Female participants who ate a diet rich in vitamins, minerals, and antioxidants, for instance, had cells with the 'youngest'-looking epigenetic age. Those on the Mediterranean diet were observed to have the slowest epigenetic clocks.

Still, the more added sugar a person consumed each day, the older their salivary DNA appeared to scientists, even when their meals were rich in foods that maintain and repair DNA.

This was true even when accounting for education, lifestyle factors, and the current health of participants.

On average, women in the study ate just over 60 grams of sugar a day, although some ate more than 300 grams a day.
The findings suggest that added sugar can significantly accelerate cellular aging, but it is important to note that this study is only based on food records collected over three non-consecutive days, and one salivary swab.

Previous studies have suggested that cells can appear epigenetically 'younger' or 'older' depending on when in the day their DNA was sampled, so longer term studies among both sexes are needed before further conclusions can be drawn.

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

Part 2

**

A bio-inspired vision sensor that can detect spectrally distinctive features

The ability to detect objects in settings with unfavorable lighting, for example at night, in shadowed locations or in foggy conditions, could greatly improve the reliability of autonomous vehicles and mobile robotic systems. Most widely employed computer vision methods, however, have been found to perform under poor lighting.

Researchers  recently introduced a new bio-inspired vision sensor that can adapt to the spectral features of the environments it captures, thus successfully detecting objects in a wider range of lighting conditions. This newly developed sensor, introduced in a paper published in Nature Electronics, is based on an array of photodiodes arranged back-to-back.

The primary objective of this recent work was to design a vision sensor that is better than other sensors at recognizing objects in an environment marked by strong light interference and when there is smoke or fog in the air. The sensor they planned to develop would also collect data with minimal time latency, consuming very little power.

Bangsen Ouyang et al, Bioinspired in-sensor spectral adaptation for perceiving spectrally distinctive features, Nature Electronics (2024). DOI: 10.1038/s41928-024-01208-x.

Brain activity associated with specific words is mirrored between speaker and listener during a conversation

When two people interact, their brain activity becomes synchronized, but it was unclear until now to what extent this "brain-to-brain coupling" is due to linguistic information or other factors, such as body language or tone of voice.

Researchers report August 2 in the journal Neuron that brain-to-brain coupling during conversation can be modeled by considering the words used during that conversation, and the context in which they are used.

Researchers could see linguistic content emerge word-by-word in the speaker's brain before they actually articulate what they're trying to say, and the same linguistic content rapidly reemerges in the listener's brain after they hear it.

To communicate verbally, we must agree on the definitions of different words, but these definitions can change depending on the context. For example, without context, it would be impossible to know whether the word "cold" refers to temperature, a personality trait, or a respiratory infection.

The contextual meaning of words as they occur in a particular sentence, or in a particular conversation, is really important for the way that we understand each other.

Part 1

To examine the role of context in driving brain coupling, the team collected brain activity data and conversation transcripts from pairs of epilepsy patients during natural conversations.

The patients were undergoing intracranial monitoring using electrocorticography for unrelated clinical purposes at the New York University School of Medicine Comprehensive Epilepsy Center. Compared to less invasive methods like fMRI, electrocorticography records extremely high-resolution brain activity because electrodes are placed in direct contact with the surface of the brain.

Next, the researchers used the large language model GPT-2 to extract the context surrounding each of the words used in the conversations, and then used this information to train a model to predict how brain activity changes as information flows from speaker to listener during conversation.

Using the model, the researchers were able to observe brain activity associated with the context-specific meaning of words in the brains of both speaker and listener.

They showed that word-specific brain activity peaked in the speaker's brain around 250 ms before they spoke each word, and corresponding spikes in brain activity associated with the same words appeared in the listener's brain approximately 250 ms after they heard them.

Compared to previous work on speaker–listener brain coupling, the team's context-based approach model was better able to predict shared patterns in brain activity. This shows just how important context is, because it best explains the brain data. Large language models take all these different elements of linguistics like syntax and semantics and represent them in a single high-dimensional vector. This work shows that this type of unified model is able to outperform other hand-engineered models from linguistics.

A shared model-based linguistic space for transmitting our thoughts from brain to brain in natural conversations, Neuron (2024). DOI: 10.1016/j.neuron.2024.06.025. www.cell.com/neuron/fulltext/S0896-6273(24)00460-4

Part 2

Scientists pin down the origins of the moon's tenuous atmosphere

While the moon lacks any breathable air, it does host a barely-there atmosphere. Since the 1980s, astronomers have observed a very thin layer of atoms bouncing over the moon's surface. This delicate atmosphere—technically known as an "exosphere"—is likely a product of some kind of space weathering. But exactly what those processes might be has been difficult to understand with any certainty.

Now, scientists  say they have identified the main process that formed the moon's atmosphere and continues to sustain it today. In a study appearing in Science Advances, the team reports that the lunar atmosphere is primarily a product of "impact vaporization."

In their study, the researchers analyzed samples of lunar soil collected by astronauts during NASA's Apollo missions.

Their analysis suggests that over the moon's 4.5-billion-year history its surface has been continuously bombarded, first by massive meteorites, then more recently, by smaller, dust-sized "micrometeoroids."

These constant impacts have kicked up the lunar soil, vaporizing certain atoms on contact and lofting the particles into the air. Some atoms are ejected into space, while others remain suspended over the moon, forming a tenuous atmosphere that is constantly replenished as meteorites continue to pelt the surface.

The researchers found that impact vaporization is the main process by which the moon has generated and sustained its extremely thin atmosphere over billions of years.

Nicole Nie, Lunar Soil Record of Atmosphere Loss over Eons, Science Advances (2024). DOI: 10.1126/sciadv.adm7074. www.science.org/doi/10.1126/sciadv.adm7074

Researchers demonstrate mechanism that may have stabilized the first RNA molecules

The origins of life remain a major mystery. How were complex molecules able to form and remain intact for prolonged periods without disintegrating? A team at ORIGINS, a Munich-based Cluster of Excellence, has demonstrated a mechanism that could have enabled the first RNA molecules to stabilize in the primordial soup.

When two RNA strands combine, their stability and lifespan increase significantly. The work is published in the journal Nature Chemistry.

In all likelihood, life on Earth began in water, perhaps in a tide pool that was cut off from seawater at low tide but flooded by waves at high tide. Over billions of years, complex molecules like DNA, RNA and proteins formed in this setting before, ultimately, the first cells emerged. 

RNA is a fascinating molecule. It can store information and also catalyze biochemical reactions. Scientists therefore think that RNA must have been the first of all complex molecules to form.

The problem, however, is that active RNA molecules are composed of hundreds or even thousands of bases and are very unstable. When immersed in water, RNA strands quickly break down into their constituent parts—a process known as hydrolysis. So, how could RNA have survived in the primordial soup?

In laboratory testing, the researchers from TUM and LMU used a model system of RNA bases that join together more easily than naturally occurring bases in our cells today.

Part 1

The researchers added these fast-joining RNA bases into a watery solution, provided an energy source and examined the length of the RNA molecules that formed. Their findings were sobering, as the resulting strands of up to five base pairs only survived for a matter of minutes.

The results were different, however, when the researchers started by adding short strands of pre-formed RNA. The free complementary bases quickly joined with this RNA in a process called hybridization. Double strands of three to five base pairs in length formed and remained stable for several hours.

The exciting part is that double strands lead to RNA folding, which can make the RNA catalytically active.

Double-stranded RNA therefore has two advantages: it has an extended lifespan in the primordial soup and serves as the basis for catalytically active RNA.

Another characteristic of double-stranded RNA could have helped bring about the origin of life. It is firstly important to note that RNA molecules can also form protocells. These are tiny droplets with an interior fully separated from the outside world. Yet, these protocells do not have a stable cell membrane and so easily merge with other protocells, which causes their contents to mix.

This is not conducive to evolution because it prevents individual protocells from developing a unique identity. However, if the borders of these protocells are composed of double-stranded DNA, the cells become more stable and merging is inhibited.

Christine M. E. Kriebisch et al, Template-based copying in chemically fuelled dynamic combinatorial libraries, Nature Chemistry (2024). DOI: 10.1038/s41557-024-01570-5

Part 2

**

Coinfecting viruses obstruct each other's cell invasion

The process by which phages—viruses that infect and replicate within bacteria—enter cells has been studied for over 50 years. In a new study, researchers  have used cutting-edge techniques to look at this process at the level of a single cell.

The field of phage biology has seen an explosion over the last decade because more researchers are realizing the significance of phages in ecology, evolution, and biotechnology. 

This new work is unique because we looked at phage infection at the level of individual bacterial cells.

The process of phage infection involves the attachment of the virus to the surface of a bacterium. Following this, the virus injects its genetic material into the cell. After entering, a phage can either force the cell to produce more phages and eventually explode, a process called cell lysis, or the phage can integrate its genome into the bacterial one and remain dormant, a process called lysogeny. The outcome depends on how many phages are simultaneously infecting the cell. A single phage causes lysis, while infection by multiple phages results in lysogeny.

In the current study, the researchers wanted to ask whether the number of infecting phages that bind to the bacterial surface corresponds to the amount of viral genetic material that is injected into the cell. To do so, they fluorescently labeled both the protein shell of the phages and the genetic material inside. They then grew Escherichia coli, used different concentrations of infecting phages, and tracked how many of them were able to inject their genetic material into E. coli.

Part 1

Scientists have known since the 70s that when multiple phages infect the same cell, it impacts the outcome of the infection. In this paper, they were able to take precise measurements.
The researchers were surprised to find that the entry of a phage's genetic material could be impeded by the other coinfecting phages. They found that when there were more phages attached to the surface of the cell, relatively fewer of them were able to enter.
Their data shows that the first stage of infection, phage entry, is an important step that was previously underappreciated. The researchers found that the coinfecting phages were impeding each other's entry by perturbing the electrophysiology of the cell.
The outermost layer of bacteria is constantly dealing with the movement of electrons and ions that are crucial for energy generation and transmitting signals in and out of the cell. Over the past decade, researchers have started realizing the importance of this electrophysiology in other bacterial phenomena, including antibiotic resistance. This paper opens a new avenue for research in bacterial electrophysiology—its role in phage biology.
By influencing how many phages actually enter, these perturbations affect the choice between lysis and lysogeny. This study also shows that entry can be impacted by environmental conditions such as the concentration of various ions.

 Thu Vu Phuc Nguyen et al, Coinfecting phages impede each other's entry into the cell, Current Biology (2024). DOI: 10.1016/j.cub.2024.05.032

Part 2

**

Researchers use vibrations from traffic to measure underground soil moisture

Researchers have developed a new method to measure soil moisture in the shallow subterranean region between the surface and underground aquifers. This region, called the vadose zone, is crucial for plants and crops to obtain water through their roots.

However, measuring how this underground moisture fluctuates over time and between geographical regions has traditionally relied on satellite imaging, which only gives low-resolution averages and cannot penetrate below the surface. Additionally, moisture within the vadose zone changes rapidly—a thunderstorm can saturate a region that dries out a few days later.

The new method relies upon seismic technology that normally measures how the ground shakes during earthquakes. However, it can also detect the vibrations of human activity, like traffic. As these vibrations pass through the ground, they are slowed down by the presence of water—the more moisture, the slower the vibration moves. The new study measures the water content in the vadose zone through seismic rumblings from everyday traffic.

The new method is based on a technique pioneered in the  lab, called distributed acoustic sensing (DAS). With this technique, lasers are pointed into unused underground fiber-optic cables (like the kind that provides the internet).

As a seismic wave, or any kind of vibration, passes through the cable, the laser light bends and refracts. Measuring the wiggles in this laser light gives researchers information about the passing wave, making the 10-kilometer cable equivalent to a line of thousands of conventional seismic sensors.

The ability to measure vadose zone moisture in real time is crucial for managing water use and conservation efforts. 

Fiber-optic seismic sensing of vadose zone soil moisture dynamics, Nature Communications (2024).

Streetlights running all night makes leaves so tough that insects can't eat them, threatening the food chain

Light pollution disrupts circadian rhythms and ecosystems worldwide—but for plants, dependent on light for photosynthesis, its effects could be profound. Now scientists writing in Frontiers in Plant Science have found that exposure to high levels of artificial light at night makes tree leaves grow tougher and harder for insects to eat, threatening urban food chains.

Compared to natural ecosystems, tree leaves in most urban ecosystems generally show little sign of insect damage. Scientists were curious as to why. Their observations show that   in two of the most common tree species in Beijing, artificial light at night led to increased leaf toughness and decreased levels of leaf herbivory.

Artificial light has increased levels of night-time brightness by almost 10%: most of the world's population experiences light pollution every night. Because plant properties affect their interactions with other plants and animals, any changes to plants caused by artificial light could have a significant impact on the ecosystem.

Leaves that are free of insect damage may bring comfort to people, but not insects. Herbivory is a natural ecological process that maintains the biodiversity of insects.

The scientists suspected that plants experiencing high levels of artificial light would focus on defense rather than growth, producing tougher leaves with more chemical defense compounds. 

In their experiments,  they  found that the more intense the light, the more frequently they encountered leaves that showed no signs at all of herbivory.

It is possible that trees exposed to artificial light at night may extend their photosynthesis duration. Additionally, these leaves might allocate a greater proportion of resources to structural compounds, such as fibers, which could lead to an increase in leaf toughness.

Lower levels of herbivory imply lower abundances of herbivorous insects, which could in turn result in lower abundances of predatory insects, insect-eating birds, and so on. 

If there 're less pollinating insects, that would also affect the fruit yield.

 Artificial light at night decreases leaf herbivory in typical urban areas, Frontiers in Plant Science (2024). DOI: 10.3389/fpls.2024.1392262

New biomaterial regrows damaged cartilage in joints

scientists have developed a new bioactive material that successfully regenerated high-quality cartilage in the knee joints of a large-animal model.

Although it looks like a rubbery goo, the material is actually a complex network of molecular components, which work together to mimic cartilage's natural environment in the body.

In the new study, the researchers applied the material to damaged cartilage in the animals' knee joints. Within just six months, the researchers observed evidence of enhanced repair, including the growth of new cartilage containing the natural biopolymers (collagen II and proteoglycans), which enable pain-free mechanical resilience in joints.

Stupp, Samuel I., A bioactive supramolecular and covalent polymer scaffold for cartilage repair in a sheep model, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2405454121

Sometimes mental effort is associated with unpleasant feelings, study says

If somebody complains that it hurts to think, they may be onto something, as mental exertion appears to be associated with unpleasant feelings in many situations, according to research published in the journal Psychological Bulletin.

Managers often encourage employees, and teachers often encourage students to exert mental effort. On the surface, this seems to work well: Employees and students do often opt for mentally challenging activities. From this, you may be tempted to conclude that employees and students tend to enjoy thinking hard. But the study results suggest that this conclusion would be false: In general, people really dislike mental effort.

Researchers conducted a meta-analysis of 170 studies, published between 2019 and 2020 and comprising 4,670 participants, to examine how people generally experience mental effort. They did so by testing whether mental effort is associated with unpleasant feelings and whether that association depends on the task or the population involved.

The studies used a variety of participants (e.g., health care employees, military employees, amateur athletes, college students) from 29 countries and involved 358 different cognitive tasks (e.g., learning a new technology, finding one's way around an unfamiliar environment, practicing golf swings, playing a virtual reality game).

In all studies analyzed, participants reported the level of effort they exerted as well as the extent to which they experienced unpleasant feelings such as frustration, irritation, stress or annoyance.

Across all populations and tasks, the greater the mental effort, the greater the unpleasantness experienced by participants.

These findings show that mental effort feels unpleasant across a wide range of populations and tasks.

This is important for professionals, such as engineers and educators, to keep in mind when designing tasks, tools, interfaces, apps, materials or instructions. When people are required to exert substantial mental effort, you need to make sure to support or reward them for their effort, say the researchers.

One interesting finding, according to them, was that while the association between mental effort and adverse feelings was still significant, it was less pronounced in studies conducted in Asian countries compared with those in Europe or North America!

This fits with the general idea that the aversiveness of mental effort may depend on people's learning history. High school students in Asian countries tend to spend more time on schoolwork than their European or North American counterparts and may therefore learn to withstand higher levels of mental exertion early on in their lives.

More important is the real-world observation that, despite the aversive nature of mentally challenging tasks, people still voluntarily engage in them.

The Unpleasantness of Thinking: A Meta-Analytic Review of the Association Between Mental Effort and Negative Affect, Psychological Bulletin (2024). DOI: 10.1037/bul0000443

Physicists develop new method to combine conventional internet with the quantum internet

Researchers  have developed a new transmitter-receiver concept for transmitting entangled photons over an optical fiber. This breakthrough could enable the next generation of telecommunications technology, the quantum internet, to be routed via optical fibers. The quantum internet promises eavesdropping-proof encryption methods that even future quantum computers cannot decrypt, ensuring the security of critical infrastructure.

In their experiment, the researchers demonstrated that the entanglement of photons is maintained even when they are sent together with a laser pulse. The research results were published in Science Advances.

The physicists could change the colour of a laser pulse with a high-speed electrical signal so that it matches the colour of the entangled photons. This effect enables them to combine laser pulses and entangled photons of the same colour in an optical fiber and separate them again.

This effect could integrate the conventional internet with the quantum internet.

Their experiment shows how the practical implementation of hybrid networks can succeed.

 Philip Rübeling et al, Quantum and coherent signal transmission on a single-frequency channel via the electro-optic serrodyne technique, Science Advances (2024). DOI: 10.1126/sciadv.adn8907

Excessive use of botanicals like turmeric, green tea are harming  livers

Botanicals like turmeric, green tea and black cohosh may seem benign, but their overuse is being increasingly linked to liver injury.

New research suggests that thousands are using at least one of the several leading botanicals. Many are ending up in hospitals for liver toxicity, researchers report.

Because there's almost no  regulatory oversight over botanicals, chemical tests of products linked to liver crises show frequent discrepancies between product labels and detected ingredients.

The researchers focused on the use of six of the most popular botanicals: Turmeric, green tea extract, the Garcinia cambodgia plant, black cohosh, red yeast rice and ashwagandha.

Millions of adults regularly take turmeric supplements, often with the notion that it can ease pain or arthritis. Unfortunately, "multiple randomized clinical trials have failed to demonstrate any efficacy of turmeric-containing products in osteoarthritis," and overdoing it on turmeric has been linked to serious liver toxicity, the researchers said.

Likewise, millions of  adults are estimated to be taking another potential liver toxin, green tea extract, usually to help boost energy and aid in weight loss.

But again, "multiple studies have failed to demonstrate any objective evidence of weight loss and sustained improvement in mood or energy levels" with products containing the active ingredients in green tea extract, the research  team noted.

Other claims, many unfounded, are made for other botanicals: Garcinia cambodgia is touted for weight loss, black cohosh for easing hot flashes and ashwagandha to help build muscle. But scientists noted that consumers may be overdosing on botanicals, or getting misled by labels that don't reflect the actual ingredients in their supplements. That may be leading to more users ending up in the ER.

Part 1

According to a US national database, cases of liver toxicity linked to botanical use, some severe or even fatal, nearly tripled between 2004 and 2014—from 7% of cases to 20%. Use of turmeric, green tea extract, Garcinia cambodgia were often implicated. Another study found such cases rising from 12.5% of liver toxicity cases in 2007 to 21.1% by 2015.
Who's using these botanicals? According to the new study, the most common consumer is an older (average age about 52) white (75% of users) female (57%), who was typically well-off.

People taking botanicals were more likely to be battling some kind of chronic illness, such as arthritis, thyroid disorders or cancer, compared to folks not using the supplements.
In two-thirds of cases, people took a botanical while also taking a prescription medicine, the study found. Because of the danger of drug interactions and the threat to liver health, it's crucial that botanical users inform their doctors, the research group said.
When botanicals are overused, the damage to the liver "can not only be severe, leading to hepatocellular [liver] injury with jaundice, but also fatal, leading to death or liver transplantation," the research team warned.

A prior study found that the number of liver transplants required due to botanical overuse jumped by 70% between 2009 and 2020.

 Alisa Likhitsup et al, Estimated Exposure to 6 Potentially Hepatotoxic Botanicals in US Adults, JAMA Network Open (2024). DOI: 10.1001/jamanetworkopen.2024.25822

Part 2

This Super-Black Material Made of Wood Can Absorb 99.3% of Light

A new super-black wood-based material has been created that absorbs more than 99 percent of the light that hits it. 

Researchers were working on water-repelling technologies for wood, using high-energy plasma gas – and noticed that the application of the gas turned the ends of wood cells completely black. Further examination revealed the incredible light absorption properties of the new super-black material.

The researchers  named their new material Nxylon.

Nxylon's composition combines the benefits of natural materials with unique structural features, making it lightweight, stiff and easy to cut into intricate shapes.

The material has a velvety appearance, its inventors report. The plasma treatment actually changes the tiny structures on the surface of the wood, introducing indentations that help to capture light and minimize any reflections.

Indeed, when a gold alloy was applied to the material, it remained black. This shows that the structure of the wood has changed – this isn't just an extra coating, but a reconfiguration of the fundamentals of the material.

Super-black materials are valuable in industries like astronomy, solar energy, and optics, where they help devices function more accurately or efficiently by reducing unwanted light reflection. For example, super-black materials can reduce glare and improve clarity on telescopes.

https://onlinelibrary.wiley.com/doi/10.1002/adsu.202400184

'Cool paint' for cars to keep drivers cooler

Car companies are trying  "cool paint" to keep people inside vehicles cooler, although the coating is six times thicker, making commercialization still a challenge.

The vehicles with the special paint looked like ordinary cars, but felt much cooler to the touch.

The cool paint lowered the cars' roof-panel temperature by 12 degrees Celsius (22 degrees Fahrenheit) and the interiors by 5 C (9 F).

Cooling materials are already widely used in buildings and other items. Cooler cars can reduce use of air-conditioning and relieve the toll from heat on engines and electric vehicle batteries.

They have  also been experimenting with paint that delivers lower cabin temperatures, mostly focusing on colours that refract the sun's rays.

The cool paint reflects sunlight better and also creates electromagnetic waves that block the rays, redirecting energy away from vehicles.

Source: Various news agencies

 How our brain decides what to do

 What exactly happens in our brain when we make a decision has been a mystery till now. But researchers  have found the solution. They have deciphered which brain chemical and which nerve cells mediate this decision: the messenger substance orexin and the neurons that produce it.

These neuroscientific fundamentals are relevant because many people don't take good decisions like getting enough exercise because they don't find it easy to decide. Most of us have probably already decided once or even several times to skip exercising in favor of one of the numerous alternative temptations of daily life. According to the World Health Organization, 80% of adolescents and 27% of adults don't get enough exercise. And obesity is increasing at an alarming rate not only among adults but also among children and adolescents.

Despite these statistics, many people manage to resist the constantly present temptations and get enough exercise.

In their experiments with mice, the researchers were able to show that orexin plays a key role in taking decisions. It's one of over a hundred messenger substances that are active in the brain. Other chemical messengers, such as serotonin and dopamine, were discovered a long time ago and their role has largely been decoded. The situation for orexin is different: Researchers discovered it relatively late, around 25 years ago, and they are now clarifying its functions step by step.

In neuroscience, dopamine is a popular explanation till now  for why we choose to do some things but avoid others. This brain messenger is critical for our general motivation. However, our current knowledge about dopamine does not easily explain why we decide to exercise instead of eating. Our brain releases dopamine both when we eat and when we exercise, which does not explain why we choose one over the other.

To find out what does explain this, the researchers devised a sophisticated behavioral experiment for mice, which were able to choose freely from among eight different options in ten-minute trials. These included a wheel they could run on and a "milkshake bar" where they could enjoy a standard strawberry-flavored milkshake.

"Mice like a milkshake for the same reason people do: It contains lots of sugar and fat and tastes good.

In their experiment, the scientists compared different groups of mice: one made up of normal mice and one in which the mice's orexin systems were blocked, either with a drug or through genetic modification of their cells.

The mice with an intact orexin system spent twice as much time on the running wheel and half as much time at the milkshake bar as the mice whose orexin system had been blocked. Interestingly, however, the behavior of the two groups didn't differ in experiments in which the scientists only offered the mice either the running wheel or the milkshake.

This means that the primary role of the orexin system is not to control how much the mice move or how much they eat. Rather, it seems central to making the decision between one and the other, when both options are available. Without orexin, the decision was strongly in favor of the milkshake, and the mice gave up exercising in favour of eating.

researchers expect that orexin may also be responsible for this decision in humans; the brain functions involved here are known to be practically the same in both species.

The researchers are now trying to verify this  in humans too.

Part 1

This could involve examining patients who have a restricted orexin system for genetic reasons—this is the case in around one in two thousand people. These people suffer from narcolepsy (a sleeping disorder). Another possibility would be to observe people who receive a drug that blocks orexin. Such drugs are authorized for patients with insomnia.

If we understand how the brain arbitrates between food consumption and physical activity, we can develop more effective strategies for addressing the global obesity epidemic and related metabolic disorders.
Interventions could be developed to help overcome exercise barriers in healthy individuals and those whose physical activity is limited.

Orexin neurons mediate temptation-resistant voluntary exercise, Nature Neuroscience (2024). DOI: 10.1038/s41593-024-01696-2

Looking inside a microchip with 4 nanometer precision: New X-ray world record

Researchers  have used X-rays to look inside a microchip with higher precision than ever before. The image resolution of 4 nanometers marks a new world record. The high-resolution three-dimensional images of the type they produced will enable advances in both information technology and the life sciences.

The researchers  reported their findings in the current issue of the journal Nature.

Since 2010, the scientists have been developing microscopy methods with the goal of producing three-dimensional images in the nanometer range. In their current research, they have succeeded for the first time in taking pictures of state-of-the-art computer chips microchips with a resolution of 4 nanometers—a world record.

Instead of using lenses, with which images in this range are not currently possible, the scientists resort to a technique known as ptychography, in which a computer combines many individual images to create a single, high-resolution picture. Shorter exposure times and an optimized algorithm were key to significantly improving upon the world record they themselves set in 2017. For their experiments, the researchers used X-rays from the Swiss Light Source SLS at PSI.

Tomas Aidukas et al, High-performance 4-nm-resolution X-ray tomography using burst ptychography, Nature (2024). DOI: 10.1038/s41586-024-07615-6

What Your Nails Say About Your Health

https://youtu.be/PRftXdvENRw?si=VgUs4ne4n_eT2KL_

Domestication causes smaller brain size in dogs than in the wolf: Study challenges notion

A recent study, published in Biology Letters, challenges the long-held notion that domestication is the primary driver of reduced brain size in domesticated animals, specifically dogs.

Employing a phylogenetic comparative approach, researchers  show that the domesticated dog does not exhibit an exceptionally small brain relative to its body size compared to other canid species, suggesting that  domestication is not as unique an evolutionary force as previously thought.

The prevailing belief has been that domestication leads to a significant reduction in brain size due to relaxed selection pressures, such as reduced need for foraging, mating competition, and predator avoidance.

This phenomenon is thought to be a result of the decreased necessity for metabolically costly brain tissue in a domesticated environment. While domesticated dogs show a substantial decrease in brain size compared to their wild ancestor, the gray wolf (Canis lupus), this study aimed to determine if this reduction is exceptional when viewed in a broader phylogenetic context.

Researchers analyzed brain and body size data for 25 canid species, including ancient dog breeds that are genetically closer to the ancestral domesticated dog.

Their phylogenetic predictions and allometric regressions showed that the reduction in brain size in domesticated dogs is not an unambiguous evolutionary singularity. The observed brain size in dogs fell within the expected range for most ancient breeds used in the study, suggesting that domestication is not uniquely influential in reducing brain size among canids.

Interestingly, the study found that the common raccoon dog (Nyctereutes procyonoides), which hibernates, is a more pronounced outlier in terms of brain size reduction. Hibernation, associated with prolonged periods of low metabolic activity and food scarcity, is hypothesized to constrain brain size evolution due to the high energy demands of large brains.

Part 1

The raccoon dog's significantly smaller brain size supports this hypothesis, highlighting that factors other than domestication, such as ecological adaptations like hibernation, can also drive reductions in brain size.

The study concludes that while domestication does contribute to brain size reduction in dogs, it should not be overemphasized as a uniquely powerful evolutionary force.

The findings suggest that other ecological and evolutionary pressures can similarly affect brain size and can mediate extreme variations in non-domesticated species as well. A more balanced and less human-focused perspective could refine our understanding of the complex interplay between domestication and brain size evolution in mammals.

 László Zsolt Garamszegi et al, The reduction in relative brain size in the domesticated dog is not an evolutionary singularity among the canids, Biology Letters (2024). DOI: 10.1098/rsbl.2024.0336 , royalsocietypublishing.org/doi … .1098/rsbl.2024.0336

Part 2

Modern aircraft emit less carbon than older aircraft, but their contrails may do more environmental harm

Modern commercial aircraft flying at high altitudes create longer-lived planet-warming contrails than older aircraft, a new study has found.

The result means that although modern planes emit less carbon than older aircraft, they may be contributing more to climate change through contrails.

The study highlights the immense challenges the aviation industry faces to reduce its impact on the climate. The new study also found that private jets produce more contrails than previously thought, potentially leading to outsized impacts on climate warming.

Contrails, or condensation trails, are thin streaks of cloud created by aircraft exhaust fumes that contribute to global warming by trapping heat in the atmosphere.

While the exact warming effect of contrails is uncertain, scientists think it is greater than warming caused by carbon emissions from jet fuel.
Published in Environmental Research Letters, the study used machine learning to analyze satellite data on more than 64,000 contrails from a range of aircraft flying over the North Atlantic Ocean.

Modern aircraft that fly at above 38,000 feet (about 12km), such as the Airbus A350 and Boeing 787 Airliners, create more contrails than older passenger-carrying commercial aircraft, the study found.

To reduce jet fuel consumption, modern aircraft are designed to fly at higher altitudes where the air is thinner with less aerodynamic drag, compared to older commercial aircraft, which usually fly at slightly lower altitudes (around 35,000ft/11km).

This means these higher-flying aircraft create less carbon emissions per passenger. However, it also means they create contrails that take longer to dissipate—creating a warming effect for longer and a complicated trade-off for the aviation industry.

Part 1

It's common knowledge that flying is not good for the climate. However, most people do not appreciate that contrails and jet fuel carbon emissions cause a double-whammy warming of the climate.
This study throws a spanner in the works for the aviation industry. Newer aircraft are flying higher and higher in the atmosphere to increase fuel efficiency and reduce carbon emissions. The unintended consequence of this is that these aircraft flying over the North Atlantic are now creating more, longer-lived, contrails, trapping additional heat in the atmosphere and increasing the climate impact of aviation.
This finding reflects the challenges the aviation industry faces when reducing its climate impact.
The study did confirm a simple step that can be taken to shorten the lifetime of contrails: Reduce the amount of soot emitted from aircraft engines, produced when fuel burns inefficiently.

Modern aircraft engines are designed to be cleaner and typically emit fewer soot particles, which cuts down the lifetime of contrails.

While other studies using models have predicted this phenomenon, the study published today is the first to confirm it using real-world observations.
Even higher in the sky, the researchers found that private jets create contrails more often than previously thought—adding to concerns about the excessive use of these aircraft by the super-rich.

Despite being smaller and using less fuel, private jets create similar contrails to much larger commercial aircraft, the analysis found.
Private jets fly higher than other planes, more than 40,000 feet above earth where there is less air traffic. However, like modern commercial aircraft creating more contrails compared to lower-flying older commercial aircraft, the high altitudes flown by private jets means they create outsized contrails.

 Operational differences lead to longer lifetimes of satellite detectable contrails from more fuel efficient aircraft, Environmental Research Letters (2024). DOI: 10.1088/1748-9326/ad5b78

Part 2

Why your best friends' genes matter

"Choose your friends wisely, no scientifically". Because ....

A study by researchers shows that your best friend's traits can rub off on you—especially ones that are in their genes.

The genetic makeup of adolescent peers may have long-term consequences for individual risk of drug and alcohol use disorders, depression and anxiety, the groundbreaking study has found.

Peers' genetic predispositions for psychiatric and substance-use disorders are associated with an individual's own risk of developing the same disorders in young adulthood.

The data of this study exemplifies the long reach of social genetic effects.

Socio-genomics—the influence of one person's genotype on the observable traits of another—is an emerging field of genomics. Research suggests that peers' genetic makeup may influence health outcomes of their friends.

In the studies conducted, even when controlling for factors such as the target individuals' own genetic predispositions and family socioeconomic factors, the researchers found a clear association between peers' genetic predispositions and target individuals' likelihood of developing a substance use or psychiatric disorder. The effects were stronger among school-based peers than geographically defined peers.

Within school groups, the strongest effects were among upper secondary school classmates, particularly those in the same vocational or college-preparatory track between ages 16 and 19. Social genetic effects for school-based peers were greater for drug and alcohol use disorders than major depression and anxiety disorder.

More research is needed to understand why these connections exist. 

The most obvious explanation for why peers' genetic predispositions might be associated with our own well-being is the idea that our peers' genetic predispositions influence their phenotype, or the likelihood that peers are also affected by the disorder.

This research also underscores the importance of disrupting processes and risks that extend for at least a decade after attendance in school. Peer genetic influences have a very long reach.

Peer Social Genetic Effects and the Etiology of Substance Use Disorders, Major Depression, and Anxiety Disorder in a Swedish National Sample, American Journal of Psychiatry (2024). DOI: 10.1176/appi.ajp.20230358

Researchers show that pesticide contamination is more than apple-skin deep

Pesticides and herbicides are critical to ensuring food security worldwide, but these substances can present a safety risk to people who unwittingly ingest them. Protecting human health, therefore, demands sensitive analytical methods to identify even trace levels of potentially harmful substances. Now, researchers reporting in Nano Letters have developed a high-tech imaging method to detect pesticide contamination at low levels, and its application on fruits reveals that current food safety practices may be insufficient.

The analytical method called surface-enhanced Raman spectroscopy (SERS) is gaining popularity as a nondestructive method for detecting chemicals from modern farming on produce. With SERS, metal nanoparticles or nanosheets are used to amplify the signals created by molecules when they are exposed to a Raman laser beam. The patterns created by the metal-enhanced scattered light serve as molecular signatures and can be used to identify small amounts of specific compounds.

In tests of the silver-embedded membrane for food safety applications, the researchers sprayed the pesticides thiram and carbendazim, alone or together, onto apples, air-dried the fruits and then washed them to mimic everyday practices. When they laid their membrane over the apples, SERS detected pesticides on the apples, even though the chemicals were present at low concentrations. The team was also able to clearly resolve scattered-light signatures for each pesticide on apples sprayed with both thiram and carbendazim, as well as detect pesticide contamination through the fruit's peel and into the outermost layer of pulp.

But the pigmented skin of apple is very important.  A raw apple with skin contains up to 332% more vitamin K, 142% more vitamin A, 115% more vitamin C, 20% more calcium, and up to 19% more potassium than a peeled apple does.

The peel of 1 apple will contain about 8.4 mg of vitamin C and 98 IU of vitamin A. When eating apples, if you peel them off, the amount of this vitamin will decrease. down to 6.4 mg of Vitamin C and 61 IU of Vitamin A.

You can't remove them without severely effecting the nutrient quality of the fruits.

However, these results suggest that washing alone could be insufficient to prevent pesticide ingestion and that peeling would be required to remove potential contamination in the skin and outer pulp, the researchers say. Beyond apples, they also used the SERS membrane system to detect pesticides on cucumbers, shrimp, chili powder and rice.

But Cellulose Surface Nanoengineering for Visualizing Food Safety, Nano Letters (2024). DOI: 10.1021/acs.nanolett.4c01513 , pubs.acs.org/doi/abs/10.1021/acs.nanolett.4c01513

Bacterial gut diversity improves the athletic performance of racehorses

The composition of gut bacteria of thoroughbred racehorses at one month old can predict their future athletic performance, according to a new study. 

In the study, foals with lower bacterial diversity at 28 days old also had a significantly increased risk of respiratory disease later in life.

This study is published in the journal Scientific Reports.

Researchers from Surrey's School of Veterinary Medicine and School of Bioscience 

investigated the composition of gut bacteria in thoroughbred foals bred for flat racing and its impact on their long-term health and athletic performance.

To investigate this, 438 fecal samples from 52 foals were analyzed, and respiratory, gastrointestinal, orthopedic and soft-tissue health issues were tracked from birth to age three. In addition, the team analyzed information regarding finishing position, official rating, and total prize money earnings as measures of athletic performance.

Minimizing the risk of disease and injury is important for the welfare of racehorses, and maximizing their athletic potential is important for their owners. Researchers have now found that gut health, in particular the health of gut bacterial communities very early in life, exerts a profound and enduring impact on racehorse health and performance.

Researchers found that the athletic performance of the foals was positively associated with higher fecal bacterial diversity at one month old. They identified that a higher abundance of the bacteria Anaeroplasmataceae was associated with a higher official rating (an evaluation of a horse based on its past performances), and increased levels of Bacillaceae at 28 days old were linked to higher race placings.

The team also investigated the long-term impact of foals receiving antibiotics during the first month of life. It was found that these foals had significantly lower fecal bacterial diversity at 28 days old than other foals who did not receive such treatments. Further analysis revealed that these foals won significantly lower prize money (an indicator of athletic performance) in their subsequent racing careers. In addition, foals who received antibiotics during their first 28 days of life had a significantly increased rate of developing a respiratory disease compared to their counterparts.

Interestingly, researchers also identified that low gut bacterial diversity in early life is associated with an increased risk of soft-tissue and orthopedic issues developing later in life. Researchers believe that the health impacts of low gut bacterial diversity in early life are likely to be related to immunological priming.

Work is currently underway to develop novel probiotics that will enhance the gut health of foals in early life and to investigate how antibiotics can be used while preserving gut health.

DNA fragments help detect kidney organ rejection

Findings from a study published in Nature Medicine show that donor-derived cell-free DNA (dd-cfDNA), also called liquid biopsy, has the potential for early detection of kidney transplant rejection.

The international study enrolled a diverse population of nearly 3,000 kidney transplant recipients—both adult and pediatric—from 14 transplantation centers in Europe and the U.S. The Department of Pediatrics at Washington University School of Medicine in St. Louis contributed one of the two pediatric datasets involved in the study.
When cells undergo apoptosis or necrosis, they release small fragments of DNA, known as cell-free DNA (cf-DNA), into the bloodstream. In inflammation associated with transplant rejection, dying cells release donor-derived cell-free DNA (dd-cfDNA). Researchers found those dd-cfDNA levels were strongly correlated with different types of transplant rejection, including antibody-mediated rejection, T cell-mediated rejection and mixed rejection. The study found similar accuracy in children and adults.

Often unnecessary and invasive graft biopsies are currently considered the "gold standard" in diagnosing transplant rejection, but dd-cfDNA could provide a non-invasive, accurate biomarker to reduce the need for biopsy.

While biopsies will continue as the method of rejection diagnosis, dd-cfDNA may improve early rejection diagnosis and enhance the care of kidney transplant recipients.

Olivier Aubert et al, Cell-free DNA for the detection of kidney allograft rejection, Nature Medicine (2024). DOI: 10.1038/s41591-024-03087-3

Processing traumatic memories during sleep leads to changes in the brain associated with improvement in PTSD symptoms

Currently, the first-choice treatment for PTSD is exposure-based psychotherapy, where therapists help rewire the emotions associated with the traumatic memory in the patient's brain, shifting from fear and arousal to a more neutral response.

PTSD is a mental health disorder that can occur after experiencing or witnessing a traumatic event. People with PTSD may experience flashbacks, nightmares, heightened vigilance, hyper-arousal, and mood and sleep problems. Currently available treatments for PTSD include eye movement desensitization and reprocessing (EMDR), where therapists guide patients through their traumatic memories while using a moving light or clicking sounds to distract them.

However, up to 50% of patients fail to respond well to this treatment.

EMDR has shown positive results, but  that success is low and dropping out from the treatment program is common among patients because revisiting traumatic memories is emotionally demanding.

In a study published on August 7 in Current Biology, scientists show for the first time that reactivating therapeutically-altered memories during sleep leads to more brain activity related to memory processing, which is associated with a reduction in PTSD symptoms.

Sleep provides a unique opportunity to enhance the memory of newly formed emotional reactions to traumatic events. During sleep, the brain focuses on consolidating memories and storing information for the long term.

Previous research has shown that if someone forms a new memory in the presence of an experimentally administered sound or scent, exposing them to the sound or scent while they sleep can improve their ability to recall that memory after waking up. This memory-enhancement technique is called targeted memory reactivation (TMR).

TMR has no negative effects on these patients. None of the patients reported more nightmares or worsened sleep after TMR.

Many psychiatric disorders, such as phobias, anxiety disorders, and addiction, are also related to maladaptive memories. This new work can inspire future research to explore the beneficial effects of TMR in treating other conditions.

Targeted memory reactivation to augment treatment in post-traumatic stress disorder, Current Biology (2024). DOI: 10.1016/j.cub.2024.07.019. www.cell.com/current-biology/f … 0960-9822(24)00922-9

Nanomaterials may enhance plant tolerance to high soil salt levels

Soil salt concentrations above the optimal threshold for plant growth can threaten global food security by compromising agricultural productivity and crop quality. An analysis published in Physiologia Plantarum has examined the potential of nanomaterials—which have emerged over the past decade as a promising tool to mitigate such "salinity stress"—to address this challenge.

Nanomaterials, which are tiny natural or synthetic materials, can modulate a plant's response to salinity stress through various mechanisms, for example by affecting the expression of genes related to salt tolerance or by enhancing physiological processes such as antioxidant activities.
When investigators assessed 495 experiments from 70 publications related to how different nanomaterials interact with plants under salinity stress, they found that nanomaterials enhance plant performance and mitigate salinity stress when applied at lower dosages. At higher doses, however, nanomaterials are toxic to plants and may even worsen salinity stress.

Also, plant responses to nanomaterials vary across plant species, plant families, and nanomaterial types.

Meta-analysis of nanomaterials and plants interaction under salinity stress, Physiologia Plantarum (2024). DOI: 10.1111/ppl.14445

Scientists uncover hidden forces causing continents to rise

Scientists have answered one of the most puzzling questions in plate tectonics: how and why "stable" parts of continents gradually rise to form some of the planet's greatest topographic features?

They have found that when tectonic plates break apart, powerful waves are triggered deep within the Earth that can cause continental surfaces to rise by over a kilometer.
Their findings help resolve a long-standing mystery about the dynamic forces that shape and connect some of the Earth's most dramatic landforms—expansive topographic features called 'escarpments' and 'plateaus' that profoundly influence climate and biology.

The new research examined the effects of global tectonic forces on landscape evolution over hundreds of millions of years. The findings are published Aug 8 in the journal Nature.

The research  results help explain why parts of the continents previously thought of as "stable" experience substantial uplift and erosion, and how such processes can migrate hundreds or even thousands of kilometers inland, forming sweeping elevated regions known as plateaus, like the Central Plateau of South Africa.

The researchers  discovered that when continents split apart, the stretching of the continental crust causes stirring movements in Earth's mantle (the voluminous layer between the crust and the core).

This process can be compared to a sweeping motion that moves towards the continents and disturbs their deep foundations.

The team noticed an interesting pattern: the speed of the mantle "waves" moving under the continents in their simulations closely matched the speed of major erosion events that swept across the landscape in Southern Africa following the breakup of the ancient supercontinent Gondwana.

The scientists pieced together evidence to propose that the Great Escarpments originate at the edges of ancient rift valleys, much like the steep walls seen at the margins of the East African Rift today. Meanwhile, the rifting event also sets about a "deep mantle wave" that travels along the continent's base at about 15–20 kilometers per million years.

This wave convectively removes layers of rock from the continental roots.

Much like how a hot-air balloon sheds weight to rise higher, this loss of continental material causes the continents to rise—a process called isostasy.

Part 1

Building on this, the team modeled how landscapes respond to this mantle-driven uplift. They found that migrating mantle instabilities give rise to a wave of surface erosion that lasts tens of millions of years and moves across the continent at a similar speed. This intense erosion removes a huge weight of rock that causes the land surface to rise further, forming elevated plateaus.
Their landscape evolution models show how a sequence of events linked to rifting can result in an escarpment as well as a stable, flat plateau, even though a layer of several thousands of meters of rocks has been eroded away.
The team's study provides a new explanation for the puzzling vertical movements of cratons far from the edges of continents, where uplift is more common.
The team has concluded that the same chain of mantle disturbances that trigger diamonds to quickly rise from Earth's deep interior also fundamentally shape continental landscapes, influencing a host of factors from regional climates and biodiversity to human settlement patterns.

Thomas Gernon, Co-evolution of craton margins and interiors during continental break-up, Nature (2024). DOI: 10.1038/s41586-024-07717-1. www.nature.com/articles/s41586-024-07717-1

Part 2

**

Microbes conquer the next extreme environment: Your microwave

Since the industrial revolution, microbes have successfully colonized one novel type of habitat after another: for example, marine oil spills, plastic floating in the oceans, industrial brownfields, and even the interior of the International Space Station.

However, it turns out that one extreme environment harboring a specialized community of highly adapted microbes is much closer to home: inside microwaves. This finding has now been reported for the first time by researchers  in a study in Frontiers in Microbiology. It's not only important from the perspective of hygiene, but could also inspire biotechnological applications—if the strains found inside microwaves can be put to good use in industrial processes that require especially hardy bacteria.

The research results reveal that domestic microwaves have a more 'anthropized' microbiome, similar to kitchen surfaces, while laboratory microwaves harbour bacteria that are more resistant to radiation.

Researchers sampled microbes from inside 30 microwaves: 10 each from single-household kitchens, another 10 from shared domestic spaces--for example, corporate centers, scientific institutes, and cafeterias--and 10 from molecular biology and microbiology laboratories. The aim behind this sampling scheme was to see if these microbial communities are influenced by food interactions and user habits.

The team used two complementary methods to inventorize the microbial diversity: next-generation sequencing and cultivation of 101 strains in five different media.

In total, the researchers found 747 different genera within 25 bacterial phyla. The most frequently encountered phyla were Firmicutes, Actinobacteria, and especially Proteobacteria.

They found that the composition of the typical microbial community partly overlapped between shared domestic and single-household domestic microwaves, while laboratory microwaves were quite different. The diversity was lowest in single-household microwaves, and highest in laboratory ones.

Part 1

However, it was also similar to the microbiome in an industrial habitat: namely, on solar panels. The authors proposed that the constant thermal shock, electromagnetic radiation, and desiccation in such highly irradiated environments has repeatedly selected for highly resistant microbes, in the same manner as in microwaves.

For both the general public and laboratory personnel, the researchers recommend regularly disinfecting microwaves with a diluted bleach solution or a commercially available disinfectant spray. In addition, it is important to wipe down the interior surfaces with a damp cloth after each use to remove any residue and to clean up spills immediately to prevent the growth of bacteria.

The microwave bacteriome: biodiversity of domestic and laboratory microwave ovens, Frontiers in Microbiology (2024). DOI: 10.3389/fmicb.2024.1395751

Part 2

Lens-free fluorescence instrument detects deadly microorganisms in drinking water

Researchers have shown that a fluorescence detection system that doesn't contain any lenses can provide highly sensitive detection of deadly microorganisms in drinking water. With further development, the new approach could provide a low-cost and easy-to-use way to monitor water quality in resource-limited settings such as developing countries or areas affected by disasters.

It could also be useful when water safety results are needed quickly, such as for swimming events, a concern highlighted during the Paris Olympics.

Current methods used to assess microbial contamination in water require culturing the water samples and then quantifying harmful bacteria. This can take over 18 hours, making it impractical when immediate confirmation of water safety is needed. This is also a key reason why water surveillance is ineffective in developing countries, where the required skilled human resources, infrastructure and reagents are not readily available.

The  new water monitoring fluorometer can detect fluorescent proteins from bacteria in water down to levels of less than one part per billion, without using any lenses.

This sensitivity meets the World Health Organization's criteria for detecting fecal contamination in drinking water.

During development, the researchers closely examined the fundamentals of optical signal generation in applications like water quality monitoring.

They discovered that while optical lenses are commonly used in devices such as cameras, microscopes and telescopes, these optical components often reduce performance for practical situations that don't require images.

This was an important finding because lenses account for a significant share of the costs of optical systems and their bulk and weight make it difficult to create practical portable devices.

The new analysis revealed that using a light source, detectors and sample sizes that are all as large and as close to each other as possible produces a stronger signal, leading to better performance for water quality monitoring.

Part 1

Based on their findings, the researchers designed a lensless fluorescence system using large (1–2 mm2) LEDs and detectors, which have recently become available in UV wavelengths. It works by using UV light to excite proteins from harmful microbes and then detecting the resulting fluorescence.

In addition to demonstrating the lensless system's sensitivity, they also showed that it produced a fluorescence signal that is about double the strength of a lensed system. They found that the performance of the lensed system was limited by its numerical aperture, the use of larger sources and detectors and the finite imaging distance required between the components and the sample.

The researchers are now developing a pocket-sized version of the lensless fluorometers for field testing.

 Asim Maharjan et al, Lensless fluorometer outperforms lensed system, Optica (2024). DOI: 10.1364/OPTICA.527289

Part 2

Study observes that similarities between physical and biological systems might be greater than we think

A crowd or a flock of birds have different characteristics from those of atoms in a material, but when it comes to collective movement, the differences matter less than we might think. We can try to predict the behavior of humans, birds, or cells based on the same principles we use for particles.

This is the finding of a study published in the Journal of Statistical Mechanics: Theory and Experiment, JSTAT, conducted by an international team of researchers.  The study, based on the physics of materials, simulated the conditions that cause a sudden shift from a disordered state to a coordinated one in "self-propelled agents" (like biological ones).

"In a way, birds are flying atoms", say the researchers, " It may sound strange, but indeed, one of our main findings was that the way a walking crowd moves, or a flock of birds in flight, shares many similarities with the physical systems of particles". 

In the field of collective movement studies, it has been assumed that there is a qualitative difference between particles (atoms and molecules) and biological elements (cells, but also entire organisms in groups). It was especially believed that the transition from one type of movement to another (for example, from chaos to an orderly flow, known as a phase transition) was completely different.

The crucial difference for physicists in this case has to do with the concept of distance. Particles moving in a space with many other particles influence each other primarily based on their mutual distance. For biological elements, however, the absolute distance is less important.

Take a pigeon flying in a flock: what matters to it are not so much all the closest pigeons, but those it can see." In fact, according to the literature, among those it can see, it can only keep track of a finite number, due to its cognitive limits.

The pigeon, in the physicists' jargon, is in a "topological relationship" with other pigeons: two birds could be at quite a large physical distance, but if they are in the same visible space, they are in mutual contact and influence each other.

It was long thought that this type of difference led to a completely different scenario for the emergence of collective motion This new study, however, suggests that this is not a crucial difference.

These statistical models, based on the physics of particles, can  also help us understand biological collective movement.

Fluctuation-Induced First Order Transition to Collective Motion, Journal of Statistical Mechanics Theory and Experiment (2024). DOI: 10.1088/1742-5468/ad6428

**

How intermittent fasting regulates aging through autophagy

Research published recently in Nature Cell Biology, sheds light on the mechanism through which spermidine regulates autophagy, a process that ensures the recycling of components within the cell, to promote the anti-aging effects of intermittent fasting.

The work demonstrated that intermittent fasting increases the levels of spermidine, a chemical compound (natural polyamine), that enhances the resilience and survival of cells and organisms, through the activation of autophagy.  

Autophagy is a process of cellular recycling, the destruction of non-functional/unnecessary components and organelles of the cell. Autophagy defects have been linked to aging, as well as, with the emergence of age-related disorders, such as diabetes, cardiovascular diseases, cancer and neurodegenerative diseases.

Dietary habits, such as low or high-fat diet, over-nutrition, or fasting can influence the development of these chronic diseases, the prevalence of which is expected to increase considerably in the coming years. Dietary interventions, such as caloric restriction and intermittent fasting, can slow down aging and promote longevity.

A key element of these interventions is the maintenance of cellular homeostasis through the induction of autophagy. Direct administration of spermidine is an alternative strategy for inducing autophagy and extending lifespan. However, the role of spermidine in the regulation of autophagy and aging upon intermittent fasting remains unclear.

Using a range of experimental models, ranging from the nematode (Caenorhabditis elegans), yeast (Saccharomyces cerevisiae), fruit fly (Drosophila melanogaster), mouse (Mus musculus), and human cell lines, the research teams of this study have shown that intermittent fasting increases the cellular levels of spermidine, which in turn induces autophagy, resulting in the prolongation of lifespan in these organisms.

Conversely, inhibition of spermidine synthesis, using appropriate inhibitors, counteracts the benefits of autophagy on lifespan through intermittent fasting.

The results of the research highlight the critical role of spermidine in regulating autophagy under intermittent fasting, thereby improving lifespan expectancy across all model organisms studied. The fact that the regulation of autophagy through spermidine and intermittent fasting is an evolutionarily conserved process, underscores its central role in monitoring and maintaining cellular homeostasis across different organisms.

Sebastian J. Hofer et al, Spermidine is essential for fasting-mediated autophagy and longevity, Nature Cell Biology (2024). DOI: 10.1038/s41556-024-01468-x

Scientists unravel how the BCG vaccine leads to the destruction of bladder cancer cells

Using zebrafish "avatars," an animal model developed by the Cancer Development and Innate Immune Evasion lab, researchers studied the initial steps of the Bacillus Calmette-Guérin (BCG) vaccine's action on bladder cancer cells.

Their results, which are published in the journal Disease Models and Mechanisms, show that macrophages—the first line of immune cells activated after an infection—literally induce the cancer cells to commit suicide and then rapidly eat away the dead cancer cells.

The BCG vaccine was first used against TB in the 1920's and then started to be used as the first cancer immunotherapy around 1976. But decades before that, in the 1890's, William Coley, a surgeon working at the New York Hospital (now Weill Cornell Medical Center) had already tested a mix of different bacteria, coined "Coley's toxins," as a cancer immunotherapy.

Coley had noticed that several virtually hopeless cancer patients at the hospital went into seemingly "miraculous" remissions from their cancer when they caught a bacterial infection following the surgery performed to remove their tumors (sterile conditions for surgical procedures were then less than optimal). His idea was that such recoveries, far from being miraculous, were in fact caused by an immune response of the patients to the infection.

Coley started trying to induce bacterial infections in a number of sarcoma patients and was able to reproduce a few cancer remissions. At the time, though, his method was far from being proven and safe—and meanwhile, other treatment methods were developed, such as radiotherapy—so his research was not pursued. But in recent years, the field of immunotherapy has gained enormous momentum, bringing new and more scientifically robust ways of boosting the immune system to fight cancer. 

BCG immunotherapy is still rather empirically used. However, since it works for many people, it has become a gold standard treatment. Surprisingly, it is a very effective immunotherapy, even when compared to so many fancy immunotherapies that are being developed."

The treatment consists of instilling the BCG vaccine directly into the bladder. When the treatment works, the 15-year survival rate for patients with so-called "non-muscle-invasive" (early-stage) bladder cancer is 60% to 70%. However, in 30% to 50% of the cases, bladder tumors are unresponsive to BCG treatment. In these cases, the whole bladder has to be removed.

Macrophages directly kill bladder cancer cells through TNF signaling in an early response to BCG therapy, Disease Models & Mechanisms (2024). DOI: 10.1242/dmm.050693

Research demonstrates genetically diverse crowds are wiser

A new study by researchers reveals that genetically diverse groups make more accurate collective judgments compared to genetically homogeneous groups.

The research, published in Personality and Individual Differences, provides new insights into the origins of the 'wisdom of crowds' phenomenon, emphasizing the role of genetic diversity in enhancing collective intelligence.

Past studies have suggested that combining individual judgments can improve accuracy, especially when individuals differ in background, education, and demography.

The study involved 602 identical and fraternal twins, who participated by making numerical judgments in pairs. These pairs consisted either of co-twins (related pairs) or non-related individuals (unrelated pairs).

The results of this study revealed that judgments made by unrelated (i.e., heterogenous) pairs were more accurate than those made by related (i.e., homogeneous) pairs. Theoretically, however, this finding could emerge either from environmental or genetic factors.

In order to distinguish between environmental and genetic factors, the study compared the performance of related and unrelated pairs, separately among identical and fraternal twins.
This comparison is relevant as genetic influences make identical twins more similar to one another compared to fraternal twins, because the former share virtually 100% of their genetic variance, whereas fraternal twins share, on average, 50% of the genetic variance.


The findings revealed that the superior performance of unrelated versus related pairs was evident for the identical twins. This underscores the impact of genetic relatedness on collective judgment.

This research is the first empirical demonstration of the benefits of genetic diversity for collective judgments.
The findings suggest that genetic diversity enhances the collective cognitive abilities of groups, providing a deeper understanding of how diverse crowds can achieve wiser outcomes. By uniquely highlighting the genetic aspect, this research adds a new dimension to the 'wisdom of crowds' phenomenon.
These findings highlight the significant impact genetic diversity can have on collective decision-making, underscoring the importance of embracing diversity in all its forms to enhance our cognitive abilities and tackle complex challenges more effectively.

Meir Barneron et al, Genetically-diverse crowds are wiser, Personality and Individual Differences (2024). DOI: 10.1016/j.paid.2024.112823

Part 2

The fat-gut-cancer link
A study in mice and people suggests why there is a link between obesity and some cancers: a high-fat diet increases the number of Desulfovibrio bacteria in the gut. These release leucine, an amino acid, which encourages the proliferation of a kind of cell that suppresses the immune system. With a suppressed immune system, breast cancer tumour growth increases. 

https://www.pnas.org/doi/10.1073/pnas.2306776121?utm_source=Live+Au...

A crustacean positively too beautiful to eat

Rare "cotton candy" lobster found in New Hampshire

This lobster's shell was a swirling mass of blue, purple, and pink pigments, which looked like glazed, opalescent pottery when wet.

Serotonin changes how people learn and respond to negative information

It is easy to advice, 'be positive, be happy, don’t respond to bad criticism, be in control of your emotions'. But can people really do this in real life situations without the help of their biochemistry?

And without a tough training to improve their behaviour?

NO!

Increasing serotonin can change how people react and learn from negative information, as well as improving how they respond to it, according to a new study published in the journal Nature Communications.

The study by scientists found people with increased serotonin levels had reduced sensitivity to punishing outcomes (for example, losing money in a game) without significantly affecting sensitivity to rewarding ones (winning money).

The researchers found that increasing serotonin made individuals better able to control their behaviour, particularly when exposed to negative information. The study also showed that elevated serotonin levels benefited different types of memory.

These findings shed new light on how serotonin shapes human behaviour, particularly in negative environments.

This provides us with some exciting new information about the role of serotonin in humans. It shows that serotonin, which has been implicated in depression and in the effects of antidepressants, has more of a role in processing negative things, rather than boosting  good responses.

These findings underscore the central role that serotonin plays in effortful cognitive processes, such as our ability to put the brakes on unwanted behaviors. This study helps to further understand why drugs that change serotonin levels are effective treatments for many mental illnesses, including depression, anxiety and obsessive-compulsive disorder. 

Michael J. Colwell et al, Direct serotonin release in humans shapes aversive learning and inhibition, Nature Communications (2024). DOI: 10.1038/s41467-024-50394-x

Unknown mechanism essential for bacterial cell division

How does matter, lifeless by definition, self-organize and make us alive? One of the hallmarks of life, self-organization, is the spontaneous formation and breakdown of biological active matter. However, while molecules constantly fall in and out of life, one may ask how they "know" where, when, and how to assemble, and when to stop and fall apart.

Researchers tried to address  these questions in the context of bacterial cell division. They developed a computational model for the assembly of a protein called FtsZ, an example of active matter. 

A previously unknown mechanism of active matter self-organization essential for bacterial cell division follows the motto "dying to align": Misaligned filaments "die" spontaneously to form a ring structure at the center of the dividing cell. The study, led by the Šarić group at the Institute of Science and Technology Austria (ISTA), was published in Nature Physics. The work could find applications in developing synthetic self-healing materials.

During cell division, FtsZ self-assembles into a ring structure at the center of the dividing bacterial cell. This FtsZ ring–called the bacterial division ring–was shown to help form a new "wall" that separates the daughter cells.

 The researchers' computational work demonstrates how misaligned FtsZ filaments react when they hit an obstacle.

By "dying" and re-assembling, they favour the formation of the bacterial division ring, a well-aligned filamentous structure. These findings could have applications in the development of synthetic self-healing materials.

FtsZ forms protein filaments that self-assemble by growing and shrinking in a continuous turnover. This process, called "treadmilling," is the constant addition and removal of subunits at opposite filament ends. Several proteins have been shown to treadmill in multiple life forms—such as bacteria, animals, or plants.

Scientists have previously thought of treadmilling as a form of self-propulsion and modeled it as filaments that move forward. However, such models fail to capture the constant turnover of subunits and overestimate the forces generated by the filaments' assembly. 

Everything in our cells is in constant turnover. Thus, we need to start thinking of biological active matter from the prism of molecular turnover and in a way that adapts to the outside environment.

What they found was striking. In contrast to self-propelled assemblies that push the surrounding molecules and create a "bump" felt at long molecular distances, they saw that misaligned FtsZ filaments started "dying" when they hit an obstacle.

"Active matter made up of mortal filaments does not take misalignment lightly. When a filament grows and collides with obstacles, it dissolves and dies.  Treadmilling assemblies lead to local healing of the active material. When misaligned filaments die, they contribute to a better overall assembly.

By incorporating the cell geometry and filament curvature into their model, the researchers showed how the death of misaligned FtsZ filaments helped form the bacterial division ring.

Part 1

Driven by the physical theories of molecular interactions, the researchers  soon made two independent encounters with experimental groups that helped confirm their results. 

At this meeting, they presented exciting experimental data showing that the death and birth of FtsZ filaments were essential for the formation of the division ring. This suggested that treadmilling had a crucial role in this process.

They also saw that the in vitro results closely matched the simulations and further confirmed the team's computational results.

Energy-driven self-organization of matter is a fundamental process in physics. Researchers are asking how to create living matter from non-living material that looks living. Thus, their present work could facilitate the creation of synthetic self-healing materials or synthetic cells.

Self-organisation of mortal filaments and its role in bacterial division ring formation, Nature Physics (2024). DOI: 10.1038/s41567-024-02597-8

Part 2

Scientists find oceans of water on Mars.  But it is too deep to tap!

Using seismic activity to probe the interior of Mars, geophysicists have found evidence for a large underground reservoir of liquid water—enough to fill oceans on the planet's surface.

The data from NASA's Insight lander allowed the scientists to estimate that the amount of groundwater could cover the entire planet to a depth of between 1 and 2 kilometers, or about a mile.

But this  reservoir won't be of much use to anyone trying to tap into it to supply a future Mars colony.

It's located in tiny cracks and pores in rock in the middle of the Martian crust, between 11.5 and 20 kilometers below the surface. Even on Earth, drilling a hole a kilometer deep is a challenge.

The finding does pinpoint another promising place to look for life on Mars, however, if the reservoir can be accessed. For the moment, it helps answer questions about the geological history of the planet.

Wright, Vashan, Liquid water in the Martian mid-crust, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2409983121. doi.org/10.1073/pnas.2409983121