Study finds pollinators are attracted to humidity, not just scent

Humidity is as important as scent in attracting pollinators to a plant, new  research finds, advancing basic biology and opening new avenues to support agriculture.

In a study published in Current Biology, a team of  researchers found that the weevil responsible for pollinating the plant Zamia furfuracea was just as sensitive to humidity as to scent.

The world of plant-insect interactions was drastically changed by the work that was done on visual and scent cues. And now we're just starting to realize how many other factors are playing a role in plant reproduction and impacting insect decision making, pollination and success.

Another groundbreaking study published in 2022 in Nature Communications  found humidity was acting as a signal to encourage hawkmoths to pollinate the sacred datura flower (Datura wrightii). Taken together, the studies demonstrate that two very distantly related plants actively use humidity to encourage pollination.

Prior to this research, humidity was seen as just an outcome of evaporation of nectar, a side note. What researchers now have found is that this is an active process of the flower, coming through specialized cells, and these organisms may even have evolved to privilege this humidity release, because it attracts pollinators.

Until now, the study of pollination and plant-insect interactions has focused on visual and scent markers—senses that humans can also interpret. Insects, however, are far more adept than humans at sensing changes in humidity, carbon dioxide and temperature.

Especially as climate change directly impacts exactly those things, it's crucial that we understand how insects utilize all of that information in their interactions with plants. While humans need relatively large changes in humidity before we can sense a difference, insects can sense minuscule changes.

Shayla Salzman et al, Cone humidity is a strong attractant in an obligate cycad pollination system, Current Biology (2023). DOI: 10.1016/j.cub.2023.03.021

Amputees feel warmth in their missing hand

Amputees can now feel warmth in their phantom hand thanks to a new device.

Scientists have developed MiniTouch, which consists of a small sensor placed on an amputee’s prosthetic finger and electrodes that mimic sensations on the residual arm.

Electrodes on the amputated arm relay the temperature of the object being touched by the finger sensor, giving “the illusion that we are cooling down, or warming up, missing fingers”.

Scientists believe the findings could allow amputees to have temperature-sensing technology built into their prosthetic limbs, without the need for invasive technology.

If you place something hot or cold on the forearm of an intact individual, that person will feel the object's temperature locally, directly on their forearm. But in amputees, that temperature sensation on the residual arm may be felt in the phantom, missing hand.

Researchers have been keen on incorporating new sensory feedback into prosthetic limbs for providing more realistic touch to amputees.

By providing temperature feedback non-invasively, via thermal electrodes (aka thermodes) placed against the skin on the residual arm, amputees  report feeling temperature in their phantom limb. They can feel if an object is hot or cold, and can tell if they are touching copper, plastic or glass. The technology was successfully tested in 17 out of 27 patients. The results are published in Science.

Of particular importance is that phantom thermal sensations are perceived by the patient as similar to the thermal sensations experienced by their intact hand.

The projection of temperature sensations into the phantom limb has led to the development of new bionic technology, one that equips prosthetics with non-invasive temperature feedback that allows amputees to discern what they're touching.

Slowing the aging of the intestine in fish slows the aging of the entire organism, discover scientists

Is it possible to extend lifespan by simply slowing the aging of an organ, such as the intestine? Researchers have discovered how to extend the life expectancy of zebrafish by reactivating a gene within intestinal cells. The results were published in the journal Nature Aging on May 4, 2023.

The intestine plays a crucial role in an anti-aging approach as well as general health. Over a century ago, Elie Metchnikov observed that aging ensued from increased inflammation of the intestine and microbial infiltration within blood circulation. The more we age, the less the digestive tract serves as a barrier, allowing the undesirable particles and bacteria that cause the more rapid aging of the organism to pass through.

In a new study researchers  have analysed the impact on aging of telomere length in the intestinal cells of zebrafish. As with humans, these chromosome extremities shrink faster in the intestine than in other organs during the course of a life, which is why this process plays such an important role in aging.

Scientists inserted a DNA fragment within zebrafish that enabled intestinal cells to produce the enzyme responsible for lengthening telomeres, telomerase. They then observed the slowing not only of the organ's decline, but also and especially that of the entire organism. This phenomenon regenerates the fertility and general health of individuals during the normal aging process, and increases lifespan with no associated risk of developing cnacer.

The proximity between telomere length among zebrafish and humans opens prospects for counteracting aging. Researchers are simultaneously studying the pathologies associated with shrinking telomere length, including cancer as well as neurodegenerative, immune, and gastrointestinal diseases.

Lab-grown meat's carbon footprint potentially worse than retail bee...

Lab-grown meat, which is cultured from animal cells, is often thought to be more environmentally friendly than beef because it's predicted to need less land, water and greenhouse gases than raising cattle. But in a preprint, not yet peer-reviewed, researchers at the University of California, Davis, have found that lab-grown or "cultivated" meat's environmental impact is likely to be "orders of magnitude" higher than retail beef based on current and near-term production methods.

Researchers conducted a life-cycle assessment of the energy needed and greenhouse gases emitted in all stages of production and compared that with beef. One of the current challenges with lab-grown meat is the use of highly refined or purified growth media, the ingredients needed to help animal cells multiply. Currently, this method is similar to the biotechnology used to make pharmaceuticals. This sets up a critical question for cultured meat production: Is it a pharmaceutical product or a food product?

"If companies are having to purify growth media to pharmaceutical levels, it uses more resources, which then increases global warming potential.

The scientists defined the global warming potential as the carbon dioxide equivalents emitted for each kilogram of meat produced. The study found that the global warming potential of lab-based meat using these purified media is four to 25 times greater than the average for retail beef.

Derrick Risner et al, Environmental impacts of cultured meat: A cradle-to-gate life cycle assessment, bioRxiv (2023). DOI: 10.1101/2023.04.21.537778

Oxygen restriction helps fast-aging lab mice live longer

For the first time, researchers have shown that reduced oxygen intake, or "oxygen restriction," is associated with longer lifespan in lab mice, highlighting its anti-aging potential.

Research efforts to extend healthy lifespan have identified a number of chemical compounds and other interventions that show promising effects in mammalian lab animals— for instance, the drug metformin or dietary restriction. Oxygen restriction has also been linked to longer lifespan in yeast, nematodes, and fruit flies. However, its effects in mammals have been unknown.

To explore the anti-aging potential of oxygen restriction in mammals, researchers conducted lab experiments with mice bred to age more quickly than other mice while showing classic signs of mammalian aging throughout their bodies. The researchers compared the lifespans of mice living at normal atmospheric oxygen levels (about 21%) to the lifespans of mice that, at 4 weeks of age, had been moved to a living environment with a lower proportion of oxygen (11%—similar to that experienced at an altitude of 5000 meters).

They found that the mice in the oxygen-restricted environment lived about 50% longer than the mice in normal oxygen levels, with a median lifespan of 23.6 weeks compared to 15.7 weeks. The oxygen-restricted mice also had delayed onset of aging-associated neurological deficits.

Prior research has shown that dietary restriction extends the lifespan of the same kind of fast-aging mice used in this new study. Therefore, the researchers wondered if oxygen restriction extended their lifespan simply by causing the mice to eat more. However, they found that oxygen restriction did not affect food intake, suggesting other mechanisms were at play.

These findings support the anti-aging potential of oxygen restriction in mammals, perhaps including humans. However, extensive additional research will be needed to clarify its potential benefits in humans and illuminate the molecular mechanisms by which it operates.

Rogers RS, Wang H, Durham TJ, Stefely JA, Owiti NA, Markhard AL, et al. Hypoxia extends lifespan and neurological function in a mouse model of aging, PLoS Biology (2023). DOI: 10.1371/journal.pbio.3002117

MRI scans and AI technology really could read what we're thinking. ...

For the first time, researchers have managed to use GPT1, precursor to the AI chatbot ChatGPT, to translate MRI imagery into text in an effort to understand what someone is thinking.

What is a black box? What it means when the inner workings of AIs are hidden?

For some people, the term "black box" brings to mind the recording devices in airplanes that are valuable for postmortem analyzes if the unthinkable happens. For others it evokes small, minimally outfitted theaters. But black box is also an important term in the world of artificial intelligence.

AI black boxes refer to AI systems with internal workings that are invisible to the user. You can feed them input and get output, but you cannot examine the system's code or the logic that produced the output.

Machine learning is the dominant subset of artificial intelligence. It underlies generative AI systems like ChatGPT and DALL-E 2. There are three components to machine learning: an algorithm or a set of algorithms, training data and a model.

An algorithm is a set of procedures. In machine learning, an algorithm learns to identify patterns after being trained on a large set of examples—the training data. Once a machine-learning algorithm has been trained, the result is a machine-learning model. The model is what people use.

For example, a machine-learning algorithm could be designed to identify patterns in images, and training data could be images of dogs. The resulting machine-learning model would be a dog spotter. You would feed it an image as input and get as output whether and where in the image a set of pixels represents a dog.

Any of the three components of a machine-learning system can be hidden, or in a black box. As is often the case, the algorithm is publicly known, which makes putting it in a black box less effective. So to protect their intellectual property, AI developers often put the model in a black box. Another approach software developers take is to obscure the data used to train the model—in other words, put the training data in a black box.

That's because researchers don't fully understand how machine-learning algorithms, particularly deep-learning algorithms, operate. The field of explainable AI is working to develop algorithms that, while not necessarily glass box, can be better understood by humans.

Part 1

Why AI black boxes matter

In many cases, there is good reason to be wary of black box machine-learning algorithms and models. Suppose a machine-learning model has made a diagnosis about your health. Would you want the model to be black box or glass box? What about the physician prescribing your course of treatment? Perhaps she would like to know how the model arrived at its decision.

What if a machine-learning model that determines whether you qualify for a business loan from a bank turns you down? Wouldn't you like to know why? If you did, you could more effectively appeal the decision, or change your situation to increase your chances of getting a loan the next time.

Black boxes also have important implications for software system security. For years, many people in the computing field thought that keeping software in a black box would prevent hackers from examining it and therefore it would be secure. This assumption has largely been proved wrong because hackers can reverse-engineer software—that is, build a facsimile by closely observing how a piece of software works—and discover vulnerabilities to exploit.

If software is in a glass box, then software testers and well-intentioned hackers can examine it and inform the creators of weaknesses, thereby minimizing cyberattacks.

original article.

Toxic Fragments of Bacteria Leaking From The Gut May Drive Weight Gain

Toxic substances leaking out from the gut can interfere with the functioning of fat cells and drive obesity, according to a recent study by a team of international researchers. The results could inform how we treat excessive and dangerous weight gain in the future.

The substances, called endotoxins, are fragments of bacteria in our guts. While they're a normal part of the digestive tract's ecosystem, the microbial debris can cause significant damage to the body should they find their way into the bloodstream.

Here, the researchers wanted to look specifically at the impact of endotoxins on fat cells (adipocytes) in people. They discovered that key processes that usually help control the buildup of fat are affected by the material.

"Gut microbe fragments that enter the bloodstream reduce normal fat cell function and their metabolic activity, which is exacerbated with weight gain, contributing to increased diabetes risk.

It appears that as we gain weight, our fat stores are less able to limit the damage that gut microbe fragments may cause to fat cells.

The study involved 156 participants, 63 of whom were classed as obese, and 26 of whom had undergone bariatric surgery for obesity – a procedure where the size of the stomach is reduced to limit food intake.

Samples from these participants were processed in the lab as the team looked at two different types of fat cell, described as white and brown.

White fat cells, which make up most of our fat storage tissues, stores lipids in larger volumes. Brown fat cells take stores of fat and break them down using their numerous mitochondria, such as when the body is cold and needs warmth. Under the right conditions, the body can convert the lipid-storing white fat cells that behave like lipid-burning brown fat cells.

Part 1

The analysis showed that endotoxins reduced the body's ability to turn white fat cells into brown-like fat cells and reduce the amount of stored fat.

Engineers harvest abundant clean energy from thin air, 24/7

A team of engineers  has recently shown that nearly any material can be turned into a device that continuously harvests electricity from humidity in the air. The secret lies in being able to pepper the material with nanopores less than 100 nanometers in diameter. The research appeared in the journal Advanced Materials.

The air contains an enormous amount of electricity. Think of a cloud, which is nothing more than a mass of water droplets. Each of those droplets contains a charge, and when conditions are right, the cloud can produce a lightning bolt—but we don't know how to reliably capture electricity from lightning. What  the engineers have done is to create a human-built, small-scale cloud that produces electricity for us predictably and continuously so that we can harvest it.

The heart of the man-made cloud depends on what the engineers call the "generic Air-gen effect".

It builds on an earlier work completed in 2020 showing that electricity could be continuously harvested from the air using a specialized material made of protein nanowires grown from the bacterium Geobacter sulfurreducens.

The ability to generate electricity from the air turns out to be generic: literally any kind of material can harvest electricity from air, as long as it has a certain property. That property: "It needs to have holes smaller than 100 nanometers (nm), or less than a thousandth of the width of a human hair."

This is because of a parameter known as the "mean free path," the distance a single molecule of a substance, in this case water in the air, travels before it bumps into another single molecule  of the same substance. When water molecules are suspended in the air, their mean free path is about 100 nm.

part1

The researchers realized that they could design an electricity harvester based around this number. This harvester would be made from a thin layer of material filled with nanopores smaller than 100 nm that would let water molecules pass from the upper to the lower part of the material. But because each pore is so small, the water molecules would easily bump into the pore's edge as they pass through the thin layer. This means that the upper part of the layer would be bombarded with many more charge-carrying water molecules than the lower part, creating a charge imbalance, like that in a cloud, as the upper part increased its charge relative to the lower part. This would effectually create a battery—one that runs as long as there is any humidity in the air.

Xiaomeng Liu et al, Generic Air‐Gen Effect in Nanoporous Materials for Sustainable Energy Harvesting from Air Humidity, Advanced Materials (2023). DOI: 10.1002/adma.202300748. onlinelibrary.wiley.com/doi/10.1002/adma.202300748

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Unique molecular machinery of a woman who can't feel pain

The biology underpinning a rare genetic mutation that allows its carrier to live virtually pain-free, heal more rapidly and experience reduced anxiety and fear, has been uncovered by new research.

The study, published in Brain, follows up the team's discovery in 2019 of the FAAH-OUT gene and the rare mutations that cause a woman, Jo Cameron, to feel virtually no pain and never feel anxious or afraid. The new research describes how the mutation in FAAH-OUT "turns down" FAAH gene expression, as well as the knock-on effects on other molecular pathways linked to wound healing and mood. It is hoped the findings will lead to new drug targets and open up new avenues of research in these areas.

Jo, who lives in Scotland, was first referred to pain geneticists at UCL in 2013, after her doctor noticed that she experienced no pain after major surgeries on her hip and hand. After six years of searching, they identified a new gene that they named FAAH-OUT, which contained a rare genetic mutation. In combination with another, more common mutation in FAAH, it was found to be the cause of Jo's unique characteristics.

The area of the genome containing FAAH-OUT had previously been assumed to be "junk" DNA that had no function, but it was found to mediate the expression of FAAH, a gene that is part of the endocannabinoid system and that is well-known for its involvement in pain, mood and memory.

In this study, the team from UCL sought to understand how FAAH-OUT works at a molecular level, the first step towards being able to take advantage of this unique biology for applications like drug discovery.

The team observed that FAAH-OUT regulates the expression of FAAH. When it is significantly turned down as a result of the mutation carried by Jo Cameron, FAAH enzyme activity levels are significantly reduced.

Hajar Mikaeili et al, Molecular basis of FAAH-OUT-associated human pain insensitivity, Brain (2023). DOI: 10.1093/brain/awad098

Mind-Blowing Dream-To-Video Could Be Coming With Stable Diffusion Video Rebuild From Brain Activity

The most effective ways of foraging can attract predators, scientists find

Animals using the most of efficient methods of searching for resources may well pay with their lives, scientists  have discovered.

The findings, published today in Behavioral Ecology, reveal why animals may not always use a searching strategy that maximizes results.

How animals move through their habitat, particularly in search for food, is a major question in biology, and has application in how animals will respond to environmental change.

Numerous studies have demonstrated that a special kind of movement, known as Lévy motion, increases the ability to find resources because it includes long-distance moves between areas being searched, as well as periods of concentrated searching in one area. It has also been shown that a range of animals use this kind of movement.

This study is the first to demonstrate a potential cost of Lévy motion in an experiment, showing prey using Lévy motion are targeted twice as often as prey using Brownian motion—the movement observed in molecules in a gas, and thus a baseline expectation.

This is because the predators prefer to target prey that are moving with straighter paths of motion, possibly because this makes the future position of the prey more predictable.

This study demonstrates that prey animals might not always use a searching strategy that maximizes finding a resource because there might be costs that were, previous to the study, unknown. This might explain why some studies have found animals use different kinds of searches other than Lévy motion.

This study shows, for the first time, that animals using a common and very effective way of searching for resources may actually pay a cost of being more susceptible to predators.

Christos C Ioannou et al, Virtual prey with Lévy motion are preferentially attacked by predatory fish, Behavioral Ecology (2023). DOI: 10.1093/beheco/arad039

Sudden infant death syndrome may have biologic cause

Sudden infant death syndrome (SIDS) is a case where the death of an apparently healthy infant before their first birthday remains unexplained even after thorough investigation. Death generally seems to occur when infants are sleeping.

Whether causing the common cold or COVID-19, coronaviruses deploy key enzymes to elude human immune response

The entire family of coronaviruses is equipped with multiple methods of evading the human immune system, and two new studies have taken a deep dive into how these viruses, including SARS-CoV-2, leverage highly specialized enzymes that keep human immune forces at bay.

The studies train a bright spotlight on the stealthy strategies that coronaviruses deploy to antagonize and destabilize human cells, steps scripted in their genetic code that ultimately help these viruses evade immune system assault.

Some members of the broad coronavirus family are more adept at these strategies than others. Indeed, one of the constants throughout the COVID pandemic has been the worrying discovery of a growing suite of molecular methods that SARS-CoV-2 uses to elude the human immune system. New research has opened a window into an evasion strategy in which coronaviruses destabilizes human cells and damages leap forward by comparing the evasion capabilities of milder coronaviruses to the trio of coronaviruses known to cause serious, even lethal respiratory infections.

Regardless of whether the coronavirus causes a bout with the common cold or serious infections, such as COVID-19 or MERS, most set the stage for immune evasion by damaging critical human proteins that prompt the immune response. Coronaviruses launch their attack by deploying the same type of protein-cleaving enzyme.

The researchers  zeroed in on the viral enzymes known as papain-like proteases, protein-cleaving enzymes that evolved to help coronaviruses ensure their survival by damaging critical signaling proteins that regulate human cells. Once attacked by these enzymes, human cells become destabilized and lose their capacity to marshal innate immune system responses.

While these enzymes have been elucidated in the trio of dangerous coronaviruses, researchers have identified protein-like proteases—PLPs—in HCoV-229E, HCoV-HKU1, and HCoV-OC43, three coronaviruses that cause the common cold. Their enzymatic properties correlated with their ability to suppress innate immune responses.

The researchers  describe how coronaviruses use their PLPs to damage the protein ubiqutin and a related ubiquitin-like protein called ISG15. Human cells use ubiquitin and ISG15 as cell regulators. By damaging these regulating proteins, the innate immune response is impaired and the viruses are free to proliferate unchecked.

 Yuxian Xiong et al, The substrate selectivity of papain-like proteases from human-infecting coronaviruses correlates with innate immune suppression, Science Signaling (2023). DOI: 10.1126/scisignal.ade1985

Dan Cao et al, The SARS-CoV-2 papain-like protease suppresses type I interferon responses by deubiquitinating STING, Science Signaling (2023). DOI: 10.1126/scisignal.add0082

Termite mounds reveal secret to creating 'living and breathing' bui...

Among the approximately 2,000 known species of termites, some are ecosystem engineers. The mounds built by some genera—for example Amitermes, Macrotermes, Nasutitermes, and Odontotermes—reach up to eight meters high, making them some of the world's largest biological structures. Natural selection has been at work improving the 'design' of their mounds over tens of millions of years. What might human architects and engineers learn if they go to the termites and consider their ways?

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Researchers discover Chinmo, 'the youth gene'

A new study published on eLife has revealed that the Chinmo gene is responsible for establishing the juvenile stage in insects. It also confirms that the Br-C and E93 genes play a regulatory role in insect maturity. These genes, which are also present in humans, act as a promoter and as a suppressor, respectively, of cancerous processes.

The results of the research, which was carried out with the fruit fly Drosophila melanogaster and the cockroach Blatella germanica, reveal that these genes have been conserved throughout the evolution of insects. Therefore, it is thought that they could play a key role in the evolution of metamorphosis.

Insects that undergo complete metamorphosis, such as flies, go through the following three stages of development: the embryo, which is formed inside the egg; the larva (juvenile stage), which grows in several phases; and the pupa, which is the stage that encompasses metamorphosis and the formation of the adult organism.

Previous studies had discovered that the Br-C gene determines pupal formation in insects. In 2019, the same IBE team that has led this study described the essential function of E93 to complete metamorphosis in insects and initiate the maturation of the tissues that go on to form the adult. However, the gene responsible for determining the juvenile stage was unknown until now. This study has now identified the Chimno gene as the main precursor of this stage in insects.

By deleting the Chinmo gene in Drosophila specimens, the scientists observed that these insects progressed to the pupal stage without completing the juvenile stage, moving to the adult stage early. These findings thus confirm that Chinmo is essential for juvenile development.

Researchers have discovered that Chinmo promotes tissue growth during the juvenile stage of Drosophila by keeping the cells undifferentiated. Thus, while Chinmo is expressed, cells cannot differentiate as the gene suppresses the action of those genes responsible for forming adult tissues.

Thus, the study concludes that the Chinmo gene has to be inactivated for Drosophila to progress from the juvenile to the pupal stage and to carry out metamorphosis successfully. Likewise, it confirms that the sequential action of the three genes, namely Chinmo, Br-C, and E93, during the larval, pupal, and adult stages, respectively, coordinate the formation of the different organs that form the adult organism.

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Chinmo and Br-C belong to the large family of BTB-ZF transcription factors—proteins involved in cancer and that are also found in humans. Although previous studies had shown that Chinmo is a precursor of cancer, the role of Br-C and E93 in this disease was unknown until now.

Understanding the molecular functioning of cell growth can help to better comprehend cancer processes. Healthy cells grow, differentiate, and mature. In contrast, cancer cells grow uncontrollably, do not differentiate, and fail to mature. So determining the role of Chinmo, Br-C, and E93 may be key to future clinical research.

The study shows that while Chinmo is an oncogenic precursor because it promotes tissue growth and prevents differentiation, C-Br and E93 serve as tumor suppressors by activating tissue maturation.

The complete metamorphosis of insects such as butterflies and flies is an evolutionary innovation that has emerged gradually during the evolution from insects that undergo a much simpler metamorphosis, such as cockroaches. To understand how this gradual process has taken place, the researchers analyzed the function of Chinmo, Br-C, and E93 in cockroaches.

"Analyzing the function of these genes in different species of insects allows us to observe how evolution works. The observation that Chinmo function is conserved in insects as evolutionarily separated as flies and cockroaches gives us clues as to how metamorphoses originated.

The results of the study indicate that the regulatory action of Chinmo and E93 in more basal insects such as the cockroach are sufficient to determine the transition from the juvenile to the adult form.

Sílvia Chafino et al, Antagonistic role of the BTB-zinc finger transcription factors chinmo and broad-complex in the juvenile/pupal transition and in growth control, eLife (2023). DOI: 10.7554/eLife.84648

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Microorganisms are key to storing carbon in soils, shows new study

According to a study recently published in Nature, microorganisms play a key role in soil carbon storage. The study, conducted by an international team of scientists  reveals that microbial carbon use efficiency is at least four times more influential than other biological or environmental factors when it comes to global soil carbon storage and distribution. The study's result has implications for improving soil health and mitigating climate change.

Soils serve as crucial carbon sinks in the battle against climate change, storing more carbon than any other terrestrial ecosystem and three times more than the atmosphere. However, the processes involved in soil carbon storage have not been well understood. While microorganisms have long been recognized as important contributors to the accumulation and loss of soil organic carbon (SOC), the specific contributions of different biological and environmental processes have remained largely unknown.

The study, titled "Microbial Carbon Use Efficiency Promotes Global Soil Carbon Storage," and published on May 24 in Nature, employed a novel approach to quantifying the processes that determine soil carbon dynamics. The international research team comprehensively explored the relationship between carbon use efficiency, SOC preservation, and various factors such as climate, vegetation, and soil properties. The study represents the first successful integration of global-scale datasets, a microbial-process explicit model, data assimilation, deep learning, and meta-analysis to examine this relationship.

Microbial carbon use efficiency (CUE) measures the proportion of carbon used by microbes for growth versus metabolism. When carbon is used for microbial growth, it becomes incorporated into microbial cells, which supports its storage in the soil. Conversely, when carbon is used for metabolism, it is released into the air as carbon dioxide,  acting as a greenhouse gas. The study emphasizes that microbial growth is more crucial than metabolism in determining the amount of carbon stored in the soil.

Feng Tao et al, Microbial carbon use efficiency promotes global soil carbon storage, Nature (2023). DOI: 10.1038/s41586-023-06042-3

Connection between immune system and brain in mice may explain why stress can worsen gut inflammation

A team of medical researchers affiliated with multiple institutions has found a connection between the immune system and the brain in mice that could explain why psychological stress can lead to worsening gut inflammation problems in people with gut ailments. In their study, reported in the journal Cell, the group tested stressed lab mice.

Prior research has shown that people with colitis or Crohn's disease, the two main types of inflammatory bowel disease (IBD), tend to experience flareups under stressors such as job loss or divorce. In this new effort, the research team sought to find the biological processes involved when such events occur. To that end, they conducted tests with lab mice.

To induce stress conditions, the mice were confined inside small tubes. They then were given chemical irritants to bring on IBD-like symptoms. Then, the mice were given drugs to block the production of inflammation-inducing glucocorticoids, which the brains of mice and humans produce during times of stress. Following that, the team conducted colonoscopies to rate intestinal damage.

They found that the mice with blocked glucocorticoid production had less damage to their intestines, suggesting that stress played a role in inflammation damage in the intestines. The research team then collected tissue samples from the colons of the mice to study their genetic makeup. They found that the mice with higher levels of glucocorticoids also had differences in glia nerve cells—such cells, the team notes perform maintenance and communication functions and tend to respond to stress hormones.

Further study of the mice cells showed that higher stress levels resulted in preventing the maturing of some nerve cells. The researchers note that this is relevant because prior research has shown that mature nerve cells are needed to drive movement of fecal material in the bowels. The research team then compared what they found in the test mice with tissue samples collected from 63 people with IBD and found similar results.

They also asked the IBD patients to fill out a questionnaire and found that those patients who experienced more stressful events, reported stronger symptoms and had more intestinal damage.

Kai Markus Schneider et al, The enteric nervous system relays psychological stress to intestinal inflammation, Cell (2023). DOI: 10.1016/j.cell.2023.05.001

Low-flavanol diet drives age-related memory loss, study finds

A large-scale study by researchers  is the first to establish that a diet low in flavanols—nutrients found in certain fruits and vegetables—drives age-related memory loss.

The study found that flavanol intake among older adults tracks with scores on tests designed to detect memory loss due to normal aging and that replenishing these bioactive dietary components in mildly flavanol-deficient adults over age 60 improves performance on these tests.

The improvement among study participants with low-flavanol diets was substantial and raises the possibility of using flavanol-rich diets or supplements to improve cognitive function in older adults.

The finding also supports the emerging idea that the aging brain requires specific nutrients for optimal health, just as the developing brain requires specific nutrients for proper development.

The current study builds on over 15 years of research  linking age-related memory loss to changes in the dentate gyrus, a specific area within the brain's hippocampus—a region that is vital for learning new memories - and showing that flavanols improved function in this brain region.

Additional research, in mice, found that flavanols—particularly a bioactive substance in flavanols called epicatechin—improved memory by enhancing the growth of neurons and blood vessels and in the hippocampus.

The research  team tested flavanol supplements in people. One small study confirmed that the dentate gyrus is linked to cognitive aging. A second, larger trial showed that flavanols improved memory by acting selectively on this brain region and had the most impact on those starting out with a poor-quality diet.

 Brickman, Adam M. et al, Dietary flavanols restore hippocampal-dependent memory in older adults with lower diet quality and lower habitual flavanol consumption, Proceedings of the National Academy of Sciences (2023). DOI: 10.1073/pnas.2216932120

Glowing Tumor Surgery 

Humans evolved to walk with an extra spring in our step, shows foot arch study

A new study has shown that humans may have evolved a spring-like arch to help us walk on two feet. Researchers studying the evolution of bipedal walking have long assumed that the raised arch of the foot helps us walk by acting as a lever which propels the body forward.

But a global team of scientists have now found that the recoil of the flexible arch repositions the ankle upright for more effective walking. The spring-like arch recoils to help the ankle lift the body. The effects in running are greater, which suggests that the ability to run efficiently could have been a selective pressure for a flexible arch that made walking more efficient too. This discovery could even help doctors improve treatments for present-day patients' foot problems.

The evolution of our feet, including the raised medial arch which sets us apart from great apes, is crucial to bipedal walking.

Michael Rainbow et al, Mobility of the human foot's medial arch enables upright bipedal locomotion, Frontiers in Bioengineering and Biotechnology (2023). DOI: 10.3389/fbioe.2023.1155439

Small fusion experiment hits temperatures hotter than the sun's core

To produce commercial energy, future fusion power plants will need to achieve temperatures of 100 million degrees C. To do so requires careful control of the plasma. In a study published in the journal Nuclear Fusion, researchers refined operating conditions to achieve the necessary temperatures in a compact spherical tokamak device called ST40.

This device is unique; it is much smaller and has a more spherical plasma than other fusion devices. To achieve these results, the researchers used an approach similar to past "supershots" that produced more than 10 million watts of fusion power in the TFTR tokamak in the 1990s.

This effort demonstrated fusion-relevant ion temperatures in a compact, high magnetic field, spherical tokamak for the first time. This confirms that the spherical tokamak can achieve one of the conditions necessary for commercial fusion energy production. These results also show that similar fusion pilot plants may lead to more compact, and potentially more economical, fusion power sources than other configurations.

In the research, ST40 plasmas operated at toroidal magnetic field values of just over 2 Tesla and were heated by 1.8 million watts of high energy neutral particles. While the ST40 plasma discharges lasted for only 150 milliseconds, the plasma showed ion temperatures of more than 100 million degrees Celsius.

S.A.M. McNamara et al, Achievement of ion temperatures in excess of 100 million degrees Kelvin in the compact high-field spherical tokamak ST40, Nuclear Fusion (2023). DOI: 10.1088/1741-4326/acbec8

New high resolution X-ray imaging technique can image biological specimens without causing damage

A pollen grain showing the nanofoam within or a diatom with the individual geometric structures inside clearly visible: Using high-energy X-rays from the PETRA III synchrotron light source at DESY, a team of scientists has managed to image these structures without damaging them.

Their new technique generates high resolution X-ray images of dried biological material that has not been frozen, coated, or otherwise altered beforehand—all with little to no damage to the sample. This method, which is also used for airport baggage scanning, can generate images of the material at nanometre resolution.

Using high energy X-rays that are intensely focused through a set of novel diffractive lenses, the special technique allows imaging to be performed at less than 1% of the X-ray damage threshold of the specimen. The results, which reveal this method as a promising tool for brighter next-generation light sources such as the planned upgrade project PETRA IV, have been published in the journal Light: Science & Applications.

X-ray light interacts with biological material in a variety of ways, mostly depending on the energy and intensity of the light. At the same time, radiation damage, such as small structural changes up to complete degradation of the sample, is the limiting factor during X-ray imaging of biological samples.

At low energies, the X-rays are primarily absorbed by the atoms in the sample, whose electrons take on the energy, causing them to spring out of the atoms and cause damage to the sample. Images using these low-energy X-rays thus map out the sample's absorption of the radiation. At higher energies, absorption is less likely, and a process called elastic scattering occurs, where the X-ray photons "bounce" off of the matter like billiard balls without depositing their energy.

Techniques such as crystallography or ptychography use this interaction. Nevertheless, absorption can still occur, meaning damage to the sample happens anyway. But there is a third interaction: Compton scattering, where the X-rays leave only a tiny amount of their energy in the target material. Compton scattering had been largely ignored as a viable method of X-ray microscopy, since it requires even higher X-ray energies where until now no suitable high-resolution lenses existed.

Tang Li et al, Dose-efficient scanning Compton X-ray microscopy, Light: Science & Applications (2023). DOI: 10.1038/s41377-023-01176-5

How the humble neutron can help solve some of the universe's deepest mysteries

Scientists are unleashing the power of neutrons to improve understanding of everyday materials and tackle fundamental questions in physics.

 The humble neutron, found in the nucleus of every atom but hydrogen, can—if manipulated in just the right way—shed light on everything from the climate crisis and energy, to health and quantum computing.

One such way is a rather spectacular process known as spallation, high energy particles destabilize an atom's nucleus, which in turn releases some of the neutrons found there.

When harnessed, these newly freed neutrons can be used like X-rays to map the inner structure of materials.

Currently under construction in Lund, Sweden, the European Spallation Source (ESS) is expected to come online in 2027. Once it achieves its full specifications, its unprecedented flux and spectral range is set to make it the most powerful and versatile neutron source for science in the world.

The purpose of the facility "is to create neutrons, a neutron beam, to be used for scientific purposes."

Once the facility is up and running, scientists from across Europe and the rest of the world will be able to use its 15 different beamlines to conduct fundamental research. 

a neutron beam "is not the same as an X-ray, but it is complementary and uses some of the same physical laws."

Like X-rays, neutrons can be used to probe materials and biological systems. But they interact with materials in different ways to the photons in high-energy X-ray beams, and therefore provide different types of information about their targets.

For example, neutron beams can say something about the interior dynamics of lithium-ion batteries, reveal obscured details from ancient artifacts or clarify the mechanisms of antibiotic resistance in bacteria. They can also be used to explore fundamental physics. It almost seems like a case of "what can't they do?"

https://cordis.europa.eu/project/id/823867

https://cordis.europa.eu/project/id/951782

https://research-and-innovation.ec.europa.eu/funding/funding-opport...

https://phys.org/news/2023-05-humble-neutron-universe-deepest-myste...

The olfactory responses of patients in a coma or vegetative state can display different signs of consciousness

Severe brain injuries or head traumas in humans can lead to various stages of so-called disorders of consciousness (DoC). These are states in which consciousness is either partly or entirely absent, such as a coma; unresponsive wakefulness syndrome, also known as a vegetative state; and minimally conscious state.

Accurately evaluating patients who have lost consciousness is of crucial importance, as it allows doctors to determine what treatments to administer and how to facilitate the re-emergence of consciousness. Typically, to clinically evaluate consciousness, doctors observe the behavior of patients in response to sensory stimuli, such as sounds or images.

For instance, while patients in a vegetative state are awake but continue to be unresponsive to external stimuli, patients with MCS exhibit some behaviors that indicate that they are conscious. So far, most methods to assess the consciousness level of patients rely on sounds or visual stimuli, yet olfactory stimuli could potentially prove useful too.

Researchers recently carried out a study investigating the responses of patients in a coma or vegetative state to smells, to understand whether they could be used to evaluate consciousness. Their findings, published in Frontiers in Neuroscience, appear to highlight the potential of olfactory stimuli for assessing consciousness in clinical settings.

This study aimed to explore whether olfactory response can be a sign of consciousness and represent higher cognitive processing in patients with disorders of consciousness (DoC) using clinical and electroencephalogram data.

As part of their study, the researchers evaluated the responses of 28 patients at different stages of DoC to olfactory stimuli. Out of these patients, 13 were in a vegetative state (UMS) and 15 in MCS. The study participants were divided into two groups based on whether they responded to olfactory stimuli or not. After three months, the outcomes of DoC patients were followed up using the coma recovery scale-revised (CRS-R)" [i.e., a standard assessment used to measure DoC in clinical settings].
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When researchers analyzed the data they collected, they found that there was a relationship between the patients' olfactory responses and their levels of consciousness. They also found that patients in the no-olfactory responses group showed higher theta functional connectivity than patients in the olfactory response group after they were presented with the vanillin scent, and lower alpha and beta relative powers than healthy participants with no DoC.

The follow-up data collected three months later showed that 10 out of 16 of the patients who responded to olfactory stimuli during the study had recovered consciousness, while only 2 out of the 12 participants who did not respond to olfactory stimuli did. This suggests that a brain response to olfactory stimuli is typically a sign that patients with DoC are gradually recovering and regaining consciousness.
Olfactory responses should be considered signs of consciousness," teh researchers explained in their paper. "The differences in olfactory processing between DoC patients with and without olfactory responses may be a way to explore the neural correlates of olfactory consciousness in these patients. The olfactory response may help in the assessment of consciousness and may contribute to therapeutic orientation."

Wanchun Wu et al, Olfactory response is a potential sign of consciousness: electroencephalogram findings, Frontiers in Neuroscience (2023). DOI: 10.3389/fnins.2023.1187471.

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Sleep deprivation is a risk factor for Alzheimer's, say scientists

Scientists have long explored the link between disturbances in sleep patterns and neurodegenerative diseases. Powerful evidence has emerged in recent years linking disrupted sleep to Parkinson's, and a massive body of research has explored the serious sleep disturbances associated with chronic traumatic encephalopathy—CTE—a condition linked with repeated head injuries, such as the trauma sustained in boxing, football and other aggressive sports.

Scientists' report world's first X-ray of a single atom

A team of scientists has taken the world's first X-ray SIGNAL (or SIGNATURE) of just one atom. This groundbreaking achievement could revolutionize the way scientists detect the materials.

An important usage of X-rays in science is to identify the type of materials in a sample. Over the years, the quantity of materials in a sample required for X-ray detection has been greatly reduced thanks to the development of synchrotron X-rays sources and new instruments. To date, the smallest amount one can X-ray a sample is in attogram, that is about 10,000 atoms or more. This is due to the X-ray signal produced by an atom being extremely weak so that the conventional X-ray detectors cannot be used to detect it. It is a long-standing dream of scientists to X-ray just one atom, which is now being realized by the research team .

Atoms can be routinely imaged with scanning probe microscopes, but without X-rays one cannot tell what they are made of. Scientists can now detect exactly the type of a particular atom, one atom-at-a-time, and can simultaneously measure its chemical state.

Once they are able to do that, they can trace the materials down to ultimate limit of just one atom. This will have a great impact on environmental and medical sciences and maybe even find a cure that can have a huge impact for humankind. This discovery will transform the world.

Saw-Wai Hla, Characterization of just one atom using synchrotron X-rays, Nature (2023). DOI: 10.1038/s41586-023-06011-w. www.nature.com/articles/s41586-023-06011-w

Biological cleanup discovered for certain 'forever chemicals'

Chemical and environmental engineering scientists have identified two species of bacteria found in soil that break down a class of stubborn "forever chemicals," giving hope for low-cost biological cleanup of industrial pollutants.

These bacteria destroy a subgroup of per- and poly-fluoroalkyl substances, or PFAS, that have one or more chlorine atoms within their chemical structure.

Unhealthful forever chemicals persist in the environment for decades or much longer because of their unusually strong carbon-to-fluorine bonds. Remarkably, the researchers found that the bacteria cleave the pollutant's chlorine-carbon bonds, which starts a chain of reactions that destroy the forever chemical structures, rendering them harmless.

What they discovered is that bacteria can do carbon-chlorine bond cleavage first, generating unstable intermediates. And then those unstable intermediates undergo spontaneous defluorination, which is the cleavage of the carbon-fluorine bond.

Bosen Jin et al, Substantial defluorination of polychlorofluorocarboxylic acids triggered by anaerobic microbial hydrolytic dechlorination, Nature Water (2023). DOI: 10.1038/s44221-023-00077-6

Darker skies are disappearing:

From genes to gestation, researchers probe predictive markers for pregnancy complications

A new study has identified genetic markers associated with preeclampsia and gestational hypertension in a large cohort study. In the paper, "Polygenic prediction of preeclampsia and gestational hypertension," published in Nature Medicine, the researchers detail how these genetic markers could be used as a predictive risk assessment and offers mechanistic insights into pregnancy disorders.

Preeclampsia and gestational hypertension are common pregnancy complications associated with adverse outcomes, including substantial morbidity and mortality for both mother and child. Current tools for prediction, prevention and treatment are limited.

The team examined the associations of maternal DNA variants in 20,064 preeclampsia cases compared to 703,117 control individuals and gestational hypertension in 11,027 cases compared with 412,788 controls. Polygenic risk scores were tuned to a UK Biobank and then tested against other data sets for validation.

The analysis identified 18 independent loci associated with preeclampsia and gestational hypertension, 12 of which were previously unknown, and an additional two genes were implicated in a follow-up meta-analysis. The genes associated highlight potential roles of natriuretic peptide signaling, angiogenesis, renal glomerular function, trophoblast development and immune dysregulation.

Interestingly, almost none of the associated genes reside on the same chromosome, making them less likely to be inherited together.

Low-dose aspirin starting after week 12 gestation is an evidence-based but underused strategy to reduce risk of preeclampsia. To probe the potential clinical impact of incorporating PRS to guide aspirin allocation, researchers examined aspirin eligibility according to current US Preventive Service Task Force major criteria. Those with polygenic risk scores in the top 10% were shown to increase identification as low-dose aspirin-eligible by 30.4%, offering a potential preemptive intervention.

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The lead risk variant at the MTHFR–CLCN6 locus has been previously associated with reduced levels of circulating N-terminal pro-BNP43. A recent analysis found that first-trimester levels of N-terminal pro-BNP were unexpectedly lower among female individuals who subsequently developed hypertensive disorders of pregnancy later in pregnancy. These findings suggest that genetic network-driven deficiency in endogenous natriuretic peptide signaling may predispose individuals to hypertensive disorders of pregnancy.

Synthetic natriuretic peptides have been developed, and the authors suggest that natriuretic peptides may represent a future therapeutic target for direct or indirect modulation toward hypertensive disorders of pregnancy prevention and treatment.

Study examines how DNA damage is repaired by antioxidant enzymes

A typical human cell is metabolically active, roaring with chemical reactions that convert nutrients into energy and useful products that sustain life. These reactions also create reactive oxygen species, dangerous by-products like hydrogen peroxide which damage the building blocks of DNA in the same way oxygen and water corrode metal and form rust. Similar to how buildings collapse from the cumulative effect of rust, reactive oxygen species threaten a genome's integrity.

Cells are thought to delicately balance their energy needs and avoid damaging DNA by containing metabolic activity outside the nucleus and within the cytoplasm and mitochondria. Antioxidant enzymes are deployed to mop up reactive oxygen species at their source before they reach DNA, a defensive strategy that protects the roughly 3 billion nucleotides from suffering potentially catastrophic mutations. If DNA damage occurs anyway, cells pause momentarily and carry out repairs, synthesizing new building blocks and filling in the gaps.

Despite the central role of cellular metabolism in maintaining genome integrity, there has been no systematic, unbiased study on how metabolic perturbations affect the DNA damage and repair process. This is particularly important for diseases like cancer, characterized by their ability to hijack metabolic processes for unfettered growth.

A research team has now addressed this challenge by carrying out various experiments to identify which metabolic enzymes and processes are essential for a cell's DNA damage response. The findings are published today in the journal Molecular Systems Biology.

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The researchers experimentally induced DNA damage in human cell lines using a common chemotherapy medication known as etoposide. Etoposide works by breaking DNA strands and blocking an enzyme that helps repair the damage. Surprisingly, inducing DNA damage resulted in reactive oxygen species being generated and accumulating inside the nucleus. The researchers observed that cellular respiratory enzymes, a major source of reactive oxygen species, relocated from the mitochondria to the nucleus in response to DNA damage.

The findings represent a paradigm shift in cellular biology because it suggests the nucleus is metabolically active. Where there's smoke there's fire, and where there's reactive oxygen species there are metabolic enzymes at work. Historically, scientists have thought of the nucleus as a metabolically inert organelle that imports all its needs from the cytoplasm, but this study demonstrates that another type of metabolism exists in cells and is found in the nucleus.

The researchers also used CRISPR-Cas9 to identify all the metabolic genes that were important for cell survival in this scenario. These experiments revealed that cells order the enzyme PRDX1, an antioxidant enzyme also normally found in mitochondria, to travel to the nucleus and scavenge reactive oxygen species present to prevent further damage. PRDX1 was also found to repair the damage by regulating the cellular availability of aspartate, a raw material that is critical for synthesizing nucleotides, the building blocks of DNA.

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The findings can guide future lines of cancer research. Some anti-cancer drugs, such as the etoposide used in this study, kill tumor cells by damaging their DNA and inhibiting the repair process. If enough damage accumulates, the cancer cell initiates a process where it autodestructs.

During their experiments, the researchers found that knocking out metabolic genes critical for cellular respiration—the process that generates energy from oxygen and nutrients—made normal healthy cells become resistant to etoposide. The finding is important because many cancer cells are glycolytic, meaning that even in the presence of oxygen they generate energy without doing cellular respiration. This means etoposide, and other chemotherapies with a similar mechanism, is likely to have a limited effect in treating glycolytic tumors.

The authors of the study call for the exploration of new strategies such as dual treatment combining etoposide with drugs that also boost the generation of reactive oxygen species to overcome drug resistance and kill cancer cells faster. They also hypothesize that combining etoposide with inhibitors of nucleotide synthesis processes could potentiate the effect of the drug by preventing the repair of DNA damage and ensuring cancer cells self-destruct correctly.

"A metabolic map of the DNA damage response identifies PRDX1 in the control of nuclear ROS scavenging and aspartate availability", Molecular Systems Biology (2023). DOI: 10.15252/msb.202211267

Part 2

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Brain’s wrinkles help to drive how it works

Our brains’ walnut-like wrinkles have a large effect on brain activity, in much the same way that the shape of a bell determines how it sounds. The discovery challenges the paradigm that brain function emerges from the intricate web of connections between specialized brain-cell populations, called the connectome. Researchers used mathematical models that predict how waves travel across surfaces, and found that the shape of the brain’s outer surface was a better predictor of brainwave data than was the model of the connectome.

We are exceeding most of Earth’s limits

In 2009, a seminal paper in Nature showed that humanity had crossed three of nine ‘Earth-system boundaries’: the limits of what the planet can support before human activities make it uninhabitable. Now, there’s a reboot of the extraordinarily influential concept that takes into account how changes to climate, ecosystems and other factors disproportionately affect vulnerable communities. We have crossed seven of the eight safe and just boundaries. Only air pollution was inside dangerous limits globally, despite it causing an estimated 4.2 million deaths annually. If our planet got a check-up, “our doctor would say that the Earth is really quite sick right now, and it is sick in terms of many different areas or systems, and this sickness is also affecting the people living on Earth”, says climate-policy researcher and co-author Joyeeta Gupta.

https://apnews.com/article/earth-environment-climate-change-nature-...

DNA: a novel, green, natural flame retardant and suppressant for cotton

DNA could be considered an intrinsically intumescent flame retardant as it contains the three main components that are usually present in an intumescent formulation, namely: the phosphate groups, able to produce phosphoric acid, the deoxyribose units acting as a carbon source and blowing agents (upon heating a (poly)saccharide dehydrates forming char and releasing water) and the nitrogen-containing bases (guanine, adenine, thymine, and cytosine) that may release ammonia. The flammability tests in horizontal configuration have clearly shown that after two applications of a methane flame for 3 s, the DNA-treated cotton fabrics do not burn at all. Furthermore, when exposed to an irradiative heat flux of 35 kW m⁻², no ignition has been observed. Finally, an LOI value of 28% has been achieved for the treated fabrics as opposed to 18% of the untreated fabric.

https://pubs.rsc.org/en/content/articlelanding/2013/ta/c3ta00107e#:...(upon%20heating%20a

Researchers find DNA can work as a flame retardant 

https://phys.org/news/2013-03-dna-flame-retardant-video.html

Scientists reveal new details of cellular process that prevents spread of cancer

Researchers have for the first time characterized a unique molecular mechanism of the early stages of programmed cell death or apoptosis, a process which plays a crucial role in prevention of cancer.

 It is the most recent in a series of research collaborations by this team, investigating the cellular proteins responsible for apoptosis.

Apoptosis is essential for human life, and its disruption can cause cancerous cells to grow and not respond to cancer treatment. In healthy cells, it is regulated by two proteins with opposing roles known as Bax and Bcl-2.

The soluble Bax protein is responsible for the clearance of old or diseased cells, and when activated, it perforates the cell mitochondrial membrane to form pores that trigger programmed cell death. This can be offset by Bcl-2, which is embedded within the mitochondrial membrane, where it acts to prevent untimely cell death by capturing and sequestering Bax proteins.

In cancerous cells, the survival protein Bcl-2 is overproduced, leading to uninhibited cell proliferation.

Using neutron reflectometry on SURF and OFFSPEC, they were able to study in real time the way that the protein interacts with lipids present in the mitochondrial membrane, during the initial stages of apoptosis. By employing deuterium-isotope labeling, they determined for the first time that when Bax creates pores, it extracts lipids from the mitochondrial membrane to form lipid-Bax clusters on the mitochondrial surface.

By using time-resolved neutron reflectometry in combination with surface infrared spectroscopy in the ISIS biolab, they were able to see that this pore creation occurred in two stages. Initial fast adsorption of Bax onto the mitochondrial membrane surface was followed by a slower formation of membrane-destroying pores and Bax-lipid clusters, which occurred simultaneously. This slower perforation process occurred on timescales of several hours, comparable to cell death in vivo.

This is the first time that scientists have found direct evidence of the involvement of mitochondrial lipids during membrane perturbing in cell death initiated by Bax proteins.

This mechanism by which Bax initiates cell death is previously unseen. Once we know more about the interplay between Bax and Bcl-2 and how it relates to this mechanism, we'll have a more complete picture of a process that is fundamental to human life.

Luke Clifton et al, Creation of distinctive Bax-lipid complexes at mitochondrial membrane surfaces drives pore formation to initiate apoptosis, Science Advances (2023). DOI: 10.1126/sciadv.adg7940. www.science.org/doi/10.1126/sciadv.adg7940

Reducing noise by ionizing air

Scientists show that a thin layer of plasma, created by ionizing air, could be promising as an active sound absorber, with applications in noise control and room acoustics.

Did you know that wires can be used to ionize air to make a loudspeaker? Simply put, it’s possible to generate sound by creating an electric field in a set of parallel wires, aka a plasma transducer, strong enough to ionize the air particles. The charged ions are then accelerated along the magnetic field lines, pushing the residual non-ionized air in a way to produce sound.

If a loudspeaker can generate sound, it can also absorb it.

While this plasma loudspeaker concept is not new,  scientists went ahead and built a demonstration of the plasma transducer, with the aim to study noise reduction. They came up with a new concept, what they call the active “plasmacoustic metalayer” that can be controlled to cancel out noise. Their results are published in Nature Communications.

Not only is the plasma efficient at high frequencies, but it is also versatile since it can be tuned to work at low frequencies as well. Indeed, the scientists show that the dynamics of thin layers of air plasma can be controlled to interact with sound over deep-subwavelength distances, to actively respond to noise and cancel it out over a broad bandwidth. The fact that their device is active is key, since passive noise reduction technologies are limited in the band of frequencies that can be controlled.

The plasma absorber is also more compact that most conventional solutions. Exploiting the unique physics of plasmacoustic metalayers, the scientists experimentally demonstrate perfect sound absorption: 100% of the incoming sound intensity is absorbed by the metalayer and nothing is reflected back.

Stanislav Sergeev, Romain Fleury, Hervé Lissek. Ultrabroadband sound control with deep-subwavelength plasmacoustic metalayers. Nature Communications, 2023; 14 (1) DOI: 10.1038/s41467-023-38522-5

First experimental confirmation that some microbes are powered by electricity

 In microbial electrosynthesis, microorganisms use CO2 and electricity to produce alcohol, for example. How this process works biologically, however, has only been speculated about, until now. Researchers have now been able to confirm experimentally for the first time that the bacteria use electrons from hydrogen and can produce more chemical substances than previously known. Their research has been published in the journal Green Chemistry.

Microbial electrosynthesis is a promising technology against the backdrop of climate change and the energy transition: it can bind carbon dioxide, produce ethanol and other organic compounds that can be used as fuel, and thus store excess electricity. Nevertheless, the technology, which has been known for more than a decade, has so far failed to achieve any significant breakthrough towards commercialization

 The researchers were able to show that bacteria do not directly absorb the electrons supplied by electric current, but instead use hydrogen to transfer the electrons. This had long been suspected as a possibility, but until now no one had provided experimental proof. They also found that the method could produce even more useful chemicals than previously thought and optimized the process for the highest possible yields.

In this way, the research team was able to optimize voltage and bacterial concentration for the highest possible acetate yields.

Santiago T. Boto et al, Microbial electrosynthesis with Clostridium ljungdahlii benefits from hydrogen electron mediation and permits a greater variety of products, Green Chemistry (2023). DOI: 10.1039/D3GC00471F

Space solar power demonstrator wirelessly transmits power in space

A space solar power prototype that was launched into orbit in January is operational and has demonstrated its ability to wirelessly transmit power in space and to beam detectable power to Earth for the first time.

MAPLE, short for Microwave Array for Power-transfer Low-orbit Experiment and one of the three key experiments within SSPD-1, consists of an array of flexible lightweight microwave power transmitters driven by custom electronic chips that were built using low-cost silicon technologies. It uses the array of transmitters to beam the energy to desired locations. For SSPP to be feasible, energy transmission arrays will need to be lightweight to minimize the amount of fuel needed to send them to space, flexible so they can fold up into a package that can be transported in a rocket, and a low-cost technology overall.

Using constructive and destructive interference between individual transmitters, a bank of power transmitters is able to shift the focus and direction of the energy it beams out—without any moving parts. The transmitter array uses precise timing-control elements to dynamically focus the power selectively on the desired location using the coherent addition of electromagnetic waves. This enables the majority of the energy to be transmitted to the desired location and nowhere else.

MAPLE features two separate receiver arrays located about a foot away from the transmitter to receive the energy, convert it to direct current (DC) electricity, and use it to light up a pair of LEDs to demonstrate the full sequence of wireless energy transmission at a distance in space. MAPLE tested this in space by lighting up each LED individually and shifting back and forth between them. The experiment is not sealed, so it is subject to the harsh environment of space, including the wide temperature swings and solar radiation that will be faced one day by large-scale SSPP units.

MAPLE also includes a small window through which the array can beam the energy. This transmitted energy was detected by a receiver on the roof of the Gordon and Betty Moore Laboratory of Engineering on Caltech's campus in Pasadena. The received signal appeared at the expected time and frequency, and had the right frequency shift as predicted based on its travel from orbit.

Space solar power provides a way to tap into the practically unlimited supply of solar energy in outer space, where the energy is constantly available without being subjected to the cycles of day and night, seasons, and cloud cover—potentially yielding eight times more power than solar panels at any location on Earth's surface. When fully realized, SSPP will deploy a constellation of modular spacecraft that collect sunlight, transform it into electricity, then convert it to microwaves that will be transmitted wirelessly over long distances to wherever it is needed—including locations that currently have no access to reliable power.

https://www.spacesolar.caltech.edu/

https://researchnews.cc/news/19753/In-a-first--Caltech-s-space-sola...

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Scientists Hacked Human Cells to Make Insulin, And It Reversed Diabetes in Mice

Chemical found in common sweetener damages DNA

A new study finds a chemical formed when we digest a widely used sweetener is "genotoxic," meaning it breaks up DNA. The chemical is also found in trace amounts in the sweetener itself, and the finding raises questions about how the sweetener may contribute to health problems.

At issue is sucralose, a widely used artificial sweetener sold under the trade name Splenda. Previous work by researchers established that several fat-soluble compounds are produced in the gut after sucralose ingestion. One of these compounds is sucralose-6-acetate.

This new work established that sucralose-6-acetate is genotoxic. Researchers also found that  trace amounts of sucralose-6-acetate can be found in off-the-shelf sucralose, even before it is consumed and metabolized.

To put this in context, the European Food Safety Authority has a threshold of toxicological concern for all genotoxic substances of 0.15 micrograms per person per day. This work suggests that the trace amounts of sucralose-6-acetate in a single, daily sucralose-sweetened drink exceed that threshold. And that's not even accounting for the amount of sucralose-6-acetate produced as metabolites after people consume sucralose.

For the study, researchers conducted a series of in vitro experiments exposing human blood cells to sucralose-6-acetate and monitoring for markers of genotoxicity. They found that sucralose-6-acetate is genotoxic, and that it effectively broke up DNA in cells that were exposed to the chemical.

The researchers also conducted in vitro tests that exposed human gut tissues to sucralose-6-acetate. When they exposed sucralose and sucralose-6-acetate to gut epithelial tissues—the tissue that lines your gut wall—they found that both chemicals caused 'leaky gut.' Basically, they make the wall of the gut more permeable. The chemicals damage the 'tight junctions,' or interfaces, where cells in the gut wall connect to each other.

A leaky gut is problematic, because it means that things that would normally be flushed out of the body in feces are instead leaking out of the gut and being absorbed into the bloodstream. 

The researchers also looked at the genetic activity of the gut cells to see how they responded to the presence of sucralose-6-acetate. They found that gut cells exposed to sucralose-6-acetate had increased activity in genes related to oxidative stress, inflammation and carcinogenicity.

This work raises a host of concerns about the potential health effects associated with sucralose and its metabolites. It's time to revisit the safety and regulatory status of sucralose, because the evidence is mounting that it carries significant risks.

Susan S. Schiffman et al, Toxicological and pharmacokinetic properties of sucralose-6-acetate and its parent sucralose: in vitro screening assays, Journal of Toxicology and Environmental Health, Part B (2023). DOI: 10.1080/10937404.2023.2213903

Genetic variants may affect treatment response to commonly prescribed type 2 diabetes medication

Various medications can be prescribed to lower blood sugar levels in individuals at high risk for developing type 2 diabetes, but it's often unclear which patients will benefit most from which drugs.

How chocolate could counter climate change

At a red-brick factory in the German port city of Hamburg, cocoa bean shells go in one end, and out the other comes an amazing black powder with the potential to counter climate change.

The plant, one of the largest in Europe, takes delivery of the used cocoa shells via a network of gray pipes from a neighboring chocolate factory.

The substance, dubbed biochar, is produced by heating the cocoa husks in an oxygen-free room to 600 degrees Celsius (1,112 Fahrenheit). The process locks in greenhouse gases and the final product can be used as a fertilizer, or as an ingredient in the production of "green" concrete.

While the biochar industry is still in its infancy, the technology offers a novel way to remove carbon from the Earth's atmosphere, experts say.

The biochar traps the CO₂ contained in the husks—in a process that could be used for any other plant.

If the cocoa shells were disposed of as normal, the carbon inside the unused byproduct would be released into the atmosphere as it decomposed.

Instead, the carbon is sequestered in the biochar "for centuries". One metric ton of biochar—or bio coal—can stock "the equivalent of 2.5 to three tons of CO₂".

Biochar was already used by indigenous populations in the Americas as a fertilizer before being rediscovered in the 20th century by scientists researching extremely fecund soils in the Amazon basin.

The surprising substance's sponge-like structure boosts crops by increasing the absorption of water and nutrients by the soil.

The production process, called pyrolysis, also produces a certain volume of biogas, which is resold .

https://phys.org/news/2023-06-chocolate-counter-climate.html?utm_so...

Source: AFP

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Breakthrough treatments for accelerated wound healing

Patients who undergo skin injuries endure hospital stays, infection and/or succumb to death; therefore, advances in wound healing aim to improve clinical practices underlying macroscale healing to effectively intervene in microscale pathophysiology. As a result, strategies that optimize wound healing have motivated the design of new therapeutic products.

In a new report in Science Advances, researchers summarized advances in the development of new drugs, biomaterial therapies and biological products suited for wound healing. They classified the products as marketed therapies and agents for clinical trials to explore their successful and accelerated translation for wound healing.

The dynamics of chronic wound healing mechanisms The timeframe of wound healing can vary and affect the process of patient recovery. Most wounds are classified as acute or chronic situations according to their clinical presentations. Untreated wounds can undergo cell death and necrosis, and represent ischemia relative to inadequate circulation due to microvascular damage and vasoconstriction. The nutritional status, fibroblast cell and progenitor health, as well as infectious bioburden, can contribute to disease progression.

Normal healing is associated with a series of events, including inflammation, remodeling and repair. Wounds that do not proceed through normal phases remain in a dysregulated inflammatory state with several delineating nuances.

For example, pressure ulcers result from an increasing depth of tissue necrosis and pain from microvascular injury causing ulceration and skin degradation to reach underlying fat or deeper structures. The resulting wounds require specialty care. Bioengineers and materials scientists in medical research have formed extensive libraries of wound care technologies to facilitate progressive healing.

Researchers observed the economic challenges of wound care on health care systems that showed an increasing risk in patients with age and obesity alongside those who presented with high-risk comorbidities. Surgical wounds are the largest wound subset, accounting for careful surgical techniques and optimal suture materials in hospitals. Existing standards for interventional healing rely on the preparation of a viable wound bed for assisted healing to remove foreign materials and ischemic tissue. More complex wounds require secondary healing or a bridge for closure. Pressure injuries represent a more serious problem in bedridden patients.

Part 1