Deliberately exposing people to the coronavirus behind covid-19 in a so-called challenge study has helped us understand why some people seem to be immune to catching the infection.

As part of the first such covid-19 study, carried out in 2021, a group of international researchers looked at 16 people with no known health conditions who had neither tested positive for the SARS-CoV-2 virus nor been vaccinated against it.

The original variant of SARS-CoV-2 was sprayed up their noses. Nasal and blood samples were taken before this exposure and then six to seven times over the 28 days after. They also had SARS-CoV-2 tests twice a day.

[…]

In total, the researchers looked at more than 600,000 blood and nasal cells across all the individuals.

They found that in the second and third groups, the participants produced interferon – a substance that helps the immune system fight infections – in their blood before it was produced in their nasopharynx, the upper part of the nose behind the throat where the nasal samples were taken from. The interferon response, when it did occur in the nasopharynx, was actually higher in the noses of those in the second group than the third, says Teichmann.

These groups also didn’t have active infections within their T-cells and macrophages, which are both types of immune cell, says team member Marko Nikolic at University College London.

The results suggest that high levels of activity of an immune system gene called HLA-DQA2 before SARS-CoV-2 exposure helped prevent a sustained infection.

[…]

However, most people have now been exposed to “a veritable mosaic of SARS-CoV-2 variants”, rather than just the ancestral variant used in this study. The results may therefore not reflect cell responses outside of a trial setting, he says.

 

Journal reference:

Nature DOI: 10.1038/s41586-024-07575-x

 

Source: We finally know why some people seem immune to catching covid-19 | New Scientist

The proliferation of microplastics (MPs) represents a burgeoning environmental and health crisis. Measuring less than 5 mm in

diameter, MPs have infiltrated atmospheric, freshwater, and terrestrial ecosystems, penetrating commonplace consumables like

seafood, sea salt, and bottled beverages. Their size and surface area render them susceptible to chemical interactions with

physiological fluids and tissues, raising bioaccumulation and toxicity concerns. Human exposure to MPs occurs through ingestion,

inhalation, and dermal contact. To date, there is no direct evidence identifying MPs in penile tissue. The objective of this study was

to assess for potential aggregation of MPs in penile tissue. Tissue samples were extracted from six individuals who underwent

surgery for a multi-component inflatable penile prosthesis (IPP).

[…]

Seven

types of MPs were found in the penile tissue, with polyethylene terephthalate (47.8%) and polypropylene (34.7%) being the most

prevalent. The detection of MPs in penile tissue raises inquiries on the ramifications of environmental pollutants on sexual health.

Our research adds a key dimension to the discussion on man-made pollutants, focusing on MPs in the male reproductive system.

IJIR: Your Sexual Medicine Journal; https://doi.org/10.1038/s41443-024-00930-6

Source: Detection of microplastics in the human penis | International Journal of Impotence Research

Mathematicians have reinvented the wheel with the discovery of shapes that can roll smoothly when sandwiched between two surfaces, even in four, five or any higher number of spatial dimensions. The finding answers a question that researchers have been puzzling over for decades.

Such objects are known as shapes of constant width, and the most familiar in two and three dimensions are the circle and the sphere. These aren’t the only such shapes, however. One example is the Reuleaux triangle, which is a triangle with curved edges, while people in the UK are used to handling equilateral curve heptagons, otherwise known as the shape of the 20 and 50 pence coins. In this case, being of constant width allows them to roll inside coin-operated machines and be recognised regardless of their orientation.

[…]

While shapes with more than three dimensions are impossible to visualise, mathematicians can define them by extending 2D and 3D shapes in logical ways. For example, just as a circle or a sphere is the set of points that sits at a constant distance from a central point, the same is true in higher dimensions. “Sometimes the most fascinating phenomena are discovered when you look at higher and higher dimensions,” says Gil Kalai at the Hebrew University of Jerusalem in Israel.

Now, Andrii Arman at the University of Manitoba in Canada and his colleagues have answered Schramm’s question and found a set of constant-width shapes, in any dimension, that are indeed smaller than an equivalent dimensional sphere.

[…]

The first part of the proof involves considering a sphere with n dimensions and then dividing it into 2ⁿ equal parts – so four parts for a circle, eight for a 3D sphere, 16 for a 4D sphere and so on. The researchers then mathematically stretch and squeeze these segments to alter their shape without changing their width. “The recipe is very simple, but we understood that only after all of our elaboration,” says team member Andriy Bondarenko at the Norwegian University of Science and Technology.

The team proved that it is always possible to do this distortion in such a way that you end up with a shape that has a volume at most 0.9ⁿ times that of the equivalent dimensional sphere. This means that as you move to higher and higher dimensions, the shape of constant width gets proportionally smaller and smaller compared with the sphere.

Visualising this is difficult, but one trick is to imagine the lower-dimensional silhouette of a higher-dimensional object. When viewed at certain angles, the 3D shape appears as a 2D Reuleaux triangle (see the middle image above). In the same way, the 3D shape can be seen as a “shadow” of the 4D one, and so on.  “The shapes in higher dimensions will be in a certain sense similar, but will grow in complexity as [the] dimension grows,” says Arman.

Having identified these shapes, mathematicians now hope to study them further. “Even with the new result, which takes away some of the mystery about them, they are very mysterious sets in high dimensions,” says Kalai.

 

Reference:

arXiv DOI: 10.48550/arXiv.2405.18501

Source: Mathematicians find odd shapes that roll like a wheel in any dimension | New Scientist

Nearly a third of U.S. adults have tattoos, so plenty of you listeners can probably rattle off the basic guidelines of tattoo safety: Make sure you go to a reputable tattoo artist who uses new, sterile needles. Stay out of the ocean while you’re healing so you don’t pick up a smidgen of flesh-eating bacteria. Gently wash your new ink with soap and water, avoid sun exposure and frequently apply an unscented moisturizer—easy-peasy.

But body art enthusiasts might face potential risks from a source they don’t expect: tattoo inks themselves. Up until relatively recently tattoo inks in the U.S. were totally unregulated. In 2022 the federal government pulled tattoo inks under the regulatory umbrella of cosmetics, which means the Food and Drug Administration can oversee these products. But now researchers are finding that many commercial inks contain ingredients they’re not supposed to. Some of these additives are simply compounds that should be listed on the packaging and aren’t. But others could pose a risk to consumers.

For Science Quickly, I’m Rachel Feltman. I’m joined today by John Swierk, an assistant professor of chemistry at Binghamton University, State University of New York. His team is trying to figure out exactly what goes into each vial of tattoo ink—and how tattoos actually work in the first place—to help make body art safer, longer-lasting and maybe even cooler.

[…]

one of the areas we got really interested in was trying to understand why light causes tattoos to fade. This is a huge question when you think about something with laser tattoo removal, where you’re talking about an industry on the scale of $1 billion a year.

And it turns out we really don’t understand that process. And so starting to look at how the tattoo pigments change when you expose them to light, what that might be doing in the skin, then led us to a lot of other questions about tattoos that we realized weren’t well understood—even something as simple as what’s actually in tattoo ink.

[…]

recently we’ve been looking at commercial tattoo inks and sort of surprised to find that in the overwhelming majority of them, we’re seeing things that are not listed as part of the ingredients….Now that doesn’t necessarily mean the things that are in these inks are unsafe, but it does cause a huge problem if you want to try to understand something about the safety of tattoos.

[…]

I think most people would agree that it would be great to know that tattoo inks are safe [and] being made safely, you know? And of course, that’s not unique to tattoo inks; cosmetics and supplements have a lot of similar problems that we need to work on.

But, if we’re going to get a better grasp on the chemistry and even the immunology of tattoos, that’s not just going to help us make them safer but, you know, potentially improve healing, appearance, longevity.

I mean, I think about that start-up that promised “ephemeral tattoos” that now folks a few years later are coming out and saying, “These tattoos have not gone away,” and thinking about how much potential there is for genuine innovation if we can start to answer some of these questions.

[…]

we can start to think about designing new pigments that might have better colorfastness, less reactivity, less sort of bleeding of the lines, right, over time. But all of those things can only happen if we actually understand tattoos, and we really just don’t understand them that well at the moment.

[…]

We looked at 54 inks, and of the 54, 45 had what we consider to be major discrepancies—so these were either unlisted pigments, unlisted additives.

And that was really concerning to us, right? You’re talking about inks coming from major, global, industry-leading manufacturers all the way down to smaller, more niche inks—that there were problems across the board.

So we found things like incorrect pigments being listed. We found issues of some major allergens being used—these aren’t necessarily compounds that are specifically toxic, but to some people they can generate a really pronounced allergic response.

And a couple of things: we found an antibiotic that’s most commonly used for urinary tract infections.

We found a preservative that the FDA has cautioned nursing mothers against, you know, having exposure to—so things that at a minimum, need to be disclosed so that consumers could make informed choices.

[…]

if somebody’s thinking about getting a tattoo, they should be working with an artist who is experienced, who has apprenticed under experienced artists, who is really following best practices in terms of sanitation, aftercare, things like that. That’s where we know you can have a problem. Beyond that, I think it’s a matter of how comfortable you are with some degree of risk.

The point I always really want to emphasize is that, you know, our work isn’t saying anything about whether tattoos are safe or not.

It’s the first step in that process. Just because we found some stuff in the inks doesn’t mean that you shouldn’t get a tattoo or that you have a new risk for skin cancer or something like that…. it’s that this is the process of how science grows, right—that we have to start understanding the basics and the fundamentals so that we can build the next questions on top of that.

And our understanding of tattoos in the body is still at such an early level that we don’t really even understand what the risk factors would be, “What should we be looking for?”

So I think it’s like with anything in life: if you’re comfortable with a degree of risk, then, yeah, go ahead and get the tattoo. People get tattoos for lots of reasons that are important and meaningful and very impactful in a positive way in their life. And I think a concern over a hypothetical risk is probably not worth the potential positives of getting a tattoo.

We know that light exposure— particularly the sunlight—is not great for the tattoo, and if we have concerns about long-term pigment breakdown, ultraviolet light is probably going to enhance that, so keeping your tattoo covered, using sunscreen when you can’t keep it covered—that’s probably very important. If you’re really concerned about the risk, we can think about the size of the tattoo. So somebody with a relatively small piece of line art on their back is in a very different potential risk category than somebody who is fully sleeved and, you know, covered from, say, neck to ankle in tattoos.

And again we’re not saying that either those people have a significant risk that they need to be worried about, but if somebody is concerned, the person with the small line art on the back is much less likely to have to worry about the risk than somebody with a huge tattoo.

We also know that certain colors, like yellow in particular, fade much more readily. That suggests that those pigments are interacting with the body a lot more.

Staying away from bright colors and focusing on black inks might be a more prudent option there, but again, right, a lot of these are hypothetical and we don’t want to alarm people or scare them.

[…]

We’re also still working on understanding what tattoo pigments break down into.

We really don’t understand a lot about laser tattoo removal, and if there is some aspect of tattooing that gives me pause, it’s probably that part. It’s a very reasonable concern, I think, that you may have pigments that are entirely safe in the skin, but once you start zapping them with high-powered lasers, we don’t know what you do to the chemistry, and so that could change the dynamic a lot. And so we’re trying to figure out how to do that and, I think, making some progress there. And then the last area—which is, is new to us but kind of fun—is actually just looking at the biomechanics of tattooing. You would think that we’d really understand how the ink goes into the skin, how it stays in the skin, but the picture there is a little bit hazy

[…]

One of the interesting things, when you talk to ink manufacturers and artists, is that they sort of have this intuitive feel for … sort of what the viscosity of the ink should be like and how much pigment is in there but can’t necessarily articulate why a particular viscosity is good or why a particular pigment loading is good. And so we think if we understand something about the process by which the ink goes…and so we think understanding the biomechanics could really open some interesting possibilities and lead to better, more interesting tattoos down the road as well.

[…]

Source: What’s Actually In Tattoo Ink? No One Really Knows | Scientific American

When the Brazilian nutritional scientist Carlos Monteiro coined the term “ultra-processed foods” 15 years ago, he established what he calls a “new paradigm” for assessing the impact of diet on health.

Monteiro had noticed that although Brazilian households were spending less on sugar and oil, obesity rates were going up. The paradox could be explained by increased consumption of food that had undergone high levels of processing, such as the addition of preservatives and flavorings or the removal or addition of nutrients.

But health authorities and food companies resisted the link, Monteiro tells the FT. “[These are] people who spent their whole life thinking that the only link between diet and health is the nutrient content of foods … Food is more than nutrients.”

Monteiro’s food classification system, “Nova,” assessed not only the nutritional content of foods but also the processes they undergo before reaching our plates. The system laid the groundwork for two decades of scientific research linking the consumption of UPFs to obesity, cancer, and diabetes.

Studies of UPFs show that these processes create food—from snack bars to breakfast cereals to ready meals—that encourages overeating but may leave the eater undernourished. A recipe might, for example, contain a level of carbohydrate and fat that triggers the brain’s reward system, meaning you have to consume more to sustain the pleasure of eating it.

In 2019, American metabolic scientist Kevin Hall carried out a randomized study comparing people who ate an unprocessed diet with those who followed a UPF diet over two weeks. Hall found that the subjects who ate the ultra-processed diet consumed around 500 more calories per day, more fat and carbohydrates, less protein—and gained weight.

The rising concern about the health impact of UPFs has recast the debate around food and public health, giving rise to books, policy campaigns, and academic papers. It also presents the most concrete challenge yet to the business model of the food industry, for whom UPFs are extremely profitable.

The industry has responded with a ferocious campaign against regulation. In part it has used the same lobbying playbook as its fight against labeling and taxation of “junk food” high in calories: big spending to influence policymakers.

FT analysis of US lobbying data from non-profit Open Secrets found that food and soft drinks-related companies spent $106 million on lobbying in 2023, almost twice as much as the tobacco and alcohol industries combined. Last year’s spend was 21 percent higher than in 2020, with the increase driven largely by lobbying relating to food processing as well as sugar.

In an echo of tactics employed by cigarette companies, the food industry has also attempted to stave off regulation by casting doubt on the research of scientists like Monteiro.

“The strategy I see the food industry using is deny, denounce, and delay,” says Barry Smith, director of the Institute of Philosophy at the University of London and a consultant for companies on the multisensory experience of food and drink.

So far the strategy has proved successful. Just a handful of countries, including Belgium, Israel, and Brazil, currently refer to UPFs in their dietary guidelines. But as the weight of evidence about UPFs grows, public health experts say the only question now is how, if at all, it is translated into regulation.

“There’s scientific agreement on the science,” says Jean Adams, professor of dietary public health at the MRC Epidemiology Unit at the University of Cambridge. “It’s how to interpret that to make a policy that people aren’t sure of.”

[…]

Source: “Deny, denounce, delay”: The battle over the risk of ultra-processed foods | Ars Technica

Scientists have developed brain implants that can decode internal speech — identifying words that two people spoke in their minds without moving their lips or making a sound.

Although the technology is at an early stage — it was shown to work with only a handful of words, and not phrases or sentences — it could have clinical applications in future.

Similar brain–computer interface (BCI) devices, which translate signals in the brain into text, have reached speeds of 62–78 words per minute for some people. But these technologies were trained to interpret speech that is at least partly vocalized or mimed.

The latest study — published in Nature Human Behaviour on 13 May — is the first to decode words spoken entirely internally, by recording signals from individual neurons in the brain in real time.

[…]

The researchers implanted arrays of tiny electrodes in the brains of two people with spinal-cord injuries. They placed the devices in the supramarginal gyrus (SMG), a region of the brain that had not been previously explored in speech-decoding BCIs.

Figuring out the best places in the brain to implant BCIs is one of the key challenges for decoding internal speech

[…]

wo weeks after the participants were implanted with microelectrode arrays in their left SMG, the researchers began collecting data. They trained the BCI on six words (battlefield, cowboy, python, spoon, swimming and telephone) and two meaningless pseudowords (nifzig and bindip). “The point here was to see if meaning was necessary for representation,” says Wandelt.

Over three days, the team asked each participant to imagine speaking the words shown on a screen and repeated this process several times for each word. The BCI then combined measurements of the participants’ brain activity with a computer model to predict their internal speech in real time.

For the first participant, the BCI captured distinct neural signals for all of the words and was able to identify them with 79% accuracy. But the decoding accuracy was only 23% for the second participant, who showed preferential representation for ‘spoon’ and ‘swimming’ and had fewer neurons that were uniquely active for each word. “It’s possible that different sub-areas in the supramarginal gyrus are more, or less, involved in the process,” says Wandelt.

Christian Herff, a computational neuroscientist at Maastricht University in the Netherlands, thinks these results might highlight the different ways in which people process internal speech. “Previous studies showed that there are different abilities in performing the imagined task and also different BCI control abilities,” adds Marchesotti.

The authors also found that 82–85% of neurons that were active during internal speech were also active when the participants vocalized the words. But some neurons were active only during internal speech, or responded differently to specific words in the different tasks.

[…]

Source: Device Decodes ‘Internal Speech’ in the Brain | Scientific American

People who develop long covid after being hospitalised with severe covid-19 have raised levels of many inflammatory immune molecules compared with those who recovered fully after such a hospitalisation, according to a study of nearly 700 people.

The findings show that long covid has a real biological basis, says team member Peter Openshaw at Imperial College London. “People are not imagining it,” he says. “It’s genuinely happening to them.”

[…]

The study by Liew and her colleagues involved measuring the levels of 368 immune molecules in the blood of 659 people who were hospitalised with covid-19, mostly early on in the pandemic. The 426 people who were still reporting symptoms more than three months later were compared with the 233 who reported being fully recovered.

The study found that the patterns of immune activation reflected the main kinds of symptoms people with long covid reported. The five main symptom types were fatigue; cognitive impairment; anxiety and depression; cardiorespiratory symptoms; and gastrointestinal symptoms.

For instance, people with gastrointestinal symptoms had higher blood levels of SCG3, a signalling protein that is also elevated in the faeces of people with irritable bowel syndrome.

The findings won’t help with diagnosing whether people have long covid or not, says team member Chris Brightling at the University of Leicester in the UK. But once the condition has been diagnosed, testing for these molecules could help reveal what kind of long covid people have, and thus what kind of interventions might help, he says.

A study last year estimated that 36 million people in Europe had or have long covid. “Many people are still suffering,” says Brightling.

[…]

Journal reference:

Nature Immunology DOI: 10.1038/s41590-024-01778-0

Source: Long covid linked to signs of ongoing inflammatory responses in blood | New Scientist

Accumulation of microplastics in the natural environment is ultimately due to the chemical nature of widely used petroleum-based plastic polymers, which typically are inaccessible to biological processing. One way to mitigate this crisis is adoption of plastics that biodegrade if released into natural environments. In this work, we generated microplastic particles from a bio-based, biodegradable thermoplastic polyurethane (TPU-FC1) and demonstrated their rapid biodegradation via direct visualization and respirometry. Furthermore, we isolated multiple bacterial strains capable of using TPU-FC1 as a sole carbon source and characterized their depolymerization products. To visualize biodegradation of TPU materials as real-world products, we generated TPU-coated cotton fabric and an injection molded phone case and documented biodegradation by direct visualization and scanning electron microscopy (SEM), both of which indicated clear structural degradation of these materials and significant biofilm formation.

Source: Rapid biodegradation of microplastics generated from bio-based thermoplastic polyurethane | Scientific Reports

In this article we’ll investigate what makes airplanes fly by looking at the forces generated by the flow of air around the aircraft’s wings. More specifically, we’ll focus on the cross section of those wings to reveal the shape of an airfoil – you can see it presented in yellow below:

We’ll find out how the shape and the orientation of the airfoil helps airplanes remain airborne. We’ll also learn about the behavior and properties of air and other flowing matter.

Source: Airfoil – Bartosz Ciechanowski

The article goes very deeply into how air flow works and is modelled, how velocity and pressure affect vectors, the shape of an airfoil, the boundry layer and the angle of attack. It requires a bit of scrolling before you get to the planes, but it’s mesmerising to play with the sliders.

From the very early days of the pandemic, brain fog emerged as a significant health condition that many experience after COVID-19.

Brain fog is a colloquial term that describes a state of mental sluggishness or lack of clarity and haziness that makes it difficult to concentrate, remember things and think clearly.

Fast-forward four years and there is now abundant evidence that being infected with SARS-CoV-2 – the virus that causes COVID-19 – can affect brain health in many ways.

In addition to brain fog, COVID-19 can lead to an array of problems, including headaches, seizure disorders, strokes, sleep problems, and tingling and paralysis of the nerves, as well as several mental health disorders.

A large and growing body of evidence amassed throughout the pandemic details the many ways that COVID-19 leaves an indelible mark on the brain. But the specific pathways by which the virus does so are still being elucidated, and curative treatments are nonexistent.

Now, two new studies published in the New England Journal of Medicine shed further light on the profound toll of COVID-19 on cognitive health.

[…]

• Large epidemiological analyses showed that people who had COVID-19 were at an increased risk of cognitive deficits, such as memory problems.
• Imaging studies done in people before and after their COVID-19 infections show shrinkage of brain volume and altered brain structure after infection.
• A study of people with mild to moderate COVID-19 showed significant prolonged inflammation of the brain and changes that are commensurate with seven years of brain aging.
• Severe COVID-19 that requires hospitalization or intensive care may result in cognitive deficits and other brain damage that are equivalent to 20 years of aging.
• […]

Most recently, a new study published in the New England Journal of Medicine assessed cognitive abilities such as memory, planning and spatial reasoning in nearly 113,000 people who had previously had COVID-19. The researchers found that those who had been infected had significant deficits in memory and executive task performance.

[…]

In the same study, those who had mild and resolved COVID-19 showed cognitive decline equivalent to a three-point loss of IQ. In comparison, those with unresolved persistent symptoms, such as people with persistent shortness of breath or fatigue, had a six-point loss in IQ. Those who had been admitted to the intensive care unit for COVID-19 had a nine-point loss in IQ. Reinfection with the virus contributed an additional two-point loss in IQ, as compared with no reinfection.

[…]

Another study in the same issue of the New England Journal of Medicine involved more than 100,000 Norwegians between March 2020 and April 2023. It documented worse memory function at several time points up to 36 months following a positive SARS-CoV-2 test.

Taken together, these studies show that COVID-19 poses a serious risk to brain health, even in mild cases, and the effects are now being revealed at the population level.

A recent analysis of the U.S. Current Population Survey showed that after the start of the COVID-19 pandemic, an additional one million working-age Americans reported having “serious difficulty” remembering, concentrating or making decisions than at any time in the preceding 15 years. Most disconcertingly, this was mostly driven by younger adults between the ages of 18 to 44.

Data from the European Union shows a similar trend – in 2022, 15 percent of people in the EU reported memory and concentration issues.

[…]

Source: COVID-19 Leaves Its Mark on the Brain. Significant Drops in IQ Scores Are Noted. | Scientific American

Zeiss Makro-Planar T*2/100mm ZE

A chemical element so visually striking that it was named for a goddess shows a “Goldilocks” level of reactivity — neither too much nor too little — that makes it a strong candidate as a carbon scrubbing tool.

The element is vanadium, and research by Oregon State University scientists has demonstrated the ability of vanadium peroxide molecules to react with and bind carbon dioxide — an important step toward improved technologies for removing carbon dioxide from the atmosphere.

[…]

how some transition metal complexes can react with air to remove carbon dioxide and convert it to a metal carbonate, similar to what is found in many naturally occurring minerals.

Transition metals are located near the center of the periodic table and their name arises from the transition of electrons from low energy to high energy states and back again, giving rise to distinctive colors. For this study, the scientists landed on vanadium, named for Vanadis, the old Norse name for the Scandinavian goddess of love said to be so beautiful her tears turned to gold.

Nyman explains that carbon dioxide exists in the atmosphere at a density of 400 parts per million. That means for every 1 million air molecules, 400 of them are carbon dioxide, or 0.04%.

“A challenge with direct air capture is finding molecules or materials that are selective enough, or other reactions with more abundant air molecules, such as reactions with water, will outcompete the reaction with CO₂,” Nyman said. “Our team synthesized a series of molecules that contain three parts that are important in removing carbon dioxide from the atmosphere, and they work together.”

One part was vanadium, so named because of the range of beautiful colors it can exhibit, and another part was peroxide, which bonded to the vanadium. Because a vanadium peroxide molecule is negatively charged, it needed alkali cations for charge balance, Nyman said, and the researchers used potassium, rubidium and cesium alkali cations for this study.

[…]

vanadium peroxide is a beautiful, purple Goldilocks that becomes golden when exposed to air and binds a carbon dioxide molecule.”

She notes that another valuable characteristic of vanadium is that it allows for the comparatively low release temperature of about 200 degrees Celsius for the captured carbon dioxide.

[…]

“Being able to rerelease the captured CO₂ enables reuse of the carbon capture materials, and the lower the temperature required for doing that, the less energy that’s needed and the smaller the cost. There are some very clever ideas about reuse of captured carbon already being implemented — for example, piping the captured CO₂ into a greenhouse to grow plants.”

[…]

Story Source:

Materials provided by Oregon State University. Original written by Steve Lundeberg. Note: Content may be edited for style and length.

---

Journal Reference:

1. Eduard Garrido Ribó, Zhiwei Mao, Jacob S. Hirschi, Taylor Linsday, Karlie Bach, Eric D. Walter, Casey R. Simons, Tim J. Zuehlsdorff, May Nyman. Implementing vanadium peroxides as direct air carbon capture materials. Chemical Science, 2024; 15 (5): 1700 DOI: 10.1039/D3SC05381D

 

Source: Key advance for capturing carbon from the air | ScienceDaily

Global warming is largely caused by carbon dioxide and other gases absorbing infrared radiation, trapping heat in Earth’s atmosphere – known as the greenhouse effect.

The most accurate climate models use precise measurements of the amount of radiation CO₂ can absorb to calculate how much heat will be trapped in the atmosphere. These models are excellent at predicting future changes in Earth’s climate, but they don’t provide a physical explanation for why this gas can absorb so much radiation, which can make their predictions difficult to explain.

Robin Wordsworth at Harvard University and his colleagues have now shown how CO₂’s heat-trapping properties can be explained in terms of quantum mechanical effects, in particular a phenomenon called the Fermi resonance.

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“Rather than just a narrow range of radiation getting absorbed, as you would naively expect, it becomes much broader,” says Wordsworth. “It’s this broadening which is really critical to understanding why carbon dioxide is an important greenhouse gas.”

The Fermi resonance describes how the different directions and patterns in which molecules vibrate can influence each other and make them vibrate more. This is similar to how two pendulums, connected by a shared string, can increase the amplitude of each other’s swinging.

A molecule of CO₂ consists of two oxygen atoms bonded to one carbon atom. Two of the molecule’s vibrations influence each other to make it absorb more light: a side-to-side stretching of the oxygen atoms, and a sidewinder snake-like zigzagging of these atoms.

Wordsworth and his colleagues came up with equations to describe how much radiation CO₂ can absorb based on its physical properties, with and without the Fermi resonance. They found that its light-absorbing features and its warming effect on Earth’s atmosphere could only be reproduced when the resonance was included.

The Fermi resonance was responsible for nearly half of the total warming effect. “Even things that are happening on the scale of our planet are determined, ultimately, by what’s going on at the micro scale,” says Wordsworth.

While it was already known that CO₂ had a particularly large Fermi resonance, having an equation that links this to the greenhouse effect could be useful for quick calculations without running a full climate model, says Jonathan Tennyson at University College London. This could also help physicists model the climate of exoplanets, which can require large amounts of computing power to fully simulate.

Something that Wordsworth and his team couldn’t explain is why CO₂ vibrates in such a unique way – a question that might never be answered without a theory of everything. “There doesn’t seem to be a clear reason why this resonance occurs in CO₂,” says Wordsworth. “One could imagine a different universe where it was slightly different, and carbon dioxide might not have the same effects.”

 

Reference:

arXiv DOI: 10.48550/arXiv.2401.15177

Source: Quantum quirk explains why carbon dioxide causes global warming | New Scientist

Researchers have profiled the entire immune system in young children to compare their response to SARS-CoV-2 with that of adults. The results, published in Cell, show that infants’ systems mount a strong innate response in their noses, where the airborne virus usually enters the body. And unlike adults, babies don’t exhibit widespread inflammatory signaling throughout their circulatory system, perhaps preventing severe COVID.

The research team, led by Stanford Medicine immunologist Bali Pulendran, took blood samples from 81 infants (54 of whom became infected with the virus between one month and three years of age) and dozens of adults. The researchers also took weekly nasal swabs from kids and adults with and without COVID. They then analyzed proteins and gene activity in these samples to track participants’ innate and adaptive immune responses to the virus. “This sort of longitudinal mapping of the immune response of infants, to any virus, had not been done before,” Pulendran says.

The team found stark differences between children and adults in both adaptive and innate immune responses. Infected infants’ noses were flooded with inflammatory signaling molecules and cells. But unlike in the adults, there were no signs of inflammation in their blood.

[…]

Even without a widespread innate response, young children had surprisingly long-lasting levels of SARS-specific antibodies in their blood, Pulendran says. Future research revealing how these innate and adaptive responses are linked could eventually help improve nasally delivered vaccines for children and, potentially, adults.

A crucial question remains: What makes SARS-CoV-2 different from other respiratory viruses, such as influenza and respiratory syncytial virus, which are more deadly for infants?

[…]

Source: Here’s Why Infants Are Strangely Resistant to COVID | Scientific American

Delivering medication to the lungs with inhalable nanoparticles may help treat chronic obstructive pulmonary disease (COPD). In mice with signs of the condition, the treatment improved lung function and reduced inflammation.

COPD causes the lungs’ airways to become progressively narrower and more rigid, obstructing airflow and preventing the clearance of mucus. As a result, mucus accumulates in the lungs, attracting bacterial pathogens that further exacerbate the disease.

This thick mucus layer also traps medications, making it challenging to treat infections. So, Junliang Zhu at Soochow University in China and his colleagues developed inhalable nanoparticles capable of penetrating mucus to deliver medicine deep within the lungs.

The researchers constructed the hollow nanoparticles from porous silica, which they filled with an antibiotic called ceftazidime. A shell of negatively charged compounds surrounding the nanoparticles blocked off pores, preventing antibiotic leakage. This negative charge also helps the nanoparticles penetrate mucus. Then, the slight acidity of the mucus transforms the shells’ charge from negative to positive, opening up pores and releasing the medication.

The researchers used an inhalable spray containing the nanoparticles to treat a bacterial lung infection in six mice with signs of COPD. An equal number of animals received only the antibiotic.

On average, mice treated with the nanoparticles had about 98 per cent less pathogenic bacteria inside their lungs than those given just the antibiotic. They also had fewer inflammatory molecules in their lungs and lower carbon dioxide in their blood, indicating better lung function.

These findings suggest the nanoparticles could improve drug delivery in people with COPD or other lung conditions like cystic fibrosis where thick mucus makes it difficult to treat infections, says Vincent Rotello at the University of Massachusetts Amherst, who wasn’t involved in the study. However, it is unclear if these nanoparticles are cleared by lungs. “If you have a delivery system that builds up over time, that would be problematic,” he says.

Source: COPD: Inhalable nanoparticles could help treat chronic lung disease | New Scientist

The rainbow looks different to a human than it does to a honeybee or a zebra finch. That’s because these animals can see colors that we humans simply can’t. Now scientists have developed a new video recording and analysis technique to better understand how the world looks through the eyes of other species. The accurate and relatively inexpensive method, described in a study published on January 23 in PLOS Biology, is already offering biologists surprising discoveries about the lives of different species.

Humans have three types of cone cells in their eyes. This trio of photoreceptors typically detects red, green and blue wavelengths of light, which combine into millions of distinct colors in the spectrum from 380 to 700 nanometers in wavelength—what we call “visible light.” Some animals, though, can see light with even higher frequencies, called ultraviolet, or UV, light. Most birds have this ability, along with honeybees, reptiles and certain bony fish.

[…]

To capture animal vision on video, Vasas and her colleagues developed a portable 3-D-printed enclosure containing a beam splitter that separates light into UV and the human-visible spectrum. The two streams are captured by two different cameras. One is a standard camera that detects visible-wavelength light, and the other is a modified camera that is sensitive to UV. On its own, the UV-sensitive camera wouldn’t be able to record detailed information on the rest of the light spectrum in a single shot. But paired together, the two cameras can simultaneously record high-quality video that encompasses a wide range of the light spectrum. Then a set of algorithms aligns the two videos and produces versions of the footage that are representative of different animals’ color views, such as those of birds or bees.

[…]

Capturing video in this way “fills a really important gap in our ability to model animal vision,” says Jolyon Troscianko, a visual ecologist at the University of Exeter in England, who wasn’t involved in the new research. He notes that in nature, “a lot of interesting things move,” such as animals that are engaging in mating dances or rapid defense displays. Until now, researchers studying these dynamic behaviors have been stuck with the human perspective.

[…]

The technique is already revealing unseen phenomena of the natural world, she adds: for example, by recording an iridescent peacock feather rotating under a light, the researchers found shifts in color that are even more vibrant to fellow peafowl than they are to humans. Vasas and her colleagues also captured the brief startle display of a black swallowtail caterpillar and saw for the first time that its hornlike defense appendages are UV-reflective.

“None of these things were hypotheses that we had in advance,” Vasas says. Moving forward, “I think it will reveal a lot of things that I can’t yet imagine.”

[…]

Source: Animals Can See Colors We Can’t–And New Tech Offers Us a Glimpse | Scientific American