporting online, please include a link to the session: https://meetingorganizer.copernicus.org/EGU25/session/53597
More information
The European Geosciences Union (EGU) is Europe’s premier geosciences union, dedicated to the pursuit of excellence in the Earth, planetary, and space sciences for the benefit of humanity, worldwide. It is a non-profit interdisciplinary learned association of scientists founded in 2002 with headquarters in Munich, Germany. The EGUpublishes a number of diverse scientific journals, which use an innovative open access format, and organises several topical meetings, and education and outreach activities. Its annual General Assembly is the largest and most prominent European geosciences event, attracting over 19,000 scientists from all over the world. The meeting’s sessions cover a wide range of topics, including volcanology, planetary exploration, the Earth’s internal structure and atmosphere, climate, energy, and resources. The EGU General Assembly 2025 is taking place in Vienna, Austria and online from 27 April– 02 May 2025. For information and press registration, please click here. If you wish to receive our press releases via email, please use the Press Release Subscription Form. Subscribed journalists and other members of the media receive EGUpress releases under embargo (if applicable) 24 hours in advance of public disseminate EGU25 website (https://www.egu25.eu/) has a tab titled ‘Media’ where you will find the full list of press conferences and presentations of media interest. Weencourage members of the press to browse the virtual EGU25 Press Centre (https://www.egu.eu/gamedia/2025/) for our Media Tip Sheets and Media Highlights of the General Assembly 2025
About the EGU
The European Geosciences Union (EGU) is the leading organisation for Earth, planetary and space science research in Europe. With our partner organisations worldwide, we foster fundamental geoscience research, alongside applied research that addresses key societal and environmental challenges. Our vision is to realise a sustainable and just future for humanity and for the planet. The annual EGU General Assembly is the largest and most prominent European geosciences event, attracting over 19,000 scientists from all over the world. The meeting’s sessions cover a wide range of topics, including volcanology, planetary exploration, the Earth’s internal structure and atmosphere, climate, as well as energy and resources. For more information about the meeting please check media.egu.eu or follow EGU on social media.
As Europe increases its reliance on solar energy to meet climate and energy security targets, a growing atmospheric phenomenon is complicating the path forward: Saharan dust. New research presented at the European Geosciences Union General Assembly (EGU25) shows that mineral dust carried on the wind from North Africa is not only reducing photovoltaic (PV) electricity generation across Europe but also making it harder to predict. In their presentation at EGU25, The shadow of the wind: photovoltaic power generation under Europe’s dusty skies, Dr. György Varga and collaborators from Hungarian and European institutions reveal how dust-laden skies disrupt PV performance and challenge existing forecasting models. Their work, grounded in field data from more than 46 Saharan dust events between 2019 and 2023, spans both Central Europe (Hungary) and Southern Europe (Portugal, Spain, France, Italy, and Greece).
The Sahara releases billions of tonnes of fine dust into the atmosphere every year, and tens of millions of tonnes reach European skies. These particles scatter and absorb sunlight, reduce irradiance at the surface, and can even promote cloud formation — all of which degrade PV output. The researchers found that conventional forecasting tools, which use static aerosol climatologies, frequently miss the mark during these events. Instead, the team recommends integrating near-real-time dust load data and aerosol-cloud coupling into forecasting models. This would allow for more reliable scheduling of solar energy and better preparedness for the variability introduced by atmospheric dust.
“There’s a growing need for dynamic forecasting methods that account for both meteorological and mineralogical factors,” says Varga.
“Without them, the risk of underperformance and grid instability will only grow as solar becomes a larger part of our energy mix.”
Beyond atmospheric effects, the team also points out to the long-term impacts of dust on the physical infrastructure of solar panels, including contamination and erosion — factors that can further reduce efficiency and increase maintenance costs. This research contributes to ongoing efforts in Hungary and the EU to improve climate resilience and renewable energy management. It is supported by the National Research, Development and Innovation Office (FK138692), the Hungarian Academy of Sciences, and the EU-funded National Multidisciplinary Laboratory for Climate Change.
Note to the media
When reporting on this story, please mention the EGU General Assembly 2025, which is taking place from 27 April – 02 May 2025.
EGU Press Contact Asmae Ourkiya Media and Communication Officer media@egu.eu
More information
The European Geosciences Union (EGU) is Europe’s premier geosciences union, dedicated to the pursuit of excellence in the Earth, planetary, and space sciences for the benefit of humanity, worldwide. It is a non-profit interdisciplinary learned association of scientists founded in 2002 with headquarters in Munich, Germany. The EGU publishes a number of diverse scientific journals, which use an innovative open access format, and organises several topical meetings, and education and outreach activities. Its annual General Assembly is the largest and most prominent European geosciences event, attracting over 19,000 scientists from all over the world. The meeting’s sessions cover a wide range of topics, including volcanology, planetary exploration, the Earth’s internal structure and atmosphere, climate, energy, and resources. The EGU General Assembly 2025 is taking place in Vienna, Austria and European Geosciences Union Press Releases 2025 Vienna, Austria and Online | 27 April – 02 May 2025 | media@egu.eu While media briefings and sessions are hosted by the EGU, research presented at the General Assembly is the responsibility of each presenter and does not necessarily reflect the views of the EGU. online from 27 April – 02 May 2025. For information and press registration, please click here. If you wish to receive our press releases via email, please use the Press Release Subscription Form. Subscribed journalists and other members of the media receive EGU press releases under embargo (if applicable) 24 hours in advance of public disseminate EGU25 website (https://www.egu25.eu/) has a tab titled ‘Media’ where you will find the full list of press conferences and presentations of media interest. We encourage members of the press to browse the virtual EGU25 Press Centre (https://www.egu.eu/gamedia/2025/) for our Media Tip Sheets and Media Highlights of the General Assembly 2025.
About the EGU
The European Geosciences Union (EGU) is the leading organisation for Earth, planetary and space science research in Europe. With our partner organisations worldwide, we foster fundamental geoscience research, alongside applied research that addresses key societal and environmental challenges. Our vision is to realise a sustainable and just future for humanity and for the planet. The annual EGU General Assembly is the largest and most prominent European geosciences event, attracting over 19,000 scientists from all over the world. The meeting’s sessions cover a wide range of topics, including volcanology, planetary exploration, the Earth’s internal structure and atmosphere, climate, as well as energy and resources. For more information about the meeting please check media.egu.eu or follow EGU on social media.
