TB antibiotic activity impacted by cell pH

Researchers have shown that an antibiotic used to treat tuberculosis (TB) is affected by pH levels in the environment the bacteria has infected.

On infection with TB, the bacteria enter into a type of immune cell, called macrophages. One of the defense mechanisms these cells use is creating an acidic environment to kill the infecting agent.

In their study, published in mBio on World TB Day (24 March), the researchers developed a fluorescence-based imaging technique to study the effects of this acidic environment on both the bacteria and antibiotics. Using this approach, they were able to monitor, in real-time, the effects of changes in pH levels.

By experimentally changing pH levels in infected cells, they found that TB is able to maintain and regulate its own pH independently of the pH of the macrophage, providing a defense against the immune system.

The researchers then tested whether four front-line TB antibiotic treatments are affected by different acidity levels. They found that one antibiotic often used as part of the TB treatment regime, pyrazinamide, is only effective within an acidic environment.

Pierre Santucci et al, Visualizing Pyrazinamide Action by Live Single-Cell Imaging of Phagosome Acidification and Mycobacterium tuberculosis pH Homeostasis, mBio (2022). DOI: 10.1128/mbio.00117-22

https://phys.org/news/2022-03-tb-antibiotic-impacted-cell-ph.html?u...

How the gut communicates with the brain

New research has discovered how the enteric nervous system -- or 'second brain' -- can communicate with both the brain and spinal cord, which up until now had remained a major mystery. The study found specialized cells within the gut wall release serotonin when stimulated by food, which then acts on the nerves to communicate with the brain. The authors say as there is a direct connection between serotonin levels in our body and depression and how we feel, understanding how the gut communicates with the brain is of major importance.

Kelsi Nicole Dodds, Lee Travis, Melinda A. Kyloh, Lauren A Jones, Damien John Keating, Nick J Spencer. The gut-brain axis: spatial relationship between spinal afferent nerves and 5-HT-containing enterochromaffin cells in mucosa of mouse colon. American Journal of Physiology-Gastrointestinal and Liver Physiology, 2022; DOI: 10.1152/ajpgi.00019.2022

https://www.sciencedaily.com/releases/2022/03/220323130316.htm

Young Man Has 'Excessive' Skin Wrinkling From Water in Incredibly Rare Medical Case

A man in his 20s developed "excessive wrinkling"; bright, white bumps; and patches of thick skin on his hands whenever he immersed them in water. Doctors initially thought the condition might be a symptom of chronic eczema, but they later determined that the wrinkling was caused by a rare skin disease, according to a new report of his case.  

The disease, known as aquagenic syringeal acrokeratoderma (ASA), mostly occurs in young women, according to the report, which was published Wednesday (March 23) in the journal JAMA Dermatology.

It's also fairly common in people with cystic fibrosis, a genetic disorder that affects hormone-producing glands in the body and causes mucus-producing organs to produce abnormally thick, sticky mucus, according to the Genetic and Rare Diseases Information Center (GARD). 

People with cystic fibrosis carry two defective copies of the cystic fibrosis transmembrane conductance regulator (CFTR) gene, but even people who have just one copy of this gene and who don't have cystic fibrosis are prone to the condition, which hints that ASA may be partially caused by a genetic mutation.

That said, the exact cause of ASA is unknown, but theories suggest that the condition may have something to do with abnormal sweat glands, according to GARD.

In the case of the young man with wrinkly hands, he reported to the dermatology department at The First Hospital of China Medical University in Shenyang after having experienced this condition for three years. The skin of his hands would become thick, swollen, wrinkly and scaly after being in water, and these changes would be accompanied by an itchy, burning sensation.

Although the ASA symptoms initially affected only his hands, the man noted that, in the past year and a half or so, the condition had also spread to his wrists and elbows.

"He attributed these changes to the need for washing hands frequently in the period of the COVID-19 epidemic," doctors wrote in the report. Upon closer examination, the doctors determined that the sweat glands and pores on the man's hands would become unusually large and dilated after exposure to water.

Part 1

"The patient's clinical process was quite interesting," the authors of the new report wrote. "The lesions only appeared after immersion in water, disappeared about 30 minutes after drying, and no lesions occurred with the absence of water contact."

These short-lived symptoms are a telltale sign of ASA known as "hand in the bucket sign."

https://jamanetwork.com/journals/jamadermatology/article-abstract/2...

https://www.livescience.com/excessive-wrinkling-young-man-case-report

Part 2

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New Kind of Ultraviolet Light Safely Kills Airborne Pathogens Indoors

A type of ultraviolet light called Far-UVC could dramatically change how we combat the transmission of airborne pathogens in indoor environments, scientists report in a new study.

Researchers say the technology represents a new 'hands off' way of curbing the spread of COVID-19, compared to existing control measures that involve significant changes in people's behavior – such as abiding by lockdowns, physical distancing, mask-wearing, or getting vaccinated.

In contrast to the challenges of these effective but often unpopular measures, installing Far-UVC lighting in indoor environments could be about as easy as changing a light bulb, scientists say – and the effectiveness of the device's antimicrobial radiation is no less impressive.

"Far-UVC rapidly reduces the amount of active microbes in the indoor air to almost zero, making indoor air essentially as safe as outdoor air.

While the germicidal properties of ultraviolet C light (UVC) have been known for decades, the radiation's ability to cause sunburn, skin cancer, and harm people's eyes have led to strict controls on its usage, with UVC mostly limited to sterilizing medical equipment.

However, in more recent times, research into shorter-wavelength Far-UVC emitters (aka Krypton Chloride or KrCl excimer lamps) suggests that this subset of the UVC spectrum doesn't pose safety risks to mouse or human skin cells, while retaining the ability to kill airborne pathogens.

According to the team, the Far-UVC lamps reduced up to 98.4 percent of the pathogen load in a matter of minutes, and maintained an ambient level of 92 percent reduction . Using this technology in locations where people gather together indoors could prevent the next potential pandemic.

https://www.nature.com/articles/s41598-022-08462-z

https://www.sciencealert.com/new-kind-of-ultraviolet-light-safely-k...

Study shows advances in street lighting are reducing the efficacy of coastal species' camouflage

Species that rely on darkness to forage and feed are losing the gift of camouflage thanks to advances in the lighting used to illuminate the world's cities and coastlines, a study has shown.

It is one of the first to examine the potential for artificial light at night (ALAN) to affect the camouflage mechanisms of coastal species.

The worldwide proliferation of energy efficient broad spectrum lighting has the potential to disrupt an array of visually guided ecological processes.

New research has demonstrated that these new lighting technologies can significantly improve a predator's ability to discriminate prey species against a natural background.

The magnitude of this effect varies depending on an organism's color, meaning certain color variations may be at greater risk.

For this study, scientists used a well-established model to determine the conspicuousness of three distinct color morphs of Littorinid snail found commonly along the world's coastlines.

They compared how the species appeared to three common coastal predators when illuminated by different forms of lighting. This included 20th century narrow spectrum Low Pressure Sodium (LPS) lighting, three types of modern broad spectrum lighting—High Pressure Sodium (HPS); Light Emitting Diodes (LEDs); and Metal Halide (MH) – and the natural light provided by the sun and moon.

Under LPS lighting, all snails were effectively camouflaged. However, when illuminated by LEDs, MH, the sun or the moon, yellow snails were significantly more visible compared to brown and olive ones in the majority of cases.

This study clearly indicates that new lighting technologies will increase the conspicuousness of prey species by reducing the efficacy of their camouflage. Our findings revealed that species of Littorinid snails found commonly on our coastlines will remain camouflaged when illuminated by older style lighting. However, when illuminated by modern broad spectrum lighting, they are clearly visible to predators and at far greater long-term risk as a result.

Oak McMahon et al, Broad spectrum artificial light at night increases the conspicuousness of camouflaged prey, Journal of Applied Ecology (2022). DOI: 10.1111/1365-2664.14146

https://phys.org/news/2022-03-advances-street-efficacy-coastal-spec...

New technology could make biopsies a thing of the past

An engineering team has developed a technology that could replace conventional biopsies and histology with real-time imaging within the living body. Described in a new paper published recently in Nature Biomedical Engineering, MediSCAPE is a high-speed 3D microscope capable of capturing images of tissue structures that could guide surgeons to navigate tumors and their boundaries without needing to remove tissues and wait for pathology results.

For many medical procedures, particularly cancer surgery and screening, it is common for doctors to take a biopsy, cutting out small pieces of tissue to be able to take a closer look at them with a microscope. The way that biopsy samples are processed hasn't changed in 100 years, they are cut out, fixed, embedded, sliced, stained with dyes, positioned on a glass slide, and viewed by a pathologist using a simple microscope. This is why it can take days to hear news back about your diagnosis after a biopsy.

Another major benefit of the approach is that cutting tissue out, just to figure out what it is, is a hard decision for doctors, especially for precious tissues such as the brain, spinal cord, nerves, the eye, and areas of the face. Although some microscopes for surgical guidance are already available, they only give doctors an image of a small, single 2D plane, making it difficult to quickly survey larger areas of tissue and interpret results. These microscopes also generally require a fluorescent dye to be injected into the patient, which takes time and can limit their use for certain patients.

Researchers have been developing new kinds of microscopes for neuroscience research that can capture very fast 3D images of living samples like tiny worms, fish, and flies to see how neurons throughout their brains and bodies fire when they move. Now they decided to test whether their technology, termed SCAPE (for Swept Confocally Aligned Planar Excitation microscopy) could see anything useful in tissues from other parts of the body.

The researchers demonstrated the power of MediSCAPE for a wide range of applications, from analysis of pancreatic cancer in a mouse, to Coley's interest in non-destructive, rapid evaluation of human transplant organs such as kidneys.

They also realized that by imaging tissues while they are alive in the body, they could get even more information than from lifeless excised biopsies. They found that they could actually visualize blood flow through tissues, and see the cellular-level effects of ischemia and reperfusion (cutting off the blood supply to the kidney and then letting it flow back in).

High-speed light-sheet microscopy for the in-situ acquisition of volumetric histological images of living tissue, Nature Biomedical Engineering (2022). DOI: 10.1038/s41551-022-00849-7

https://medicalxpress.com/news/2022-03-technology-biopsies.html?utm...

Deleting a protein might reduce cardiovascular disease

Macrophages travel through our arteries, gobbling fat . But fat-filled macrophages can narrow blood vessels and cause heart disease. Now, researchers describe in Nature Cardiovascular Research how deleting a protein could prevent this and potentially prevent heart attacks and strokes in humans.

Macrophages are large white blood cells that cruise through our body as a kind of clean-up crew, clearing hazardous debris. But in people with atherosclerosis—fatty deposits and inflammation in their blood vessels— macrophages can cause trouble. They eat excess fat inside artery walls, but that fat causes them to become foamy. And foamy macrophages tend to encourage inflammation in the arteries and sometimes bust apart plaques, freeing clots that can cause heart attack, stroke or embolisms elsewhere in the body.

Changing how macrophages express a certain protein could prevent that kind of bad behaviour, reports a team of researchers.

They found that the protein, called TRPM2, is activated by inflammation. It signals macrophages to start eating fat. Since inflammation of the blood vessels is one of the primary causes of atherosclerosis, TRPM2 gets activated quite a bit. All that TRPM2 activation pushes macrophage activity, which leads to more foamy macrophages and potentially more inflamed arteries. They form a vicious cycle promoting the development of atherosclerosis. 

Researchers now demonstrated one way to stop the cycle, at least in mice. They deleted TRPM2 from a type of lab mouse that tends to get atherosclerosis. Deleting that protein didn't seem to hurt the mice, and it prevented the macrophages from getting foamy. It also alleviated the animals' atherosclerosis.

The team is now looking at whether increased TRPM2 expression in monocytes (precursors of macrophages) in the blood correlates with severity of cardiovascular disease in humans. If they find that there is a correlation, high levels of TRPM2 might be a risk marker for heart attack and stroke.

TRPM2 deficiency in mice protects against atherosclerosis by inhibiting TRPM2–CD36 inflammatory axis in macrophages, Nature Cardiovascular Research, 2022. 10.1038/s44161-022-00027-7 , www.nature.com/articles/s44161-022-00027-7

https://medicalxpress.com/news/2022-03-deleting-protein-cardiovascu...

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New method for making tissue transparent could speed the study of many diseases

Scientists have unveiled a new tissue-clearing method for rendering large biological samples transparent. The method makes it easier than ever for scientists to visualize and study healthy and disease-related biological processes occurring across multiple organ systems.

Described in a paper in Nature Methods on March 28, 2022, and dubbed HYBRiD, the new method combines elements of the two main prior approaches to tissue-clearing technology, and should be more practical and scalable than either for large-sample applications.

This is a simple and universal tissue-clearing technique for studies of large body parts or even entire animals.

Tissue-clearing involves the use of solvents to remove molecules that make tissue opaque (such as fat), rendering the tissue optically transparent—while keeping most proteins and structures in place. Scientists commonly use genetically encoded or antibody-linked fluorescent beacons to mark active genes or other molecules of interest in a lab animal, and tissue-clearing in principle allows these beacons to be imaged all at once across the entire animal.

Scientists started developing tissue-clearing methods about 15 years ago, mainly for the purpose of tracing nerve connections within whole brains. While the methods work well for brains, they don't work so well when applied to other body parts or whole bodies, which contain harder-to-dissolve structures.

These methods until now have used either organic solvents or water-based solvents. The former generally work more quickly and powerfully but tend to diminish fluorescent signals. Methods using water-based solvents are better at preserving fluorescence but are impractically weak for clearing non-brain tissue. In addition, both types of method require burdensome, labor-intensive procedures, often using hazardous chemicals.

"An ordinary lab generally can't use these methods routinely and at scale

Part 1

The new method devised now  uses a sequential combination of organic solvents and water-based detergents, and makes use of water-based hydrogels to protect those molecules within the tissue that need to be preserved. It often does not require the pumping of solvents through the sample.In many cases, you can just put the whole thing in a jar and keep it in a shaker on your benchtop until it's done.

Victoria Nudell et al, HYBRiD: hydrogel-reinforced DISCO for clearing mammalian bodies, Nature Methods (2022). DOI: 10.1038/s41592-022-01427-0

https://phys.org/news/2022-03-method-tissue-transparent-diseases.ht...

Part 2

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If this title is funny, will you cite me? Citation impacts of humour and other features of article titles in ecology and evolution

Titles of scientific papers pay a key role in their discovery, and “good” titles engage and recruit readers. A particularly interesting aspect of title construction is the use of humour, but little is known about whether funny titles boost or limit readership and citation of papers. We used a panel of volunteer scorers to assess title humour for 2,439 papers in ecology and evolution, and measured associations between humour scores and subsequent citation (both self-citation and citation by others). Papers with funnier titles were cited less often, but this appears to result from a confound with paper importance. Self-citation data suggest that authors give funnier titles to papers they consider less important. After correction for this confound, papers with funny titles have significantly higher citation rates, suggesting that humour recruits readers. We also examined associations between citation rates and several other features of titles. Inclusion of acronyms and taxonomic names was associated with lower citation rates, while assertive-statement phrasing and presence of colons, question marks, and political regions were associated with somewhat higher citation rates. Title length had no effect on citation. Our results suggest that scientists can use creativity with titles without having their work condemned to obscurity.

https://www.biorxiv.org/content/10.1101/2022.03.18.484880v1

Hubble spots most distant single star ever seen, at a record distance of 28 billion lightyears

With a fortuitous lineup of a massive cluster of galaxies, astronomers discovered a single star across most of the entire observable Universe. This is the farthest detection of a single star ever. The star may be up to 500 times more massive than the Sun. The discovery has been published recently in the journal Nature.

Gazing at the night sky, all the stars that you see lie within our own galaxy, the Milky Way. Even with the most powerful telescopes, under normal circumstances individual stars can only be resolved in our most nearby galactic neighbors. In general, distant galaxies are seen as the blended light from billions of stars.

But with the marvelous natural phenomenon known as "gravitational lensing," astronomers  were nevertheless able to detect a distance where even detecting entire galaxies is challenging.

Among the wonders predicted by Einstein's theory of relativity is the ability of mass to "curve" space itself. As light passes close to massive objects, its path follows the curved space and changes direction. If a massive object happens to lie between us and a distant background source of light, the object may deflect and focus the light toward us as a lens, magnifying the intensity.

Galaxies magnified several times are routinely discovered by way of this method. But in an astounding cosmic coincidence, the galaxies in a cluster named WHL0137-08 happened to line up in such a way as to focus the light of a single star toward us, magnifying its light thousands of times.

A combination of this gravitational lens and nine hours of exposure time with the Hubble Space Telescope enabled an international team of astronomers to detect the star.

The astronomers nicknamed the star Earendel, from the Old English word meaning "morning star," or "rising light." They calculate that the star it at least 50 times as massive as our Sun, possibly up to 500, and millions of times as bright.

Brian Welch, A highly magnified star at redshift 6.2, Nature (2022). DOI: 10.1038/s41586-022-04449-y. www.nature.com/articles/s41586-022-04449-y

https://phys.org/news/2022-03-hubble-distant-star-distance-billion....

Oxytocin treatment can take lions from ferocious to friendly

Lions typically aren't keen on making new friends. The giant cats guard their territory fiercely and can mortally wound a foe with a single swipe. While aggression is an advantage for apex predators in the wild, it poses real challenges for lions on reserves or in captivity, a number that is growing due to habitat loss. Researchers working on a wildlife reserve in Dinokeng, South Africa found that an intranasal application of the "love hormone" oxytocin could make lion meet-cutes less life-threatening. Their work appears March 30 in the journal iScience.

By spraying the oxytocin directly up the nose, we know it can travel up the trigeminal nerve and the olfactory nerve straight up into the brain. Otherwise the blood brain barrier could filter it out.

After these treatments researchers observed that the 23 lions who were given oxytocin were more tolerant of other lions in their space and displayed less vigilance towards intruders. 

The hope is that this will translate to animals being relocated in the wild, helping them to become more inclined to their new social environment so they're more curious and less fearful, leading to more successful bonding.

Jessica C. Burkhart, Oxytocin promotes social proximity and decreases vigilance in groups of African lions, iScience (2022). DOI: 10.1016/j.isci.2022.104049. www.cell.com/iscience/fulltext … 2589-0042(22)00319-4

https://phys.org/news/2022-03-oxytocin-treatment-lions-ferocious-fr...

Concert hall acoustics for non-invasive ultrasound brain treatments

Metformin Prescriptions Linked to Sons’ Birth Defects

A new cohort study finds that boys whose fathers took the type 2 diabetes drug metformin three months before their conception were more likely to have a birth defect.

Men who took the type 2 diabetes drug metformin three months before conceiving their children seem to have an increased risk of having sons with birth defects, new research finds.

The study, a retroactive analysis of Denmark’s federal registry of healthcare data that was published Tuesday (March 29) in Annals of Internal Medicine, found a significantly increased risk of genital birth defects among boys whose fathers had filled a prescription for metformin—commonly branded as Glucophage, Riomet, and Glumetza—about three months prior to conception, roughly the duration of time it takes for sperm to mature. A correlation between birth defects and paternal metformin prescriptions was not seen in girls, according to the study.

https://www.acpjournals.org/doi/10.7326/M21-4389

https://www.the-scientist.com/news-opinion/metformin-prescriptions-...

Air pollution dims India's solar energy potential

Prospects for India achieving the target of generating 100 gigawatts of solar power in 2022 have waned because of high levels of atmospheric pollution.

Atmospheric pollution reduces solar power generation in two main ways: by absorbing and scattering the sun's rays and by soiling solar panels.

A study carried out by IIT Delhi and published March in Environmental Research Letters, calculates that between 2001 and 2018 India lost 29 percent of its solar energy potential as a result of atmospheric pollution—equivalent to an annual loss of US$835 million. As of March this year, India had only reached the halfway mark of 50 gigawatts of installed solar capacity, according to the research group, Mercom India.

Put simply, aerosols, which include fine particulate matter, dust, mist and fumes suspended in the air, significantly reduce incoming solar radiation in what we call the 'atmospheric attenuation effect. This needs to be factored in when undertaking large solar energy projects.

Such projects are also failing to account for the "soiling effect" of aerosols depositing on solar panels, blocking solar radiation from reaching the photovoltaic cells. Since air pollution over South Asia has been on the rise, both effects need to be addressed and mitigation steps taken to maximize benefits from solar power installations.

In heavily polluted regions particulate matter can cause a drop in photovoltaic solar power generation by more than 50 percent, most of it caused the soiling of panels, according to a previous study. Aerosols in the atmosphere also work against solar power generation by increasing cloudiness and interfering with rainfall which could wash out particles.

Acid rain can also corrode solar power equipment and support structures, adding to maintenance costs.

Sushovan Ghosh et al, Cleaner air would enhance India's annual solar energy production by 6-28 TWh, Environmental Research Letters (2022). DOI: 10.1088/1748-9326/ac5d9a

Xiaoyuan Li et al, Global reduction of solar power generation efficiency due to aerosols and panel soiling, Nature Sustainability (2020). DOI: 10.1038/s41893-020-0553-2

https://phys.org/news/2022-03-air-pollution-dims-india-solar.html?u...

Researchers identify compound with potent antiseizure effects

Study sheds light on why immunodeficiency affects only one identical twin

Scientists have long queried the causes of immune disorders in only one of two identical twins with identical genes. New research  has found the answer lies in both alterations in immune cell-cell communication and the epigenome, the host of biological processes that regulate how our genes function.

The study, published today in Nature Communications, is the first cell atlas to categorize common variable immunodeficiency (CVID) at the single-cell resolution. Researchers found that 'communication problems' resulting from defects in B cells and other immune cell types impaired immune response, highlighting a number of pathways that are promising targets for epigenetic treatments. In addition, they also identified major defects in the epigenome.

Common variable immunodeficiency (CVID) encompasses a range of immune disorders caused by a reduced ability to produce protective antibodies, which leaves the individual vulnerable to persistent or repeated infection. These individuals usually have low levels of immunoglobulin, more commonly known as antibodies, due to problems with the B cells that create them.

Though identical twins share the same genome, most will be born with a small number of genetic and epigenetic differences and the number of variations will increase over their lifetime. But where one twin experiences a health problem that their sibling does not, in most cases genetic differences alone cannot explain why this has occurred.

Around 20 percent of CVID cases can be attributed to a defect in a gene associated with the condition. But with four in five cases remaining largely unexplained, scientists have predicted that other factors must be involved. This was confirmed by a recent study, which linked CVID to DNA methylation, an epigenetic process that turns the level of a particular gene up or down.

Part1

In this new study, researchers from the Wellcome Sanger Institute and the Josep Carreras Leukemia Research Institute generated single-cell data to investigate epigenetic factors involved in CVID. Samples were taken from a pair of identical twins, only one of whom suffered from CVID, as well as a wider group of CVID patients and healthy individuals.

Analysis of the identical twin participants found that not only did the sibling with CVID have fewer B cells, but that B cell defects resulted in epigenetic problems with DNA methylation, chromatin accessibility and transcriptional defects in memory B cells themselves. In addition, researchers found massive defects in the cell-to-cell communication required for the immune system to function normally.

Single-Cell Atlas of Common Variable Immunodeficiency reveals germinal center-associated epigenetic dysregulation in B cell responses, Nature Communications (2022). DOI: 10.1038/s41467-022-29450-x

https://medicalxpress.com/news/2022-04-immunodeficiency-affects-ide...

Part 2

Creature that blows fire like a dragon?

There are no fire-breathing dragons, but there is the bombardier beetle, which ejects a hot, fiery mixture from its butt when threatened. The spray is produced by the reaction between two chemicals; hydroquinone and hydrogen peroxide, which are stored in separate abdominal compartments before coming together with a bang.

The resulting heat brings the mixture to almost 100°C and produces gas which drives the expulsion. This means that if a bombardier beetle gets eaten by a toad, it can literally fart its way out of trouble. It lets rip inside the amphibian’s belly until the predator vomits it up.

https://www.sciencefocus.com/nature/can-any-creature-blow-fire-like...

Spiders Don't Have Ears, But They Can Boost Their 'Hearing' Through Giant Webs

Spider webs are essential for capturing food – but they might also be used as giant hearing aids for the arachnids that spin them, according to new research. 

Spiders don't have ears, but they can 'hear' vibrations through their legs. When prey or predators are on the move, having those vibrations boosted through the web could be invaluable, the new study suggests, with webs spun that are sometimes 10,000 times the size of the actual creatures.

The researchers used a collection of orb-weaver spiders, known for making large webs, for their experiments, getting them to produce webs inside rectangular frames in the lab that could then be put through a series of tests.

They find that the wispy, wheel-shaped orb web acts as a hyperacute acoustic antenna to capture the sound-induced air particle movements.

A laser vibrometer was used to measure the response of spider web silk to music in an anechoic chamber, a room designed to minimize sound wave reflections. The measurements showed that the webs moved in almost perfect unison with the sound, potentially capturing the audio as it hits.

Sounds of different frequencies and from different directions were tested with the webs, which then got related responses from the spiders – they typically turned, crouched, or flattened out in response. In the case of the directional audio, the spiders oriented themselves towards the location the sound was coming from.

Further experiments with miniature speakers placed close to the edge of the web showed sounds traveling further through the webs than through the air, and some of the spiders responded to the vibrations even when the sound hadn't reached the spiders through the air. 

We know that spiders are able to hunt in packs, for example, via web vibrations passed through the sensory organs on the tarsal claws at the tip of spider legs. In this case, they're obviously responding to something when the sound waves hit, but further research will be required to figure out how the spiders are processing this information.

https://www.pnas.org/doi/10.1073/pnas.2122789119

https://www.sciencealert.com/study-shows-how-spiders-can-use-their-...

First audio recorded on Mars reveals two speeds of sound

The first audio recordings on Mars reveal a quiet planet with occasional gusts of wind where two different speeds of sound would have a strange delayed effect on hearing.

After NASA's Perseverance rover landed on Mars in February last year, its two microphones started recording, allowing scientists to hear what it is like on the Red Planet for the first time.

In a study published in the Nature journal on Friday, the scientists gave their first analysis of the five hours of sound picked up by Perseverance's microphones.

The audio revealed previously unknown turbulence on Mars.

 S. Maurice et al, In situ recording of Mars soundscape, Nature (2022). DOI: 10.1038/s41586-022-04679-0

https://phys.org/news/2022-04-audio-mars-reveals.html?utm_source=nw...

RNA switches 'on' and 'off'

Similar to a light switch, RNA switches (called riboswitches) determine which genes turn "on" and "off." Although this may seem like a simple process, the inner workings of these switches have confounded biologists for decades.Now researchers led by Northwestern University and the University at Albany discovered one part of RNA smoothly invades and displaces another part of the same RNA, enabling the structure to rapidly and dramatically change shape. Called "strand displacement," this mechanism appears to switch genetic expression from "on" to "off."

Using a simulation they launched last year, the researchers made this discovery by watching a slow-motion simulation of a riboswitch up close and in action. Affectionately called R2D2 (short for "reconstructing RNA dynamics from data"), the new simulation models RNA in three dimensions as it binds to a compound, communicates along its length and folds to turn a gene "on" or "off."

The findings could have potential implications for engineering new RNA-based diagnostics and for designing successful drugs to target RNA to treat illness and disease.
Luyi Cheng et al, Cotranscriptional RNA strand exchange underlies the gene regulation mechanism in a purine-sensing transcriptional riboswitch, Nucleic Acids Research (2022). DOI: 10.1093/nar/gkac102

Angela M Yu et al, Computationally reconstructing cotranscriptional RNA folding from experimental data reveals rearrangement of non-native folding intermediates, Molecular Cell (2021). DOI: 10.1016/j.molcel.2020.12.017

https://phys.org/news/2022-03-unprecedented-videos-rna.html?utm_sou...

Large-Scale Study Confirms Hybrid Immunity Best Protects Against COVID

People with the "hybrid immunity" of having been both fully vaccinated and previously infected with COVID-19 have the strongest protection against the virus, two new studies said  recently.

After two years of a pandemic that has seen nearly 500 million people infected and billions vaccinated, the studies highlighted the importance of getting jabbed for those who have natural immunity after recovering from the disease.

One of the two studies published in The Lancet Infectious Diseases medical journal analyzed the health data of more than 200,000 people in 2020 and 2021 in hard-hit Brazil, which has the world's second-largest COVID death toll.

It found that for people who have already had COVID, Pfizer and AstraZeneca's vaccines offered 90 percent effectiveness against hospitalization and death, China's CoronaVac had 81 percent and Johnson & Johnson's one-shot jab had 58 percent.

All four of these vaccines have proven to provide significant extra protection for those with a previous COVID-19 infection.

Hybrid immunity due to exposure to natural infection and vaccination is likely to be the norm globally and might provide long-term protection even against emerging variants.

Source:News agencies

https://www.sciencealert.com/huge-study-confirms-hybrid-immunity-gi...

Hydrocephalus often caused by disrupted brain development

One in 1,000 children is born with hydrocephalus. The serious condition is the most common reason for brain surgery in childhood. Nevertheless, those affected often suffer from intellectual and motor impairments for the rest of their lives.

In hydrocephalus, the fluid-filled cavities in the brain, the ventricles, are significantly enlarged. This significantly increases the intracranial pressure. The cause is thought to be disruptions of the cerebrospinal fluid balance. This fluid surrounds the brain and removes toxins. It also acts like a cushion to protect the brain from shocks and ensures that the cavities do not collapse.

Hydrocephalus in children often has completely different causes than previously assumed. This is the conclusion of an international study. The researchers identified a series of mutations that cause disruption of early brain development. The characteristic enlargements of the fluid-filled cavities in the brain are a consequence of this. The findings of this study also have implications for the diagnosis and treatment of this serious condition. The results are published in the journal Nature Neuroscience.

Kristopher Kahle, Impaired neurogenesis alters brain biomechanics in a neuroprogenitor-based genetic subtype of congenital hydrocephalus, Nature Neuroscience (2022). DOI: 10.1038/s41593-022-01043-3. www.nature.com/articles/s41593-022-01043-3

https://medicalxpress.com/news/2022-04-hydrocephalus-disrupted-brai...

Widely used food additive affects the human gut microbiota

Have you heard about the food additive E415? It is also known as xanthan gum. Most likely, you eat it several times a week. Xanthan gum is used in everyday foods such as baked goods, ice cream and salad dressings. The additive is also widely used as a substitute for gluten in gluten-free foods.

When xanthan gum was first introduced, it was thought that the additive went straight through the body without affecting the person who ate it.

Xanthan gum is a different type of carbohydrate from those that the human body is used to consume, such as starch from plant food. It has a different chemical structure. Xanthan gum is a type of complex carbohydrate that is not similar to any of the plant fibers we normally eat.

When it was first introduced, xanthan gum was thought to not affect us as it was not digested by the human body. However, the new study shows that the additive nevertheless affects the bacteria that live in our intestines. And these bacteria are important for our health and well-being.

The gut bacteria researchers have investigated show genetic changes and a rapid adaptation to enable them to digest this particular additive.

the new study shows that gut bacteria break down xanthan gum to its constituent monosaccharides, which are subsequently fermented to produce short-chain fatty acids that can be assimilated by the human body. Short-chain fatty acids are known to supply up to 10 percent of calories to humans.

This suggests xanthan gum could in fact add to a person's calorie intake.

We only see these changes in gut bacteria of people eating a 'westernized diet' where processed foods and additives make up a significant part of the food intake. For example, we do not see the same changes in indigenous people from different parts of the globe who eat limited amounts of processed foods.

Matthew P. Ostrowski et al, Mechanistic insights into consumption of the food additive xanthan gum by the human gut microbiota, Nature Microbiology (2022). DOI: 10.1038/s41564-022-01093-0

https://medicalxpress.com/news/2022-04-widely-food-additive-affects...

Treating diabetes without drugs: Novel non-pharmacologic treatments are on the horizon

A research team demonstrated the ability to use ultrasound to stimulate specific neurometabolic pathways in the body to prevent or reverse the onset of type 2 diabetes in three different preclinical models. 

The team of investigators is now conducting human feasibility trials with type 2 diabetic subjects, moving medicine closer to the day when diabetes is no longer monitored and managed with blood sugar tests, insulin injections, and drug treatments. The goal of the studies is to provide a long-lasting treatment for people with type 2 diabetes to alleviate and potentially reverse the disease.

If this ongoing clinical trials confirm the promise of the preclinical studies reported in this new study, and ultrasound can be used to lower both insulin and glucose levels, ultrasound neuromodulation would represent an exciting and entirely new addition to the current treatment options for the patients.

The reported findings represent a significant milestone in the field of bioelectronic medicine, which is exploring new ways to treat chronic diseases such as diabetes using novel medical devices to modulate the body's nervous system. 

 Victoria Cotero et al, Stimulation of the hepatoportal nerve plexus with focused ultrasound restores glucose homoeostasis in diabetic mice, rats and swine, Nature Biomedical Engineering (2022). DOI: 10.1038/s41551-022-00870-w

https://medicalxpress.com/news/2022-04-diabetes-drugs-non-pharmacol...

Presentation #4pBAb11, "Therapeutic ultrasound-induced insulin release in vivo" will be at 4:40 p.m., Thursday, May 16, in the Nunn room of the Galt House in Louisville, Kentucky. acousticalsociety.org/asa-meetings/

Ultrasound used to trigger insulin release in mice shows promise for diabetes therapy

https://medicalxpress.com/news/2019-05-ultrasound-trigger-insulin-m...

Scientists develop a recyclable pollen-based paper for repeated printing and 'unprinting'

Scientists  have developed a pollen-based "paper" that, after being printed on, can be "erased" and reused multiple times without any damage to the paper.

In a research paper published online in Advanced Materials on 5 April, the NTU Singapore scientists demonstrated how high-resolution color images could be printed on the non-allergenic pollen paper with a laser printer, and then "unprinted"—by completely removing the toner without damaging the paper—with an alkaline solution. They demonstrated that this process could be repeated up to at least eight times.

This innovative, printer-ready pollen paper could become an eco-friendly alternative to conventional paper, which is made via a multi-step process with a significant negative environmental impact.

It could also help to reduce the carbon emissions and energy usage associated with conventional paper recycling, which involves repulping, de-toning (removal of printer toner) and reconstruction.

Ze Zhao et al, Recyclable and Reusable Natural Plant‐Based Paper for Repeated Digital Printing and Unprinting, Advanced Materials (2022). DOI: 10.1002/adma.202109367

https://techxplore.com/news/2022-04-scientists-recyclable-pollen-ba...

Researchers develop injectable microtissue to preserve muscle function in rats with severed sciatic nerves

Researchers engineered the first injectable microtissue containing motor and sensory neurons encased in protective tissue, called tissue engineered neuromuscular interfaces (TE-NMIs). The TE-NMI neurons provide a source of axons to muscles in rats who suffered nerve injuries, and “babysit” the muscles to prevent degeneration and loss of function, while the damaged nerve regrows, according to the researchers.

The TE-NMIs are comprised of nerve cells encapsulated in a protective hydrogel, and the entire microenvironment is injected in close proximity to muscles. This “ship in a bottle” method protects the neurons and increases the likelihood that a greater quantity of axons will connect with the muscle and maintain regenerative pathways.

Researchers severed the sciatic nerve in rats, and injected them with either a TE-NMI or a microtissue without any neurons. In the group that received TE-NMIs, researchers were able to electrically stimulate the nerve stump being “babysat” by the TE-NMI and record a muscle response up to five months after the tissue was implanted. No muscle response was detected in the control group.

Justin C. Burrell, Suradip Das, Franco A. Laimo, Kritika S. Katiyar, Kevin D. Browne, Robert B. Shultz, Vishal J. Tien, Phuong T. Vu, Dmitriy Petrov, Zarina S. Ali, Joseph M. Rosen, D. Kacy Cullen. Engineered neuronal microtissue provides exogenous axons for delayed nerve fusion and rapid neuromuscular recovery in rats. Bioactive Materials, 2022; 18: 339 DOI: 10.1016/j.bioactmat.2022.03.018

https://researchnews.cc/news/12532/Penn-researchers-develop-injecta...

Microplastics found in lung tissue from live human beings for the first time

A team of researchers has identified minute particles of plastic in lung tissue removed from live human patients, marking the first time such materials have been observed in living human patients. The group has published a paper describing their findings in the journal Science of the Total Environment.

Prior studies have shown that plastics of all sizes have been winding up in places all across the planet. More recently, studies have found tiny bits of plastics in animals and in humans. Such particles have been found in the spleen, kidneys and liver of both live and deceased humans. And just last month a team in the Netherlands reported finding microplastics in the bloodstream of a live human patient. In this new effort, the researchers report having found microplastics in lung tissue taken from live patients in a hospital.

Suspecting that micro-sized bits of plastic might be inhaled by some people, the researchers worked with surgical teams at Castle Hill Hospital and their patients. The patients were undergoing surgery for treatment of various lung ailments and agreed to allow tissue removed from their lungs during surgery to be examined by the research team. Under such an arrangement, the research team was able to collect 13 samples, each of which went under the microscope. They found bits of plastic in 11 of them.

In studying the bits of plastic, the researchers found 12 different kinds, including those used in common household applications, such as clothing, packaging and bottles. But most surprising was where the plastic bits were found. In addition to the upper part of the lungs, where such particles would be expected to collect, the team found them in the lower regions. This was surprising because the airways in such parts of the lungs are much smaller, making it much more difficult for particles to reach them. The researchers were also surprised to find higher levels of the plastics in male patients as opposed to female patients.

Lauren C. Jenner et al, Detection of microplastics in human lung tissue using μFTIR spectroscopy, Science of The Total Environment (2022). DOI: 10.1016/j.scitotenv.2022.154907

https://phys.org/news/2022-04-microplastics-lung-tissue-human.html?...

Old skin cells reprogrammed to regain youthful function

Research  has developed a method to "time jump" human skin cells by 30 years, turning back the aging clock for cells without losing their specialized function. Work by researchers in the  Epigenetics research program has been able to partly restore the function of older cells, as well as rejuvenating the molecular measures of biological age. The research is published recently in the journal eLife, and while this topic is still at an early stage of exploration, it could revolutionize regenerative medicine.

As we age, our cells' ability to function declines and the genome accumulates marks of aging. Regenerative biology aims to repair or replace cells including old ones. One of the most important tools in regenerative biology is our ability to create "induced" stem cells. The process is a result of several steps, each erasing some of the marks that make cells specialized. In theory, these stem cells have the potential to become any cell type, but scientists aren't yet able to reliably recreate the conditions to re-differentiate stem cells into all cell types.

The new method, based on the Nobel Prize-winning technique scientists use to make stem cells, overcomes the problem of entirely erasing cell identity by halting reprogramming part of the way through the process. This allowed researchers to find the precise balance between reprogramming cells, making them biologically younger, while still being able to regain their specialized cell function.

Multi-omic rejuvenation of human cells by maturation phase transient reprogramming, eLife, 2022. DOI: 10.7554/eLife.71624

https://phys.org/news/2022-04-skin-cells-reprogrammed-regain-youthf...

The Problem with Deep Space Travel

What Is Life? (featuring Prof. Brian Cox)

Climatic variability might not drive evolutionary change as much as previously thought, study finds

A new study combining climate data with fossil records of large mammals that lived across Africa during the last 4 million years casts doubt on a long-standing hypothesis that repeated shifts in climate acted as major drivers of evolutionary change in mammals, including human ancestors.

Published in the journal Proceedings of the National Academy of Sciences, the study yields an African continent-wide synthesis of environmental variability during the Plio-Pleistocene, a period in Earth's history that spans roughly the last 5 million years and includes the last ice age about 20,000 years ago.

The study finds that environmental variability during that time mirrors changes in the Earth's orbit and orientation with respect to the sun, as predicted by a natural phenomenon known as Milankovic cycles. These cycles expose our planet to varying intensity of solar radiation, resulting in well-documented, cyclical effects on Earth's climate at various frequencies.

The researchers observed a long-term trend of increasing environmental variability across Africa attributable to variations in global ice volume and ocean temperature. The results did not, however, yield a significant correlation between environmental variation and rates of species origination or extinction, suggesting that environmental variability and species turnover may not be closely related.

Plio-Pleistocene environmental variability in Africa and its implications for mammalian evolution, Proceedings of the National Academy of Sciences (2022). DOI: 10.1073/pnas.2107393119.

https://phys.org/news/2022-04-climatic-variability-evolutionary-pre...

Decoy particles trick coronavirus as it evolves

They might look like cells and act like cells. But a new potential COVID-19 treatment is actually a cleverly disguised trickster, which attracts viruses and binds them, rendering them inactive.

As the ever-evolving SARS-CoV-2 virus begins to evade once promising treatments, such as monoclonal antibody therapies, researchers have become more interested in these "decoy" nanoparticles. Mimicking regular cells, decoy nanoparticles soak up viruses like a sponge, inhibiting them from infecting the rest of the body.

In a new study, Northwestern University synthetic biologists set out to elucidate the design rules needed make decoy nanoparticles effective and resistant to viral escape. After designing and testing various iterations, the researchers identified a broad set of decoys—all manufacturable using different methods—that were incredibly effective against the original virus as well as mutant variants.

In fact, decoy nanoparticles were up to 50 times more effective at inhibiting naturally occurring viral mutants, compared to traditional, protein-based inhibitor drugs. When tested against a viral mutant designed to resist such treatments, decoy nanoparticles were up to 1,500 times more effective at inhibiting infection.

Although much more research and clinical evaluations are needed, the researchers believe decoy nanoparticle infusions someday could potentially be used to treat patients with severe or prolonged viral infections.

Taylor F. Gunnels et al, Elucidating Design Principles for Engineering Cell‐Derived Vesicles to Inhibit SARS‐CoV‐2 Infection, Small (2022). DOI: 10.1002/smll.202200125

https://phys.org/news/2022-04-decoy-particles-coronavirus-evolves.h...

New evidence shows blood or plasma donations can reduce the PFAS ‘forever chemicals’ in our bodies

You might have heard of PFAS, a synthetic chemical found in certain legacy firefighting foams, non-stick pans, carpets, clothes and stain- or water-resistant materials and paints.

PFAS stands for “per- and poly-fluorinated alkyl substances”. These molecules, made up of chains of carbon and fluorine atoms, are nicknamed “forever chemicals” because they don’t degrade in our bodies.

There is global concern about PFAS because they have been used widely, are persistent in the environment and accumulate in our bodies over time.

There was no way to reduce the amount of PFAS found in the body – until now.

But a new randomised clinical trial, published in the journal JAMA Network Open, has found regularly donating blood or plasma can reduce blood PFAS levels.

The trial involved 285 Fire Rescue Victoria staff and contractors with elevated levels of PFOS, a common detected type of PFAS used in some firefighting foams.

They were randomly allocated to donate plasma every six weeks, to donate whole blood every 12 weeks, or to make no donations (the control group) for 12 months.

Their PFAS levels were measured at four intervals: at recruitment, the start of the trial, after 12 months of following their treatment plan, and again three months later to test if the results were sustained.

Both blood and plasma donation resulted in significantly lower PFAS chemicals than the control group, and these differences were maintained three months later.

Plasma donation was most effective, resulting in a roughly 30% decrease in average blood serum PFAS concentrations over the 12-month trial period.

Part 1

Reductions in PFAS levels from blood or plasma donations may be because PFAS are bound to proteins primarily found in the serum; many other organic pollutants are bound to fats.

The finding that plasma was more effective than blood donation might be because firefighters in the plasma donation group donated blood every six weeks, whereas those in the blood donation group donated every 12 weeks.

In addition, each plasma donation can amount to as much as 800mL compared with 470mL for whole blood.

Plasma PFAS concentrations are also about two times higher than blood PFAS concentrations, which could make plasma donation more efficient at reducing the body burden of PFAS chemicals.

This study provides the first avenue for affected individuals to remove PFAS from their bodies and redress the effects of their PFAS exposure.

https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2790905

https://theconversation.com/new-evidence-shows-blood-or-plasma-dona...

part 2

New study reveals how to rejuvenate the immune system of elderly people and reduce their risk of infectious disease

A new study identifies a reason for why older adults are significantly more susceptible to infectious diseases than younger people. Study results also pave the way for new potential therapeutic targets to rejuvenate the immune system in older adults and thereby reduce their risk of infectious disease.

T cell immunity declines with aging, thereby increasing severity and mortality from infectious disease. T cells are the quarterback of the immune system and coordinate immune responses to fight off infections. The addition of complex and branched carbohydrate chains ('glycans') to proteins suppresses T cells function.

In this study, researchers show that the branched glycans increase with age in T cells from females more than in males due to age-associated increases in an important sugar metabolite (N-acetylglucosamine) and signaling by the T cell cytokine interleukin-7.

This research reveals that reversing the elevation in branched glycans rejuvenates human and mouse T cell function and reduces severity of Salmonella infection in old female mice.

This suggests several potential novel therapeutic targets to revitalize old T cells, such as altering branched glycans or the age-triggered elevation in serum N-acetylglucosamine and IL-7 signaling.

Haik Mkhikian et al, Age-associated impairment of T cell immunity is linked to sex-dimorphic elevation of N-glycan branching, Nature Aging (2022). DOI: 10.1038/s43587-022-00187-y

https://medicalxpress.com/news/2022-04-reveals-rejuvenate-immune-el...

Keeping web-like NETs from clogging blood vessels could improve stroke outcomes

Preventing the formation of a sticky, web-like substance that can form in blood vessels after a stroke could protect the brain and lead to better outcomes for patients, studies in mice suggest.

Stroke is a leading cause of disability in the world. The most common form, ischemic stroke, occurs when a vessel-blocking clot impedes the flow of blood to the brain. Quick treatment to break up or remove the clot can restore blood flow and limit damage to the brain.

But according to the new study, the blood that comes rushing back carries cells with the potential to cause further harm. Brain damage can worsen even after a clot has been eliminated when immune cells in the blood release sticky webs, known as neutrophil extracellular traps (NETs), that further clog vessels.

Those NETs can gum up the vessels [in the brain] by trapping other cells and reducing the amount of blood flow, causing more brain injury. Markers of NETs correlated with poorer stroke outcomes in patients.

Researchers now found they could prevent these effects in a mouse model of stroke by treating animals with a NET-blocking compound.

Frederik Denorme et al, Neutrophil extracellular traps regulate ischemic stroke brain injury, Journal of Clinical Investigation (2022). DOI: 10.1172/JCI154225

https://medicalxpress.com/news/2022-04-web-like-nets-clogging-blood...

The lifespan secret

Ageing is linked to accumulated mutations - according to new research.

 Declining nitrogen availability in a nitrogen rich world

Research and discussion in recent times  has focused on the negative effects of excess nitrogen on terrestrial and aquatic ecosystems. However, new evidence indicates that the world is now experiencing a dual trajectory in nitrogen availability with many areas experiencing a hockey-stick shaped decline in the availability of nitrogen. In a new review paper in the journal Science, researchers have described the causes for these declines and the consequences on how ecosystems function.

There is both too much nitrogen and too little nitrogen on Earth at the same time now. 

Over the last century, humans have more than doubled the total global supply of reactive nitrogen through industrial and agricultural activities. This nitrogen becomes concentrated in streams, inland lakes, and coastal bodies of water, sometimes resulting in eutrophication, low-oxygen dead-zones, and harmful algal blooms. These negative impacts of excess nitrogen have led scientists to study nitrogen as a pollutant. However, rising CO2 and other global changes have increased demand for nitrogen by plants and microbes. In many areas of the world that are not subject to excessive inputs of nitrogen from people, long-term records demonstrate that nitrogen availability is declining, with important consequences for plant and animal growth.

Nitrogen is an essential element in proteins and as such its availability is critical to the growth of plants and the animals that eat them. Gardens, forests, and fisheries are almost all more productive when they are fertilized with moderate amounts of nitrogen. If plant nitrogen becomes less available, plants grow more slowly and their leaves are less nutritious to insects, potentially reducing growth and reproduction, not only of insects, but also the birds and bats that feed on them.

When nitrogen is less available, every living thing holds on to the element for longer, slowing the flow of nitrogen from one organism to another through the food chain. This is why we can say that the nitrogen cycle is slowing down.

Researchers reviewed long-term, global and regional studies and found evidence of declining nitrogen availability. 

These declines are likely caused by multiple environmental changes, one being elevated atmospheric CO2 changes. Atmospheric carbon dioxide has reached its highest level in millions of years, and terrestrial plants are exposed to about 50% more of this essential resource than just 150 years ago. Elevated atmospheric carbon dioxide fertilizes plants, allowing faster growth, but diluting plant nitrogen in the process, leading to a cascade of effects that lower the availability of nitrogen. On top of increasing atmospheric CO2, warming and disturbances, including wildfire, can also reduce availability over time.

Declining nitrogen availability is also likely constraining the ability of plants to remove carbon dioxide from the atmosphere.

Rachel E. Mason et al, Evidence, Causes, and Consequences of Declining Nitrogen Availability in Terrestrial Ecosystems, Science (2022). DOI: 10.1126/science.abh3767. www.science.org/doi/10.1126/science.abh3767

Scientists experimentally confirm new fundamental law for liquids

The first experimental evidence to validate a newly published universal law that provides insights into the complex energy states for liquids has been found using an advanced nuclear technique.

The equation for the vibrational density of states formulated by Alessio Zaccone and Matteo Bagglioli was published in a paper in PNAS in 2021, providing an answer to a question that has been elusive for at least a century.

The elegant mathematical theory has solved the problem of obtaining the distribution of these complex energy states for liquids.

"One of the most important quantities in the physics of matter is the distribution of the frequencies or vibrational energies of the waves that propagate in the material. It is particularly important as it is the starting point for calculating and understanding some fundamental properties of matter, such as specific heat and thermal conductivity, and the light-matter interaction.

The big problem with liquids is that, in addition to acoustic waves, there are other types of vibrational excitations related to low energies of the disordered motion of atoms and molecules— excitations that are almost absent in solids. These excitations are typically short-lived and are linked to the dynamic chaos of molecular motions but are nevertheless very numerous and important, especially at low energies. Mathematically, these excitations, known as 'instantaneous normal modes' or INMs in the specialized literature are very difficult to deal with as they correspond to energy states described by imaginary numbers.

Part 1

The time-of-flight neutron spectrometer Pelican at ANSTO's Center for Neutron Scattering has been used to measure the vibrational densities of states for several liquid systems including water, liquid metal, and polymer liquids. The Pelican instrument has the extreme sensitivity to measure rotational and translational vibrations over short time intervals and at low energies.

The experiments at ANSTO confirmed the linear relationship of the vibrational density of states with frequency at low energies as predicted earlier.

Caleb Stamper et al, Experimental Confirmation of the Universal Law for the Vibrational Density of States of Liquids, The Journal of Physical Chemistry Letters (2022). DOI: 10.1021/acs.jpclett.2c00297

Alessio Zaccone et al, Universal law for the vibrational density of states of liquids, Proceedings of the National Academy of Sciences (2021). DOI: 10.1073/pnas.2022303118

https://phys.org/news/2022-04-surfing-atomic-scale-scientists-exper...

Part 2

Gut bacterium supports growth in infants with severe acute malnutrition

About 18 million children under age five suffer from severe acute malnutrition, and more than 3 million children die from it each year. Treatment with high-calorie supplemental foods and antibiotics can prevent deaths, but these interventions often have limited impact on the long-term effects of severe acute malnutrition, such as persistent stunted growth, disrupted immune function and impaired brain development. Even when treated with standard therapeutic foods, many children continue to have moderate forms of the disease and are at risk of falling back into severe acute malnutrition.

A new study, published April 13 in the journal Science Translational Medicine, from Washington University School of Medicine in St. Louis and the International Center for Diarrheal Disease Research in Dhaka, Bangladesh (icddr,b), shows that a standard milk-based therapy plus treatment with a specific strain of gut bacteria known as Bifidobacterium infantis (B. infantis) for four weeks promotes weight gain in infants with severe acute malnutrition, with accompanying reductions in gut inflammation. 

The B. infantis strain was chosen for the trial because it has been shown to be safe to give to infants as a probiotic and is known to thrive on specific carbohydrates present in human breast milk. Importantly, the investigators found that B. infantis was either undetectable or present in markedly reduced amounts in infants with severe acute malnutrition compared to those with healthy growth.

 Michael J. Barratt et al, Bifidobacterium infantis treatment promotes weight gain in Bangladeshi infants with severe acute malnutrition, Science Translational Medicine (2022). DOI: 10.1126/scitranslmed.abk1107

https://medicalxpress.com/news/2022-04-gut-bacterium-growth-infants...

Injectable stem cell assembly for cartilage regeneration

A new study  has established an injectable hybrid inorganic (IHI) nanoscaffold-templated stem cell assembly and applied it to the regeneration of critically-sized cartilage defects.

Cartilage injuries are often devastating and most of them have no cures due to the intrinsically low regeneration capacity of cartilage tissues. The rise of 3D stem cell culture systems has led to breakthroughs in developmental biology, disease modeling, and regenerative medicine. For example, stem cells, once transplanted successfully, could initially secret trophic factors for reducing inflammation at sites of cartilage injuries and then differentiate into cartilage cells (e.g., chondrocytes) for functional restoration. Nevertheless, there are critical barriers remaining to be overcome before the therapeutic potential of stem cell therapies can be realized. The limited control over the chondrogenic differentiation of stem cells in vivo has often resulted in compromised regenerative outcomes. Moreover, due to the prevalence of oxidative stress and inflammation in the microenvironment of injury sites, stem cells frequently undergo apoptosis after injection. To address these challenges, the researchers demonstrated the development of a 3D IHI nanoscaffold-templated stem cell assembly system for advanced 3D stem cell culture and implantation. 3D-IHI nanoscaffold rapidly assembles stem cells into injectable tissue constructs through tailored 3D cell-cell and cell-matrix interactions, deeply and homogeneously delivers chondrogenic proteins in the assembled 3D culture systems, and controllably induces chondrogenesis through nanotopographical effects.

Once implanted in vivo in a rabbit cartilage injury model, 3D-IHI nanoscaffold effectively modulates dynamic microenvironment after cartilage injury through the integration of the aforementioned regenerative cues, and simultaneously scavenges reactive oxygen species using a manganese dioxide-based composition. In this way, accelerated repair of cartilage defects with rapid tissue reconstruction and functional recovery is realized both in the short term and long term. Given the excellent versatility and therapeutic outcome of 3D-IHI nanoscaffold-based cartilage regeneration, it may provide promising means to advance a variety of tissue engineering applications.

Shenqiang Wang et al, Injectable hybrid inorganic nanoscaffold as rapid stem cell assembly template for cartilage repair, National Science Review (2022). DOI: 10.1093/nsr/nwac037

https://phys.org/news/2022-04-stem-cell-cartilage-regeneration.html...

Latest recommendations on how waist-to-height ratio can impact your health

New health guidance on the need to keep your waist size to half your height to ensure healthy living was recommended by Bayes Business School eight years ago.

In 2014, research from Bayes Business School showed that the waist-to-height ratio (WHtR) is a better predictor of mortality risk than the commonly used BMI.

Today, draft guidance from the National Institute for Health and Care Excellence (NICE) has stated that an adult's waist should be less than half their height to reduce health risks, including type 2 diabetes and heart disease.

The guidance, published ahead of the release of a full report in September, also says that while measuring body mass index (BMI) is useful it doesn't consider excess weight around the abdomen—scientifically termed "central adiposity."

These new recommendations come after researchers at Bayes Business School and Ashwell Associates called for the measurement—waist circumference divided by height—to replace BMI in primary public health screening.

The study found that as many as 20 years of life for men can be lost by failing to sustain your waistline. The figure is approximately 10 years for women.

Margaret Ashwell et al, Waist-to-Height Ratio Is More Predictive of Years of Life Lost than Body Mass Index, PLoS ONE (2014). DOI: 10.1371/journal.pone.0103483

https://medicalxpress.com/news/2022-04-latest-waist-to-height-ratio...

**

International collaboration reveals how the human brain evolved to harness abstract thought

 The human brain is organized in functional networks—connected brain regions that communicate with each other through dedicated pathways. That is how we perceive our senses, how the body moves, how we are able to remember the past and plan for the future. The "default mode" network is the part of our connected brain that is responsible for abstract and self-directed thought. When we process external sensory information, the default mode network turns off, and when there is less going on outside our bodies it turns on. Whether the same default mode network is found in mammals similar to humans has not been firmly answered; different studies have yielded different conclusions.

In an international collaboration across seven laboratories, in five institutions, across three countries , researchers compared data from humans and non-hominoid primates (macaques, marmosets and mouse lemurs) to more definitively answer this question.
Surprisingly, these results showed that in all species other than humans, the brain areas that comprise the default mode network involve two systems not strongly connected with each other.

These regions, one responsible for suppression of external events and one for more cognitive tasks, appear to be linked only recently in evolution. It is this linkage that may have facilitated the capacity for abstract thought that led to the rapid evolution of human cognitive abilities.

The unexpected finding changes the way we think about brain networks. Atypical patterns of connectivity between brain areas are signatures of neurodevelopmental disorders and mental illnesses. These conditions are a significant health and societal issue that affects individuals' ability to healthily function in society. Understanding how unusual patterns of brain connectivity emerge could lead to better diagnosis and treatment of these conditions.

The article, "An evolutionary gap in primate default mode network organization" was published in the journal Cell Reports on April 12.

https://engineering.vanderbilt.edu/news/2022/international-collabor...

https://researchnews.cc/news/12686/International-collaboration-reve...

Some Microbes Breathe Methane And Turn It Into Electricity in a Weird Living Battery

As far as greenhouse gases go, methane is the quiet villain that could stealthily drag us ever deeper into the climate crisis. In our atmosphere, it is at least 25 times more effective at trapping heat than carbon dioxide.

It's also not that efficient – through burning, less than half of the energy in the natural gas can be converted into electrical power.

In an effort to squeeze more electrons from every puff of methane, researchers in the Netherlands have explored a rather unconventional form of power station – one you'd need a microscope to see.

"In the current biogas installations, methane is produced by microorganisms and subsequently burnt, which drives a turbine, thus generating power. Less than half of the biogas is converted into power, and this is the maximum achievable capacity. But can we  do better using microorganisms?

Scientists found a type of archaea – bacteria-like microbes known for their extraordinary talents of surviving under strange and harsh conditions, including being able to break down methane in environments deprived of oxygen.

This specific type, known as anaerobic methanotrophic (ANME) archaea, manage this metabolic trick by offloading electrons in a chain of electrochemical reactions, employing some kind of metal or metalloid outside of their cells or even donating them to other species in their environment.

First described in 2006, the ANME genus Methanoperedens was found to oxidize methane with a little help from nitrates, making them right at home in the wet bogs of the Netherland's fertilizer-soaked agricultural culverts.

Attempts to pull electrons from this process in microbial fuel cells have resulted in tiny voltages being produced, without any clear confirmation on exactly which processes might be behind the conversion.

If these archaea are to ever show promise as methane-gobbling power cells, they'd really need to churn out a current in a clear, unambiguous fashion.

Part 1

Researchers gathered a sample of microbes they knew to be dominated by this methane-slurping archaea, and grew them in an oxygen-lacking environment where methane was the only electron donor.

Near this colony they also placed a metal anode set at zero voltage, effectively creating an electrochemical cell primed to generate a current.

They created a kind of battery with two terminals, where one of these is a biological terminal and the other one is a chemical terminal. 

Researchers grew the bacteria on one of the electrodes, to which the bacteria donate electrons resulting from the conversion of methane. 

After analyzing the conversion of methane to carbon dioxide and measuring fluctuating currents that spiked as high as 274 milliamps per square centimeter, the team deduced a little over a third of the current could be attributed directly to the breaking down of methane.

As far as efficiency goes, 31 percent of the energy in the methane had transformed into electrical power, making it somewhat comparable with some power stations.

Tinkering more with the process could see to the creation of highly efficient living batteries that run on biogas, wringing more spark from every bit of gas and reducing the need for piping methane over long distances. 

https://www.frontiersin.org/articles/10.3389/fmicb.2022.820989/full

https://www.sciencealert.com/these-microbes-breathe-in-methane-and-...

Part 2

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