The two peaks of aging in humans
The progress of a human being through life might be thought of as a mostly gradual succession of changes from the ovum to the grave.
But according to new research into the molecular changes associated with aging, humans experience two drastic lurches forward, one at the average age of 44 and the other at the average age of 60.
We're not just changing gradually over time; there are some really dramatic changes at these peaks. 
It turns out the mid-40s is a time of dramatic change, as is the early 60s. And that's true no matter what class of molecules you look at.
Researchers noticed that in some conditions, such as Alzheimer's and cardiovascular disease, risk doesn't rise gradually with time, it escalates sharply after a certain age.
 Using the samples from their cohort, the researchers have been tracking different kinds of biomolecules. The different molecules studied include RNA, proteins, lipids, and gut, skin, nasal, and oral microbiome taxa, for a total of 135,239 biological features.
Scientists now noticed that there's a very clear change in the abundances of many different kinds of molecules in the human body at two distinct stages.
Around 81 percent of all the molecules they studied showed changes during one or both of these stages. Changes peaked in the mid-40s, and again in the early 60s, with slightly different profiles.

The mid-40s peak showed changes in molecules related to the metabolism of lipids, caffeine, and alcohol, as well as cardiovascular disease, and dysfunctions in skin and muscle. The early 60s peak was associated with carbohydrate and caffeine metabolism, cardiovascular disease, skin and muscle, immune regulation, and kidney function.

The first peak, the mid-40s, is typically when women start undergoing menopause or perimenopause, but the researchers ruled this out as a main factor: men, too, also underwent significant molecular changes at the same age.

This suggests that while menopause or perimenopause may contribute to the changes observed in women in their mid-40s, there are likely other, more significant factors influencing these changes in both men and women

https://www.nature.com/articles/s43587-024-00692-2

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Fatherhood at Fifty Impacts your Child Health

We all know that motherhood is constrained by a biological clock. 

And there is a "diminished concerns of the male 'biological clock' !

But mature fatherhood comes with its own risks, and a new study finds the proportion of US fathers aged 50 or older at the time of their child's birth is on the rise, meaning more children are likely to be impacted.

A 2018 study identified many of the risks of mature fatherhood, using data from 2007 to 2016 for more than 40 million live births in the US.

The data revealed that babies born to fathers over the age of 35 were at higher risk for adverse outcomes like low birth weight, seizures, and breathing problems immediately after birth.

And the older a father was, the greater the risk – for a man aged 45 years or older, his baby was 14 percent more likely to be born prematurely, and for a man aged 50 or older, his child was 28 percent more at risk of being admitted to neonatal intensive care.

Even after controlling for maternal age and other factors, every 10-year increase in the father's age increased the proportion of births that relied on assisted reproductive technology (ART). It was also associated with a higher likelihood of being the mother's first birth, and an increased risk of preterm birth and low birth weight compared to fathers aged 30 to 39.

Age-related conditions, such as erectile dysfunction and hypogonadism, impair paternal fecundity, while older age is associated with decreased semen volume, motility, and morphology.

Research has also linked older paternal age to declines in sperm quality, meaning the squiggly little gene packets that contribute half of a baby's DNA are more likely to be affected by DNA fragmentation, abnormal chromosome numbers, new mutations, and epigenetic alterations.

Overall, the accumulation of alterations in older men may increase the risk of conditions like autism, pediatric cancers, achondroplasia, and schizophrenia; decrease likelihood of ART success; and heighten risk of perinatal complications.

There were no significant differences found in infant sex ratio based on a father's age, except among fathers aged 70 years or older, who were more likely to have a female baby.

https://jamanetwork.com/journals/jamanetworkopen/fullarticle/282181...

Poisonous books containing toxic dyes!

If you come across brightly colored, cloth-bound books from the Victorian era, you might want to handle them gently, or even steer clear altogether. Some of their attractive hues come from dyes that could pose a health risk to readers, collectors or librarians.

The latest research on these poisonous books used three techniques—including one that hasn't previously been applied to books—to assess dangerous dyes in a university collection and found some volumes may be unsafe to handle.

The researchers present their results at the fall meeting of the American Chemical Society.

These old books with toxic dyes may be in universities, public libraries and private collections. Users can be put at risk if pigments from the cloth covers rub onto their hands or become airborne and are inhaled.

Emerald-green pigment was used in Victorian-era wallpaper, garments and—as researchers found out—in cloth book covers. This discovery led to the launch of the Poison Book Project, a crowdsourced research effort that uses X-ray fluorescence (XRF), Raman spectroscopy and other techniques to reveal toxic pigments in books around the world.

Weinstein-Webb and the Lipscomb students he recruited launched their own investigation in 2022. For the Lipscomb book project, the team used three spectroscopic techniques:

XRF to qualitatively check whether arsenic or other heavy metals were present in any of the book covers.

Inductively coupled plasma optical emission spectroscopy (ICP-OES) to determine the concentration of those metals.

X-ray diffraction (XRD) to identify the pigment molecules that contain those metals.

Researchers used XRF data to show that lead and chromium were present in some of the Lipscomb books. To quantify the amounts, they snipped samples roughly the size of a small paperclip from the cloth covers and then dissolved them in nitric acid.

Their analysis by ICP-OES showed that lead and chromium were both present at high levels in some samples. Subsequent XRD testing indicated that in some instances these heavy metals were in the form of lead(II) chromate, one of the compounds that contributes to the chrome yellow pigment favoured by Vincent van Gogh in his sunflower paintings.

Source: Multimodal detection of toxic metals in Victorian era book cloths as part of the Beaman library collection, ACS Fall 2024.

Researchers develop an instant version of trendy, golden turmeric milk

"Golden" turmeric milk is the new trend in the USA. Though recently advertised as a caffeine-free, healthy coffee alternative, the drink is a fancified version of haldi doodh—a traditional Indian beverage often used as an at-home cold remedy.

Now, researchers have developed an efficient method to make a plant-based, instant version that maintains the beneficial properties of the ingredients while also extending its shelf life.

The researchers present their results at the fall meeting of the American Chemical Society.

They first added turmeric powder to an alkaline solution, where the high pH made the curcumin more soluble and easier to extract than in plain water. This deep red solution was then added to a sample of soy milk, turning it a dark yellow colour. They brought it down to a neutral pH around 7.

Just like low-pH acids, high-pH bases are not the most pleasant things to consume. The neutralized pseudo-golden milk could be enjoyed as-is, but to further preserve it, the team removed the water from the solution through freeze-drying, producing an instant golden milk powder.

Not only does the method extract curcumin from turmeric more efficiently than existing methods, but it also encapsulates the curcumin in oil droplets within the soy milk. This means that when consumed, our bodies recognize the curcumin as fat and digest it as such, theoretically making the curcumin more bioavailable, or likely to be absorbed and able to have an effect in the body.

Encapsulating the curcumin also protects it from air and water, preserving it and keeping it shelf-stable for longer.

Utilizing a green pH-driven approach for developing curcumin-infuse..., ACS Fall 2024.

New statistical mechanics formula suggests urban street networks and building density shape severity of floods

Cities around the globe are experiencing increased flooding due to the compounding effects of stronger storms in a warming climate and urban growth. New research  suggests that urban form, specifically the building density and street network of a neighborhood, is also affecting the intensity of flooding.

For a paper published recently in Nature Communications, researchers  turned to statistical mechanics to generate a new formula allowing urban planners to more easily assess flood risks presented by land development changes.

 Sarah K. Balaian et al, How urban form impacts flooding, Nature Communications (2024). DOI: 10.1038/s41467-024-50347-4 www.nature.com/articles/s41467-024-50347-4

Spider exploits firefly's flashing signals to lure more prey

Fireflies rely on flashing signals to communicate to other fireflies using light-emitting lanterns on their abdomens. In fireflies of the species Abscondita terminalis, males make multi-pulse flashes with two lanterns to attract females, while females make single-pulse flashes with their one lantern to attract males.

Now researchers reporting in the journal Current Biology on August 19 have evidence that an orb-weaving spider (Araneus ventricosus) manipulates the flashing signals of male fireflies ensnared in its web such that they mimic the typical flashes of a female firefly, thereby luring other males to serve as their next meal.

Araneus ventricosus practices deceptive interspecific communication by first ensnaring firefly males in its web and then predisposing the entrapped male fireflies to broadcast bioluminescent signals that deviate from female-attracting signals typically made by A. terminalis males and instead mimic the male-attracting signals typically made by females," the researchers wrote.

The outcome is that the entrapped male fireflies broadcast false signals that lure more male fireflies into the web.

The findings show that animals can use indirect yet dynamic signaling to target an exceptionally specific category of prey in nature.

Spiders manipulate and exploit bioluminescent signals of male fireflies, Current Biology (2024). DOI: 10.1016/j.cub.2024.07.011. www.cell.com/current-biology/f … 0960-9822(24)00914-X

Animals with higher body temperatures are more likely to evolve into herbivores, study finds

A new study has uncovered a surprising relationship between an animal's body temperature and its likelihood of evolving into an herbivore. The study, published in the journal Global Ecology and Biogeography, offers fresh insights into the evolution of plant-based diets across tetrapods, which include the land vertebrates—amphibians, birds, reptiles and mammals. The findings could reshape scientists' understanding of the evolution of animal diets.

The study, which analyzed data from 1,712 species, found a consistent pattern: Animals with higher body temperatures are more likely to evolve into herbivores. This relationship holds true across the major land vertebrate groups.

The relationship between body temperature and herbivory is linked to the unique digestive challenges posed by a plant-based diet.

Higher body temperatures may be necessary to support the gut bacteria that break down cellulose, the primary component of plant cell walls. The relationship between an animal's body temperature and its gut microbiome could be key to understanding why certain species are better equipped to adopt and maintain herbivorous diets.

The research team conducted extensive analyses, examining various other factors that might influence the evolution of diet, including body size and day or night activity patterns. Body temperature ultimately emerged as the most crucial factor in predicting the evolution of an herbivorous diet.

The researchers really didn't see any herbivores that don't have a high body temperature. Typically, the body temperature was more than 86 degrees Fahrenheit.

 Kristen E. Saban et al, Diet Evolution and Body Temperature in Tetrapods: Cool Old Carnivores and Hot Young Herbivores, Global Ecology and Biogeography (2024). DOI: 10.1111/geb.13900

Researchers discover new way to control the sense of touch

Researchers have found a new way to manage the receptors that control the sense of touch, which could lead to treating chronic pain more effectively.

Identifying a natural molecule that specifically reduces pain sensitivity offers hope for new therapeutic strategies in the management of pain.

A natural molecule called phosphatidic acid can reduce the activity of certain touch-sensing ion channels in the body, according to the study published in Nature Communications.

Researchers found that increasing the levels of phosphatidic acid in cells makes them less sensitive to touch. This finding was confirmed through experiments on sensory neurons and tests in mice, where the animals became more sensitive to touch when the formation of phosphatidic acid was inhibited.

This finding adds to a growing body of evidence suggesting that lipids are key regulators of somatosensation (the body's ability to perceive sensations such as touch, temperature and pain).

By targeting the natural pathways that regulate these channels, we can develop more targeted and effective pain treatments that could be especially useful for conditions involving inflammatory pain, where current pain relief options are often inadequate.

Matthew Gabrielle et al, Phosphatidic acid is an endogenous negative regulator of PIEZO2 channels and mechanical sensitivity, Nature Communications (2024). DOI: 10.1038/s41467-024-51181-4

Study finds constipation is a significant risk factor for major cardiac events

An international study led by Monash University researchers has found a surprising connection between constipation and an increased risk of major adverse cardiac events (MACE), including heart attacks, strokes and heart failure.

The study, led by Professor Francine Marques from the School of Biological Sciences and published in the American Journal of Physiology-Heart and Circulatory Physiology analyzed data from over 400,000 participants in the UK Biobank.

The study suggests that constipation, a common yet often overlooked health issue, may be a significant contributor to cardiovascular disease .

 Traditional cardiovascular risk factors such as high blood pressure, obesity and smoking have long been recognized as key drivers of heart disease.

However, these factors alone do not fully explain the occurrence of major cardiac events. This study explored the potential role of constipation as an additional risk factor, revealing concerning results.

The research team analyzed data from 408,354 individuals, identifying 23,814 cases of constipation.

The findings showed that individuals suffering from constipation were more than twice as likely to suffer from a major cardiac event as those without constipation.

Moreover, the study highlighted a particularly concerning link between constipation and hypertension.

Hypertensive individuals who also suffered from constipation were found to have a 34% increased risk of subsequent cardiac events compared to those with hypertension alone.

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In addition to these epidemiological findings, the study also explored the genetic links between constipation and cardiovascular disease.

Positive genetic correlations were identified between constipation and various forms of MACE, indicating that shared genetic factors may underlie both conditions. This discovery opens new avenues for research into the underlying mechanisms that connect gut health and heart health.

 Tenghao Zheng et al, Constipation is associated with an increased risk of major adverse cardiac events in a UK population, American Journal of Physiology-Heart and Circulatory Physiology (2024). DOI: 10.1152/ajpheart.00519.2024

Part 2 

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Why laws are written in an incomprehensible style

Legal documents are notoriously difficult to understand, even for lawyers. This raises the question: Why are these documents written in a style that makes them so impenetrable?

MIT cognitive scientists think they have uncovered the answer to that question. Just as "magic spells" use special rhymes and archaic terms to signal their power, the convoluted language of legalese acts to convey a sense of authority, they conclude.

In a study appearing in the Proceedings of the National Academy of Sciences, the researchers found that even non-lawyers use this type of language when asked to write laws.

People seem to understand that there's an implicit rule that this is how laws should sound, and they write them that way.

The analysis revealed that legal documents frequently have long definitions inserted in the middle of sentences—a feature known as "center-embedding." Linguists have previously found that this kind of structure can make text much more difficult to understand.

Legalese somehow has developed this tendency to put structures inside other structures, in a way which is not typical of human languages.

 Lawyers don't like it, laypeople don't like it, so the point of this current paper was to try and figure out why they write documents this way.

The researchers had a couple of hypotheses for why legalese is so prevalent. One was the "copy and edit hypothesis," which suggests that legal documents begin with a simple premise, and then additional information and definitions are inserted into already existing sentences, creating complex center-embedded clauses.

Researchers  thought it was plausible that what happens is you start with an initial draft that's simple, and then later you think of all these other conditions that you want to include. And the idea is that once you've started, it's much easier to center-embed that into the existing provision.

Martínez, Eric, Even laypeople use legalese, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2405564121. doi.org/10.1073/pnas.2405564121

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Blood platelet score detects previously unmeasured risk of heart attack and stroke

Platelets are circulating cell fragments known to clump up and form blood clots that stop bleeding in injured vessels. Researchers and cardiologists have long known that platelets can become "hyperreactive" to cause abnormal clotting that blocks arteries and contributes to heart attack, stroke, and poor blood flow (peripheral artery disease) in the legs.

Despite this major contribution to cardiovascular risk, routine measurement of whether each patient's platelets clump (aggregate) too much has been infeasible to date. This is because results delivered by the method typically used to determine platelet activity, called platelet aggregometry, vary too much from lab to lab.

To address this challenge, a new study  by researchers has precisely identified a group of patients with platelet hyperreactivity, and then surveyed them to reveal 451 genes, the activity of which differed significantly in those with hyperreactive platelets versus those without. Publishing in Nature Communications, the research team then used bioinformatics to assign a weight to each genetic difference and generate each patient's Platelet Reactivity ExpresSion Score (PRESS).

The researchers found that their new score can detect platelet hyperreactivity, both in patients at imminent risk of heart attack, and in healthy patients whose future risk may otherwise remain unknown.

Physicians currently prescribe aspirin, a medication that counters platelet activity, to patients based on available risk factors, including high cholesterol or high blood pressure, which are not directly related to platelet function.

PRESS promises to help physicians confine anti-platelet treatment to the people most likely to benefit: those with platelet hyperreactivity.

By acting on platelets, aspirin is known to protect against abnormal clotting, but in doing so, increases risk of bleeding, said the study authors. The field needs a reliable way to identify patients for whom protection against heart attack outweighs bleeding risk. This work helps with that.

A Platelet Reactivity ExpreSsion Score Predicts 1 Cardiovascular Risk, Nature Communications (2024). DOI: 10.1038/s41467-024-50994-7

When a foe turns a friend: Deadly sea snail toxin could be key to making better medicines

Scientists are finding clues on how to treat diabetes and hormone disorders in an unexpected place: a toxin from one of the most venomous animals on the planet.

A multinational research team led by University of Utah scientists has identified a component within the venom of a deadly marine cone snail, the geography cone, that mimics a human hormone called somatostatin, which regulates the levels of blood sugar and various hormones in the body. The hormone-like toxin's specific, long-lasting effects, which help the snail hunt its prey, could also help scientists design better drugs for people with diabetes or hormone disorders, conditions that can be serious and sometimes fatal.

The somatostatin-like toxin the researchers characterized could hold the key to improving medications for people with diabetes and hormone disorders. Somatostatin acts like a brake pedal for many processes in the human body, preventing the levels of blood sugar, various hormones, and many other important molecules from rising dangerously high.

The cone snail toxin, called consomatin, works similarly, the researchers found—but consomatin is more stable and specific than the human hormone, which makes it a promising blueprint for drug design.

By measuring how consomatin interacts with somatostatin's targets in human cells in a dish, the researchers found that consomatin interacts with one of the same proteins that somatostatin does. But while somatostatin directly interacts with several proteins, consomatin only interacts with one. This fine-tuned targeting means that the cone snail toxin affects hormone levels and blood sugar levels but not the levels of many other molecules.

In fact, the cone snail toxin is more precisely targeted than the most specific synthetic drugs designed to regulate hormone levels, such as drugs that regulate growth hormone. Such drugs are an important therapy for people whose bodies overproduce growth hormone. Consomatin's effects on blood sugar could make it dangerous to use as a therapeutic, but by studying its structure, researchers could start to design drugs for endocrine disorders that have fewer side effects.

Consomatin is more specific than top-of-the-line synthetic drugs—and it also lasts far longer in the body than the human hormone, thanks to the inclusion of an unusual amino acid that makes it difficult to break down. This is a useful feature for pharmaceutical researchers looking for ways to make drugs that will have long-lasting benefits.

 Disruption of Glucose Homeostasis in Prey: Combinatorial Use of Weaponized Mimetics of Somatostatin and Insulin by a Fish-Hunting Cone Snail, Nature Communications (2024). DOI: 10.1038/s41467-024-50470-2. www.nature.com/articles/s41467-024-50470-2

Extraterrestrial chemistry with earthbound possibilities

Who are we? Why are we here? We are stardust, the result of chemistry occurring throughout vast clouds of interstellar gas and dust. To better understand how that chemistry could create prebiotic molecules—the seeds of life on Earth and possibly elsewhere—researchers have investigated the role of low-energy electrons created as cosmic radiation traverses through ice particles. Their findings may also inform medical and environmental applications on our home planet.

The first detection of molecules in space was made by Wellesley College alum Annie Jump Cannon more than a hundred years ago. Since Cannon's discovery, scientists have been interested in finding out how extraterrestrial molecules form.

A new work's   goal is to explore the relative importance of low-energy electrons versus photons in instigating the chemical reactions responsible for the extraterrestrial synthesis of these prebiotic molecules. 

The few studies that previously probed this question suggested that both electrons and photons can catalyze the same reactions. Recent Studies , however, hint that the prebiotic molecule yield from low-energy electrons and photons could be significantly different in space.

Their calculations suggest that the number of cosmic-ray-induced electrons within cosmic ice could be much greater than the number of photons striking the ice. Therefore, electrons likely play a more significant role than photons in the extraterrestrial synthesis of prebiotic molecules

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Aside from cosmic ice, the present research into low-energy electrons and radiation chemistry also has potential applications on Earth. The researchers studied the radiolysis of water, finding evidence of electron-stimulated release of hydrogen peroxide and hydroperoxyl radicals, which destroy stratospheric ozone and act as damaging reactive oxygen species in cells.

A lot of their water radiolysis research findings could be used in medical applications and medical simulations.
Humans are basically bags of water. So scientists are investigating how low-energy electrons produced in water affect our DNA molecules.
In attempting to better understand prebiotic molecule synthesis, the researchers didn't limit their efforts to mathematical modeling; they also tested their hypothesis by mimicking the conditions of space in the lab. They use an ultrahigh-vacuum chamber containing an ultrapure copper substrate that they can cool to ultralow temperatures, along with an electron gun that produces low-energy electrons and a laser-driven plasma lamp that produces low-energy photons. The scientists then bombard nanoscale ice films with electrons or photons to see what molecules are produced.
Although researchers have previously focused on how this research is applicable to interstellar submicron ice particles, it is also relevant to cosmic ice on a much larger scale, like that of Jupiter's moon Europa, which has a 20-mile-thick ice shell.
The research team's results will be presented at the fall meeting of the American Chemical Society (ACS). ACS Fall 2024
Source: American Chemical Society
https://www.acs.org/meetings/acs-meetings/fall.html
Part 2
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How air pollution increases thunderstorm danger

Air pollution is increasing the severity of summertime thunderstorms, according to a recent study conducted by researchers at James Madison University and published in the journal Atmospheric Research.

Pollution acts as cloud nuclei. It gets brought into the cloud through the updraft; the updraft and downdraft then separate the pollution particles, which divides the electrical charges in the cloud and leads to more lightning production.

The three-year study examined nearly 200,000 thunderstorms.

Using 12 years of lightning data from the National Lightning Detection Network, US, and data from hundreds of air pollution stations, the researchers were able to determine that in environments with high instability, adding more pollution increases cloud-to-ground lightning strikes.

Similar research on Bangkok, a megacity with more pollution than most US cities and located in a hot, tropical climate, show similar results, albeit with lightning rates even higher in those storms.

It looks like no matter where you go in the world, urban pollution is capable of enhancing thunderstorms and lightening, the researchers conclude.

Mace Bentley et al, Toward untangling thunderstorm-aerosol relationships: An observational study of regions centered on Washington, DC and Kansas City, MO, Atmospheric Research (2024). DOI: 10.1016/j.atmosres.2024.107402

Genomic surveillance method tracks multiple superbugs in hospitals

Researchers have developed a new genomic technique that can track the spread of multiple superbugs in a hospital simultaneously, which could help prevent and manage common hospital infections quicker and more effectively than ever before.

The proof-of-concept study details a new deep sequencing approach that captures all the common infectious bacteria in a hospital at once. Current methods culture and sequence all pathogens separately, which takes longer and requires more work.

Published 20 August in the Lancet Microbe, the study captured the whole population of pathogenic bacteria found in multiple hospital intensive care units (ICUs) and ordinary wards during the first wave of the 2020 COVID-19 pandemic. Researchers could see the type of bacteria patients had, including any well-known antibiotic-resistant pathogens found in hospitals.

They discovered that each ICU patient tested in the study was colonized by at least one such treatment-resistant bacteria, while the majority were colonized by several of them simultaneously.

Researchers think their approach could be integrated with existing hospital clinical surveillance systems. As drug resistance is a widespread issue in hospitals and other clinical settings, this system could identify, track and limit the spread of common multiple treatment-resistant bacteria at the same time.

Bacteria are commonly found in or on the body without causing harm, known as colonization. However, if certain strains get into the bloodstream due to a weakened immune system, they can cause severe and life-threatening infections, unless they can be effectively treated with antibiotics.

As an added challenge for health care providers, some of these bacteria are antibiotic-resistant (AMR). Infections caused by AMR bacteria are a major issue in hospitals, with these treatment-resistant bacteria predicted to cause more deaths than cancer by 2050. While some hospitals test for AMR bacteria on arrival, no system effectively tracks all multi-drug resistant bacteria throughout a hospital.

Part 1

Over the last 15 years, genomic surveillance has become a powerful tool for tracking pathogen evolution and transmission, giving critical insights to help manage the spread of disease.

However, current methods involve culturing a single strain of bacteria in a sample at a time and then conducting whole genome sequencing for all of them separately. This is a labor-intensive process, which can easily take several days and only provides a partial snapshot of all the clinically relevant bacteria found in a sample.

In this new study the research team developed a new approach that captured whole genome sequencing data across multiple pathogens at once. This is known as a 'pan-pathogen' deep sequencing approach and can provide genomic data as rapidly as hospitals can process the samples.

Pan-pathogen deep sequencing of nosocomial bacterial pathogens during the early COVID-19 pandemic, spring 2020: A prospective cohort study, The Lancet Microbe (2024). DOI: 10.1016/S2666-5247(24)00113-7

Part 2

A galactic theory disproven: Dark matter and stars not interacting as previously thought

A longstanding theory in astronomy—that stars and dark matter are interacting in inexplicable ways—has been overturned by an international team of astronomers, in a paper in Monthly Notices of the Royal Astronomical Society.

The  theory emerged to explain a phenomenon that had puzzled astronomers for a quarter of a century. The density of matter in different galaxies appeared to be decreasing at the same rate from their center to outer edges. This was perplexing because galaxies are diverse, with many different ages, shapes, sizes, and numbers of stars. So why would they have the same density structure?

This homogeneity suggested that dark matter and stars must somehow compensate for each other in order to produce such regular mass structures.

Part 1

Like many conspiracies, no researcher could come up with a mechanism. If dark matter and stars could interact in this way, then we would need to change our understanding of how galaxies form and evolve. But they also couldn't find an alternate reason to explain what they were seeing, until now.

Present research work found that the similarity in density might not be due to the galaxies themselves but in how astronomers were measuring and modeling them.

The team which made this observation observed 22 middle-aged galaxies (looking back some four billion years in the past due to their great distance) in extraordinary detail, using the European Southern Observatory's Very Large Telescope in Chile. It enabled them to create more complex models that better captured the diversity of galaxies in the universe.
In the past, people built simple models that had too many simplifications and assumptions. Galaxies are complicated, and researchers have to model them with freedom or they're going to measure the wrong things. The new models ran on the OzStar supercomputer at Swinburne University, using the equivalent of about 8,000 hours of desktop computing time.

C Derkenne et al, The MAGPI Survey: Evidence against the bulge-halo conspiracy, Monthly Notices of the Royal Astronomical Society (2024). DOI: 10.1093/mnras/stae1836

Part 2

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Gut microbial pathway identified as target for improved heart disease treatment

 Researchers have made a significant discovery about how the gut microbiome interacts with cells to cause cardiovascular disease. The study published in Nature Communications found that phenylacetylglutamine (PAG), produced by gut bacteria as a waste product, then absorbed and formed in the liver, interacts with previously undiscovered locations on beta-2 adrenergic receptors on heart cells once it enters the circulation.

PAG was shown to interact with beta-2 adrenergic receptors to influence how forcefully the heart muscle cells contract—a process that investigators think contributes to heart failure. Researchers showed mutating parts of the beta-2 adrenergic receptor that were previously thought to be unrelated to signaling activity in preclinical models prevented PAG from depressing the function of the receptor.

The same researchers earlier demonstrated that elevated circulating levels of PAG in subjects are associated with heightened risk for developing heart failure, and lead to worse outcomes for patients with heart failure.

They also showed that the gut microbial PAG signaling pathway was mechanistically linked to numerous heart failure-related features and cardiovascular disease risks. The new findings bring us one step closer to therapeutically targeting this pathway to develop an improved treatment for the prevention of heart failure.

 Prasenjit Prasad Saha et al, Gut microbe-generated phenylacetylglutamine is an endogenous allosteric modulator of β2-adrenergic receptors, Nature Communications (2024). DOI: 10.1038/s41467-024-50855-3

Research pinpoints how early-life antibiotics turn immunity into allergy

Researchers  have shown for the first time how and why the depletion of microbes in a newborn's gut by antibiotics can lead to lifelong respiratory allergies.

In a study published recently in the Journal of Allergy and Clinical Immunology, a research team from the school of biomedical engineering (SBME) has identified a specific cascade of events that lead to allergies and asthma. In doing so, they have opened many new avenues for exploring potential preventions and treatments.

This new research  finally shows how the gut bacteria and antibiotics shape a newborn's immune system to make them more prone to allergies.

Allergies are a result of the immune system reacting too strongly to harmless substances like pollen or pet dander, and a leading cause for emergency room visits in kids. Normally, the immune system protects us from harmful invaders like bacteria, viruses and parasites. In the case of allergies, it mistakes something harmless for a threat—in this case, parasites—and triggers a response that causes symptoms like sneezing, itching or swelling.

The stage for our immune system's development is set very early in life. Research over the past two decades has pointed toward microbes in the infant gut playing a key role. Babies often receive antibiotics shortly after birth to combat infections, and these can reduce certain bacteria. Some of those bacteria produce a compound called butyrate, which is key to halting the processes uncovered in this research.

The same researchers had previously shown that infants with fewer butyrate-producing bacteria become particularly susceptible to allergies. They had also shown that this could be mitigated or even reversed by providing butyrate as a supplement in early life.

Now, by studying the process in mice, they have discovered how this works.
Mice with depleted gut bacteria who received no butyrate supplement developed twice as many of a certain type of immune cell called ILC2s. These cells, discovered less than 15 years ago, have quickly become prime suspects in allergy development.

The researchers showed that ILC2s produce molecules that 'flip a switch' on white blood cells to make them produce an abundance of certain kinds of antibodies. These antibodies then coat cells as a defense against foreign invaders, giving the allergic person an immune system that is ready to attack at the slightest provocation.

Ahmed Kabil et al, Microbial intestinal dysbiosis drives long-term allergic susceptibility by sculpting an ILC2-B1 cell–innate IgE axis., Journal of Allergy and Clinical Immunology (2024). DOI: 10.1016/j.jaci.2024.07.023

A legend in one's own mind: The link between ambition and leadership evaluations

Ambitious people aren't born leaders, research suggests

Do ambitious people make good leaders? Ambition can lead people to strive for leadership roles. But could there be a mismatch between qualities that motivate people to strive for leadership and qualities that make people good leaders?

asked 472 executives enrolled in a leadership development program offered by a West Coast business school in the United States to rate their ambition. The authors then compared these ambition scores with 360-degree leadership assessments obtained from the executives themselves, as well as their current managers, peers, and subordinates.

Thepaper is published in the journal PNAS Nexus.

The authors found, as expected, that leadership ambition increases self-ratings of effectiveness in a leadership role. That is, leaders with high self-reported ambition also rated themselves as highly-effective leaders. However, the authors found no relationship between leadership ambition and third-party ratings of leadership effectiveness; highly ambitious executives, compared to less ambitious executives, were rated as no more effective in their leadership roles by their managers, peers, or direct reports.

These results suggest that the pool of people striving for leadership roles may be filled with ambitious people who seek extrinsic rewards, such as high salaries and social status, and regard themselves more positively than others do. According to the authors, society may want to develop alternative approaches to choosing and training leaders.

Researchers develop world's fastest microscope that can see electrons in motion

Imagine owning a camera so powerful it can take freeze-frame photographs of a moving electron—an object traveling so fast it could circle the Earth many times in a matter of a second. Researchers have developed the world's fastest electron microscope that can do just that.

And they think their work will lead to groundbreaking advancements in physics, chemistry, bioengineering, materials sciences and more.

This transmission electron microscope is like a very powerful camera in the latest version of smart phones; it allows us to take pictures of things we were not able to see before—like electrons. With this microscope, the researchers hope the scientific community can understand the quantum physics behind how an electron behaves and how an electron moves.

A transmission electron microscope is a tool used by scientists and researchers to magnify objects up to millions of times their actual size in order to see details too small for a traditional light microscope to detect.

Instead of using visible light, a transmission electron microscope directs beams of electrons through whatever sample is being studied. The interaction between the electrons and the sample is captured by lenses and detected by a camera sensor in order to generate detailed images of the sample.

Ultrafast electron microscopes using these principles were first developed in the 2000's and use a laser to generate pulsed beams of electrons. This technique greatly increases a microscope's temporal resolution—its ability to measure and observe changes in a sample over time.

In these ultrafast microscopes, instead of relying on the speed of a camera's shutter to dictate image quality, the resolution of a transmission electron microscope is determined by the duration of electron pulses.

The faster the pulse, the better the image.

Ultrafast electron microscopes previously operated by emitting a train of electron pulses at speeds of a few attoseconds. An attosecond is one quintillionth of a second. Pulses at these speeds create a series of images, like frames in a movie—but scientists were still missing the reactions and changes in an electron that takes place in between those frames as it evolves in real time.

In order to see an electron frozen in place,  researchers, for the first time, generated a single attosecond electron pulse, which is as fast as electrons move, thereby enhancing the microscope's temporal resolution, like a high-speed camera capturing movements that would otherwise be invisible.

Part 1

The researchers who developed this microscope based their work on the Nobel Prize-winning accomplishments of Pierre Agostini, Ferenc Krausz and Anne L'Huilliere, who won the Novel Prize in Physics in 2023 after generating the first extreme ultraviolet radiation pulse so short it could be measured in attoseconds.

Using that work as a steppingstone, the researchers developed a microscope in which a powerful laser is split and converted into two parts—a very fast electron pulse and two ultra-short light pulses. The first light pulse, known as the pump pulse, feeds energy into a sample and causes electrons to move or undergo other rapid changes.

The second light pulse, also called the "optical gating pulse" acts like a gate by creating a brief window of time in which the gated, single attosecond electron pulse is generated. The speed of the gating pulse therefore dictates the resolution of the image. By carefully synchronizing the two pulses, researchers control when the electron pulses probe the sample to observe ultrafast processes at the atomic level.
The electron movements happen in attoseconds. But now, for the first time, researchers are able to attain attosecond temporal resolution with their electron transmission microscope—and they coined it 'attomicroscopy.' For the first time, they could see pieces of the electron in motion.

Dandan Hui et al, Attosecond electron microscopy and diffraction, Science Advances (2024). DOI: 10.1126/sciadv.adp5805. www.science.org/doi/10.1126/sciadv.adp5805

Part 2

New research suggests rainwater helped form the first protocell walls

In the paper, published in Science Advances researchers show how rainwater could have helped create a meshy wall around protocells 3.8 billion years ago, a critical step in the transition from tiny beads of RNA to every bacterium, plant, animal, and human that ever lived.

The research looks at "coacervate droplets"—naturally occurring compartments of complex molecules like proteins, lipids, and RNA. The droplets, which behave like drops of cooking oil in water, have long been eyed as a candidate for the first protocells. But there was a problem. It wasn't that these droplets couldn't exchange molecules between each other, a key step in evolution, the problem was that they did it too well, and too fast.

Any droplet containing a new, potentially useful pre-life mutation of RNA would exchange this RNA with the other RNA droplets within minutes, meaning they would quickly all be the same. There would be no differentiation and no competition—meaning no evolution.

And that means no life. If molecules continually exchange between droplets or between cells, then all the cells after a short while will look alike, and there will be no evolution because you are ending up with identical clones.

DNA is the molecule which encodes information, but it cannot do any function. Proteins are the molecules which perform functions, but they don't encode any heritable information.

RNA is a molecule which, like DNA, can encode information, but it also folds like proteins so that it can perform functions such as catalysis as well.

RNA was a likely candidate for the first biological material. Coacervate droplets were likely candidates for the first protocells. Coacervate droplets containing early forms of RNA seemed a natural next step.

What the researchers now showed in this new paper is that you can overcome at least part of that problem by transferring these coacervate droplets into distilled water—for example, rainwater or freshwater of any type—and they get a sort of tough skin around the droplets that restricts them from exchanging RNA content.

Where do you think distilled water could come from in a prebiotic world? Rain!

Working with RNA samples the researchers found that transferring coacervate droplets into distilled water increased the time scale of RNA exchange—from mere minutes to several days. This was long enough for mutation, competition, and evolution.

Part 1

If you have protocell populations that are unstable, they will exchange their genetic material with each other and become clones. There is no possibility of Darwinian evolution. But if they stabilize against exchange so that they store their genetic information well enough, at least for several days, so that the mutations can happen in their genetic sequences, then a population can evolve.
In their experiments with the actual rainwater and with lab water modified to mimic the acidity of rainwater, the researchers found the same results. The meshy walls formed, creating the conditions that could have led to life.
The new paper proves that this approach of building a meshy wall around protocells is possible and can work together to compartmentalize the molecules of life, putting researchers closer than ever to finding the right set of chemical and environmental conditions that allow protocells to evolve.

Aman Agrawal et al, Did the exposure of coacervate droplets to rain make them the first stable protocells?, Science Advances (2024). DOI: 10.1126/sciadv.adn9657. www.science.org/doi/10.1126/sciadv.adn9657

Part 2

A free-living eukaryote is the first known to have lost its mitochondria

An international team of geneticists and molecular biologists has discovered the first-known, free-living eukaryote to have lost its mitochondria. In their study, published in Nature Communications, the group found the eukaryote while investigating the patterns and processes of genome and mitochondrion-related organelles' evolution in metamonads in water samples collected from saltwater lakes and shallow marine environments.

Mitochondria are organelles in almost every living eukaryotic cell on Earth. They are responsible for generating the energy that allows creatures to grow and to move around. Mitochondria have a double membrane and use aerobic respiration to generate adenosine triphosphate (ATP)—the fuel that provides the energy for the cell. Eukaryotes belong to one of four types: plants, animals, fungi and protists.

Prior research has shown that there are eukaryotes that have devolved mitochondria to the point that they have none—generally because they get their energy elsewhere. Such creatures are able to gather energy by absorbing nutrients directly from another creature that does have functioning mitochondria—several have been found in the human gut, for example.

For this new research, the team studied eukaryote evolution in metamonads, a type of microscopic eukaryote. They collected specimens from various locations and studied them in their lab. They found five that caught their eye: three found in salty soda lake sediment beds and two in shallow ocean sediments.

One stood out clearly from the other four due to its complete lack of mitochondria. They named it Skoliomonas litria and noted that it was the first-ever finding of a free-living eukaryote to have lost its mitochondria. They also note that more work is required to determine how the creature makes its ATP without using oxygen.

Shelby K. Williams et al, Extreme mitochondrial reduction in a novel group of free-living metamonads, Nature Communications (2024). DOI: 10.1038/s41467-024-50991-w

Crystal coating keeps clothes feeling cool

Wouldn’t it be nice if your clothes could keep you as cool as your A/C? This new, durable fabric coating can cool the wearer by up to 15 degrees Fahrenheit without using any additional energy, thanks to special crystals that reflect both infrared and ultraviolet light.

“Functional reflective textile coatings for personal cooling” Presented at ACS Fall 2024 on Aug. 21, 2024

The Wow! Signal deciphered—it was hydrogen all along, study says

In 1977, astronomers received a powerful, peculiar radio signal from the direction of the constellation Sagittarius. Its frequency was the same as neutral hydrogen, and astronomers had speculated that any ETIs attempting to communicate would naturally use this frequency. Now the signal, named the WOW! Signal has become lore in the SETI world.

The signal has another name: 6EQUJ5. This has been interpreted as a message hidden in the signal, but it really represents how the signal's intensity varied over time.

The signal generated a lot of excitement. Some thought it was extraterrestrial in origin, some thought it could come from some type of human-generated interference, and some thought it could be from an unexplained natural phenomenon.

New research shows that the Wow! Signal has an entirely natural explanation.

The research is titled "Arecibo Wow! I: An Astrophysical Explanation for the Wow! Signal." The lead author is Abel Méndez from the Planetary Habitability Laboratory at the University of Puerto Rico at Arecibo. It's available on the preprint server arXiv.

The latest observations, made between February and May 2020, have revealed similar narrowband signals near the hydrogen line, though less intense than the original Wow! Signal

Researchers detected signals similar to the Wow! signal but with some differences. They're far less intense and come from multiple locations. The authors say these signals are easily explained by an astrophysical phenomenon and that the original Wow! signal is too.

Part 1

The researchers hypothesize that the Wow! Signal was caused by sudden brightening from stimulated emission of the hydrogen line due to a strong transient radiation source, such as a magnetar flare or a soft gamma repeater (SGR)," they write. Those events are rare and rely on precise conditions and alignments. They can cause clouds of hydrogen to brighten considerably for seconds or even minutes.

The researchers say that what Big Ear saw in 1977 was the transient brightening of one of several H1 (neutral hydrogen) clouds in the telescope's line of sight. The 1977 signal was similar to what the researchers saw now in many respects. The only difference between the signals observed now and the Wow! Signal is their brightness. It is precisely the similarity between these spectra that suggests a mechanism for the origin of the mysterious signal," the authors write.
These signals are rare because the spatial alignment between source, cloud, and observer is rare. The rarity of alignment explains why detections are so rare.
The new hypothesis explains all observed properties of the Wow! Signal, proposes a new source of false positives in technosignature searches, and suggests that the Wow! Signal could be the first recorded event of an astronomical maser flare in the hydrogen line," the authors explain in their conclusion.

 Abel Méndez et al, Arecibo Wow! I: An Astrophysical Explanation for the Wow! Signal, arXiv (2024). DOI: 10.48550/arxiv.2408.08513

This simple schematic shows how the Wow! Signal was generated and detected. A radiative source such as a magnetar or a soft gamma repeater is positioned behind a cloud of cold neutral hydrogen. Energy from the source stimulates emission from the HI cloud, which brightens abruptly and is observable from Earth. Credit: arXiv (2024). DOI: 10.48550/arxiv.2408.08513

Part 3

Researchers train a robot dog to combat invasive fire ants

A multidisciplinary research team based across China and Brazil has used a dog-like robot and AI to create a new way to find fire ant nests. Published in the journal Pest Management Science, the study highlights how a "CyberDog" robot integrated with an AI model can automate the identification and control of Red Imported Fire Ants (RIFA), a globally destructive pest.

Field tests carried out by the researchers reveal the robotic system can significantly outperform human inspectors, identifying three times more RIFA nests with greater precision.

Fire ant nests are difficult for untrained personnel to identify and confirm in the field, and searching large areas can be time-consuming and exhausting under the hot sun. A robot could automatically locate the nests without requiring specially trained individuals and operate at various times of the day regardless of temperature conditions.

They conducted rigorous field tests to measure the system's effectiveness. The CyberDog was programmed to press the nest with its front paw: when a fire ant nest mound is disturbed, the workers will rush out from cracks and openings displaying aggressive behavior. This, the researchers said, is key for diagnosing active mounds from abandoned nests, and to avoid false positives with mounds inhabited by other species.

The implementation of robotic dogs in automatic detection and surveillance of red imported fire ant nests, Pest Management Science (2024). DOI: 10.1002/ps.8254

Self-repairing mitochondria use novel recycling system, study finds

Mitochondria depend on a newly discovered recycling mechanism identified by scientists.

Mitochondria are tiny structures inside of cells that carry out a wide range of critical functions, including generating energy to help keep cells healthy. Every mitochondrion has two layers of membranes: the outer membrane and the inner membrane. On the inner membrane, folds called cristae contain proteins and molecules needed for energy production. When cristae are damaged, there can be a negative impact on an entire cell.

This new research work  shows, for the first time, that mitochondria are able to recycle a localized injury, removing damaged cristae, and then function normally afterward.

In addition to being essential to keeping mitochondria healthy, the research team thinks this mechanism could present a future target for the diagnosis and treatment of conditions characterized by mitochondrial dysfunction, including infection, fatty liver disease, aging, neurodegenerative conditions and cancer.

In cells, structures called lysosomes act as recycling centers that can digest different kinds of molecular material. With state-of-the art microscopes the researchers  identified that a mitochondria's damaged crista can squeeze through its outer membrane to have a lysosome directly engulf it and break it down successfully.

The researchers named the novel process VDIM formation, which stands for vesicles derived from the inner mitochondrial membrane. By removing damaged cristae through VDIMs, cells can prevent harm from spreading to the rest of the mitochondria and the whole cell.

Forming a VDIM involved several steps and molecules.

First, a damaged crista releases a signal that activates a channel on the nearby lysosome to allow calcium to flow out of the lysosome.

Calcium then activates another channel on the outer membrane of the mitochondria to form a pore and allow damaged cristae to squeeze out of the mitochondria into the lysosome, which digests the damaged material—something that has never been seen before. By recycling just the damaged crista, mitochondria can continue its regular function.

Understanding this process gives us insight into how mitochondria stay healthy, which is important to everyone's overall health and longevity.

Nicola Jones et al, Lysosomes drive the piecemeal removal of mitochondrial inner membrane, Nature (2024). DOI: 10.1038/s41586-024-07835-w. www.nature.com/articles/s41586-024-07835-w

Bacteria make thermally stable plastics similar to polystyrene and PET for the first time

Bioengineers around the world have been working to create plastic-producing microbes that could replace the petroleum-based plastics industry. Now, researchers  have overcome a major hurdle: getting bacteria to produce polymers that contain ring-like structures, which make the plastics more rigid and thermally stable.

Because these molecules are usually toxic to microorganisms, the researchers had to construct a novel metabolic pathway that would enable the E. coli bacteria to both produce and tolerate the accumulation of the polymer and the building blocks it is composed of.

The resulting polymer is biodegradable and has physical properties that could lend it to biomedical applications such as drug delivery, though more research is needed. The results are presented August 21 in Trends in Biotechnology.

Microbial Production of an Aromatic Homo-Polyester, Trends in Biotechnology (2024). DOI: 10.1016/j.tibtech.2024.06.001

Human-wildlife overlap expected to increase across more than half of land on Earth by 2070

As the human population grows, more than half of Earth's land will experience an increasing overlap between humans and animals by 2070, according to a new study by scientists.

Greater human-wildlife overlap could lead to more conflict between people and animals, say the researchers. But understanding where the overlap is likely to occur—and which animals are likely to interact with humans in specific areas—will be crucial information for urban planners, conservationists and countries that have pledged international conservation commitments. Their findings are published in Science Advances.

They found that the overlap between populations of humans and wildlife will increase across about 57% of the global lands, but it will decrease across only about 12% of the global lands. They  also found that agricultural and forest areas will experience substantial increases of overlap in the future.

The study showed that the human-wildlife overlap will be driven by human population growth rather than climate change. That is, the increase in people settling in previously undeveloped areas will drive the overlap rather than climate change, causing animals to shift where they live.

In many places around the world, more people will interact with wildlife in the coming decades and often those wildlife communities will comprise different kinds of animals than the ones that live there now.

This means that all sorts of novel interactions, good and bad, between people and wildlife will emerge in the near future.

Deqiang Ma et al, Global Expansion of Human-Wildlife Overlap in the 21st Century, Science Advances (2024). DOI: 10.1126/sciadv.adp7706. www.science.org/doi/10.1126/sciadv.adp7706

Study discovers an electric current in the gut that attracts pathogens like Salmonella
How do bad bacteria find entry points in the body to cause infection? This question is fundamental for infectious disease experts and people who study bacteria. Harmful pathogens, like Salmonella, find their way through a complex gut system where they are vastly outnumbered by good microbes and immune cells. Still, the pathogens navigate to find vulnerable entry points in the gut that would allow them to invade and infect the body.

A team of researchers has discovered a novel bioelectrical mechanism these pathogens use to find these openings. Their study was published  in Nature Microbiology.

Salmonella cause  several illnesses and  deaths in the world every year. To infect someone, this pathogen needs to cross the gut lining border.

When ingested, Salmonella find their way to the intestines. There, they are vastly outnumbered by over 100 trillion good bacteria (known as commensals). They are facing the odds of one in a million. But still they can infect people. 

The intestine has a very complex landscape. Its epithelial structure includes villus epithelium and follicle-associated epithelium (FAE). Villus epithelium is made of absorptive cells (enterocytes) with protrusions that help with nutrient absorption.

FAE, on the other hand, contains M cells overlying small clusters of lymphatic tissue known as Peyer's patches. These M cells are tasked with antigen sampling. They act as the immune system's first line of defense against microbial and dietary antigens.

Part 1

The research that was done on a mouse model showed that Salmonellae detect electric signals in FAE. They move toward this part of the gut where they find openings through which they can enter. This process of cell movement in response to electric fields is called galvanotaxis, or electrotaxis.

This study found that this 'entry point' has electric fields that the Salmonella bacteria take advantage of to pass.

The study also showed that E. coli and Salmonella respond differently to bioelectric fields. They have opposite responses to the same electric cue. While E. coli clustered next to the villi, Salmonella gathered to FAE.

The study detected electric currents that loop by entering the absorptive villi and exiting the FAE.

Notably, the bioelectric field in the gut epithelia is configured in a way that Salmonellae take advantage of to be sorted to the FAE and less so for E. coli. The pathogen seems to prefer the FAE as a gateway to invade the host and cause infections.

Previous studies have indicated that bacteria use chemotaxis to move around. With chemotaxis, the bacteria sense chemical gradients and move towards or away from specific compounds. But the new study suggests that the galvanotaxis of Salmonella to the FAE does not occur through chemotaxis pathways.

The study might have the potential to explain complex chronic diseases, such as inflammatory bowel disease (IBD).

This mechanism represents a new pathogen-human body 'arms race' with potential implications for other bacterial infections as well as prevention and treatment possibilities. It is thought that the root cause of IBD is an excessive and abnormal immune response against good bacteria. It will be interesting to learn whether patients prone to have IBD also have aberrant bioelectric activities in gut epithelia.

Yao-Hui Sun et al, Gut epithelial electrical cues drive differential localization of enterobacteria, Nature Microbiology (2024). DOI: 10.1038/s41564-024-01778-8

Part 2

Study finds 'DNA scavengers' can stop some antibiotic resistance from spreading

For nearly a century, scientists have waged war on antibiotic-resistant microbes. Researchers now found a new way to prevent it—by unleashing "DNA scavengers" in wastewater treatment plants.

They found an enzyme that breaks up strands of antibiotic-resistant DNA floating in wastewater before bacteria can pick them up and take on their antibiotic-resistant properties. 

This could be a powerful, environmentally friendly tool to control the spread of antibiotic resistance in wastewater and help keep antibiotics effective.

But as with any new discovery, there is more work to be done to optimize the technology.

Yang Li et al, Engineered DNA scavenger for mitigating antibiotic resistance proliferation in wastewater treatment, Nature Water (2024). DOI: 10.1038/s44221-024-00289-4

Mechanism for removing dead cells identified

Billions of our cells die every day to make way for the growth of new ones. Most of these goners are cleaned up by phagocytes—mobile immune cells that migrate where needed to engulf problematic substances. But some dying or dead cells are consumed by their own neighbors, natural tissue cells with other primary jobs. How these cells sense the dying or dead around them has been largely unknown till now.

Now researchers from The Rockefeller University have shown how a sensor system operates in hair follicles, which have a well-known cycle of birth, decay, and regeneration put into motion by hair follicle stem cells (HFSCs). In a new study published in Nature, they demonstrate that a duo of sensors works in tandem to pick up signals from both dying and living HFSCs, removing debris before tissue damage can occur and ceasing operation before healthy cells are consumed.

The system is seemingly spatially tuned to the presence of corpses, and it only functions when each receptor picks up the signal is attuned to. If one of them disappears, the mechanism stops operating. It's a really beautiful way to keep the area clean without consuming healthy cells.

By diverting their attention towards eating their dying neighbors, HFSCs keep inflammation-generating immune cells away. They also likely benefit from these extra calories, but as soon as the debris is cleared, they must quickly return to their jobs of maintaining the stem cell pool and making the body's hair.

Part 1

To initiate the process, hair follicle stem cells (HFSCs), located in the "bulge" of the follicle's upper root sheath, signal to epithelial and mesenchymal cells, sparking growth. This stage takes its time, lasting from two to six years.

The destructive, or catagen, stage that follows is brief but intense, obliterating about 80% of the hair follicle in just a few weeks. The process begins at the follicle base and works its way upwards towards the HFSC niche. The result is a mass of dying and dead cells that need removal to prevent the resulting decay from triggering inflammatory or autoimmune responses.

Normally, this would be the job of phagocytes like macrophages, but few are found in the hair follicle, meaning they must fall to local epithelial cells to keep things tidy.

 Elaine Fuchs, Stem cells tightly regulate dead cell clearance to maintain tissue fitness, Nature (2024). DOI: 10.1038/s41586-024-07855-6. www.nature.com/articles/s41586-024-07855-6

Part 2

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Mother's gut microbiome during pregnancy shapes baby's brain development, mouse study finds

A study in mice has found that the bacteria Bifidobacterium breve in the mother's gut during pregnancy supports healthy brain development in the fetus. The results are published in the journal Molecular Metabolism.

Researchers have compared the development of the fetal brain in mice whose mothers had no bacteria in their gut, to those whose mothers were given Bifidobacterium breve orally during pregnancy, but had no other bacteria in their gut.

Nutrient transport to the brain increased in fetuses of mothers given Bifidobacterium breve, and beneficial changes were also seen in other cell processes relating to growth.

Bifidobacterium breve is a 'good bacteria' that occurs naturally in our gut, and is available as a supplement in probiotic drinks and tablets.

Obesity or chronic stress can alter the gut microbiome of pregnant women, often resulting in fetal growth abnormalities. The babies of up to 10% of first-time mothers have low birth weight or fetal growth restriction. If a baby hasn't grown properly in the womb, there is an increased risk of conditions like cerebral palsy in infants and anxiety, depression, autism, and schizophrenia in later life.

These results suggest that improving fetal development—specifically fetal brain metabolism—by taking Bifidobacterium breve supplements while pregnant may support the development of a healthy baby.

Previous work by the same team of researchers found that treating pregnant mice with Bifidobacterium breve improves the structure and function of the placenta. This also enables a better supply of glucose and other nutrients to the developing fetus and improves fetal growth.

Although further research is needed to understand how these effects translate to humans, this exciting discovery may pave the way for future clinical studies that explore the critical role of the maternal microbiome in supporting healthy brain development before birth.

Jorge Lopez-Tello et al, Maternal gut Bifidobacterium breve modifies fetal brain metabolism in germ-free mice, Molecular Metabolism (2024). DOI: 10.1016/j.molmet.2024.102004

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How much does your phone's blue light really delay your sleep? Relax, it's just 2.7 minutes!

It's one of the most pervasive messages about technology and sleep. We're told bright, blue light from screens prevents us falling asleep easily. We're told to avoid scrolling on our phones before bedtime or while in bed. We're sold glasses to help filter out blue light. We put our phones on "night mode" to minimize exposure to blue light.

But what does the science actually tell us about the impact of bright, blue light and sleep? When a group of sleep experts from Sweden, Australia and Israel compared scientific studies that directly tested this, they   found the overall impact was close to meaningless. Sleep was disrupted, on average, by less than three minutes.

Scientists showed the message that blue light from screens stops you from falling asleep is essentially a myth, albeit a very convincing one.

Instead, they found a more nuanced picture of technology and sleep.

https://www.sciencedirect.com/science/article/pii/S1087079224000376...

Part 1

The blue light theory involves melatonin, a hormone that regulates sleep. During the day, we are exposed to bright, natural light that contains a high amount of blue light. This bright, blue light activates certain cells at the back of our eyes, which send signals to our brain that it's time to be alert. But as light decreases at night, our brain starts to produce melatonin, making us feel sleepy.

It's logical to think that artificial light from devices could interfere with the production of melatonin and so affect our sleep. But studies show it would require light levels of about 1,000–2,000 lux (a measure of the intensity of light) to have a significant impact.

Device screens emit only about 80–100 lux. At the other end of the scale, natural sunlight on a sunny day provides about 100,000 lux.

We know that bright light does affect sleep and alertness. However, research indicates the light from devices such as smartphones and laptops is nowhere near bright or blue enough to disrupt sleep.
There are many factors that can affect sleep, and bright, blue screen light likely isn't one of them.

Part 2

‘Dark Oxygen’ Is Coming from These Ocean Nodules

Micro- and nanoplastics ingested by Drosophila cause changes in heart size and function

Plastics are ubiquitous in products we use every day, and recent studies have begun to reveal the effects of micro- and nanoplastics (MPs and NPs) on the health of humans and animals.

Much research on the health effects of MPs and NPs to date has focused on marine life, especially fish. A few early studies have investigated possible toxic effects of plastics on terrestrial species such as birds, earthworms, insects, humans and other mammals, but myriad specifics remain unknown.

A team of researchers from Iowa State University, using fruit flies (Drosophila melanogaster), has now made the first examination of the effects of MP and NP toxicity on the heart. The team's work is published in a Brief Research Report in Frontiers in Toxicology.

Drosophila hearts and vertebrate hearts are similar with respect to functional and genetic changes during development and aging. For this new study, the researchers obtained wild-type Drosophila fly larvae and divided them into a control group and two test groups.
They fed all the flies a diet of cornmeal from the beginning of their development until they reached maturity (pupation). Flies in the two test groups received cornmeal to which the researchers added polystyrene MPs (larger than 100 nm and smaller than 5 mm) or NPs (smaller than 100 nm).

Five days after the flies hatched, the researchers collected approximately 15 flies of each sex from each of the two test groups and the control group. The team anesthetized the flies, dissected their beating hearts, and recorded high-speed video at over 200 frames/second for analysis.

Among the notable results, the analysis indicates that plastic exposure produces different results in males and females. The heart rates of female flies exposed to both MPs and NPs decreased 13%, while their heart periods (time between the beginning of a heartbeat and the beginning of the next heartbeat) increased correspondingly. Male flies did not exhibit this change, but males fed MPs exhibited greater variability than those fed NPs and those in the control group.
Part 1

In female flies fed NPs, heart size (diastolic diameter) increased, and diastolic intervals increased in females fed both MPs and NPs. Meanwhile, heart sizes of male flies fed both sizes of plastic exhibited significant changes to diastolic and systolic diameters.

Furthermore, the researchers write, "Unlike females, male flies also see changes to Systolic Interval (SI) Time and fractional shortening. Total SI time is reduced by 40% in flies exposed to MPs while female flies see no change. Finally, males exposed to NPs experience an 11% reduction in fractional shortening. This phenomenon is unique to males, as females see no change to fractional shortening following dietary exposure to either plastic size."
The researchers note that they had initially hypothesized that the changes they recorded might have resulted from MPs and NPs actually creating a physical barrier to normal heart development. They also believe that "molecular interactions between the plastics and the heart itself" are responsible for the sexually dimorphic changes they observed, especially the differences in male and female heart sizes.

However, they acknowledge, "The true mechanism behind these observed changes is unknown, and so further research is needed to identify if exposure to MPs and NPs interacts with any mammalian conserved genes which may lead to cardiac dysfunction."
They also suggest that further research could include a variety of ingestible plastic shapes, and that further research should also focus on pinpointing the specific molecular changes causing the observed functional disorders.

 Alyssa M. Hohman et al, The heart of plastic: utilizing the Drosophila model to investigate the effects of micro/nanoplastics on heart function, Frontiers in Toxicology (2024). DOI: 10.3389/ftox.2024.1438061

Part 2

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Faulty gene makes the brain too big—or too small

A gene called ZNRF3, known to be involved in cancer, also messes with the mind. The human brain relies on two copies of this gene to build a correctly sized brain. If one of the copies is defective, the brain will be either too small or too large—known as mirror effect—leading to various neurological symptoms.

Scientists tested the faulty versions of the gene in the lab and found a correlation between patients' brain size and the location of the mutations in the gene. After a long diagnostic odyssey, they were finally able to establish a definitive cause for the disease of these patients. Their study is published in the American Journal of Human Genetics.

The gene ZNRF3 produces two copies of a protein that prevents the brain from making too many or too few brain cells. It also does the same in many other organs, so that mutations in its DNA sequence can lead to uncontrolled cell proliferation and are therefore associated with a variety of tumors, such as colon or adrenal cancer.

One of their analyses revealed that there is a small region of the ZNRF3 gene, called RING, where many mutations found in cancers are located compared to the rest of the gene. In fact, most of the patients with abnormally large brains have their mutations in the RING region. This means that they may have an increased risk of developing tumors during their lifetime.

Further analyses showed that almost all the mutations that lead to abnormal development are located in two distinct regions of the gene: one in the RING region, and the other in a smaller region that is important for interacting with another gene called RSPO. It turned out that almost all the defects in the RING region were from the patients with an abnormally large brain, while the defect in the RSPO-interacting region came from the patient with an abnormally small brain.

However, one patient had a fault in the RING region but had an abnormally small brain. We traced his family history and found that his mother used drugs heavily during her pregnancy, which could explain his abnormally small—instead of large—brain. Apparently, environmental influences can override genetic defects in this condition.

The gene ZNRF3 orchestrates the perfect balance of biochemical signals, particularly in the Wnt signaling pathway, needed to produce the right number of brain cells. This gene works in concert with the gene RSPO, which also interacts with the Wnt signaling.

These results showed that the right brain size depends on a balanced Wnt signaling, which, once tipped toward too much or too little, can cause the brain to become too large or too small.

 Paranchai Boonsawat et al, Deleterious ZNRF3 germline variants cause neurodevelopmental disorders with mirror brain phenotypes via domain-specific effects on Wnt/β-catenin signaling, The American Journal of Human Genetics (2024). DOI: 10.1016/j.ajhg.2024.07.016

This desert school's unique design offers respite from heat

In the sweltering heat of India's Thar desert, where summer highs soar above 50 degrees Celsius, an architecturally striking school is an oasis of cool thanks to a combination of age-old techniques and modern design.

The school used the same yellow sandstone as the 12th-century fort in nearby Jaisalmer, in India's western state of Rajasthan, dubbed the "golden city" due to the colour of the rock.

Like the fort, the school has thick rubble walls that help bounce back the heat, while the interior is plastered with lime, a porous material that regulates humidity and aids natural cooling.
Unlike the ancient fort, its roof is lined with solar panels, which provide all the school's power in an area with frequent electricity cuts.

Temperatures inside the school, designed by US-based architect Diana Kellogg and built by local artisans—many of them parents of pupils—can be as much as 20 percent lower than those outside.

The air inside feels as if it is coming from an AC.

Elevated windows allow hot air to escape as it rises. Rainwater is harvested from the flat roof.

In some places, the walls are dotted with perforations—a technique known as "jali" that was traditionally used for modesty, shielding women from view in the conservative society.

At the school, it is used to promote ventilation, creating a breeze channeled by the building's oval shape.

There is cross-ventilation. And the white tiles on the terrace reflect the sunlight.

Combining tradition with modern design and sustainable techniques was key for this 'cool school'.

Colorful traits in primates ease tensions between groups, data suggest

Primate ornamentation plays a crucial role in communication not only within social groups but also between them, according to a new study. The research, published in Evolution Letters, reveals that the males of species with overlapping home ranges often display vibrant colors or elaborate features, traits that may help reduce intergroup aggression by enabling quick assessment of potential rivals.

Ornaments are sexually selected traits that serve as powerful signals, often indicating an individual's genetic quality, health or physical strength.

These differences in appearance between males and females, known as dimorphic traits, are expressed in features like colorful fur or elaborate body structures. Examples include the golden snub-nosed monkey's lip wart and blueish face, the mandrill's vivid facial features with its red nose and blue skin, the gelada baboon's impressive mane and red chest patch, or the proboscis monkey's remarkably large nose.

A new study has uncovered an intriguing link between these dimorphic traits and how primates interact with other groups.

The researchers analyzed data from 144 primate species, including both monkeys and apes (prosimians and anthropoids). They focused on how ornamentation relates to the overlap of home ranges, which measures how much living space groups share with their neighbours.

The research shows that the vibrant colours  and elaborate body ornaments seen in many primate species may do more than attract mates or establish social hierarchies. These features also play an important role in communication between different social groups.

The findings showed a clear pattern: "Species that shared more space with their neighbors had significantly greater differences in ornamentation between the sexes. In species where groups frequently interact, males are more likely to sport flashy traits that set them apart from females."

The study also found that intergroup encounters were less likely to be aggressive in species with greater home range overlap. Encounters deemed conflict-related included behaviors such as physical confrontation, displays of strength, avoidance, displacement, vigilance and vocal warnings.

This suggests that vivid physical traits might help to reduce conflict between groups, possibly by allowing them to quickly assess potential rivals from a distance.

The study sheds new light on the evolution of primate ornamentation and provides valuable insights into the complex world of animal communication.

Cyril C Grueter et al, The role of between-group signaling in the evolution of primate ornamentation, Evolution Letters (2024). DOI: 10.1093/evlett/qrae045