The team tested various samples of silicone, including some they synthesized themselves as well as commercial-grade medical tubing used for urinary catheters. They then subjected these samples to mechanical forces to create surface damage. Their experiments showed that the microcracks can be formed very easily.

Even  wiping with lab tissue was enough to create surface damage. To the unaided  eye it still looks fine, but under the microscope, scientists could already see microcracks of the size that bacteria could get into. Bacteria are only a few micrometers big, so it doesn't take much. They saw that the bacteria very clearly preferred to attach in these microscopic cracks.

In the bent samples, there were four to five times as many bacteria on the side that was in tension versus the side that was in compression. These cells have full choice about where to grow, but they clearly love the side where all these microcracks are opened up.

Now scientists are researching methods to reduce surface damage, or modifying the silicone surface to reduce the formation of such cracks.

Desmond van den Berg et al, Mechanical deformation of elastomer medical devices can enable microbial surface colonization, Scientific Reports (2023). DOI: 10.1038/s41598-023-34217-5

Part 2

Heat wave in Asia made 30 times more likely because of climate change, scientists say

A searing heat wave in parts of southern Asia in April this year was made at least 30 times more likely by climate change, according to a rapid study by international scientists released recently.

Sizzling temperatures of up to 45 degrees Celsius (113 degrees Fahrenheit) were recorded in monitoring stations in parts of India, Bangladesh, Thailand and Laos last month—which was unusually high for the time of year.

The climate-change-fueled heat caused deaths, widespread hospitalizations, damaged roads, sparked fires and led to school closures in the region.

The World Weather Attribution group uses established models to quickly determine whether climate change played a part in extreme weather events. While the studies themselves are not yet peer-reviewed, which is the gold standard for science, they are often later published in peer-reviewed journals.

The southern Asian region is considered among the most vulnerable to climate change in the world, according to various global climate studies. But India, the largest country in the region and the most populous in the world is also currently the third highest emitter of planet-warming gases.

Scientists say that drastic measures to reduce carbon dioxide emissions immediately is the only solution.

Heat waves will become more common, temperatures will rise even more and the number of hot days will increase and become more frequent if we continue to pump greenhouse gases into the atmosphere, according to them.

www.worldweatherattribution.or … e-event-attribution/

Source: AP

https://phys.org/news/2023-05-asia-climate-scientists.html?utm_sour...

Our Earth is becoming unlivable. Can we still turn the tide?

We have crossed six of the nine boundaries within which human life on Earth will still be possible for future generations. That is not good news. Can the tide still be turned?

The planetary boundaries were discussed on May 9 as part of the Leiden University Green Office's Sustainability Day. They include climate change, biodiversity loss and ocean acidification. Six of the nine boundaries have already been crossed (see figure above). Crossing planetary boundaries increases the risk of large-scale abrupt or irreversible environmental changes.

Drastic changes are needed to ensure that the Earth remains habitable. Systemic changes are needed in food, energy and how we live and consume. In fact, all planetary boundaries are interconnected.

For example, once the nitrogen limit is exceeded, it affects biodiversity and climate. Besides planetary boundaries, experts also stress the importance of social boundaries, which include education, social equality and health care. Planetary boundaries and social  boundaries affect each other, and if we are to preserve a livable Earth, they must be addressed in an integrated way—which is possible.

One approach that can help keep the Earth livable is to let communities come up with their own local solutions. You see that communities often achieve more than their original goal. There is hope if we give communities responsibility for themselves.

source: https://www.universiteitleiden.nl/en

CRISPR zeroes in on death cap antidote

The CRISPR–Cas9 gene-editing tool might have cracked the mystery of how death cap mushrooms (Amanita phalloides) kill — and it led researchers to a potential antidote. Using the gene-editing technology, researchers created a pool of human cells — each with different genetic mutations — and exposed them to the mushrooms’ toxin. The toxin could not enter cells that lacked a functional version of an enzyme called STT3B, and cell survival increased. The researchers then sifted through thousands of chemical compounds to find one that would block the action of STT3B. They uncovered indocyanine green, a dye developed by the photography company Kodak in the 1950s and used in medical imaging. Indocyanine green has not yet been tested as an antidote in humans, but it reduced deaths when given to mice.

https://www.nature.com/articles/s41467-023-37714-3.epdf?sharing_tok...

WHO warns against artificial sweeteners

Sweeteners don’t help people to lose weight in the long run and could increase the risk of type 2 diabetes and cardiovascular diseases if consumed continuously, the World Health Organization (WHO) advises. The guideline includes both artificial and natural sweeteners, such as aspartame and stevia. But it’s conditional, in keeping with life’s complexities — the WHO isn’t warning against sweetened toothpaste, for example, or recommending a change for people with pre-existing diabetes. The announcement contradicts some findings that sweeteners are harmless, even if they don’t offer any health benefits.

https://www.who.int/publications/i/item/9789240073616?utm_source=Na...

Human DNA is everywhere. That's a boon for science, and an ethical quagmire

In the water, on the land, in the air. In most cases the quality of DNA is almost equivalent to if you took a sample from a person.

We  cough, spit, shed and flush our DNA into all of these places and countless more. Signs of human life can be found nearly everywhere, short of isolated islands and remote mountaintops, according to a new  study.

That ubiquity is both a scientific boon and an ethical dilemma, say the UF researchers who sequenced this widespread DNA. The DNA was of such high quality that the scientists could identify mutations associated with disease and determine the genetic ancestry of nearby populations. They could even match genetic information to individual participants who had volunteered to have their errant DNA recovered.

Ethically handled environmental DNA samples could benefit fields from medicine and environmental science to archaeology and criminal forensics. For example, researchers could track cancer mutations from wastewater or spot undiscovered archaeological sites by checking for hidden human DNA. Or detectives could identify suspects from the DNA floating in the air of a crime scene.

But this level of personal information must be handled extremely carefully. Now, scientists and regulators must grapple with the ethical dilemmas inherent in accidentally—or intentionally—sweeping up human genetic information, not from blood samples but from a scoop of sand, a vial of water or a person's breath.

Published May 15 in Nature Ecology and Evolution, a paper by researchers outlines the relative ease of collecting human DNA nearly everywhere they looked.

Because of the ability to potentially identify individuals, the researchers say that ethical guardrails are necessary for this kind of research. The study was conducted with approval from the institutional review board of UF, which ensures that ethical guidelines are adhered to during research studies.

1. Liam Whitmore, Mark McCauley, Jessica A. Farrell, Maximilian R. Stammnitz, Samantha A. Koda, Narges Mashkour, Victoria Summers, Todd Osborne, Jenny Whilde, David J. Duffy. Inadvertent human genomic bycatch and intentional capture raise beneficial applications and ethical concerns with environmental DNA. Nature Ecology & Evolution, 2023; DOI: 10.1038/s41559-023-02056-2

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Cosmic Cycles: Earth, Our Home

Humans were making fires at least 250,000 years ago in Europe, research finds

Early humans in Europe were making and controlling fire at least 50,000 years earlier than previously thought, researchers have found.

In a paper published in the journal, Scientific Reports, the scientists set out evidence that our ancestors in Europe were using fires for activities like cooking, heating and defense at least 250,000 years ago. Previous evidence had suggested humans were managing fire in Europe much later than this, around 200,000 years ago.

Using forensic chemical methods to identify molecules of incomplete burning, the research team detected fire at Valdocarros II, an archaeological site near Madrid in Spain.

Researchers have found definitive evidence of things being burnt and those remains are organized into a pattern, suggesting it's humans who are making and controlling the fire. Either they were using the fire to cook or to defend themselves. The spatial patterning in the fire tells us that they were encircling something, like a home or sleeping area, a living room or kitchen, or an enclosure for animals.

The chemical profiles of the charred remains also suggest our human ancestors chose certain types of firewood for its burning properties, such as heat and lack of smoke.

The findings are "very exciting" and close a gap in our understanding of human-controlled fire and human development.

This is important because our species is defined by our use of fire. Being able to cook food to feed our big brains is one of the things that made us so successful in an evolutionary sense. Fire also brings protection and fosters communication and family connection. And scientists now have definitive, incontrovertible evidence that humans were starting and stopping fires in Europe about 50,000 years earlier than researchers suspected.

Clayton Magill et al, Organic geochemical evidence of human‑controlled fires at Acheulean site of Valdocarros II (Spain, 245 kya), Scientific Reports (2023). DOI: 10.1038/s41598-023-32673-7

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Researchers transform our understanding of crystals

When most people think of crystals, they picture suncatchers that act as rainbow prisms or the semi-transparent stones that some believe hold healing powers. However, to scientists and engineers, crystals are a form of materials in which their constituents—atoms, molecules, or nanoparticles—are arranged regularly in space. In other words, crystals are defined by the regular arrangement of their constituents. Common examples are diamonds, table salt, or sugar cubes.

However, in research just published in Soft Matter, a team  of researchers discovered that crystal structures are not necessarily always regularly arranged. The discovery advances the field of materials science and has unrealized implications for the materials used for semiconductors, solar panels, and electric vehicle technologies.

One of the most common and important classes of crystal structures is the close-packed structures of regular spheres constructed by stacking layers of spheres in a honeycomb arrangement. There are many ways to stack the layers to construct close-packed structures, and how nature selects specific stacking is an important question in materials and physics research. In the close-packing construction, there is a very unusual structure with irregularly spaced constituents known as the random stacking of two-dimensional hexagonal layers (RHCP). This structure was first observed from cobalt metal in 1942, but it has been regarded as a transitional and energetically unpreferred state.

Researchers now  collected X-ray scattering data from soft model nanoparticles made of polymers and realized that the scattering data contains important results about RHCP but is very complicated.

What they found 's that the RHCP structure is, very likely, a stable structure, and this is the reason that RHCP has been widely observed in many materials and naturally occurring crystal systems. This finding challenges the classical definition of crystals. 

The study provides insights into the phenomenon known as polytypism, which enables the formation of RHCP and other close-packed structures. A representative material with polytypism is silicon carbide, widely used for high-voltage electronics in electric vehicles and as hard materials for body armor. These new  findings indicate that those polytypic materials may have continuous structural transitions, including the non-classical random arrangements with new useful properties.

 Juhong Ahn et al, Continuous transition of colloidal crystals through stable random orders, Soft Matter (2023). DOI: 10.1039/D3SM00199G

Half of the world's largest lakes are losing water

More than 50% of the largest lakes in the world are losing water, according to a new assessment published recently in Science . The key culprits are not surprising: warming climate and unsustainable human consumption.

Researchers combined three decades of observations from an array of satellites with models to quantify and attribute trends in lake storage globally.

For the new paper, the team used 250,000 lake-area snapshots captured by satellites between 1992–2020 to survey the area of 1,972 of Earth's biggest lakes. They collected water levels from nine satellite altimeters and used long-term water levels to reduce any uncertainty. For lakes without a long-term level record, they used recent water measurements made by newer instruments on satellites. Combining recent level measurements with longer-term area measurements allowed scientists to reconstruct the volume of lakes dating back decades.

The results were staggering: 53% of lakes globally experienced a decline in water storage. 

Lakes in both dry and wet areas of the world are losing volume. The losses in humid tropical lakes and Arctic lakes indicate more widespread drying trends than previously understood.

Researchers also assessed storage trends in reservoirs. They found that nearly two-thirds of Earth's large reservoirs experienced significant water losses.

Sedimentation dominated the global storage decline in existing reservoirs. In long-established reservoirs—those that filled before 1992—sedimentation was more important than droughts and heavy rainfall years.

 Fangfang Yao, Satellites reveal widespread decline in global lake water storage, Science (2023). DOI: 10.1126/science.abo2812. www.science.org/doi/10.1126/science.abo2812

Human evolution has no single birthplace

Humans did not emerge from a single region of Africa, but from several populations that moved around the continent one millio... and intermingled for millennia. The widely held idea of a single origin of Homo sapiens is based in part on fossil records. Computer modelling and genome data from modern African and European populations revealed that “our roots lie in a very diverse overall population made up of fragmented local populations”, says evolutionary archaeologist Eleanor Scerri. This means human evolution looks more like a tangled vine than a ‘tree of life.’

https://www.nature.com/articles/s41586-023-06055-y.epdf?sharing_tok...

Human-evolution story rewritten by fresh data and more computing power

A global effort to identify critical illness in some COVID-19 patients highlights genetic risk, potential treatments

Researchers  have led a study in collaboration with scientists worldwide, looking into cases of critical illness in COVID-19 patients.

Critical illness in COVID-19 is an extreme and clinically consistent disease phenotype the team has found presenting in patients with shared genetic attributes. These shared genetics hint at a shared mechanism for the critical illness not seen in other patients and potential therapies to address the condition.

Patients with confirmed COVID-19 and requiring continuous cardiorespiratory monitoring or organ support (a generalizable definition for critical illness) were recruited in 2020–2022.

Researchers analyzed 24,202 cases of COVID-19 with critical illness with a combination of microarray genotyping and whole-genome sequencing data from the international GenOMICC study (11,440 cases) and other studies recruiting hospitalized patients with severe and critical illness, including the COVID-19 Human Genetics Initiative, the International Severe Acute Respiratory and Emerging Infection Consortium, the Spanish Coalition to Unlock Research on Host Genetics consortium and 23andMe.

The team found 49 genome-wide significant associations, of which 16 have not been reported previously and 196 significantly associated genes in a gene-level analysis. Although the implicated variants are not directly causing illness in the patients, they can highlight molecular mechanisms that make some COVID-19 infections much more severe. The findings are published in the journal Nature.

Part 1

Many genes implicated in critical COVID-19 are highly expressed in the monocyte-macrophage system, which has poor coverage in existing expression quantitative trait loci datasets. Macrophages synthesize many substances involved in host defense and inflammation and play a pivotal role in immune system reactions.

Additionally, the investigation found variation in circulating protein levels with 15 unique proteins linked to critical illness and some with well-studied biomarkers that make them good candidates for drug targeting.

The research has identified several potential druggable targets in multiple systems, including inflammatory signaling, monocyte-macrophage activation and endothelial permeability. Some of the targets found have already seen positive results with therapeutic signals in multiple drug trials, providing a good proof-of-concept for drug target identification using comparative genetics.

 Erola Pairo-Castineira et al, GWAS and meta-analysis identifies 49 genetic variants underlying critical COVID-19, Nature (2023). DOI: 10.1038/s41586-023-06034-3

Part2

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Scientists urge crackdown on methane emissions with only 13% regulated

New research  shows that only around 13% of global methane emissions are regulated, despite methane emissions causing at least 25% of current global warming.

The global review, published on May 19 in One Earth, also found that little is known about the effectiveness of the policies that exist, with potentially unrepresentative methane emission estimations used rather than actual measurements. Inaccurate estimations can also mean the issue is taken less seriously by decision-makers by masking its severity.

The researchers argue that the lack of regulation and clarity into their impact must urgently be addressed if we are to meet our global climate targets. The review suggests a consistent approach worldwide with robust quantification and reporting could unlock new opportunities to drastically reduce global warming levels.

To meet the Paris Agreement 1.5°C objective, man-made methane emissions should be reduced by at least 40%–45% by 2030, compared to the 2020 levels. Methane mitigation is not only a cost-effective strategy to reduce global warming but could also improve the air quality. Today methane emissions are increasing faster than at any time since the 1980s.

A global review of methane policies reveals only 13% of emissions are covered with unclear effectiveness, One Earth (2023). DOI: 10.1016/j.oneear.2023.04.009

Plastic pervasive in food supply, says new study

Micro and nanoplastics are pervasive in our food supply and may be affecting food safety and security on a global scale, a new study led by CSIRO has found.

The study is one of the first to analyze the academic literature on microplastics from a food safety and food security risk viewpoint, building on past studies which primarily tracked plastics in fish.

It shows that plastics and their additives are present at a range of concentrations not only in fish but in many products including meat, chicken, rice, water, take-away food and drink, and even fresh produce.

These plastics enter the human food chain through numerous pathways, such as ingestion as shown in the fish studies, but one of the main ways is through food processing and packaging. The research is published in the journal TrAC Trends in Analytical Chemistry.

Fresh food for example can be plastic free when it's picked or caught but contain plastics by the time it's been handled, packaged and makes its way to us. Machinery, cutting boards, plastic wrapping can all deposit micro and nanoplastics onto our food that we then consume. This study highlights the need to understand what plastic could end up in food to manage food safety and security.

Another important pathway for these contaminants to enter our agriculture system is through biosolids sourced from wastewater treatment.

Biosolids are a rich fertilizer for agricultural land, but they can contain plastic particles from many sources, such as from the washing of synthetic clothing.

These particles could build up in the soil and change the soil structure over time, which may affect crop production, food security and ecosystem resilience. For example, plastic materials can "trick" the good bacteria in the soil into thinking they are the roots of plants, meaning the plants end up with less of the nutrients they need.

The study also discussed how additives in plastics that help make plastic work in our modern world can leach into our environment, potentially contaminating our food supply. Additives that make plastic flexible or resistant to UV radiation, for example, can include flame retardants, heavy metals, phthalates, hardeners or other chemical compounds.

We can no longer ignore this problem, according to scientists.

Joost L.D. Nelis et al, The measurement of food safety and security risks associated with micro- and nanoplastic pollution, TrAC Trends in Analytical Chemistry (2023). DOI: 10.1016/j.trac.2023.116993

Fatty acids might exist in space

A team of physicists have discovered that the environment of a molecular cloud in interstellar space can support the existence of fatty acids, a key component of life on Earth.

Astronomers have made great strides over the past few years in identifying a variety of organic and prebiotic molecules in interstellar gas clouds. These molecules, rich in carbon and oxygen, form the basic building blocks of the chemistry used by life. For example, astronomers have recently discovered some amino acids, which are the fundamental components of all proteins used by life on Earth.

As astronomers continue to discover ever more complex organic molecules, it's natural to wonder what else could be out there. But space is an exceptionally harsh environment for life, not just because of its low temperatures, but also because of the intense radiation constantly flooding through any region of interstellar space.

Despite these challenges, a team of physicists ran a series of computer simulations of the typical interstellar environment and discovered that fatty acids can form and stabilize there. Fatty acids are chains of carbon and hydrogen atoms that form the building blocks of every kind of fat that we consume and maintain in our bodies.

The researchers discovered that carbon and hydrogen can naturally link together in spite of the low temperature and low pressure environments of interstellar gas clouds. These chains then form stable bonds that can persist for long timescales. Their research is available on the arXiv pre-print server.

Part 1

Fatty acids also combine with amino acids to form much more complex protein structures, and so the discovery of fatty acids in nebulae would confirm that the ingredients for life are abundant throughout the cosmos.

To find these fatty acids the astronomers discovered that we can use existing techniques. One such technique is called microwave rotational spectra. The fatty acids can rotate in certain ways which release particular frequencies of microwave radiation that we can detect. Further observations will be necessary to discover if these essential ingredients truly exist in the depths of space.

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.

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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.

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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