Jul 20, 2024

Another intermediate-mass black hole discovered at the center of our galaxy

While researching a cluster of stars in the immediate vicinity of the supermassive black hole SgrA* (Sagittarius A*) at the centre of our galaxy, an international team of researchers led by PD Dr Florian Peißker has found signs of another, intermediate-mass black hole. Despite enormous research efforts, only about ten of these intermediate-mass black holes have been found in our entire universe so far. Scientists believe that they formed shortly after the Big Bang. By merging, they act as 'seeds' for supermassive black holes. The study 'The Evaporating Massive Embedded Stellar Cluster IRS 13 Close to Sgr A*. II. Kinematic structure' was published in The Astrophysical Journal.

The analysed star cluster IRS 13 is located 0.1 light years from the centre of our galaxy.

This is very close in astronomical terms, but would still require travelling from one end of our solar system to the other twenty times to cover the distance.

The researchers noticed that the stars in IRS 13 move in an unexpectedly orderly pattern.

They had actually expected the stars to be arranged randomly.

Two conclusions can be drawn from this regular pattern: On the one hand, IRS 13 appears to interact with SgrA*, which leads to the orderly motion of the stars.

On the other hand, there must be something inside the cluster for it to be able to maintain its observed compact shape.

Multi-wavelength observations with the Very Large Telescope as well as the ALMA and Chandra telescopes now suggest that the reason for the compact shape of IRS 13 could be an intermediate-mass black hole located at the centre of the star cluster.

This would be supported by the fact that the researchers were able to observe characteristic X-rays and ionized gas rotating at a speed of several 100 km/s in a ring around the suspected location of the intermediate-mass black hole.

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Waste Styrofoam can now be converted into polymers for electronics

University of Delaware and Argonne National Laboratory have come up with a chemical reaction that can convert Styrofoam into a high-value conducting polymer known as PEDOT:PSS. In a new paper published in JACS Au, the study demonstrates how upgraded plastic waste can be successfully incorporated into functional electronic devices, including silicon-based hybrid solar cells and organic electrochemical transistors.

The research group of corresponding author Laure Kayser, assistant professor in the Department of Materials Science and Engineering in UD's College of Engineering with a joint appointment in the Department of Chemistry and Biochemistry in the College of Arts and Sciences, regularly works with PEDOT:PSS, a polymer that has both electronic and ionic conductivity, and was interested in finding ways to synthesize this material from plastic waste.

After connecting with Argonne chemist David Kaphan during an event hosted by UD's research office, the research teams at UD and Argonne began evaluating the hypothesis that PEDOT:PSS could be made by sulfonating polystyrene, a synthetic plastic found in many types of disposable containers and packing materials.

Sulfonation is a common chemical reaction where a hydrogen atom is replaced by sulfonic acid; the process is used to create a variety of products such as dyes, drugs and ion exchange resins. These reactions can either be "hard" (with higher conversion efficiency but that require caustic reagents) or "soft" (a less efficient method but one that uses milder materials).

In this paper, the researchers wanted to find something in the middle: "A reagent that is efficient enough to get really high degrees of functionalization but that doesn't mess up your polymer chain," Kayser explained.

The researchers first turned to a method described in a previous study for sulfonating small molecules, one that showed promising results in terms of efficiency and yield, using 1,3-Disulfonic acid imidazolium chloride ([Dsim]Cl). But adding functional groups onto a polymer is more challenging than for a small molecule, the researchers explained, because not only are unwanted byproducts harder to separate, any small errors in the polymer chain can change its overall properties.

To address this challenge, the researchers embarked on many months of trial and error to find the optimal conditions that minimized side reactions, said Kelsey Koutsoukos, a materials science doctoral candidate and second author of this paper.

"We screened different organic solvents, different molar ratios of the sulfonating agent, and evaluated different temperatures and times to see which conditions were the best for achieving high degrees of sulfonation," he said.

The researchers were able to find reaction conditions that resulted in high polymer sulfonation, minimal defects and high efficiency, all while using a mild sulfonating agent. And because the researchers were able to use polystyrene, specifically waste Styrofoam, as a starting material, their method also represents an efficient way to convert plastic waste into PEDOT:PSS.

Once the researchers had PEDOT:PSS in hand, they were able to compare how their waste-derived polymer performed compared to commercially available PEDOT:PSS.

"In this paper, we looked at two devices -- an organic electronic transistor and a solar cell," said Chun-Yuan Lo, a chemistry doctoral candidate and the paper's first author. "The performance of both types of conductive polymers was comparable, and shows that our method is a very eco-friendly approach for converting polystyrene waste into high-value electronic materials."

Specific analyses conducted at UD included X-ray photoelectron spectroscopy (XPS) at the surface analysis facility, film thickness analysis at the UD Nanofabrication Facility, and solar cell evaluation at the Institute of Energy Conversion. Argonne's advanced spectroscopy equipment, such as carbon NMR, was used for detailed polymer characterization. Additional support was provided by materials science and engineering professor Robert Opila for solar cell analysis and by David C. Martin, the Karl W. and Renate Böer Chaired Professor of Materials Science and Engineering, for the electronic device performance analyses.

One unexpected finding related to the chemistry, the researchers added, is the ability to use stoichiometric ratios during the reaction.

"Typically, for sulfonation of polystyrene, you have to use an excess of really harsh reagents. Here, being able to use a stoichiometric ratio means that we can minimize the amount of waste being generated," Koutsoukos said.

This finding is something the Kayser group will be looking into further as a way to "fine-tune" the degree of sulfonation. So far, they've found that by varying the ratio of starting materials, they can change the degree of sulfonation on the polymer. Along with studying how this degree of sulfonation impacts the electrical properties of PEDOT:PSS, the team is interested in seeing how this fine-tuning capability can be used for other applications, such as fuel cells or water filtration devices, where the degree of sulfonation greatly impacts a material's properties.

"For the electronic devices community, the key takeaway is that you can make electronic materials from trash, and they perform just as well as what you would purchase commercially," Kayser said. "For the more traditional polymer scientists, the fact that you can very efficiently and precisely control the degree of sulfonation is going to be of interest to a lot of different communities and applications."

The researchers also see great potential for how this research can contribute to ongoing global sustainability efforts by providing a new way to convert waste products into value-added materials.

"Many scientists and researchers are working hard on upcycling and recycling efforts, either by chemical or mechanical means, and our study provides another example of how we can address this challenge," Lo said.

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Ancient microbes offer clues to how complex life evolved

A new study published in Science Advances reveals a surprising twist in the evolutionary history of complex life. Researchers at Queen Mary University of London have discovered that a single-celled organism, a close relative of animals, harbors the remnants of ancient giant viruses woven into its own genetic code. This finding sheds light on how complex organisms may have acquired some of their genes and highlights the dynamic interplay between viruses and their hosts.

The study focused on a microbe called Amoebidium, a unicellular parasite found in freshwater environments.

By analysing Amoebidium's genome, the researchers led by Dr Alex de Mendoza Soler, Senior Lecturer at Queen Mary's School of Biological and Behavioural Sciences, found a surprising abundance of genetic material originating from giant viruses -- some of the largest viruses known to science.

These viral sequences were heavily methylated, a chemical tag that often silences genes.

"It's like finding Trojan horses hiding inside the Amoebidium's DNA," explains Dr de Mendoza Soler.

"These viral insertions are potentially harmful, but Amoebidium seems to be keeping them in check by chemically silencing them."

The researchers then investigated how widespread this phenomenon might be. They compared the genomes of several Amoebidium isolates and found significant variation in the viral content.

This suggests that the process of viral integration and silencing is ongoing and dynamic.

"These findings challenge our understanding of the relationship between viruses and their hosts," says Dr. de Mendoza Soler.

"Traditionally, viruses are seen as invaders, but this study suggests a more complex story. Viral insertions may have played a role in the evolution of complex organisms by providing them with new genes. And this is allowed by the chemical taming of these intruders DNA."

Read more at Science Daily

Jul 18, 2024

Sun-like stars found orbiting hidden companions

Most stars in our universe come in pairs. While our own Sun is a loner, many stars like our Sun orbit similar stars, while a host of other exotic pairings between stars and cosmic orbs pepper the universe. Black holes, for example, are often found orbiting each other. One pairing that has proved to be quite rare is that between a Sun-like star and a type of dead star called a neutron star.

Now, astronomers led by Caltech's Kareem El-Badry have uncovered what appear to be 21 neutron stars in orbit around stars like our Sun. Neutron stars are dense burned-out cores of massive stars that exploded. On their own, they are extremely faint and usually cannot be detected directly. But as a neutron star orbits around a Sun-like star, it tugs on its companion, causing the star to shift back and forth in the sky. Using the European Space Agency's Gaia mission, the astronomers were able to catch these telltale wobbles to reveal a new population of dark neutron stars.

"Gaia is continuously scanning the sky and measuring the wobbles of more than a billion stars, so the odds are good for finding even very rare objects," says El-Badry, an assistant professor of astronomy at Caltech and an adjunct scientist at the Max Planck Institute for Astronomy in Germany.

The new study, which includes a team of co-authors from around the world, was published in The Open Journal for Astrophysics. Data from several ground-based telescopes, including the W. M. Keck Observatoryon Maunakea, Hawai'i; La Silla Observatory in Chile; and the Whipple Observatory in Arizona, were used to follow up the Gaia observations and learn more about the masses and orbits of the hidden neutron stars.

While neutron stars have previously been detected in orbit around stars like our Sun, those systems have all been more compact. With little distance separating the two bodies, a neutron star (which is heavier than a Sun-like star) can steal mass away from its partner. This mass transfer process makes the neutron star shine brightly at X-ray or radio wavelengths. In contrast, the neutron stars in the new study are much farther from their partners -- on the order of one to three times the distance between Earth and the Sun.

That means the newfound stellar corpses are too far from their partners to be stealing material from them. They are instead quiescent and dark. "These are the first neutron stars discovered purely due to their gravitational effects," El-Badry says.

The discovery comes as somewhat of a surprise because it is not clear how an exploded star winds up next to a star like our Sun.

"We still do not have a complete model for how these binaries form," explains El-Badry. "In principle, the progenitor to the neutron star should have become huge and interacted with the solar-type star during its late-stage evolution." The huge star would have knocked the little star around, likely temporarily engulfing it. Later, the neutron star progenitor would have exploded in a supernova, which, according to models, should have unbound the binary systems, sending the neutron stars and Sun-like stars careening in opposite directions.

"The discovery of these new systems shows that at least some binaries survive these cataclysmic processes even though models cannot yet fully explain how," he says.

Gaia was able to find the unlikely companions due to their wide orbits and long periods (the Sun-like stars orbit around the neutron stars with periods of six months to three years). "If the bodies are too close, the wobble will be too small to detect," El-Badry says. "With Gaia, we are more sensitive to the wider orbits." Gaia is also most sensitive to binaries that are relatively nearby. Most of the newly discovered systems are located within 3,000 light-years of Earth -- a relatively small distance compared, for example, to the 100,000 light-year-diameter of the Milky Way Galaxy.

The new observations also suggest just how rare the pairings are. "We estimate that about one in a million solar-type stars is orbiting a neutron star in a wide orbit," he said.

El-Badry also has an interest in finding unseen dormant black holes in orbit with Sun-like stars. Using Gaia data, he has found two of these quiet black holes hidden in our galaxy. One, called Gaia BH1, is the closest known black hole to Earth at 1,600 light-years away.

Read more at Science Daily

Rural belts around cities can reduce urban summer temperatures by up to 0.5°C

The key to cooling 'urban heat islands' may lie in the countryside, according to a new study from scientists at the University of Surrey and Southeast University (China).

Using 20 years of data, researchers showed how nearby rural areas could bring a city's temperature down.

The biggest cooling effects happen where the rural ring around a city extends for at least half the city's diameter.

Professor Shi-Jie Cao, the lead author and visiting professor at the University of Surrey's Global Centre for Clean Air Research (GCARE), said:

"We often focus on how green spaces, wetlands or waterways can cool down cities. Yet, urban land is precious, and these measures can be hard to find space for. We have now shown how land use outside a city can make a big difference to temperatures downtown.

"Our findings allow us to make quite specific recommendations. We found that urban over-heating was mitigated more by joining up patches of rural land, planting more woodland scattered around a city, and by having fewer, bigger lakes rather than lots of little bodies of water.

As warm air rises in a city, it creates a layer of low pressure close to the ground.

This sucks cooler air in from surrounding rural areas. This process is greatly shaped by the size of a city, and the land cover of neighbouring rural areas.

To find out exactly how, scientists compared the areas around 30 Chinese cities between 2000-2020.

Satellite data told them how warm the ground was, and how the land was used.

Professor Prashant Kumar, one of the authors of the study, founding director of GCARE and co-director of Surrey's Institute of Sustainability, said:

"We already suspected that belts of rural land around a city could help cool down the urban centre. Now, thanks to our detailed analysis, we can say which forms of land use lead to the biggest effects.

Read more at Science Daily

Scientists define new type of memory loss in older adults

Researchers at Mayo Clinic have established new criteria for a memory-loss syndrome in older adults that specifically impacts the brain's limbic system. It can often be mistaken for Alzheimer's disease. The good news: Limbic-predominant Amnestic Neurodegenerative Syndrome, or LANS, progresses more slowly and has a better prognosis, and is now more clearly defined for doctors working to find answers for memory loss patients.

Prior to the researchers developing clinical criteria published in the journal Brain Communications, the hallmarks of the syndrome could be confirmed only by examining brain tissue after a person's death. The proposed criteria provide a framework for neurologists and other experts to classify the condition in patients living with symptoms, offering a more precise diagnosis and potential treatments. They consider factors such as age, severity of memory impairment, brain scans, and biomarkers indicating the deposits of specific proteins in the brain.

The criteria were developed and validated using data from more than 200 participants in databases for the Mayo Clinic Alzheimer's Disease Research Center, the Mayo Clinic Study of Aging and the Alzheimer's Disease Neuroimaging Initiative.

Understanding the condition will lead to better management of symptoms and more tailored therapies for patients suffering from this type of cognitive decline, distinct from Alzheimer's disease, says David T. Jones, M.D., a Mayo Clinic neurologist and senior author of the study.

"In our clinical work, we see patients whose memory symptoms appear to mimic Alzheimer's disease, but when you look at their brain imaging or biomarkers, it's clear they don't have Alzheimer's. Until now, there has not been a specific medical diagnosis to point to, but now we can offer them some answers," Jones says. "This research creates a precise framework that other medical professionals can use to care for their patients. It has major implications for treatment decisions, including amyloid-lowering drugs and new clinical trials, and counseling on their prognosis, genetics and other factors."

Decades of work to understand and classify different types of dementia is ongoing, says Nick Corriveau-Lecavalier, Ph.D., the paper's first author. These findings build upon scientists' continued efforts to untangle neurological conditions that often have similar symptoms or can occur simultaneously, but can have drastically different treatments and prognoses.

"Historically, you might see someone in their 80s with memory problems and think they may have Alzheimer's disease, and that is often how it's being thought of today," Corriveau-Lecavalier says. "With this paper, we are describing a different syndrome that happens much later in life. Often, the symptoms are restricted to memory and will not progress to impact other cognitive domains, so the prognosis is better than with Alzheimer's disease."

Without signs of Alzheimer's disease, the researchers looked at the involvement of one possible culprit -- a buildup of a protein called TDP-43 in the limbic system that scientists have found in the autopsied brain tissue of older adults. Researchers have classified the build-up of these protein deposits as limbic-predominant age-related TDP-43 encephalopathy, or LATE. These protein deposits could be associated with the newly defined memory loss syndrome, but there are also other likely causes and more research is needed, the authors say.

With clinical criteria established by Jones, Corriveau-Lecavalier and co-authors, practitioners could soon diagnose LANS in patients so those living with memory loss might better understand options for treatment and potential progression of the disease, opening doors for research to further illuminate the characteristics of the disease.

Read more at Science Daily

Llama nanobodies: A breakthrough in building HIV immunity

A research team at Georgia State University has developed tiny, potent molecules that are capable of targeting hidden strains of HIV. The source? Antibody genes from llama DNA.

The research, led by Assistant Professor of Biology Jianliang Xu, uses llama-derived nanobodies to broadly neutralize numerous strains of HIV-1, the most common form of the virus. A new study from this team has been published in the journal Advanced Science.

"This virus has evolved a way to escape our immune system. Conventional antibodies are bulky, so it's difficult for them to find and attack the virus' surface," Xu explained. "These new antibodies can do this in an easier way."

Scientists in pursuit of effective HIV treatment and prevention have been working with animals in the camelid family -- like llamas -- for about 15 years. That's because the shape and features of their antibodies make them nimbler and more effective at identifying and neutralizing foreign objects, like the HIV virus.

This new research presents a widely applicable method to enhance the performance of nanobodies. Nanobodies are engineered antibody fragments that are about one-tenth the size of a conventional antibody. They are derived from flexible, Y-shaped heavy chain-only antibodies -- made up of two heavy chains -- which are more effective at fighting certain viruses than conventional antibodies with light chains.

The nanobodies are derived from flexible, Y-shaped antibodies made up of heavy-chain peptides which may be more effective at fighting certain viruses.

For the study, researchers immunized llamas with a specially designed protein which results in the production of neutralizing nanobodies. Xu and his team then identified nanobodies that can target vulnerable sites on the virus. When the team engineered the nanobodies into a triple tandem format -- by repeating short lengths of DNA -- the resulting nanobodies demonstrated remarkable effectiveness, neutralizing 96 percent of a diverse panel of HIV-1 strains.

Further analysis uncovered that these nanobodies mimic the recognition of the CD4 receptor -- a key player in HIV infection. To enhance their potency, the nanobodies were fused with a broadly neutralizing antibody (bNAb), resulting in a new antibody with unprecedented neutralizing abilities.

"Instead of developing a cocktail of antibodies, now we can make a single molecule that can neutralize HIV," Xu said. "We are working with a broadly neutralizing nanobody that can neutralize over 90 percent of the circulating HIV strains, and when we combine that with another bNAb which also neutralizes some 90 percent, together, they can neutralize close to 100 percent."

Xu began this research at the National Institutes of Health Vaccine Research Center in Bethesda, Md., where he collaborated with a team of more than 30 scientists. The team included Peter Kwong, professor of biochemistry and molecular biophysics at Columbia University and co-author of the study. Since coming to Georgia State in 2023, Xu has been mentoring Payton Chan, a Ph.D. candidate at Georgia State. Together, they are working to expand these potential remedies.

Chan said she is excited about the prospects of the innovative research.

"These nanobodies are the best and most potently neutralizing antibodies to date, which I think is very promising for the future of HIV therapeutics and antibody research," Chan said. "I hope one day there will be approval of these nanobodies for the treatment of HIV."

Read more at Science Daily

Jul 17, 2024

Bizarre 'garden sprinkler-like' jet is spotted shooting out of neutron star

A strange 'garden sprinkler-like' jet coming from a neutron star has been pictured for the first time.

The S-shaped structure is created as the jet changes direction due to the wobbling of the disc of hot gas around the star -- a process called precession, which has been observed with black holes but, until now, never with neutron stars.

This particular object sits in the binary system Circinus X-1 more than 30,000 light-years from Earth and formed from the core of a massive supergiant star that collapsed around the same time Stonehenge was built.

It is so dense that a teaspoon of its material weighs as much as Mount Everest.

Binary systems have two stars that are bound together by gravity. In the case of Circinus X-1, one of these is a neutron star.

Both neutron stars and black holes are cosmological monsters which form when the biggest stars in the Universe die and collapse under their own gravity.

However, the latter are considerably more massive and can only be detected through their gravitational effects, while the former can be observed directly despite their denseness.

They are some of the most extreme objects in the Universe and have interiors almost entirely made of neutrons.

The jet emanating from the neutron star was spotted by a team of astronomers at the University of Oxford, who used MeerKAT -- a radio telescope in South Africa -- to create the most detailed, high-resolution images of Circinus X-1.

The pictures, which were presented at this week's National Astronomy Meeting at the University of Hull, include the first-ever image of an S-shaped jet coming from a confirmed neutron star -- a breakthrough that could help unravel the extreme physics behind the astronomical phenomenon.

Lead researcher Fraser Cowie said there was another system known for its S-shaped jets, called SS433, but recent results suggest that object is likely a black hole.

"This image is the first time we have seen strong evidence for a precessing jet from a confirmed neutron star," he said.

"This evidence comes from both the symmetric S shape of the radio-emitting plasma in the jets and from the fast, wide shockwave, which can only be produced by a jet changing direction.

"This will give valuable information about the extreme physics behind the launching of the jet, a phenomenon which is still not well understood."

The neutron star's huge density creates a strong force of gravity that strips gas from the companion star, forming a disc of hot gas around it that spirals down towards its surface.

This process, called accretion, releases huge amounts of energy per second with more power than a million Suns. Some of this energy powers jets -- narrow beams of outflowing material from the binary system travelling close to the speed of light.

Recent upgrades to the MeerKAT telescope have resulted in excellent sensitivity and higher-resolution images. With these the team saw clear evidence of an S-shaped structure, similar in shape to water spraying from a garden sprinkler, in Circinus X-1's jet.

Not only that, but researchers also discovered moving termination shocks -- the first recorded from an X-ray binary. These are regions where the jet violently rams into the surrounding material, causing a shockwave.

Cowie's team measured the waves moving at roughly 10 per cent of the speed of light, confirming that they were caused by the fast-moving jet and not something slower such as a wind of material from the stars.

"The fact that these shockwaves span a wide angle agrees with our model," Cowie said. "So we have two strong pieces of evidence telling us the neutron star jet is precessing."

Measuring the velocity of the shockwaves will also help astronomers understand what the jet causing them is made from.

The shockwaves effectively act as particle accelerators in space -- producing high-energy cosmic rays -- and the maximum energy of particles that can be accelerated depends on their velocity.

"Circinus X-1 is one of the brightest objects in the X-ray sky and has been studied for over half a century," Cowie said. "But despite this, it remains one of the most enigmatic systems we know of.

"Several aspects of its behaviour are not well explained so it's very rewarding to help shed new light on this system, building on 50 years of work from others."

He added: "The next steps will be to continue to monitor the jets and see if they change over time in the way we expect.

"This will allow us to more precisely measure their properties and continue to learn more about this puzzling object."

Read more at Science Daily

Nature-based solutions to disaster risk from climate change are cost effective

A new global assessment of scientific literature led by researchers at the University of Massachusetts Amherst finds that nature-based solutions (NbS) are an economically effective method to mitigate risks from a range of disasters -- from floods and hurricanes to heatwaves and landslides -- which are only expected to intensify as Earth continues to warm.

NbS are interventions where an ecosystem is either preserved, sustainably managed or restored to provide benefits to society and to nature. For instance, they can mitigate risk from a natural disaster, or facilitate climate mitigation and adaptation. NbS have emerged in combination with or as an alternative to engineering-based solutions. A classic example is restoring wetlands to address coastal flooding rather than constructing a seawall.

"Nature-based solutions are now recognized by major national policies and international global framework agreements to combat climate change, including those drafted by the U.N. and the White House. However, there has been limited scientific knowledge about the cost-effectiveness and equity outcomes of NbS," says Marta Vicarelli, assistant professor of economics and public policy at UMass Amherst and the study's lead author. "Our results indicate that not only are NbS economically effective in mitigating hazards, but that their benefits are still underestimated."

NbS were proven to be a consistently cost-effective approach to mitigating hazards in 71% of the more than 20,000 English-language peer-reviewed studies that researchers examined for the article, which is published in Science of the Total Environment. Another 24% of the studies found NbS to be cost effective under certain conditions. The ecosystem-based interventions most frequently found effective in mitigating hazards are associated with mangroves (80%), forests (77%) and coastal ecosystems (73%).

Of the studies that compared NbS with engineering-based solutions, 65% found the former always to be more effective at mitigating hazards and 24% partially more effective. No study found NbS consistently less effective than engineering solutions.

While every study reviewed for the article examined the hazard-mitigation benefits of NbS, many did not consider added environmental and socioeconomic benefits, such as maintaining biodiversity, climate mitigation and supporting underserved communities.

"The other benefits of NbS are vastly underestimated because they are difficult to quantify," Vicarelli explains. "How should we value improvements in air quality or in soil quality? How should we value the protection of an endangered species or the overall increase in biodiversity after the implementation of an NbS? And how about estimating the cultural or even spiritual value of an environmental asset? These assessments require complex and potentially expensive valuation techniques. For this reason, the additional benefits of NbS are often understudied and underestimated."

Another key finding of the research is that NbS have been financed mainly by the public sector, even when the interventions involve private property. For these solutions to have a truly global impact, additional funding is required, and a significant share must come from the private sector, Vicarelli says.

"A transformative upscaling of Nature-based Solutions requires both public and private financing," she adds. "The next step is developing innovative nature-based insurance and investment solutions."

Read more at Science Daily

Scientists find that small regions of the brain can take micro-naps while the rest of the brain is awake and vice versa

Sleep and wake: they're totally distinct states of being that define the boundaries of our daily lives. For years, scientists have measured the difference between these instinctual brain processes by observing brain waves, with sleep characteristically defined by slow, long-lasting waves measured in tenths of seconds that travel across the whole organ.

For the first time, scientists have found that sleep can be detected by patterns of neuronal activity just milliseconds long, 1000 times shorter than a second, revealing a new way to study and understand the basic brain wave patterns that govern consciousness. They also show that small regions of the brain can momentarily "flicker" awake while the rest of the brain remains asleep, and vice versa from wake to sleep.

These findings, described in a new study published in the journal Nature Neuroscience, are from a collaboration between the laboratories of Assistant Professor of Biology Keith Hengen at Washington University in St. Louis and Distinguished Professor of Biomolecular Engineering David Haussler at UC Santa Cruz. The research was carried out by Ph.D. students David Parks (UCSC) and Aidan Schneider (WashU).

Over four years of work, Parks and Schneider trained a neural network to study the patterns within massive amounts of brain wave data, uncovering patterns that occur at extremely high frequencies that have never been described before and challenge foundational, long-held conceptions of the neurological basis of sleep and wake.

"With powerful tools and new computational methods, there's so much to be gained by challenging our most basic assumptions and revisiting the question of 'what is a state?'" Hengen said. "Sleep or wake is the single greatest determinant of your behavior, and then everything else falls out from there. So if we don't understand what sleep and wake actually are, it seems like we've missed the boat."

"It was surprising to us as scientists to find that different parts of our brains actually take little naps when the rest of the brain is awake, although many people may have already suspected this in their spouse, so perhaps a lack of male-female bias is what is surprising," Haussler quipped.

Understanding sleep

Neuroscientists study the brain via recordings of the electrical signals of brain activity, known as electrophysiology data, observing voltage waves as they crest and fall at different paces. Mixed into these waves are the spike patterns of individual neurons.

The researchers worked with data from mice at the Hengen Lab in St. Louis. The freely-behaving animals were equipped with a very lightweight headset that recorded brain activity from 10 different brain regions for months at a time, tracking voltage from small groups of neurons with microsecond precision.

This much input created petabytes -- which are one million times larger than a gigabyte -- of data. David Parks led the effort to feed this raw data into an artificial neural network, which can find highly complex patterns, to differentiate sleep and wake data and find patterns that human observation may have missed. A collaboration with the shared academic compute infrastructure located at UC San Diego enabled the team to work with this much data, which was on the scale of what large companies like Google or Facebook might use.

Knowing that sleep is traditionally defined by slow-moving waves, Parks began to feed smaller and smaller chunks of data into the neural network and asked it to predict if the brain was asleep or awake.

They found that the model could differentiate between sleep and wake from just milliseconds of brain activity data. This was shocking to the research team -- it showed that the model couldn't have been relying on the slow-moving waves to learn the difference between sleep and wake.. Just as listening to a thousandth of a second of a song couldn't tell you if it had a slow rhythm, it would be impossible for the model to learn a rhythm that occurs over several seconds by just looking at random isolated milliseconds of information.

"We're seeing information at a level of detail that's unprecedented," Haussler said. "The previous feeling was that nothing would be found there, that all the relevant information was in the slower frequency waves. This paper says, if you ignore the conventional measurements, and you just look at the details of the high frequency measurement over just a thousandth of a second, there is enough there to tell if the tissue is asleep or not. This tells us that there is something going on a very fast scale -- that's a new hint to what might be going on in sleep."

Hengen, for his part, was convinced that Parks and Schneider had missed something, as their results were so contradictory to bedrock concepts drilled into him over many years of neuroscience education. He asked Parks to produce more and more evidence that this phenomena could be real.

"This challenged me to ask myself 'to what extent are my beliefs based on evidence, and what evidence would I need to see to overturn those beliefs?" Hengen said. "It really did feel like a game of cat and mouse, because I'd ask David [Parks] over and over to produce more evidence and prove things to me, and he'd come back and say 'check this out!' It was a really interesting process as a scientist to have my students tear down these towers brick by brick, and for me to have to be okay with that."

Local patterns

Because an artificial neural network is fundamentally a black box and does not report back on what it learns from, Parks began stripping away layers of temporal and spatial information to try to understand what patterns the model could be learning from.

Eventually, they got down to the point where they were looking at chunks of brain data just a millisecond long and at the highest frequencies of brain voltage fluctuations.

"We'd taken out all the information that neuroscience has used to understand, define, and analyze sleep for the last century, and we asked 'can the model still learn under these conditions?'" Parks said. "This allowed us to look into signals we haven't understood before."

By looking at these data, they were able to determine that the hyper-fast pattern of activity between just a few neurons was the fundamental element of sleep that the model was detecting. Crucially, such patterns cannot be explained by the traditional, slow and widespread waves. The researchers hypothesize that the slow moving waves may be acting to coordinate the fast, local patterns of activity, but ultimately reached the conclusion that the fast patterns are much closer to the true essence of sleep.

If the slow moving waves traditionally used to define sleep are compared to thousands of people in a baseball stadium doing the wave, then these fast-moving patterns are the conversations between just a few people deciding to participate in the wave. Those conversations occurring are essential for the overall larger wave to take place, and are more directly related to the mood of the stadium -- the wave is a secondary result of that.

Observing flickers


In further studying the hyperlocal patterns of activity, the researchers began to notice another surprising phenomenon.

As they observed the model predicting sleep or wake, they noticed what looked at first like errors, in which for a split second the model would detect wake in one region of the brain while the rest of the brain remained asleep. They saw the same thing in wake states: for a split second, one region would fall asleep while the rest of the regions were awake. They call these instances "flickers."

"We could look at the individual time points when these neurons fired, and it was pretty clear that [the neurons] were transitioning to a different state," Schneider said. "In some cases, these flickers might be constrained to the area of just an individual brain region, maybe even smaller than that."

This compelled the researchers to explore what flickers could mean about the function of sleep, and how they affect behavior during sleep and wake.

"There's a natural hypothesis there; let's say a small part of your brain slips into sleep while you're awake -- does that mean your behavior suddenly looks like you're asleep? We started to see that that was often the case," Schneider said.

In observing the behavior of mice, the researchers saw that when a brain region would flicker to sleep while the rest of the brain was awake, the mouse would pause for a second, almost like it had zoned out. A flicker during sleep (one brain region "wakes up") was reflected by an animal twitching in its sleep.

Flickers are particularly surprising because they don't follow established rules dictating the strict cycle of the brain moving sequentially between wake to non-REM sleep to REM sleep.

"We are seeing wake to REM flickers, REM to non-REM flickers -- we see all these possible combinations, and they break the rules that you would expect based on a hundred years of literature," Hengen said. "I think they reveal the separation between the macro-state -- sleep and wake at the level of the whole animal, and the fundamental unit of state in the brain -- the fast and local patterns."

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Paleolithic diets are not without risks

High-protein diets, known as ''Paleolithic diets'', are popular. Using mouse models, scientists at the University of Geneva (UNIGE) have studied their impact. While effective in regulating weight and stabilizing diabetes, these diets are not without risks. Excess protein greatly increases ammonium production, overwhelming the liver. Excess ammonium can cause neurological disorders and, in severe cases, lead to coma. These results, published in the Journal of Biological Chemistry, suggest caution when following these diets.

Type 2 diabetes is a metabolic disease that is constantly increasing.

Due to a sedentary lifestyle and an excessively rich diet, the damaged pancreas struggles to regulate blood sugar levels.

While current treatments help control the progression of the disease, they do not cure diabetes.

Losing weight is often an essential part of the treatment.

''Diets rich in animal and/or plant proteins, known as Paleolithic diets, can be used to stabilize type 2 diabetes and regulate weight,'' explains Pierre Maechler, full professor at the Department of Cell Physiology and Metabolism at the UNIGE Faculty of Medicine, who led this research.

These diets are inspired by the meat-based diets of pre-agricultural time.

''But what impact do they have on the body? Are they harmless?

That's what we set out to find out.''

Liver under Pressure

Ammonium is a normal waste product of protein breakdown, essentially eliminated in the liver by the enzyme glutamate dehydrogenase (GDH). In the event of protein overload, the GDH enzyme comes under pressure.

To study the impact of high-protein diets, Pierre Maechler's team fed healthy mice and mice lacking the GDH enzyme in their liver a diet with a protein content mimicking the so-called Paleolithic diet.

Scientists observed that in healthy mice, although excess protein increased ammonium production, the liver managed this excess due to the action of the GDH enzyme, which detoxifies ammonium before it can cause damage.

''In contrast, in mice lacking the GDH enzyme, the liver is unable to eliminate the excess of toxic ammonium derived from proteins.

No need to wait for weeks or months; a change of diet lasting a few days is enough to observe major consequences,'' explains Karolina Luczkowska, a former PhD student at the Department of Cell Physiology and Metabolism at the UNIGE Faculty of Medicine, and the study's first author.

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Jul 16, 2024

NASA's Webb investigates eternal sunrises, sunsets on distant world

Researchers using NASA's James Webb Space Telescope have finally confirmed what models have previously predicted: An exoplanet has differences between its eternal morning and eternal evening atmosphere. WASP-39 b, a giant planet with a diameter 1.3 times greater than Jupiter, but similar mass to Saturn that orbits a star about 700 light-years away from Earth, is tidally locked to its parent star. This means it has a constant dayside and a constant nightside -- one side of the planet is always exposed to its star, while the other is always shrouded in darkness.

Using Webb's NIRSpec (Near-Infrared Spectrograph), astronomers confirmed a temperature difference between the eternal morning and eternal evening on WASP-39 b, with the evening appearing hotter by roughly 300 Fahrenheit degrees (about 200 Celsius degrees). They also found evidence for different cloud cover, with the forever morning portion of the planet being likely cloudier than the evening.

Astronomers analyzed the 2- to 5-micron transmission spectrum of WASP-39 b, a technique that studies the exoplanet's terminator, the boundary that separates the planet's dayside and nightside. A transmission spectrum is made by comparing starlight filtered through a planet's atmosphere as it moves in front of the star, to the unfiltered starlight detected when the planet is beside the star. When making that comparison, researchers can get information about the temperature, composition, and other properties of the planet's atmosphere.

"WASP-39 b has become a sort of benchmark planet in studying the atmosphere of exoplanets with Webb," said Néstor Espinoza, an exoplanet researcher at the Space Telescope Science Institute and lead author on the study. "It has an inflated, puffy atmosphere, so the signal coming from starlight filtered through the planet's atmosphere is quite strong."

Previously published Webb spectra of WASP-39b's atmosphere, which revealed the presence of carbon dioxide, sulfur dioxide, water vapor, and sodium, represent the entire day/night boundary -- there was no detailed attempt to differentiate between one side and the other.

Now, the new analysis builds two different spectra from the terminator region, essentially splitting the day/night boundary into two semicircles, one from the evening, and the other from the morning. Data reveals the evening as significantly hotter, a searing 1,450 degrees Fahrenheit (800 degrees Celsius), and the morning a relatively cooler 1,150 degrees Fahrenheit (600 degrees Celsius).

"It's really stunning that we are able to parse this small difference out, and it's only possible due Webb's sensitivity across near-infrared wavelengths and its extremely stable photometric sensors," said Espinoza. "Any tiny movement in the instrument or with the observatory while collecting data would have severely limited our ability to make this detection. It must be extraordinarily precise, and Webb is just that."

Extensive modeling of the data obtained also allows researchers to investigate the structure of WASP-39 b's atmosphere, the cloud cover, and why the evening is hotter. While future work by the team will study how the cloud cover may affect temperature, and vice versa, astronomers confirmed gas circulation around the planet as the main culprit of the temperature difference on WASP-39 b.

On a highly irradiated exoplanet like WASP-39 b that orbits relatively close to its star, researchers generally expect the gas to be moving as the planet rotates around its star: Hotter gas from the dayside should move through the evening to the nightside via a powerful equatorial jet stream. Since the temperature difference is so extreme, the air pressure difference would also be significant, which in turn would cause high wind speeds.

Using General Circulation Models, 3-dimensional models similar to the ones used to predict weather patterns on Earth, researchers found that on WASP-39 b the prevailing winds are likely moving from the night side across the morning terminator, around the dayside, across the evening terminator and then around the nightside. As a result, the morning side of the terminator is cooler than the evening side. In other words, the morning side gets slammed with winds of air that have been cooled on the nightside, while the evening is hit by winds of air heated on the dayside. Research suggests the wind speeds on WASP-39 b can reach thousands of miles an hour!

"This analysis is also particularly interesting because you're getting 3D information on the planet that you weren't getting before," added Espinoza. "Because we can tell that the evening edge is hotter, that means it's a little puffier. So, theoretically, there is a small swell at the terminator approaching the nightside of the planet."

The team's results have been published in Nature.

The researchers will now look to use the same method of analysis to study atmospheric differences of other tidally locked hot Jupiters, as part of Webb Cycle 2 General Observers Program 3969.

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Complex impact of large wildfires on ozone layer dynamics

In a revelation highlighting the fragile balance of our planet's atmosphere, scientists from China, Germany, and the USA have uncovered an unexpected link between massive wildfire events and the chemistry of the ozone layer. Using satellite data and numerical modelling, the team discovered that an enormous smoke-charged vortex nearly doubles the southern hemispheric aerosol burden in the middle stratosphere of the Earth and reorders ozone depletion at different heights. Published in Science Advances, this study reveals how wildfires, such as the catastrophic 2019/20 Australian bushfires, impact the stratosphere in previously unseen ways.

The ozone layer, a crucial shield protecting life on Earth from harmful ultraviolet (UV) radiation, has been on a path to recovery thanks to the Montreal Protocol. This landmark international treaty, adopted in 1987, successfully led to phasing out the production of numerous substances responsible for ozone depletion. Over the past decades, the ozone layer has shown significant signs of healing, a testament to global cooperation and environmental policy.

However, the stability of this vital atmospheric layer is now facing a new and unexpected challenge. During the 2019/20 Australian wildfires, researchers observed a dramatic increase in stratospheric aerosols -- tiny particles that can influence climate, health, and atmospheric chemistry.

Smoke-charged vortex transports aerosol up to 35 kilometers

Utilizing new satellite data and numerical modeling, the research team successfully demonstrated the impact of wildfires through a novel phenomenon: the smoke-charged vortex (SCV).

"The SCV is a powerful, smoke-laden whirlpool that transports wildfire smoke into the middle stratosphere, reaching altitudes of up to 35 kilometers," explained Prof. Hang Su from the Institute of Atmospheric Physics at the Chinese Academy of Sciences, one of the corresponding authors of the study. "This process led to at least a doubling of the aerosol burden in the southern hemisphere's middle stratosphere. Once reaching such high altitudes, these aerosols initiated a series of chemical reactions at their surface that impacted ozone concentrations."

The international team discovered that these wildfire-induced aerosols facilitated heterogeneous chemical reactions in the stratosphere, which paradoxically led to both ozone depletion and ozone increase at different atmospheric layers.

While the lower stratosphere experienced significant ozone depletion, the new study shows that the increase of smoke aerosol particles in the middle stratosphere enhances the heterogeneous uptake and hydrolysis of N2O5, which leads to a decrease of reactive nitrogen gases, e.g., NOx, and an increase of ozone. In Southern Mid-Latitudes, the complex interplay managed to buffer approximately 40% (up to 70%) of the ozone depletion observed in the lower stratosphere in the following months of the mega-bushfire events.

So why does this matter?

"Our study uncovers an unexpected and crucial mechanism by which the absorbing aerosols in wildfire smoke, such as black carbon, can induce and sustain enormous smoke-charged vortices spanning thousands of kilometers, fundamentally changing the stratospheric circulation. The vortices can persist for months, carrying aerosols deeply into the stratosphere and affecting the ozone layer in distinct ways at different altitudes. This highlights the need for continued vigilance and research as climate change progresses," said Prof. Yafang Cheng, another leading author from the Max Planck Institute for Chemistry.

"We've made a significant step forward in simulating the SCV as a new effective pathway for wildfires to modify stratospheric dynamics and chemistry, especially the ozone layer. I love this study because it once again demonstrates how closely different parts of the Earth system are connected. Smoke from a forest fire can significantly change the wind and circulation tens of kilometers above the ground, which allows the smoke to modify the ozone layer, influencing life on our planet," said Dr. Chaoqun Ma, the first author of the study and postdoc researcher in Cheng's team at the MPIC.

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Unveiling 1,200 years of human occupation in Canada's Arctic

A recent study provides new insights into ancient cultures in Canada's Arctic, focusing on Paleo-Inuit and Thule-Inuit peoples over thousands of years. Jules Blais, professor of biology at the University of Ottawa, and a team of researchers detected human presence and settlements on Somerset Island, Nunavut, by analyzing sediment samples.

The Arctic has been home to various cultures, such as the Paleo-Inuit (2500 BCE to 1250 CE) and the Thule-Inuit (1200 to 1500 CE). Although historical evidence is scarce, this recent study provides valuable insight into their presence.

The study discovered evidence of Paleo-Inuit presence on Somerset Island in Nunavut, Canada, where it was lacking.

The innovative research methodologies revealed detailed information about past human history without traditional artifacts.

Professor Jules Blais says, "By analyzing pond sediment samples, we were able to construct detailed histories of site occupation. This includes clear evidence of Paleo-Inuit presence and indications that the Thule-Inuit arrived earlier than previously estimated."

The research used archeological evidence and sedimentary biomarkers to study prehistoric settlement on Somerset Island.

Sediment cores from island ponds were analyzed for trace elements and organic compounds.

Results showed that the Thule-Inuit population increased from the 13th to 15th centuries.

The researchers also showed high levels of metals like lead, copper, zinc and nickel in twentieth-century sediment, suggesting air pollution during that time.

Blais says, "We used generalized additive models (GAMs) and radiocarbon dating techniques to identify key time points in the sediment record corresponding to the expected dates of Thule-Inuit arrival and site abandonment. This approach allowed us to detect periods of significant change in sediment proxies, providing a chronological framework for understanding the history of human occupation on the island."

This research underscores the importance of interdisciplinary approaches in archeology and highlights the significance of sedimentary archives in reconstructing past human activities and environmental conditions.

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New research demonstrates potential for increasing effectiveness of popular diabetes, weight-loss drugs

A network of proteins found in the central nervous system could be harnessed to increase the effectiveness and reduce the side effects of popular diabetes and weight-loss drugs, according to new research from the University of Michigan.

The study, appearing today in the Journal of Clinical Investigation, focused on two proteins called melanocortin 3 and melanocortin 4 found primarily on the surface of neurons in the brain that play a central role in regulating feeding behavior and maintaining the body's energy balance.

Melanocortin 3 and melanocortin 4 impact everything from sensing long-term energy stores to processing signals from the gut regarding short-term fullness, or satiety, said U-M physiologist Roger Cone, who led the study.

The class of drugs known as GLP-1 agonists, which includes semaglutides (e.g., Ozempic) and tirzepatides (e.g., Mounjaro), have received substantial attention recently for their effectiveness in treating not only type 2 diabetes, but also obesity, heart disease and potentially addiction. They work by mimicking a natural hormone that the gut produces when it is full, triggering the brain to reduce feeding behavior.

"So the obvious question for us was: How do these GLP-1 drugs, which work by manipulating satiety signals, function when we prime the melanocortin system?" said Cone, professor of molecular and integrative physiology at the U-M Medical School and director of the U-M Life Sciences Institute where his lab is located.

Working in mouse models, Cone and his colleagues tested the effects of several hormones that reduce food intake. They compared the results in normal mice with mice that genetically lacked the MC3R protein, in mice that were given chemicals to block the activity of MC3R, and in mice that were given a drug to increase the activity of MC4R. (Because MC3R is a natural negative regulator of MC4R, meaning it decreases the activity of MC4R, blocking MC3R and increasing MC4R activity has similar effects.)

In all cases, Naima Dahir, first author of the study and a postdoctoral research fellow in Cone's lab, and colleagues found that adjusting the melanocortin system -- either by inhibiting MC3R or increasing MC4R activity -- made the mice more sensitive to GLP-1 drugs and other hormones that affect feeding behavior. The mice that were given a GLP-1 drug in combination with an MC4R agonist or MC3R antagonist showed up to five times more weight loss and reduced feeding than mice receiving only the GLP-1 drugs.

"We found that activating the central melanocortin system hypersensitizes animals to the effects of not just GLP-1s, but to every anti-feeding hormone we tested," Cone said.

The researchers also measured activity in parts of the brain thought to trigger nausea in response to GLP-1 drugs and observed no increased activation when GLP-1 drugs were combined with alterations to the melanocortin system. In contrast, priming of the melanocortin neurons significantly increased GLP-1 drug activation of neurons in hypothalamic feeding centers in the brain.

The findings indicate that pairing the existing GLP-1 drugs with an MC4R agonist could increase sensitivity to the desired effects of the drugs by up to fivefold, without increasing unwanted side effects.Ultimately, this approach could enable patients who are sensitive to the side effects to take a lower dose, or could improve the results in patients who have not responded to the existing drug dosages. Further drug development and clinical testing are needed before this can occur.

While this research has been conducted only in mouse models, Cone is optimistic that the results will translate well to humans.

"The melanocortin system is highly conserved in humans," he said. "Everything we've observed in the mouse over the past decades studying these proteins has also been found in humans, so I suspect that these results would also be translatable to patients."

Read more at Science Daily

Jul 15, 2024

Scorching storms on distant worlds revealed

Astronomers have created the most detailed weather report so far for two distant worlds beyond our own solar system.

The international study -- the first of its kind -- reveals the extreme atmospheric conditions on the celestial objects, which are swathed in swirling clouds of hot sand amid temperatures of 950C.

Using NASA's powerful James Webb Space Telescope (JWST), researchers set out to capture the weather on a pair of brown dwarfs -- cosmic bodies that are bigger than planets but smaller than stars.

These brown dwarfs, named collectively as WISE 1049AB, are the brightest and closest objects of their type to Earth, around six light years away.

The team tracked each brown dwarf's atmosphere by measuring the light waves emitted from their surfaces, which change as more or less cloudy regions revolve in and out of view.

By visualising this data through light curves -- a plot of how the brightness of light from each object changes over time -- the team was able to build up a detailed 3D picture of how the brown dwarfs' weather changed over the course of a full rotation or day, between five and seven hours.

The team was also able to plot how the light from each object varied by wavelength, to demonstrate the presence and complex interplay of gases such as water, methane, and carbon monoxide in their atmospheres.

The insights may help astronomers develop the understanding of brown dwarfs as a potential missing link between stars and planets -- promising new insights into both.

By observing the infrared part of the light spectrum, the JWST is able to observe wavelengths of light that are blocked by our own atmosphere.

This capability opens frontiers in the study of the early universe, star formation, and so-called exoplanets such as brown dwarfs which lie beyond our solar system.

The latest study builds on previous studies of brown dwarfs, which have mainly been confined to capturing static snapshots of their atmosphere on only one side. This approach is limited, as brown dwarfs are known to rotate relatively quickly and their weather can vary greatly over time, researchers say.

Their findings will pave the way for more detailed studies into brown dwarfs and other distant celestial objects.

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Nanoplastics and 'forever chemicals' disrupt molecular structures, functionality

Researchers at The University of Texas at El Paso have made significant inroads in understanding how nanoplastics and per- and polyfluoroalkyl substances (PFAS) -- commonly known as forever chemicals -- disrupt biomolecular structure and function. The work shows that the compounds can alter proteins found in human breast milk and infant formulas -- potentially causing developmental issues downstream.

Nanoplastics and forever chemicals are manmade compounds present throughout the environment; a series of recent studies have linked them to numerous negative health outcomes. While nanoplastics originate primarily as a result of the degradation of larger plastic materials, like water bottles and food packaging, forever chemicals are found in various products like cookware and clothing.

The UTEP research team focused on the compounds' impact on three proteins critical to human development and function: beta-lactoglobulin, alpha-lactalbumin and myoglobin. Their findings, which provide an atomic-level insight into the detrimental effects of nanoplastics and PFAS on human health, are described in two recent articles in the Journal of the American Chemical Society and ACS Applied Materials and Interfaces.

"By understanding the molecular mechanisms of how nanoplastics and forever chemicals disrupt cellular functions, scientists can develop safer alternatives to these materials," said Mahesh Narayan, Ph.D., a professor, fellow of the Royal Society of Chemistry and chief of the Division of Biochemistry in UTEP's Department of Chemistry and Biochemistry, who oversaw the two studies. "The insights gained from this research have far-reaching implications."

Narayan said that, most importantly, their research revealed that nanoplastics and PFAS completely "dissolved" a region of proteins known as the alpha helix, converting them into structures called beta sheets.

"We weren't expecting them all to have this similar impact on the alpha helix," Narayan said. "It was a complete coincidence." The team observed that this alteration also occurs in amyloid proteins, which can cause neurodegeneration and neurotoxic outcomes if the synthetic chemicals reach the brain.

Additional key findings of the studies are described below.

Milk Protein: Beta-Lactoglobulin (BLG)


BLG is a protein found in the milk of sheep and cows and is commonly used as an ingredient in infant formula. The protein binds to retinol (vitamin A) and fatty acids and is crucial for vision and brain development in infants.

The research team discovered that the binding efficiency of BLG to retinol and fatty acids decreases upon exposure to nanoplastics and PFAS. This decrease, modeled by Lela Vukovic, Ph.D., associate professor in the Department of Chemistry and Biochemistry, can lead to significant developmental issues in neonatal infants, the team said.

Additionally, for the first time ever, the team observed that PFAS binds to the milk protein, turning it into a carrier for these compounds.

Human Breast Milk: Alpha-Lactalbumin

Alpha-lactalbumin is found in human breast milk, participates in lactose synthesis and is ingested by infants to help meet nutritional needs. UTEP researchers found that nanoplastics and PFAS corrupt the structure of alpha-lactalbumin protein, thereby potentially compromising lactose formation. The team said the disruption can lead to downstream developmental defects in neonatal infants, such as compromised immunity and reduced mineral absorption.

Oxygen Storage: Myoglobin

Myoglobin, found in the blood and muscle tissue of most mammals, is crucial for storing oxygen. The UTEP research team found that nanoplastics and PFAS compromise the functionality of the myoglobin protein, disrupting its ability to store oxygen. This disruption could lead to health issues such as breathlessness and anemia.

Additional experiments by the team demonstrated that exposure to nanoplastics impairs locomotion in worms, with effects comparable to paraquat -- an herbicide that has been tied to causing Parkinson's disease.

"This work has the potential to significantly impact public health and environmental policies, highlighting the vital role of scientific research in addressing global challenges," said Robert Kirken, Ph.D., dean of the College of Science. "I am proud of the groundbreaking research conducted by Dr. Narayan, Dr. Vukovic and their teams. Their innovative approach to understanding how these manmade materials disrupt biomolecular functions is a prime example of the transformative work UTEP researchers do on a regular basis."

Read more at Science Daily

Origins of creativity in the brain

Have you ever had the solution for a tough problem suddenly hit you when you're thinking about something entirely different? Creative thought is a hallmark of humanity, but it's an ephemeral, almost paradoxical ability, striking unexpectedly when it's not sought out.

And the neurological source of creativity -- what's going on in our brains when we think outside the box -- is similarly elusive.

But now, a research team led by a University of Utah Health researcher and based in Baylor College of Medicine has used a precise method of brain imaging to unveil how different parts of the brain work together in order to produce creative thought.

Their findings published in BRAIN on June 18.

The new results could ultimately help lead to interventions that spark creative thought or aid people who have mental illnesses that disrupt these regions of the brain.

Outside the bo

Higher cognitive processes like creativity are especially hard to study. "Unlike motor function or vision, they're not dependent on one specific location in the brain," says Ben Shofty, MD, PhD, assistant professor of neurosurgery in the Spencer Fox Eccles School of Medicine and senior author on the paper. "There's not a creativity cortex."

But there's evidence that creativity is a distinct brain function. Localized brain injury caused by stroke can lead to changes in creative ability -- both positive and negative. That discovery suggests that narrowing down the neurological basis of creativity is possible.

Shofty suspected that creative thought might rely strongly on parts of the brain that are also activated during meditation, daydreaming, and other internally focused types of thinking. This network of brain cells is the default mode network (DMN), so called because it's associated with the "default" patterns of thought that happen in the absence of specific mental tasks. "Unlike most of the functions that we have in the brain, it's not goal-directed," Shofty says. "It's a network that basically operates all the time and maintains our spontaneous stream of consciousness."

The DMN is spread out across many dispersed brain regions, making it more difficult to track its activity in real time. The researchers had to use an advanced method of brain activity imaging to understand what the network was doing moment-to-moment during creative thought. In a strategy most commonly used to pinpoint the location of seizures in patients with severe epilepsy, tiny electrodes are implanted in the brain to precisely track the electrical activity of multiple brain regions.

Participants in the study were already undergoing this kind of seizure monitoring, which meant that the research team could also use the electrodes to measure brain activity during creative thinking. This provided a much more detailed picture of the neural basis of creativity than researchers had been able to capture before. "We could see what's happening within the first few milliseconds of attempting to perform creative thinking,"Shofty says.

Two steps toward originality


The researchers saw that during a creative thinking task in which participants were asked to list novel uses for an everyday item, like a chair or a cup, the DMN lit up with activity first. Then, its activity synchronized with other regions in the brain, including ones involved in complex problem-solving and decision-making. Shofty believes this means that creative ideas originate in the DMN before being evaluated by other regions.

What's more, the researchers were able to show that parts of the network are required specifically for creative thought. When the researchers used the electrodes to temporarily dampen the activity of particular regions of the DMN, people brainstormed uses for the items they saw that were less creative. Their other brain functions, like mind wandering, remained perfectly normal.

Eleonora Bartoli, PhD, assistant professor of neurosurgery at Baylor College of Medicine and co-first author on the paper, explains that this result shows that creativity isn't just associated with the network but fundamentally depends on it. "We moved beyond correlational evidence by using direct brain stimulation," she says. "Our findings highlight the causal role of the DMN in creative thinking."

The activity of the network is changed in several disorders, such as ruminative depression, in which the DMN is more active than normal, possibly related to increased dwelling on negative internally directed thoughts. Shofty says that a better understanding of how the network operates normally may lead to better treatments for people with such conditions.

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New geological datings place the first European hominids in the south of the Iberian Peninsula 1.3 million years ago

One of the most important controversies about human evolution and expansion is when and by what route the first hominids arrived in Europe from the African continent. Now, geological dating techniques at the Orce sites (Baza basin, Granada, Spain) place the human remains found in this area as the oldest in Europe, at approximately 1.3 million years old. These results reinforce the hypothesis that humans arrived in Europe through the south of the Iberian Peninsula, through the Strait of Gibraltar, instead of returning to the Mediterranean via the Asian route. The study, led by Lluís Gibert, researcher and lecturer at the University of Barcelona's Faculty of Earth Sciences, has involved the participation of researchers from the Berkeley Geochronology Centre and Murray State University (United States).

Analysis of a new sampling area

The new dating has been based on the analysis of the paleomagnetism of an area of the Orce region, which has never been sampled before and which has been protected from the erosion that this basin has suffered over the years. This technique is a relative dating method based on the study of the inversion of the magnetic poles of the planet due to the internal dynamics of the Earth. These changes do not have a specific periodicity, but they are recorded in the minerals and make it possible to establish time periods from the different magnetic events.

These new data are very precise thanks to the long sedimentary sequence that outcrops in Orce. "The uniqueness of these sites is that they are stratified and within a very long sedimentary sequence, more than eighty metres long. Normally, the sites are found in caves or within very short stratigraphic sequences, which do not allow you to develop long palaeomagnetic sequences in which you can find different magnetic reversals," says Lluís Gibert.

The researchers have been able to identify a magnetic polarity sequence "with five magnetic events that allow them to place the three Orce sites with human presence between the Olduvai and Jaramillo subchron, that is, between 1.77 and 1.07 million years ago (Ma)," says the researcher. Subsequently, they have applied a statistical age model to accurately refine the chronology of the different stratigraphic levels with a margin of error of only 70,000 years. The result of this innovative methodology is that the oldest site with human presence in Europe would be Venta Micena with an age of 1.32 Ma, followed by Barranco León, with an age of 1.28 and finally Fuente Nueva 3, with an age of 1.23 Ma. "With these data, the other major site on the peninsula, the Sima del Elefante in Atapuerca, would be relegated to second place, far behind Orce, between 0.2 and 0.4 Ma more modern," adds the researcher.

Fauna underpins the antiquity of the site

To complete the dating, the study has also analyzed the fauna found at the different sites in Orce, as this is different depending on the period, and compared it with that found at other Early Pleistocene sites in other parts of Europe.

In this sense, the paper presents a detailed analysis of the micromammals and large mammals from all the Orce sites, carried out by the expert Robert Martin, based on the palaeontological collections stored at the Museum of the Catalan Institute of Palaeontology Miguel Crusafont (IPS) in Sabadell. "The results indicate that the small and large fauna of Orce is more primitive than, for example, that of the Sima del Elefante, where the evidence shows that the rodent Allophaiomys lavocati is more evolved than the Allophaiomys recovered from the Orce sites," Gibert explains.Another relevant indicator of the age of the Orce sites is the absence of the ancestors of the pigs. "These animals are considered to be Asian immigrants and have not been found in any European site between 1 and 1.5 Ma, while they have been found in the Sima del Elefante, supporting that the Orce fauna is older," explains the researcher.

Evidence pointing to passage through Gibraltar


This new dating would be added, according to the researcher, to other evidence that would tip the balance in favour of the colonization of Europe through the Strait of Gibraltar, rather than the alternative route: the return to the Mediterranean via Asia, such as "the existence of a lithic industry with similarities to that found in the north of the African continent and also the presence of remains of African fauna in the south of the peninsula, such as those of Hippopotamus, found in the sites of Orce, and those of Theropithecus oswaldi, an African primate similar to a baboon, found in the Victoria cave, a site near Cartagena (Murcia), non-existent anywhere else in Europe."

"We also defend the hypothesis -- adds the researcher -- that they arrived from Gibraltar because no older evidence has been found at any other site along the alternative route."

These new data are very precise thanks to the long sedimentary sequence that outcrops in Orce.

Similarity with hominids from the island of Flores

With these results, the researchers point to a "diachronism" between the oldest occupation of Asia, measuring 1.8 Ma, and the oldest occupation of Europe, which would be 1.3 Ma ago, so that African hominids would have arrived in southwestern Europe more than 0.5 Ma after leaving Africa for the first time about 2 Ma ago. "These differences in human expansion can be explained by the fact that Europe is isolated from Asia and Africa by biogeographical barriers that are difficult to overcome, both to the east (Bosphorus Strait, Dardanelles, Sea of Marmara) and to the west (Strait of Gibraltar). Humanity arrived in Europe when it had the necessary technology to cross maritime barriers, as happened before a million years ago on the island of Flores (Indonesia)," says Gibert. In this sense, the researcher adds that the Gibraltar route currently requires crossing up to fourteen kilometres of sea route, but "perhaps in the past this distance was shorter at certain times due to the high tectonic activity in this region and the fluctuations in sea level that favoured migrations."

"As cited in the paper -- he adds -- , we have identified other migrations of African fauna through Gibraltar at earlier times, 6.2 and 5.5 Ma ago when the Strait of Gibraltar was very narrow."

Human remains in Orce

A total of five human remains were found at the Orce sites since excavations began in 1982 by the palaeoanthropologist Josep Gibert. Firstly, two fragments of humerus bitten by hyenas were found at Venta Micena, as well as parts of a cranial fragment consisting of two parietals and an occipital, associated with an abundant Early Pleistocene fauna. The human provenance of these remains generated great controversy for years, although independent palaeoproteomic studies by the universities of Granada and San Francisco identified human proteins in the remains.

 Read more at Science Daily