Biological clocks in nature

Much of what we know about plant circadian rhythms is the result of laboratory experiments where inputs such as light and temperature can be tightly controlled.

Less is known about how these biological timing mechanisms operate in the more unpredictable natural world where they evolved to align living things to daily and seasonal cycles.

A pioneering collaborative study between  researchers has helped redress the balance with a series of innovative field experiments that show how plants combine clock signals with environmental cues under naturally fluctuating conditions.

 This research team has produced statistical models based on these field-based studies that could help us predict how plants, major crops among them, might respond to future temperatures.

In this present study, "Circadian and environmental signal integration in a natural population of Arabidopsis," which appears in PNAS, the research team set out to identify this mechanism in nature.

In two field studies around the March and September equinoxes, they analyzed a natural population of Arabidopsis halleri plants on a rural Japanese field site. They monitored how gene expression in the plants changed over 24-hour cycles as light and temperature varied.

Experiments involved extracting RNA from plants every two hours, freezing these samples and taking them back to the lab for analysis so that they could track gene expression levels in tissues.

Using the information collected from samples, the researchers observed patterns in the expression of genes in the previously discovered genetic pathway that integrates information from the plant circadian clock with light and temperature signals.

The data collected showed that the plants in wild populations showed the same sensitivity to cold and bright dawn conditions previously observed in laboratory experiments.

Based on this information, the team developed statistical models which accurately predict how gene expression activity under control of the circadian clock will respond to environmental signals over a day in nature.

This is the first time anyone has modeled a whole circadian clock signaling pathway in plants growing outdoors.

If we can produce models that can accurately predict gene expression in relation to environmental conditions, then it may be possible to breed plants that are able to adapt to future climate conditions.

Haruki Nishio et al, Circadian and environmental signal integration in a natural population of Arabidopsis, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2402697121

Yeast meiosis study finds temperature changes result in shorter meiotic chromosome axes and more crossovers

In a study of meiosis in budding yeast, a research team found that yeast senses temperature changes by increasing the level of DNA negative supercoils to increase crossovers and modulate chromosome organization during meiosis.

Meiosis is a specialized cell division producing gametes with the half chromosome complement of their progenitor cells. Meiotic crossovers between homologous (maternal and paternal) chromosomes, which result in the reciprocal exchange of chromosome fragments, play two important roles: physically holding the homologous chromosomes together to ensure their proper segregation, and promoting the genetic diversity of their progeny.

The formation of crossovers is regulated by the architecture of meiotic chromosomes, each of which is organized as a linear array of loops anchored at their bases to a proteinaceous axis.
The researchers studied yeast meiosis, and found that changes in temperature (either decreased or increased) resulted in shorter meiotic chromosome axes and more crossovers. The research teams further found that temperature changes coordinately enhanced the hyperabundant distribution of axis proteins (such as Red1 and Hop1) on chromosomes and the number of putative crossover marker Zip3 foci.

Importantly, temperature-induced changes in the distribution of axis proteins and Zip3 foci depend on changes in DNA negative supercoils, which have been shown to regulate the number of crossovers. In addition, temperature changes regulate the abundance of axis-associated proteins and thus axis length, independently of changes in DNA negative supercoils.

These results suggest that yeast meiosis senses temperature changes by increasing the level of DNA negative supercoils to increase the number of crossovers and modulate chromosome organization. These findings provide a new perspective on understanding the effect and mechanism of temperature on meiotic crossovers and chromosome organization, with important implications for evolution and breeding.

: Yingjin Tan et al, Temperature regulates negative supercoils to modulate meiotic crossovers and chromosome organization, Science China Life Sciences (2024). DOI: 10.1007/s11427-024-2671-1

Even mild concussions can have lifelong brain impacts

A team of neuroscientists, brain specialists and psychiatrists has found evidence suggesting that minor brain injuries that occur early in life, may have health impacts later on.

In their paper published in the journal JAMA Network Open, the group describes how they analyzed and compared MRI scans from hundreds of people participating in the U.K.'s Prevent Dementia study.
Prior research has suggested that some forms of dementia could be related to some types of brain injuries. In this new effort, the research team, hoping to learn more about the impact of concussions or other minor brain injuries on dementia, looked at MRI scans of 617 people between the ages of 40 to 59 who had volunteered to take part in the Prevent Dementia study and who had undergone at least three MRI scans. They also studied their medical histories, focusing most specifically on whether they had had brain injuries anytime during their life.

The research team noted that 36.1% of the volunteers reported having experienced at least one brain injury that was serious enough to have caused them to be unconscious for a short period of time—such injuries are classified as traumatic brain injuries (TBIs).

Looking at the MRI scans, the researchers found higher than normal instances of cerebral microbleeds (1 in 6 of them) and other symptoms of what they describe as evidence of small vessel disease of the brain. They also found that those patients with at least one TBI were more likely to smoke cigarettes, had more sleep problems, were more likely to have gait issues and to suffer from depression. They also noted that the more TBIs a person had, the more such problems became apparent.

Another thing that stood out, the team notes, was that those people who had experienced a TBI when younger had a higher risk of memory problems than did patients with cardiovascular disease, high blood pressure or diabetes, a possible clue about their likelihood of developing dementia.

Audrey Low et al, Neuroimaging and Clinical Findings in Healthy Middle-Aged Adults With Mild Traumatic Brain Injury in the PREVENT Dementia Study, JAMA Network Open (2024). DOI: 10.1001/jamanetworkopen.2024.26774

Researchers identify piRNAs as a highly relevant genetic cause of male infertility

Many couples struggle with infertility. Contrary to popular belief, men are just as often the cause of an unfulfilled desire for children as women—and genetics play a significant role in this. Researchers from the Institute of Reproductive Genetics at the University of Münster have now provided new insights on this topic.

The study, published in Nature Communications, shows for the first time that disruptions in the so-called piRNA pathway are an underestimated cause of defective sperm production.

RNA, short for ribonucleic acid, is a single-stranded molecule composed of nucleotides present in every cell of an organism and acts as a carrier of genetic information. PiRNA refers to specialized, very small RNA fragments found in the testes that help suppress the activity of transposons, also known as jumping genes. 

The researchers analyzed the DNA of more than 2,000 infertile men, mostly from the Münster Center for Reproductive Medicine and Andrology, for variations in piRNA pathway genes.

They identified 39 men with variations in 14 piRNA genes, many of which are reported  for the first time.  Their findings reveal that faulty regulation of piRNAs is a far more common cause of male infertility than previously recognized.

The impact of these genetic variants on sperm production differed between humans and mouse models, suggesting that findings from mice are not universally applicable to humans. In some patients with piRNA variants, an increased number of transposons was detected.

A higher count of jumping genes in germ cells causes genomic instability, leading to various disruptions in sperm production, from abnormal shapes to complete absence of sperm.

While the newly discovered disruptions in the piRNA pathway cannot yet be treated, these insights will help provide more men with an accurate diagnosis in the future—offering relief to many who have faced years of uncertainty and allowing for more targeted treatments.

Birgit Stallmeyer et al, Inherited defects of piRNA biogenesis cause transposon de-repression, impaired spermatogenesis, and human male infertility, Nature Communications (2024). DOI: 10.1038/s41467-024-50930-9

Smallpox vaccination in childhood could offer protection against monkeypox clade II viruses, study finds

A study by co-authors from the ECDC, WHO and national public health institutes in four European countries, and published in Eurosurveillance, has found that prior smallpox vaccination in childhood could protect against infections caused by monkeypox virus (MPXV) clade II in men. However, the estimated degree of protection varied among countries, highlighting the need for further research to validate the study findings.

The study findings suggest that historical childhood smallpox vaccination in a European setting could protect two-thirds of men against mpox caused by MPXV clade II. However, there was significant uncertainty in the results and variation between countries. The results of this study are therefore not sufficient to support differential smallpox vaccination to protect against mpox based on historical smallpox vaccination status or age.

The authors recommend that individuals with a high risk of exposure be offered mpox vaccination, regardless of vaccination history.

 Effectiveness of historical smallpox vaccination against mpox clade II in Denmark, France, the Netherlands and Spain, 2022, Eurosurveillance (2024). DOI: 10.2807/1560-7917.ES.2024.29.34.2400139. www.eurosurveillance.org/conte … S.2024.29.34.2400139

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Mathematicians Prove Hawking Wrong About the Most Extreme Black Holes

The trick the sellers play:Why orange netting packaging makes oranges look more appealing

People who shop for groceries at their local supermarket may have noticed that some of the fruit they purchase may not look the same at home as it did in the store—or more specifically, after it is removed from its packaging. This is due to what has come to be known as the "confetti illusion"—in which pieces of coloured material partially obstructing the view of an image can change the way our brain processes its colouring.

Karl Gegenfurtner, a psychologist at Giessen University, in Germany, has found that the "confetti illusion" used by fruit sellers and others to push products is due to a perceptual illusion that involves the way our brains are programmed to interpret visual information. In his paper published in the journal i-Perception, he describes a brain phenomenon called color assimilation and how it contributes to optical illusions.

Food growers learned a long time ago that if they packed oranges in orange netting, the oranges inside look more orange, which the mind interprets as a more luscious ripe fruit. The same thing is true for yellow netting for lemons and green netting for limes. The color of the fruit as seen between the plastic netting is altered by what Gegenfurtner describes as colour assimilation.

This could be explained by prior research showing that sensory stimuli are always made up of partial information—the things we see are assembled into images only after the brain has knitted together input from several sources. When we look at an ordinary sidewalk, for example, we may perceive different images depending on ambient temperature, scents like recently mowed grass, or even the leftover residue in our mouths from our latest meal. 

By posting pictures of human faces with colored bars drawn across their faces in his paper, Gegenfurtner demonstrates that the change in fruit color is not due to the way light reflects off the netting. Because the images are 2D, there is no chance of colors from the bars reflecting off the imagery under them, yet the skin color and tone of the person behind them seems to change anyway.

Karl R. Gegenfurtner, Perceptual ripening of oranges, i-Perception (2024). DOI: 10.1177/20416695241258748

A new compound shows great potential for patients with neutrophil-associated inflammation

A newly developed compound that reduces harmful inflammation caused by overactive neutrophils in rats shows great potential as a safer treatment for various inflammatory diseases in humans.

Neutrophils are the most abundant type of white blood cells in the human body, and they play a crucial role in immune response. These immune cells help fight infections by engulfing pathogens and releasing enzymes that kill the invaders.

But although they're essential for fighting infections, neutrophils can also become overactive, leading to various inflammatory diseases. When they are activated by infection, neutrophils can release neutrophil extracellular traps (NETs), web-like structures consisting of DNA and proteins, which trap and kill pathogens as a part of the normal host defense mechanism. However, too much NET formation can significantly damage tissues, thus contributing to inflammation.

A team of researchers  has investigated a recently-developed drug candidate, MOD06051, which reduces harmful inflammation in rat models by targeting neutrophils. The results of their joint research appear in Nature Communications.

They found that MOD06051 works as a selective inhibitor for Cathepsin C (CatC), a key regulator that activates multiple enzymes inside of neutrophils known as neutrophil serine proteases (NSPs). One such NSP is neutrophil elastase, an enzyme involved in killing pathogens but also an essential factor for NET formation.

The scientists found that inhibiting CatC reduces the active form of neutrophil elastase and decreases the ability of neutrophils to form NETs. Excessive NET formation has been linked to several diseases, including vasculitis, lupus, rheumatoid arthritis, and diabetes.

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When they tested the compound in rats that have a specific type of vasculitis, it decreased the disease severity, which was evident by reduced inflammation and damage in the blood vessels, especially in their kidneys and lungs.
Their findings suggest that CatC inhibition shows promise as a new treatment strategy to reduce neutrophil overactivation and improve conditions in diseases where overactive neutrophils and excessive NET formation play a critical role. This approach differs from current treatments that may have broader immunosuppressive effects.
Current treatments for inflammatory diseases often involve the use of glucocorticoids and immunosuppressive drugs which suppress the immune system's activity as a whole and can lead to secondary immunodeficiency, increasing the risk of opportunistic infections. By specifically targeting the activation of multiple NSPs through CatC inhibition without broadly suppressing the immune system, MOD06051 potentially offers a safer alternative that could reduce the risk of infections and other side effects.

These findings pave the way for further research and clinical trials to evaluate the safety and efficacy of MOD06051 in humans. The team is optimistic that this novel approach holds the promise of providing safer and more effective therapies for patients around the world suffering from a variety of inflammatory diseases, improving their quality of life.

Cathepsin C inhibition reduces neutrophil serine protease activity and improves activated neutrophil-mediated disorders, Nature Communications (2024). DOI: 10.1038/s41467-024-50747-6

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For first time, DNA tech offers both data storage and computing functions

Researchers have demonstrated a technology capable of a suite of data storage and computing functions—repeatedly storing, retrieving, computing, erasing or rewriting data—that uses DNA rather than conventional electronics. Previous DNA data storage and computing technologies could complete some but not all of these tasks.

The paper, titled "A Primordial DNA Store and Compute Engine," appears in the journal Nature Nanotechnology.

In conventional computing technologies, we take for granted that the ways data are stored and the way data are processed are compatible with each other.

But in reality, data storage and data processing are done in separate parts of the computer, and modern computers are a network of complex technologies.

DNA computing has been grappling with the challenge of how to store, retrieve and compute when the data is being stored in the form of nucleic acids.

For electronic computing, the fact that all of a device's components are compatible is one reason those technologies are attractive. But, to date, it's been thought that while DNA data storage may be useful for long-term data storage, it would be difficult or impossible to develop a DNA technology that encompassed the full range of operations found in traditional electronic devices: storing and moving data; the ability to read, erase, rewrite, reload or compute specific data files; and doing all of these things in programmable and repeatable ways.

Now researchers have  demonstrated that these DNA-based technologies are viable, because  they have made one.

The new technology is made possible by recent techniques that have enabled the creation of soft polymer materials that have unique morphologies.

Specifically, the tech developers have created polymer structures that they call dendricolloids—they start at the microscale, but branch off from each other in a hierarchical way to create a network of nanoscale fibers.

This morphology creates a structure with a high surface area, which allows the techies to deposit DNA among the nanofibrils without sacrificing the data density that makes DNA attractive for data storage in the first place.

You could put a thousand laptops' worth of data into DNA-based storage that's the same size as a pencil eraser.

The ability to distinguish DNA information from the nanofibers it's stored on allows us to perform many of the same functions you can do with electronic devices.

We can copy DNA information directly from the material's surface without harming the DNA. We can also erase targeted pieces of DNA and then rewrite to the same surface, like deleting and rewriting information stored on the hard drive. It essentially allows us to conduct the full range of DNA data storage and computing functions. In addition, they found that when we deposit DNA on the dendricolloid material, the material helps to preserve the DNA.

The researchers have demonstrated that the new data storage and computing technology—which they call a "primordial DNA store and compute engine"—is capable of solving simple sudoku and chess problems. Testing suggests that it could store data securely for thousands of years in commercially available spaces without degrading the information-storing DNA.

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What's more, the dendrocolloidal host material itself is relatively inexpensive and easy to fabricate.

 A Primordial DNA Store and Compute Engine, Nature Nanotechnology (2024). DOI: 10.1038/s41565-024-01771-6. www.nature.com/articles/s41565-024-01771-6

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Thyroid hormone fuels the drive to explore by rewiring brain circuits, new study suggests

Thyroid hormone plays a key role in regulating a range of physiologic functions, including metabolism, temperature, heart rate, and growth. It accomplishes this impressive array of activities by interacting with almost every organ system in the body. Yet despite a long history of research on how thyroid hormone influences different organs, its effects on arguably the most crucial organ—the brain—have remained shrouded in mystery.

Now, scientists have gained new insights into thyroid hormone's effects on the brain. The work, conducted in mice and published Aug. 22 in Cell, shows that thyroid hormone changes the wiring of brain circuits in a manner that drives animals to engage in exploratory behaviour. 

By simultaneously changing brain wiring and altering metabolic rate, the researchers concluded that thyroid hormone coordinates the brain and body to produce exploratory behavior when it is most needed—for example, during seasons when animals need to find mates or stockpile resources.

It's well known that thyroid hormone modulates metabolism, and now scientists have shown that it also modulates exploratory behaviours through direct action on the brain.

The findings also help elucidate how low levels of the hormone could lead to depressive states marked by a low desire to explore, while too much could precipitate manic states characterized by an extreme desire for exploration. Thus, the researchers see their work as an important step toward understanding how aberrant levels of thyroid hormone could contribute to certain psychiatric conditions.

Daniel Hochbaum et al, Thyroid hormone remodels cortex to coordinate body-wide metabolism and exploration, Cell (2024). DOI: 10.1016/j.cell.2024.07.041. www.cell.com/cell/fulltext/S0092-8674(24)00835-3

Researchers discover gene scissors that switch off with a built-in timer

CRISPR gene scissors, as new tools of molecular biology, have their origin in an ancient bacterial immune system. But once a virus attack has been successfully overcome, the cell has to recover.

Researchers  have discovered a timer integrated into the gene scissors that enables the gene scissors to switch themselves off. The results of the study have been published in the journal Nucleic Acids Research.

Sophie C Binder et al, The SAVED domain of the type III CRISPR protease CalpL is a ring nuclease, Nucleic Acids Research (2024). DOI: 10.1093/nar/gkae676

Some bacteria have developed CRISPR gene scissors in response to attacks by so-called phages. This bacterial immune system recognizes the phage genetic material, destroys it and thus protects against viral attacks.

When detecting phages, the type III variants of these immune systems produce messenger substances with cyclic oligoadenylates (cOAs), which the bacteria use to switch on a complex emergency plan. This ensures that a virus can be fought optimally and on a broad front.

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Mitochondria are flinging their DNA into our brain cells, study shows

As direct descendants of ancient bacteria, mitochondria have always been a little alien. Now a study shows that mitochondria are possibly even stranger than we thought.

The study, titled "Somatic nuclear mitochondrial DNA insertions are prevalent in the human brain and accumulate over time in fibroblasts," appears in PLOS Biology.

Mitochondria in our brain cells frequently fling their DNA into the nucleus, the study found, where the DNA becomes integrated into the cells' chromosomes. And these insertions may be causing harm: Among the study's nearly 1,200 participants, those with more mitochondrial DNA insertions in their brain cells were more likely to die earlier than those with fewer insertions.
We used to think that the transfer of DNA from mitochondria to the human genome was a rare occurrence. It's stunning that it appears to be happening several times during a person's lifetime.

Researchers now found lots of these insertions across different brain regions, but not in blood cells, explaining why dozens of earlier studies analyzing blood DNA missed this phenomenon.

Mitochondria live inside all our cells, but unlike other organelles, mitochondria have their own DNA, a small circular strand with about three dozen genes. Mitochondrial DNA is a remnant from the organelle's forebears: ancient bacteria that settled inside our single-celled ancestors about 1.5 billion years ago.

In the past few decades, researchers discovered that mitochondrial DNA has occasionally "jumped" out of the organelle and into human chromosomes.

The mitochondrial DNA behaves similar to a virus in that it makes use of cuts in the genome and pastes itself in, or like jumping genes known as retrotransposons that move around the human genome.

The insertions are called nuclear-mitochondrial segments—NUMTs ("pronounced new-mites")—and have been accumulating in our chromosomes for millions of years.

As a result, all of us are walking around with hundreds of vestigial, mostly benign mitochondrial DNA segments in our chromosomes that we inherited from our ancestors.

Mitochondrial DNA insertions are common in the human brain Research in just the past few years has shown that "NUMTogenesis" is still happening today. "Jumping mitochondrial DNA is not something that only happened in the distant past

It's rare, but a new NUMT becomes integrated into the human genome about once in every 4,000 births. This is one of many ways, conserved from yeast to humans, by which mitochondria talk to nuclear genes.

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Inherited NUMTs are mostly benign, probably because they arise early in development and the harmful ones are weeded out.
But if a piece of mitochondrial DNA inserts itself within a gene or regulatory region, it could have important consequences on that person's health or lifespan. Neurons may be particularly susceptible to damage caused by NUMTs because when a neuron is damaged, the brain does not usually make a new brain cell to take its place.
The researchers' analysis showed that nuclear mitochondrial DNA insertion happens in the human brain—mostly in the prefrontal cortex—and likely several times over during a person's lifespan.
They also found that people with more NUMTs in their prefrontal cortex died earlier than individuals with fewer NUMTs. "This suggests for the first time that NUMTs may have functional consequences and possibly influence lifespan.
"NUMT accumulation can be added to the list of genome instability mechanisms that may contribute to aging, functional decline, and lifespan.
Stress accelerates NUMTogenesis
What causes NUMTs in the brain, and why do some regions accumulate more than others?

To get some clues, the researchers looked at a population of human skin cells that can be cultured and aged in a dish over several months, enabling exceptional longitudinal "lifespan" studies.

These cultured cells gradually accumulated several NUMTs per month, and when the cells' mitochondria were dysfunctional from stress, the cells accumulated NUMTs four to five times more rapidly.

This shows a new way by which stress can affect the biology of our cells.Stress makes mitochondria more likely to release pieces of their DNA and these pieces can then 'infect' the nuclear genome. It's just one way mitochondria shape our health beyond energy production.
Mitochondria are cellular processors and a mighty signaling platform. Now we know mitochondria can even change the nuclear DNA sequence itself.

Somatic nuclear mitochondrial DNA insertions are prevalent in the human brain and accumulate over time in fibroblasts, PLoS Biology (2024). On bioRxiv: DOI: 10.1101/2023.02.03.527065

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Mosquitoes sense infrared from body heat to help track humans down, study shows

While a mosquito bite is often no more than a temporary bother, in many parts of the world it can be scary. One mosquito species, Aedes aegypti, spreads the viruses that cause over 100,000,000 cases of dengue, yellow fever, Zika and other diseases every year. Another, Anopheles gambiae, spreads the parasite that causes malaria. The World Health Organization estimates that malaria alone causes more than 400,000 deaths every year. Indeed, their capacity to transmit disease has earned mosquitoes the title of deadliest animal.

Male mosquitoes are harmless, but females need blood for egg development. It's no surprise that there's over 100 years of rigorous research on how they find their hosts. Over that time, scientists have discovered there is no one single cue that these insects rely on. Instead, they integrate information from many different senses across various distances.

A team of researchers  has added another sense to the mosquito's documented repertoire: infrared detection. Infrared radiation from a source roughly the temperature of human skin doubled the insects' overall host-seeking behavior when combined with CO₂ and human odor.

The mosquitoes overwhelmingly navigated toward this infrared source while host seeking. The researchers also discovered where this infrared detector is located and how it works on a morphological and biochemical level. The results are detailed in the journal Nature.

Craig Montell, Thermal infrared directs host-seeking behaviour in Aedes aegypti mosquitoes, Nature (2024). DOI: 10.1038/s41586-024-07848-5. www.nature.com/articles/s41586-024-07848-5

How insulin, zinc and pH can block harmful protein clumps linked to type 2 diabetes

An estimated 462 million people around the world suffer from type 2 diabetes, a chronic disease in which the body has problems using sugar as a fuel, leading to a buildup of sugar in the blood and chronic health issues.

New research shows how zinc, pH levels and insulin work together to inhibit the buildup of protein clumps that contribute to this disease. The work, which points toward promising avenues for innovative treatments, was published in Communications Biology.

The research focuses on the intricate dance between insulin and the hormone amylin, or human islet amyloid polypeptide (hiAPP). Amylin is a naturally occurring peptide hormone that plays a role in regulating glycemia and energy balance. But human amylin can form amyloid fibers, which can destroy insulin-producing cells in the pancreas.

Amylin is produced in the pancreas alongside insulin and has a tendency to clump into aggregates called amyloid. They're like the plaques that form in the brain with Alzheimer's or Parkinson's disease.

For individuals with type 2 diabetes, amylin tends to cluster into harmful amyloid plaques, devastating the islet cells responsible for hormone production. However, insulin emerges as a potential hero, showing capabilities to hinder amylin's aggregation.

This study unravels the nuances of their interaction, alongside the roles of zinc and pH levels, bringing scientists closer to decoding the cellular intricacies of diabetes.

The results promise not just groundbreaking insights into this biomedical mystery, but also practical solutions. The research will help drug development aimed at neutralizing amylin's toxicity.

This could potentially revolutionize treatment approaches, offering hope to those battling this pervasive illness.

Samuel D. McCalpin et al, Zinc and pH modulate the ability of insulin to inhibit aggregation of islet amyloid polypeptide, Communications Biology (2024). DOI: 10.1038/s42003-024-06388-y

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Autism spectrum disorders linked to neurotransmitter switching in the brain

Autism spectrum disorders (ASD) involve mild to severe impairment of social, behavioral and communication abilities. These disorders can significantly impact performance at school, in employment and in other areas of life. 

Neurobiologists have now found evidence of altered development of the nervous system in mouse models of autism spectrum disorders. They linked environmentally induced forms of ASD to changes in neurotransmitters, the chemical messengers that allow neurons to communicate with each other. They also discovered that manipulating these neurotransmitters at early stages of development can prevent the appearance of autistic-like behaviours.

The researchers say the new results are consistent with other evidence that altering signaling in the nervous system during the early stages of development can later carry negative consequences as the brain matures.

Swetha K. Godavarthi et al, Embryonic exposure to environmental factors drives transmitter switching in the neonatal mouse cortex causing autistic-like adult behavior, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2406928121. doi.org/10.1073/pnas.2406928121

Sustainable solution to vitamin B12 deficiency

In new research published in the journal Discover Food, researchers report the use of state-of-the-art biotechnology to cultivate photosynthetically-controlled Spirulina, and produce carbon–neutral and nutritious biomass containing unopposed, biologically active vitamin B₁₂, in levels comparable to beef meat. This is the first time biologically active vitamin B₁₂ has been reported in Spirulina.

Their new study reveals a potential solution to one of the most widespread micronutrient deficiencies: vitamin B₁₂. With more than a billion individuals worldwide suffering from low levels of this essential vitamin, the reliance on meat and dairy products for adequate B₁₂ intake (2.4 µg/day) presents significant environmental challenges.

While Spirulina blue-green algae (Arthrospira platensis) has been proposed as a healthier and more sustainable substitute for meat and dairy, the so-called traditional Spirulina has fallen short as a viable alternative due to its content of pseudo-vitamin B₁₂, a form not bioavailable to humans. This limitation has hindered its potential to address vitamin B₁₂ deficiencies, and fully replace beef meat in human diets.

In the present study, the research team evaluated a biotechnology system developed by VAXA Technologies in Iceland, focusing on its engineering components, inputs (such as energy), and outputs, including biomass composition. The system employs photonic management (modified light conditions) to enhance active vitamin B₁₂ production in Spirulina, along with other bioactive  compounds with antioxidant, anti-inflammatory, and immune-boosting properties.

This innovative approach yielded carbon-neutral, nutritious biomass containing biologically active vitamin B12 at levels comparable to beef (1.64 µg/100g in PCS vs. 0.7–1.5 μg/100g in beef).

The findings demonstrate that photosynthetically controlled Spirulina can produce desirable levels of active vitamin B12, offering a sustainable alternative to traditional animal-source foods.

This breakthrough marks a significant step towards addressing global vitamin B12 deficiency sustainably, reducing reliance on environmentally taxing meat and dairy production.

A. Tzachor et al, Photonic management of Spirulina (Arthrospira platensis) in scalable photobioreactors to achieve biologically active unopposed vitamin B12, Discover Food (2024). DOI: 10.1007/s44187-024-00152-1

First visualization of valence electrons reveals fundamental nature of chemical bonding

The distribution of outermost shell electrons, known as valence electrons, of organic molecules was experimentally observed for the first time by a team led by Nagoya University in Japan. As the interactions between atoms are governed by the valence electrons, their findings shine light on the fundamental nature of chemical bonds, with implications for pharmacy and chemical engineering. The results were published in the Journal of the American Chemical Society.

The behavior of the electrons in atoms is complex, forming electron orbitals that have different functions depending on their closeness to the nucleus. The inner shell electrons, called core electrons, are used for self-stabilization and do not interact with other atoms. On the other hand, the outer electrons, or valence electrons, define most of the material's properties, especially during bonding with other atoms.

Understanding a material's properties requires extracting information about its valence electrons. However, it has been difficult to experimentally isolate only the valence electron information, leading to researchers having to rely on theoretical models and spectroscopy to estimate it. By conducting world-class synchrotron X-ray diffraction experiments at SPring-8, the research group discovered that it is possible to selectively extract only the valence electron density of atoms in a crystal.

They named this method the CDFS method. Using this method, they observed the electron state of the glycine molecule, a type of amino acid.

Although the method was relatively simple to perform, the result was impressive. The observed electron cloud did not exhibit the smooth, enveloping shape that many predicted, but rather a fragmented, discrete state.

Hara, T. et al. Unveiling the Nature of Chemical Bonds in Real Space, Journal of the American Chemical Society (2024). DOI: 10.1021/jacs.4c05673

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Mediterranean diet supplement can affect epigenetics associated with healthy aging

As life expectancy increases, the attention and interest in safe and effective lifestyle interventions to promote healthy aging are growing rapidly. One of the elements explored is that of unhealthy diets, with poor nutritional value. Therefore, lifestyle changes which include dietary interventions could promote positive effects, and potentially reduce the risk of developing aging-related diseases.

Previous studies showed that phytonutrients, natural compounds found in vegetables, fruits and berries, support health and lower the risk of age-related conditions such as cardiovascular disease and dementia.

The Mediterranean diet is mainly based on abundant phytonutrients. The Mediterranean diet consists of olive oil as the primary source of fat, fresh fruit, low to moderate amounts of seafood, poultry, dairy products, wine and eggs. Sweets containing sugar or honey and red meat are consumed sparingly. Adhering to this diet could be protective against several conditions.

DailyColors is a dietary supplement designed to mimic the benefits of the Mediterranean diet by providing important nutrients found in fruits, berries, and vegetables. These nutrients, like Quercetin and Anthocyanins, are known for their potential health benefits, particularly in aging.

A collaborative study between the Center for Healthy Brain Aging at King's and Center for Age-related Medicine, Stavanger University Hospital, Norway, aimed to explore how DailyColors affects certain blood markers linked to aging and related diseases, such as how our cells produce energy, inflammation, and stress in the body.

The study also looked at changes in DNA methylation in saliva, which can provide indicators of biological aging.

Part 1

Thirty adults, aged 55–80, with a body mass index over 25, participated in the study. Participants took either DailyColors or a placebo for one week, then switched after a break.

During the placebo phase, a blood marker called CD38, which is linked to poor cell function and inflammation, increased. This didn't happen when participants took DailyColors. There was also a trend showing reduced oxidative stress (a process that can damage cells) after taking the supplement.

This nutraceutical clinical study highlights the strengths at King's in academic-industry collaborations, involving researchers from across four continents in nine institutions and two companies.
This study is the first to show that a novel supplement containing plant compounds found in the Mediterranean diet can alter blood biomarkers and epigenetic profiles that are associated with healthy aging.

In a follow-up study with 26 participants who continued to take DailyColors for a month, the study found changes in the way DNA is marked, which might slow down some of the negative effects of aging. Although the effects observed were minimal, the study suggests that DailyColors could help slow down certain aging processes. However, more extensive studies are needed to confirm these benefits.

The work is published in the journal Antioxidants.

Autologous platelet-gel (APG) is the process of harvesting ones own cells (platelets), concentrating them most often through centrifugation, exposing them to an agonist which induces activation which releases intrinsic substances, and applying them to a target area to accelerate wound healing. APG is attractive because it concentrates a large number of biologically active substances, which are primarily proteins that participate in complex series of mechanisms involved in inflammation and wound healing. It has been used in numerous applications including sports medicine, dermatology, and surgery.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4813532/

Test of a prototype quantum internet runs under New York City for half a month

To introduce quantum networks into the marketplace, engineers must overcome the fragility of entangled states in a fiber cable and ensure the efficiency of signal delivery. Now, scientists at Qunnect Inc. in Brooklyn, New York, have taken a large step forward by operating just such a network under the streets of New York City.

While others have transmitted entangled photons before, there has been too much noise and polarization drift in the fiber environment for entanglement to survive, particularly in a long-term stable network.

Now  this team's new network design, methods and results are published in PRX Quantum.

For their prototype network, the Qunnect researchers used a leased 34-kilometer-long fiber circuit they called the GothamQ loop. Using polarization-entangled photons, they operated the loop for 15 continuous days, achieving an uptime of 99.84% and a compensation fidelity of 99% for entangled photon pairs transmitted at a rate of about 20,000 per second. At a half-million entangled photon pairs per second, the fidelity was still nearly 90%.

The polarization of a photon is the direction of its electric field. (This may be easier to understand in the wave picture of light.) You're perhaps familiar with the phenomenon from polarized sunglasses, which are filters that let light from one polarization direction through but block others, thus cutting down on glare reflected off water, snow and glass, for instance.

Polarized photons are useful because they are easy to create, simple to manipulate (with polarized filters) and to measure.

Qunnect's GothamQ loop demonstration was especially noteworthy for its duration, the hands-off nature of the operation time, and its uptime percentage. It showed, they wrote, "progress toward a fully automated practical entanglement network" that would be required for a quantum internet.

Alexander N. Craddock et al, Automated Distribution of Polarization-Entangled Photons Using Deployed New York City Fibers, PRX Quantum (2024). DOI: 10.1103/PRXQuantum.5.030330

Part 2

'Humanity is failing': Official report warns our chance to save the Great Barrier Reef is fast closing

The Great Barrier Reef will continue to deteriorate, largely due to climate change, and the window to secure its future is rapidly closing. That is the sobering conclusion of a major new report into the state of the reef.

The report was released by the Great Barrier Reef Marine Park Authority. It confirms what scientists have long known: humanity is killing the Great Barrier Reef, and other reefs around the world, by failing to curb the greenhouse gas emissions that cause global warming. 

Unless humanity takes dramatic action to halt climate change, we will lose the beautiful, complex reefs that have existed on Earth for millennia. As this latest report shows, even governments and officials now acknowledge this fact.

Warming oceans and severe tropical cyclones are compounding other threats such as crown-of-thorns starfish outbreaks, poor water quality and unsustainable fishing.

While recent recovery in some ecosystem values demonstrates that the reef is still resilient, its capacity to tolerate and recover is jeopardized by a rapidly changing climate.

Bleaching occurs when corals become so heat-stressed they eject the tiny algae living inside their tissues. These organisms give coral some of its color and help power its metabolism. In mild bleaching events, corals can recover. But in the severe events that are becoming more common, corals do not survive.

Part 1

The report said climate-driven disturbances are compounding the effects of other chronic damage to the reef from:

unsustainable fishing
pollution
sediment runoff
outbreaks of crown-of-thorns starfish.
Among other key findings of the report were that:

most populations of marine turtles have declined
species such as seabirds, sharks, rays, dugongs and seagrasses have recovered in some areas and plateaued or declined in others
populations of estuarine crocodiles are recovering
many species in declines are listed as threatened or protected.
Humanity must take urgent action to limit global temperature rise. But we are failing. We are failing the Great Barrier Reef and indeed, coral reefs across the planet.
2024 opens a new chapter for the reef. Future warming already locked into the climate system means that further degradation is inevitable. This is the sobering calculus of climate change.
Humanity has all the facts in front of us. Earth is in an uncharted time of very rapid change. If we don't respond, we will lose the Great Barrier Reef and corals across the world's oceans.

https://theconversation.com/humanity-is-failing-official-report-war...

Part 2

Paper types ranked by likelihood of paper cuts

Via testing with a skin stand-in, a trio of physicists has ranked the types of paper that are the most likely to cause a paper cut. In an article published in Physical Review E, they tested the cutting ability and circumstances involved in paper cuts to compile their rankings.

Paper cuts occur through the handling of paper products. In addition to the nuisance factor due to the sudden flow of blood, there is also often a great deal of pain involved. In this new effort, the researchers noted that most research done on the topic revolves around infection factors. They chose instead to focus on the types of paper most likely to cause a cut, thereby allowing paper users a means to reduce their chances of an injury.

To test the cutting ability of different types of paper, the researchers used ballistics gelatin as a stand-in for skin. They then attempted to cut the gelatin using multiple types of paper. They noted the sturdiness and thickness of the paper, and the angles that were involved when cutting occurred.

The research team found that paper that was the most thin was unlikely to cause a cut because it tended to buckle instead. Also, thick paper rarely led to a cut because its surface was spread over too large an area. That left paper that is neither too thick nor too thin, like the kind that is used in newspapers or dot-matrix printers—the two types tied for the title "Most likely to cut skin."

Other culprits were Post-It notes, printed magazines and office paper. Some that were less likely to cut include tissue and photo paper. They noted that to cause cuts, the paper had to be angled slightly.

The researchers also noted that some papers, such as those used in dot-matrix printers, are exceptionally good at cutting. They proved this to be the case by connecting a small piece of it to a scalpel and using the results as a "papermachete." They found their little knife was capable of slicing through vegetable skin and even some meats.

 Sif Fink Arnbjerg-Nielsen et al, Competition between slicing and buckling underlies the erratic nature of paper cuts, Physical Review E (2024). DOI: 10.1103/PhysRevE.110.025003

The physics of paper cuts. Credit: Physical Review E (2024). DOI: 10.1103/PhysRevE.110.025003

How much microplastic are you drinking? New tool can tell you in minutes

Micro- and nanoplastics are in our food, water and the air we breathe. They are showing up in our bodies, from testicles to brain matter. Now,  researchers have developed a low-cost, portable tool to accurately measure plastic released from everyday sources like disposable cups and water bottles.

The device, paired with an app, uses fluorescent labeling to detect plastic particles ranging from 50 nanometers to 10 microns in size—too small to be detected by the naked eye—and delivers results in minutes.

The method and findings are detailed in ACS Sensors.

The breakdown of larger plastic pieces into microplastics and nanoplastics presents significant threats to food systems, ecosystems, and human health.

This new technique allows quick, cheap detection of these plastics, which could help protect our health and ecosystems.

Nano and microplastics are byproducts of degrading plastic materials such as lunchboxes, cups and utensils. As very small particles with a large surface area, nanoplastics are particularly concerning to human health due to their increased ability to absorb toxins and penetrate biological barriers within the human body.

Detecting these plastics typically requires skilled personnel and expensive equipment.

They created a small, biodegradable, 3D-printed box containing a wireless digital microscope, green LED light and an excitation filter. To measure the plastics, they customized MATLAB software with machine-learning algorithms and combined it with image capture software.

The result is a portable tool that works with a smartphone or other mobile device to reveal the number of plastic particles in a sample. The tool only needs a tiny liquid sample—less than a drop of water—and makes the plastic particles glow under the green LED light in the microscope to visualize and measure them. The results are easy to understand, whether by a technician in a food processing lab or just someone curious about their morning cup of coffee.

To reduce plastic ingestion, it is important to consider avoiding petroleum-based plastic products by opting for alternatives like glass or stainless steel for food containers. The development of biodegradable packaging materials is also important for replacing traditional plastics and moving towards a more sustainable world, say the researchers.

Haoxin Ye et al, Cost-Effective and Wireless Portable Device for Rapid and Sensitive Quantification of Micro/Nanoplastics, ACS Sensors (2024). DOI: 10.1021/acssensors.4c00957

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'Alarming' rise in deadly lightning strikes in India: scientists

Climate change is fueling an alarming increase in deadly lightning strikes in India, killing nearly 1,900 people a year in the world's most populous country, scientists warn.

Lightning caused a staggering 101,309 deaths between 1967 and 2020, with a sharp increase between 2010 and 2020, a team of researchers say.

The results indicate a steady increase in lightning activity in India, positioning it as a major killer among climate change-induced natural disasters.

While the report looked at data on deaths, not the number of strikes, it said "lightning activity in India is becoming increasingly unpredictable".

Data showed that the average annual fatalities per Indian state rose from 38 in the period 1967 to 2002, to 61 from 2003 to 2020 -- a period when the country's population has also rapidly grown to 1.4 billion people.

Lightning strikes are common in India during the June-September monsoon rains, which is crucial to replenishing regional water supplies.

But scientists say their frequency is increasing due to rising global temperatures, unleashing a cascade of extreme weather events. Higher air temperatures create more water vapour, which after it cools at altitude, creates electric charges that spark lightning.

The high number of fatalities in India is also due to ineffective early warning systems and a lack of awareness of how to reduce the risk, the report added, published in the international journal of Environment, Development and Sustainability.

Mass fatalities from a single strike are common, such as when farmers shelter in groups from lashing rain under a tree.

The report said the data on recorded deaths from lightning indicates "an increasing trend, with the last two decades showing the highest increase", calling it "an alarming development". The "rising trend of extreme climate conditions is likely to exacerbate the situation", it added, with a "pressing need" for policy changes to mitigate the impact.

Source: Various news agencies

Anthropocene: Why it matters even without a formal geological definition

For the last seven decades, Earth has been operating in unprecedented ways, leading many researchers to argue that we have entered a new geological epoch known as the Anthropocene.

While it may not have been formally accepted onto the geological time scale, the Anthropocene is real and its effects have drastically and irrevocably changed the living conditions on our planet. It should therefore be treated as a de facto new epoch of Earth's history, say some experts.

That argument is at the crux of an article published in the journal Nature .

The article was also co-signed by more than 50 other researchers representing many different disciplines and institutes from around the world. It summarizes the evidence of massive physical, chemical and biological change on the planet, including the rapidly warming climate.

For many thousands of years, large human populations coexisted with relatively stable planetary conditions and left abundant traces of their existence and their environmental impacts.

But the planet is now sharply different, and the significance of these changes extends far beyond the Earth sciences to affect the social sciences, the humanities and arts—and to form a now-permanent context for the work of planners and decision-makers.

The authors emphasize that it makes sense to precisely delimit the beginning of the Anthropocene at 1952. That year not only marks the prominent upturn of artificial radionuclide fallout around the Earth from hydrogen bomb tests, they note, but closely coincides with many other changes, such as the appearance of plastics and many other novel compounds and the rapid growth of greenhouse gases, as well as widespread social, economic and political changes as the postwar world entered a period of unprecedented growth.

Wide acceptance of such a definition would make for more precise analysis of the many phenomena associated with the Anthropocene, and allow us to communicate clearly, say these experts.

The Anthropocene may have been rejected by the International Commission on Stratigraphy—for now. But it is all too alive in the real world, and we should recognize that.

Jan Zalasiewicz et al, The meaning of the Anthropocene: why it matters even without a formal geological definition, Nature (2024). DOI: 10.1038/d41586-024-02712-y

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Lack of pollinators limits worldwide food production

A team of researchers  has analyzed crop yields of more than 1,500 fields on six continents, and found that production worldwide of important, nutritionally dense foods such as fruits, vegetables, nuts and legumes is being limited by a lack of pollinators.

The results, detailed in Nature Ecology & Evolution, showed that across diverse crops and locations, one-third to two-thirds of farms contain fields that aren't producing at the levels they should be due to a lack of pollinators. The phenomenon of a low crop yield because of insufficient visits by insects is known as 'pollinator limitation'.

The study is especially timely given recent concern about global declines in insect abundance.

The scientists reached their conclusions by conducting a statistical analysis of more than 200,000 "bee visitations" to crop flowers, contained within one of the most comprehensive databases on crop pollination in the world.

The open-source database incorporates three decades of field observations of bees and other pollinators visiting plants.

The recent  study doesn't apply to major food crops, such as rice and wheat, which don't require pollinators to reproduce. But pollination by bees and other animals is critical to the proliferation of what Scientists describe as "nutrient-dense and interesting foods that we like and are culturally relevant," such as fruits, vegetables, nuts, and legumes.

Pollination is the process of transferring pollen from the male part of a flower to the female part, which allows a plant to become fertilized and produce seeds, fruits and young plants. Pollen can be moved by wind, water or pollinators such as honeybees and wild bees and other insects and other animals, such as bats.

Pollinators support the reproduction of about 88% of the world's flowering plants and 76% of the leading global food crops, according to previous research by this group and also other scientists.

Part 1

Bees are generally considered the most effective pollinators because Rutgers scientists identified that blueberry, coffee and apple crops were most frequently affected by pollinator limitations. They visit more flowers and carry more pollen than other insects.

Researchers found yield deficits for 25 unique crops and in 85% of the countries evaluated.

On the bright side, scientists think current yield deficits could be remediated with realistic increases in pollinator visitation across individual crop fields. The study revealed in some cases an adequate number of bees were already visiting some fields.

If field managers could improve consistency across high- and low-yield fields, much of the observed yield problems could be addressed.
The findings are significant because crop yields, which measure the amount of crops grown per unit area of land, are relevant to assessing the adequacy of the world's food supply relative to its population.

Katherine J. Turo et al, Insufficient pollinator visitation often limits yield in crop systems worldwide, Nature Ecology & Evolution (2024). DOI: 10.1038/s41559-024-02460-2

Part 2

Pregnancy after sterilization turns out to be surprisingly common

Tubal sterilization is thought to be a permanent form of birth control and is the most common method of contraception in several parts of the world. But a new study reports that tubal surgery fails often enough that some other forms of birth control are usually more effective.

The authors found that 3–5% of women in the  US who had their tubes tied later reported an unplanned pregnancy. This failure rate led the authors to suggest that patients who really want to avoid future pregnancy should instead use a contraceptive arm implant or intrauterine device (IUD).

The paper appears August 27 in NEJM Evidence.

Schwarz, E. B. et al. Pregnancy after Tubal Sterilization in the United States, 2002 to 2015, NEJM Evidence (2024). DOI: 10.1056/EVIDoa2400023. evidence.nejm.org/doi/10.1056/EVIDoa2400023

Menopause potentially linked to adverse cardiovascular health through blood fat profile changes

New research presented at the ESC Congress 2024 in London, UK (30 August—2 September) shows that women in the menopause transition period show changes in their blood cholesterol profiles which could have an adverse impact on their cardiovascular health.

There is an increase in 'bad' low-density type lipoprotein (LDL) particles and a decrease in 'good' high-density lipoprotein particles (HDL) that takes place during and after the menopause transition. Taken together, these changes suggest that menopause is associated with a transition to a higher-risk lipoprotein profile that could be more likely to cause cardiovascular disease, such as coronary artery disease.

Cardiovascular disease (CVD) is the biggest killer of women, despite the misconception that CVD is a "man's disease"—40% of all deaths in women are from CVD. While women develop cardiovascular disease (CVD) approximately ten years later than men, risk of CVD in women rises after menopause.

In the present study, the researchers found that found that menopause is associated with adverse changes in lipoprotein profiles, with the most pronounced changes found to be in increases in 'bad' LDL-particles and subfractions observed for peri-menopausal women. When looked at together, these changes could help explain the increase of cardiovascular disease in post-menopausal women and help determine if earlier interventions are warranted.

 esc365.escardio.org/ESC-Congress/sessions/11918

EEE, West Nile, malaria: Know the difference between these mosquito-borne diseases

The world's deadliest animal can be squashed flat with a quick slap: It's the mosquito.

The buzzing insects are more than annoying—they spread disease. When they bite and drink blood from a person or animal they can pick up viruses or germs too. If they can go on to bite someone or something else, they deposit the germ right under the skin.

The best way to avoid getting sick is of course to avoid getting bitten, which means taking steps like using repellent, wearing clothing with long sleeves and long pants and staying indoors when the mosquitoes are out. Local health departments also work to reduce mosquito numbers, including spraying neighborhoods with insecticide.

Here's a look at some common—and not so common—mosquito-borne diseases.

Part 1

Eastern equine encephalitis

Most people infected with eastern equine encephalitis don't develop symptoms, but some can come down with fever or swelling of the brain and about one third of people infected die.

 It is caused by a virus and is not very common around the world. The virus typically spreads in certain swamps.

West Nile virus

About 2 in 10 people infected with West Nile virus develop symptoms, which can include fever and swelling of the brain. About 1 in 10 people who develop severe symptoms die. 

Malaria

Malaria infected nearly 250 million people globally in 2022 and killed more than 600,000, mostly children. It is caused by a parasite carried by mosquitoes and mainly infects people in tropical regions, especially Africa. A vaccination campaign has been launched in recent months that health officials hope will help reduce cases and deaths.

Dengue

Also known as "break-bone fever" because it can be so painful, dengue is becoming more common. The World Health Organization says that about half the world's population is at risk of getting the disease, and there are 100 million to 400 million infections every year. Not everyone gets symptoms, which can include fever, severe headaches and pain in the muscles and joints.

Source: News agencies

Part 2

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How mindset could affect the body's response to vaccination

In a recent study, researchers found that beliefs and assumptions people have about COVID-19 vaccines seemed to influence their vaccination experience—including side effects and, in some cases, immune response.

While most people can appreciate that vaccination is an amazing achievement, their enthusiasm might falter when it comes time to schedule and receive their own. And new research suggests that might influence how the vaccine affects them.

Researchers studied the effects of different types of positive and negative mindsets regarding the COVID-19 vaccine.

Their work, published in the journal Brain, Behavior & Immunity—Health, suggests that a positive mindset is associated with more positive outcomes, such as less stress and side effects, better mood, and possibly even better immune response.

*Details of the findings include: All positive vaccine-related mindsets predict lower anxiety on the day of the appointment, and lower stress and sadness—and more happiness—in the days around vaccination.

*A positive mindset about the efficacy of the vaccine and how the body will respond to vaccination were linked to fewer negative physical side effects.

*The vaccine mindset that side effects indicate "the vaccine is working" was associated with better immune response—specifically, higher antibodies six months later.

Many people will be surprised by these findings, but they shouldn't be," said the authors. Our brains are connected to every physiological system in our bodies, and we know from decades of previous research on placebo effects and psychoneuroimmunology that our mindsets can influence physiological outcomes, including the immune system.

Darwin A. Guevarra et al, Examining the association of vaccine-related mindsets and post-vaccination antibody response, side effects, and affective outcomes, Brain, Behavior, & Immunity - Health (2024). DOI: 10.1016/j.bbih.2024.100818

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Some bats are surviving and thriving with blood sugar levels that would be lethal for other mammals

Humans must regulate blood sugar concentrations to stay healthy and to fuel our cells. Too little or too much can cause serious health complications, and high blood sugar is a hallmark of the metabolic condition, diabetes. New research  may enable potential solutions to metabolic disease by turning to evolution and to bats.

Published in Nature Ecology and Evolution, the study reports the highest naturally occurring blood sugar concentrations in mammals ever observed, a finding that suggests bats have evolved strategies to survive, and even thrive, with this extreme trait.

This new study  reports blood sugar levels that are the highest we have ever seen in nature—what would be lethal, coma-inducing levels for mammals, but not for bats.

Thirty million years ago, the Neotropical leaf-nosed bat survived solely on insects. Since then, these bats have diversified into many different species by changing what they eat. From insects, different lineages now specialize in diets including fruits, nectar, meat, and everything in between—even just blood.

The new study reports the highest naturally occurring blood sugar concentrations in mammals ever observed, a finding that suggests bats have evolved strategies to survive, and even thrive, with this extreme trait. Credit: Stowers Institute for Medical Research

Part 1

Looking to animals that have existed for millions of years allows us to start to catalog changes that have happened over evolution. What makes Neotropical leaf-nosed bats so unique to study is that this group is comprised of many different species with very diverse diets, making it feasible to find answers about how diet evolves. The hope is that we can extend this understanding to other mammals, including humans, where there may be ways to learn how to better protect our own health.
To uncover how bats diversified their diets, the research team traveled to the jungles of Central America, South America, and the Caribbean to conduct fieldwork over several years. These catch-and-release expeditions were focused on performing glucose tolerance tests—measuring the concentration of sugar in blood—on nearly 200 wild-caught bats across 29 species after a single feeding of one of three types of sugars associated with diets of insects, fruits, or nectar.
They observed various ways sugar is assimilated—absorbed, stored and used in the body—and how this process has become specialized due to different diets.
The mechanism for maintaining blood sugar levels within a narrow, healthy range is called glucose homeostasis, which is typically regulated by the hormone insulin and is what goes awry in diabetes. Different species of leaf-nosed bats reveal a spectrum of adaptations to glucose homeostasis, ranging from changes in intestinal anatomy to genetic alterations for proteins that transport sugar from blood to cells.
Fruit bats have honed their insulin signaling pathway to lower blood sugar. On the other extreme, nectar bats can tolerate high blood glucose levels, similar to what is observed in people with unregulated diabetes. They have evolved a different mechanism, and it does not seem to depend on insulin.
Although precisely how nectar bats are managing glucose is still under investigation, the researchers found potential clues for alternative metabolic strategies for glucose regulation. Bats with sugar-rich diets were observed to have longer portions of their intestines and to have intestinal cells with greater surface areas for absorbing nutrients from food, compared to bats with other diets. In addition, nectar bats, separate from fruit bats, have a continual expression of a gene responsible for sugar transport, a trait also observed in a species of hummingbird.
Part 2

This study establishes extremely important resources for the field.
It provides not only metabolic characteristics of various bat species with different diets, but also their intestinal morphology, and candidate genomic regions and protein structural differences that could be driving dietary adaptations.
The datasets will fuel future research that aims to differentiate mammalian dietary differences and could progress the development of novel therapeutics for a variety of metabolic diseases in humans.

Oh yes, if that happens, you can eat your favourite sweets or ice creams without thinking about any health consequences!

Sugar assimilation underlying dietary evolution of Neotropical bats, Nature Ecology & Evolution (2024). DOI: 10.1038/s41559-024-02485-7

Part 3

Scientists discover a  global electric field on Earth

Using observations from a NASA suborbital rocket, an international team of scientists, for the first time, has successfully measured a planet-wide electric field thought to be as fundamental to Earth as its gravity and magnetic fields.

Known as the ambipolar electric field, scientists first hypothesized over 60 years ago that it drove how our planet's atmosphere can escape above Earth's North and South Poles. Measurements from the rocket, NASA's Endurance mission, have confirmed the existence of the ambipolar field and quantified its strength, revealing its role in driving atmospheric escape and shaping our ionosphere—a layer of the upper atmosphere—more broadly.

Understanding the complex movements and evolution of our planet's atmosphere provides clues not only to the history of Earth but also gives us insight into the mysteries of other planets and determining which ones might be hospitable to life. A research paper on this topic is published in the journal Nature.

Part 1

Since the late 1960s, spacecraft flying over Earth's poles have detected a stream of particles flowing from our atmosphere into space. Theorists predicted this outflow, which they dubbed the "polar wind," spurring research to understand its causes.

Some amount of outflow from our atmosphere was expected. Intense, unfiltered sunlight should cause some particles from our air to escape into space, like steam evaporating from a pot of water. But the observed polar wind was more mysterious. Many particles within it were cold, with no signs they had been heated—yet they were traveling at supersonic speeds.

Something had to be drawing these particles out of the atmosphere.

Scientists suspected that a yet-to-be-discovered electric field could be at work.

The hypothesized electric field, generated at the subatomic scale, was expected to be incredibly weak, with its effects felt only over hundreds of miles. For decades, detecting it was beyond the limits of existing technology. In 2016, researchers got to work inventing a new instrument they thought was up to the task of measuring Earth's ambipolar field.

The team's instruments and ideas were best suited for a suborbital rocket flight launched from the Arctic. In a nod to the ship that carried Ernest Shackleton on his famous 1914 voyage to Antarctica, the team named their mission Endurance. The scientists set a course for Svalbard, a Norwegian archipelago just a few hundred miles from the North Pole and home to the northernmost rocket range in the world.

Svalbard is the only rocket range in the world where you can fly through the polar wind and make the measurements that 're needed.

On May 11, 2022, Endurance launched and reached an altitude of 477.23 miles (768.03 kilometers), splashing down 19 minutes later in the Greenland Sea. Across the 322-mile altitude range where it collected data, Endurance measured a change in electric potential of only 0.55 volts.

A half a volt is almost nothing—it's only about as strong as a watch battery. But that's just the right amount to explain the polar wind.

Hydrogen ions, the most abundant type of particle in the polar wind, experience an outward force from this field 10.6 times stronger than gravity.

"That's more than enough to counter gravity—in fact, it's enough to launch them upwards into space at supersonic speeds.

Heavier particles also get a boost. Oxygen ions at that same altitude, immersed in this half-a-volt field, weigh half as much. In general, the team found that the ambipolar field increases what's known as the "scale height" of the ionosphere by 271%, meaning the ionosphere remains denser to greater heights than it would be without it.

It's like this conveyor belt , lifting the atmosphere up into space.

Endurance's discovery has opened many new paths for exploration. The ambipolar field, as a fundamental energy field of our planet alongside gravity and magnetism, may have continuously shaped the evolution of our atmosphere in ways we can now begin to explore. Because it's created by the internal dynamics of an atmosphere, similar electric fields are expected to exist on other planets, including Venus and Mars.

Any planet with an atmosphere should have an ambipolar field. Now that we've finally measured it, we can begin learning how it's shaped our planet as well as others over time.

Glyn A. Collinson et al, Earth's ambipolar electrostatic field and its role in ion escape to space, Nature (2024). DOI: 10.1038/s41586-024-07480-3

Part 2

 New brain mechanism uncovered

Researchers have discovered how two brain areas, the neocortex and the thalamus, work together to detect discrepancies between what animals expect from their environment and actual events. These prediction errors are implemented by selective boosting of unexpected sensory information. These findings enhance our understanding of predictive processing in the brain and could offer insights into how brain circuits are altered in autism spectrum disorders (ASDs) and schizophrenia spectrum disorders (SSDs).

The research, published in Nature, outlines how scientists at the Sainsbury Wellcome Centre at UCL studied mice in a virtual reality environment to take us a step closer to understanding both the nature of prediction error signals in the brain as well as the mechanisms by which they arise.

Our brains constantly predict what to expect in the world around us and the consequences of our actions. When these predictions turn out wrong, this causes strong activation of different brain areas, and such prediction error signals are important for helping us learn from our mistakes and update our predictions. But despite their importance, surprisingly little is known about the neural circuit mechanisms responsible for their implementation in the brain.

To study how the brain processes expected and unexpected events, the researchers placed mice in a virtual reality environment where they could navigate along a familiar corridor to get to a reward. The virtual environment enabled the team to precisely control visual input and introduce unexpected images on the walls. By using a technique called two-photon calcium imaging, the researchers were able to record the neural activity of many individual neurons in the primary visual cortex, the first area in our neocortex to receive visual information from the eyes.

Previous theories proposed that prediction error signals encode how the actual visual input is different from expectations, but surprisingly the present study found no experimental evidence for this. Instead, it was discovered that the brain boosts the responses of neurons that have the strongest preference for the unexpected visual input.

The error signal we observe is a consequence of this selective amplification of visual information. This implies that our brain detects discrepancies between predictions and actual inputs to make unexpected events more salient.

To understand how the brain generates this amplification of the unexpected sensory input in the visual cortex, the team used a technique called optogenetics to inactivate or activate different groups of neurons. They found two groups of neurons that were important for causing the prediction error signal in the visual cortex: vasoactive intestinal polypeptide (VIP)-expressing inhibitory interneurons in V1 and a thalamic brain region called the pulvinar, which integrates information from many neocortical and subcortical areas and is strongly connected to V1.

Part 1

But the researchers found that these two groups of neurons interact in a surprising way.

This work revealed that VIP neurons and pulvinar act synergistically together. VIP neurons act like a switchboard: When they are off, the pulvinar suppresses activity in the neocortex, but when VIP neurons are on, the pulvinar can strongly and selectively boost sensory responses in the neocortex. The cooperative interaction of these two pathways thus mediates the sensory prediction error signals in the visual cortex.

Sonja Hofer, Cooperative thalamocortical circuit mechanism for sensory prediction errors, Nature (2024). DOI: 10.1038/s41586-024-07851-w. www.nature.com/articles/s41586-024-07851-w

Part 2

Researchers take inspiration from viruses to improve delivery of nucleic acid-based therapies to cancer cells

Researchers are developing a patent-pending platform technology that mimics the dual-layer structure of viruses to deliver nucleic acid (NA)-based therapies to targeted cancer cells.

 The carrier system is called LENN. 

LENN includes two protective layers. The inner shell condenses the nucleic acid; the outer shell protects it from the immune system so it can circulate freely and target cancer cells. The researchers are mimicking the strategies of viral particles that have been doing this effectively for millions of years.

The data shows that this agile nanocarrier is flexible in its targeting ability, cargo size and disassembly kinetics. It provides an alternative route for nucleic acid delivery using a biomanufacturable, biodegradable, biocompatible and highly tunable vehicle capable of targeting a variety of cells depending on their tumor-specific surface markers.

Nucleic acid-based therapies are revolutionizing biomedical research through their ability to control cellular functions at the genetic level. Therapies comprising several constructs are being explored to expand the druggable sites of the human genome.

Aayush Aayush et al, Development of an Elastin-like Polypeptide-Based Nucleic Acid Delivery System Targeted to EGFR+ Bladder Cancer Cells Using a Layer-by-Layer Approach, Biomacromolecules (2024). DOI: 10.1021/acs.biomac.4c00165

Dark matter, dark matter, where are you?

New results from the world's most sensitive dark matter detector narrow down its characteristics, edging closer to unraveling one of the biggest mysteries of the universe.

LZ is intricately and innovatively designed to find direct evidence of dark matter—a mysterious invisible substance thought to make up most of the mass of the universe. Dark matter is particularly challenging to detect, as it does not emit or absorb light or any other form of radiation.

The LZ detector tries to capture the very rare and very faint interactions between dark matter and its 7-tonne liquid xenon target. To do this, LZ must be carefully and delicately calibrated and any background noise removed so the experiment can be perfectly tuned to observe these interactions.
These theorized elementary particles interact with gravity, which confirms the existence of dark matter in the first place, and possibly through a new weak interaction too.

This means WIMPs are expected to collide with ordinary matter—albeit very rarely and very faintly. This is why very quiet and very sensitive particle detectors are needed for WIMP detection.
At the center of the experiment is a large liquid xenon particle detector maintained at around -110oC, surrounded by photo-sensors. If a WIMP interacts with a xenon atom, a tiny amount of light should be emitted and the sensors will capture it. But in order to see these rare interactions, the team had to carefully remove as much as possible background radiation from the detector materials first.

But this is not enough and explains why LZ is operating around a mile underground. This shields it from cosmic rays, which bombard experiments at the surface of the earth. The detector and its cryostat sit inside a huge water tank to protect the experiment from particles and radiation coming from the laboratory walls.
For dark matter searches it is of vital importance to suppress any sources of background radiation, in particular neutrons and gamma rays. LZs veto detectors enable us to reject such processes and to gain the sensitivity to extremely rare dark matter interactions.

"Finally, LZ made sure that the liquid xenon itself is as pure as possible by carefully removing a key contaminant through a complex years-long process. Many complex systems had to come together for LZ to work, and these results show they are performing in seamless harmony.

Source: https://indico.uchicago.edu/event/427/overview

Part 2

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