Four in five bird species cannot tolerate intense human pressures, data show

Currently 14% of the world's 11,000 bird species are threatened with extinction. A new study assessed the populations of bird species across a spectrum of landscapes from pristine habitats to human-dominated environments.

Threatened species, and species with declining populations, are less tolerant to breeding in human-dominated habitats. For example, the Fern Wren, a species occurring only in tropical forests of northeastern Australia, is endangered, has a declining population and a very low tolerance to any human pressure, say the researchers. However, not all species are as sensitive to living alongside humans. Some species can tolerate even the most intense human pressures on all continents. Common Swifts are an example of such species that can be found breeding in urban areas all around the world.
Following the UN's Kunming–Montreal Global Biodiversity Framework, goals have been set to protect 30% of the Earth's land for conservation, but not much of that percentage will be pristine habitat.
This new study enables us to identify species that are particularly sensitive to human activity and need more protected habitats to thrive, for example the Great Snipe in Europe, the Nkulengu Rail in Africa and the Hume's Lark in Asia. Conservation action to protect or restore habitat can then be targeted towards the species and locations that need it most.
Part 1

Europe and North America had higher proportions of human-tolerant bird species than Latin America and Africa did. Europe has a long history of environmental impacts spanning millennia, which, according to the researchers, may have resulted in historical disappearances of sensitive species and also in a long time frame for the remaining species to adapt to the gradually changing landscapes.

The researchers quantified tolerance to breeding in human-dominated environments for 6,000 bird species. The data on birds originated from citizen science observations from the eBird project from 2013–2021. The data on the extent of human impact was the Human Footprint Index that summarizes the combined pressures of built environments, human population density, night-time lights, agriculture and roads.

Emma‐Liina Marjakangas et al, Bird species' tolerance to human pressures and associations with population change, Global Ecology and Biogeography (2024). DOI: 10.1111/geb.13816

Part 2

Bird flu has infected a person after spreading to cows

A strain of avian influenza that has likely sickened and killed millions of birds around the globe has popped up in an unexpected species: Cows.

On April 1, the U.S. Department of Agriculture confirmed that cattle on a farm in New Mexico had tested positive for a strain of bird flu called H5N1. The news followed a March 25 announcement that officials had detected the virus on two dairy farms in Kansas and two Texas farms. The virus was also detected in a Michigan herd that had recently received cows from Texas, the USDA reported on March 29. Five additional herds in Texas have tested positive, and an outbreak in Idaho is presumed to have been caused by H5N1.

A person exposed to cattle on one of those Texas farms has tested positive too, becoming only the second person in the United States ever documented to be infected with H5N1, the U.S. Centers for Disease Control and Prevention reported April 1. The individual is being treated with an antiviral drug for a single symptom, eye redness. It’s unclear how the cows were infected, although consuming wild bird excrement is a possibility. The person was probably infected while in close contact with the cows. Most people fall ill with H5N1 only after close contact with infected animals, typically poultry, and these infections can be mild to deadly. Right now, the CDC considers H5N1’s risk to people to be low. But milk from infected cows should be thrown out before reaching our food supply, the USDA says. Pasteurization would also kill the virus, so it should not spread through the country’s milk, the agency said.

https://www.cdc.gov/media/releases/2024/p0401-avian-flu.html

A new study has linked microplastics to heart attacks and strokes. Here’s what we know 

The results have renewed concerns about plastics’ potential effects on human health

Tiny flecks of plastic inside in the arteries may ramp up the risks of cardiovascular disease.

An analysis of artery-clogging plaques in 257 patients found that the presence of these microplastics was associated with a roughly quadr..., researchers report March 7 in the New England Journal of Medicine. 

The extent of that enhanced risk is “stunning,” say the researchers. Because  “very, very, very few things have that much of a risk.”

The study has gained attention worldwide and renewed concerns about the effects of plastics on human health. It’s also one of a growing number of reports that have found microscopic particles of plastic inside our bodies’ tissues, including the lungs, liver and blood.

Plastic is everywhere and enters our body through multiple routes 

When plastic toys, pipes, food containers and other objects inevitably break down over time, they can shed infinitesimal particles into our environment. Scientists have already documented how broadly these plastic smithereens have scattered.

Particles speckle even extreme locations, from the depths of the ocean to nearly the peak of Mount Everest.  Microplastics, which are smaller than 5 millimeters (about the size of a peppercorn) and nanoplastics, which are roughly one five-thousandth that size, can get into our water, accumulate in soil and waft along whispers of wind.

These specks of plastic pollution can travel into our bodies via food and drink, the air we breathe and even directly through the skin. And our exposure to microplastics will only go up, say experts.

Part 1

Scientists examined plaque samples from patients who had undergone surgery to clean out their carotid arteries, blood vessels in the neck that carry blood to the brain. They found that more than half of patients had evidence of at least one type of plastic.

These patients’ plaques all contained polyethylene, a ubiquitous material used in everything from cling wrap to cutting boards. And in 12 percent of the patients, scientists also found polyvinyl chloride, or PVC. 

Of 150 people with evidence of these plastics, 30 died or experienced a nonfatal stroke or heart attack within roughly the next three years. That’s compared to eight out of 107 people whose plaques appeared to be plastic-free, the team reports.

It’s too early to say whether microplastics in the arteries can cause heart attacks

It’s possible that plastics inside the arteries drive inflammation, further kindling cardiovascular disease. Plaques embedded with plastic, for instance, tended to contain more inflammatory molecules than plastic-free plaques, the research  team found.

The researchers did not prove that microplastics are harmful, scientists say. They simply exposed a link between plastics in plaques and poor outcomes in patients.

The plaque study offers yet another reason why it’s probably a good idea to reduce plastic use 

R. Marfella et al. Microplastics and nanoplastics in atheromas and cardiovascular events. The New England Journal of Medicine. Published online March 7, 2024. doi: 10.1056/NEJMoa2309822.

M. A. Garcia et al. Quantitation and identification of microplastics accumulation in hu... Toxicological Sciences. Published online February 17, 2024. doi:10.1093/toxsci/kfae021.

Part 2

Huge star explosion to appear in sky in once-in-a-lifetime event

Sometime between now and September, a massive explosion 3,000 light years from Earth will flare up in the night sky, giving amateur astronomers a once-in-a-lifetime chance to witness this space oddity.

The binary star system in the constellation Corona Borealis—"northern crown"—is normally too dim to see with the naked eye.

But every 80 years or so, exchanges between its two stars, which are locked in a deadly embrace, spark a runaway nuclear explosion.

The light from the blast travels through the cosmos and makes it appear as if a new star—as bright as the North Star, according to NASA—has suddenly just popped up in our night sky for a few days.

It will be at least the third time that humans have witnessed this event, which was first discovered by Irish polymath John Birmingham in 1866, then reappeared in 1946.

There are only around 10 recurring novas in the Milky Way and surrounding galaxies. Normal novas explode "maybe every 100,000 years". But recurrent novas repeat their outbursts on a human timeline because of a peculiar relationship between their two stars.

The other is a white dwarf, a later stage in the death of a star, after all the atmosphere has blown away and only the incredibly dense core remains.

Their size disparity is so huge that it takes T Coronae Borealis's white dwarf 227 days to orbit its red giant. 

The two are so close that matter being ejected by the red giant collects near the surface of the white dwarf.

Once the mass roughly of Earth has built up on the white dwarf—which takes around 80 years—it heats up enough to kickstart a runaway thermonuclear reaction. This ends up in a "big explosion and within a few seconds the temperature goes up 100-200 million degrees Celsius". 

But you do not need  advanced technology to witness this rare event—whenever it may happen. You simply have to go out and look in the direction of the Corona Borealis .... and you can see it with your own naked eyes!

This particular star explosion is unique for its brief yet intense display, completing its cycle in merely a week. 

Source: AFP and other news agencies

Differences between nova and supernova explosions

The cosmos is a stage for some of the most spectacular and powerful events known to science. Among these, nova and supernova explosions stand out for their brilliance and the fundamental roles they play in the universe’s lifecycle.

Despite the similarity in their names, novae and supernovae differ vastly in their origins, mechanisms, and consequences. This article demystifies these cosmic phenomena, highlighting their distinct characteristics.

What is a nova?

As discussed above, a nova occurs in a binary star system, where a white dwarf and a companion star orbit closely. The white dwarf, a dense remnant of a star that has exhausted its nuclear fuel, pulls material — primarily hydrogen — from its companion.

This material accumulates on the white dwarf’s surface, eventually igniting in a thermonuclear explosion. The explosion causes the white dwarf to brighten significantly, but it does not result in the star’s destruction. Instead, the process may repeat if the white dwarf continues to accrete material.

What is a supernova?

In contrast, a supernova is a cataclysmic event marking the death of a star. Supernovae can occur in one of two primary ways:

Core-Collapse Supernova: This type happens at the end of a massive star’s life cycle. When the star’s core runs out of nuclear fuel, it can no longer support the outer layers against gravity. The core collapses, resulting in a massive explosion that obliterates the star.

Type Ia Supernova: This type involves a binary system where a white dwarf accretes material from a companion star, similar to a nova. However, in this case, the white dwarf reaches a critical mass (Chandrasekhar limit), leading to a runaway nuclear reaction that completely destroys the white dwarf.

Key differences between novae and supernovae

Scale and Energy

The most striking difference lies in their scale and the energy released. Supernovae are among the universe’s most energetic events, outshining entire galaxies and releasing vast amounts of energy. Novae, while still bright and powerful, are far less energetic and only cause a temporary increase in brightness.

Frequency and Visibility

Supernovae are relatively rare events, occurring about once every 50 years in a galaxy the size of the Milky Way. Novae, on the other hand, are more common, with several occurring in our galaxy each year. Despite their rarity, supernovae can often be seen from greater distances due to their immense brightness.

Enigmatic white dwarfs

Central to the spectacle of T Coronae Borealis is the white dwarf, a stellar remnant that offers profound insights into the life cycles of stars.

White dwarfs are the end products of stars that originally had masses up to eight times that of the Sun but ended their lives in a relatively peaceful manner, without exploding as supernovae.

These stellar cores are fascinating for several reasons:

• Density and Composition: Despite their diminutive size, white dwarfs are incredibly dense. Their mass is comparable to that of the Sun, but they have a volume similar to Earth’s. This high density arises because the matter within them is in a degenerate state, where electrons are packed closely together.
• Cooling Process: After their formation, white dwarfs embark on a long cooling process. They start out extremely hot but gradually radiate away their heat over billions of years, eventually fading into black dwarfs — theoretical objects that have not yet been observed because the universe is not old enough.
• Limiting Mass: The Chandrasekhar limit, approximately 1.4 times the mass of the Sun, defines the maximum mass a white dwarf can have. Beyond this limit, the star would collapse under its own gravity to form a neutron star or a black hole.

Window into cosmic evolution

In summary, the study of T Coronae Borealis and white dwarfs opens a window into the complex processes governing stellar evolution.

Part3

Scientists discover speed of visual perception ranges widely in humans

Using a blink-and-you'll-miss-it experiment, researchers from Trinity College Dublin have discovered that individuals differ widely in the rate at which they perceive visual signals. Some people perceive a rapidly changing visual cue at frequencies that others cannot, which means some access more visual information per timeframe than others.

This discovery suggests some people have an innate advantage in certain settings where response time is crucial, such as in ball sports, or in competitive gaming.

The rate with which we perceive the world is known as our "temporal resolution," and in many ways it is similar to the refresh rate of a computer monitor.

The researchers found that there is considerable variation among people in their temporal resolution, meaning some people effectively see more "images per second" than others.

To quantify this, the scientists used the "critical flicker fusion threshold," a measure for the maximum frequency at which an individual can perceive a flickering light source.

If the light source flickers above a person's threshold, they will not be able to see that it is flickering, and instead see the light as steady. Some participants in the experiment indicated they saw the light as completely still when it was in fact flashing about 35 times per second, while others were still able to perceive the flashing at rates of over 60 times per second.

The researchers  also measured temporal resolution on multiple occasions in the same participants and found that even though there is significant variation among individuals, the trait appears to be quite stable over time 'within' individuals.

Part 1

Though our visual temporal resolution is quite stable from day to day in general, a post-hoc analysis did suggest that there may be slightly more variation over time within females than within males.

We don't yet know how this variation in visual temporal resolution might affect our day-to-day lives, but scientists think that individual differences in perception speed might become apparent in high-speed situations where one might need to locate or track fast-moving objects, such as in ball sports, or in situations where visual scenes change rapidly, such as in competitive gaming, or escaping a speeding vehicle.
This suggests that some people may have an advantage over others before they have even picked up a racquet and hit a tennis ball, or grabbed a controller and jumped into some fantasy world online.
What is really interesting about this project is how a zoologist, a geneticist and a psychologist can all find different angles to this work. For me as a zoologist the consequences of variation in visual perception likely has profound implications for how predators and prey interact, with various arms-races existing for investment in brain processing power and clever strategies to exploit weaknesses in one's enemy.
Because we only have access to our own subjective experience, we might naively expect that everyone else perceives the world in the same way we do. Examples like color blindness show that isn't always true, but there are many less well known ways that perception can vary too.

"This study characterizes one such difference—in the 'frame rate' of our visual systems. Some people really do seem to see the world faster than others."

Now if I can read 80 research papers per day, and can write 50 reviews and articles per day, or can answer 10 tough questions per day, remember, there is nothing wrong with you. 

Our worlds are just different from each other! :)

PLoS ONE (2024). DOI: 10.1371/journal.pone.0298007

Exploring how oxytocin interacts with testosterone while humans play a game modeling intergroup conflict

Over the past decades, numerous studies have investigated the neural and cognitive processes underpinning intergroup conflict, as this could help to explain what fuels belligerent behavior, political clashes, and wars. While these works gathered some interesting findings, much about these processes remains poorly understood until now.

Researchers  recently carried out a study specifically exploring how the hormones oxytocin and testosterone modulate people's behavior during an experimental game modeling intergroup conflict.

Their findings, published in Communications Psychology, suggest that oxytocin interacts with men's testosterone reactivity to modulate parochial altruism (i.e., behavior that benefits the group one belongs to, while negatively impacting competing groups).

Individuals regularly carry out actions which are costly to themselves, but advance the interests of their own group, often even at the expense of rival groups.

We see examples of such behavior all the time, including sports rivalries (playing injured), political partisanship (voting along party lines), and in extreme cases ethnic, religious, or national conflicts.

"Evolutionary theories, going back to Darwin, suggest that such acts of parochial altruism—the favoring of one's ingroup—emerged during human ancestry because they provided an advantage for group survival."

The researchers set out to study how individuals make decisions in a controlled laboratory setting modeling intergroup conflict, as this could shed light on the dynamics driving behaviors commonly observed outside laboratory settings.

Past social psychology research consistently found that people's social regard (i.e., their willingness to trust others, empathize with them and behave altruistically) is greatly influenced by their belonging to specific groups. Nonetheless, the biological underpinnings of these group-driven behaviors are yet to be clearly elucidated.

Part 1

Previous research,  suggested independent roles of oxytocin and testosterone—hormones that are associated with intergroup relations and cooperation-aggression—in shaping behaviour during intergroup conflict.

How the two hormones interact, had yet to be tested. These hormones exert contrasting effects on various social behaviors, leading us to hypothesize that their combined influence might hold the key to understanding intergroup dynamics. This study filled that gap.

The primary objective of the recent work  by researchers was to better understand how the interaction between oxytocin and testosterone influences behavior in the context of intergroup conflict. While many past studies focusing on this topic only included male participants, the researchers decided to also include female participants, as this would allow them to discover any sex differences that may exist.
To model intergroup conflict in an experimental setting, the researchers used an adaptation of the game commonly referred to as "chicken." This game has often been portrayed in popular media, including in the movies "Rebel without a Cause," "Footloose" and "Grease," and is also used in political science to describe elements of conflict between nations, such as the nuclear brinkmanship of the Cuban Missile crisis.
Part 2

The classic version of the game of 'chicken' pits two drivers against each other on a collision course.

To carry out their experiments, Israel, Cherki and their colleagues used a laboratory-based adaptation of the chicken game, known as the "intergroup chicken game." This version of the game has the same underlying rules, but with players divided into groups that are pitted against each other.

The researchers' experiment was double-blind and included a placebo condition. They recruited 204 participants and divided them into groups of eight or 12, each of which contained an equal number of males and females.

These groups of participants completed 30 rounds of the intergroup chicken game and at the beginning of each experimental session, participants were asked to self-administer either a placebo gas or oxytocin. Notably, neither the participants nor the experimenters were aware of what was being inhaled, which eliminated biases and prevented prior knowledge of what was administered during each trial from impacting the results.

One of the most notable observations of this study was that the interaction between oxytocin and testosterone greatly influenced the behavior of male participants. Contrarily, the interplay between these two hormones did not appear to impact the behavior of female participants.

Researchers observed that under placebo conditions, elevations in testosterone levels corresponded to heightened aggression towards outgroups. However, the administration of internasal oxytocin cancelled out this association, suggesting a regulatory role for oxytocin in moderating testosterone-induced aggression within intergroup dynamics.

Overall, the recent findings gathered by this team of researchers suggest that there could be notable sex differences in the dynamics underlying parochial altruism in intergroup conflict. In fact, they showed no substantial link between testosterone reactivity and outgroup aggression in females.

This underscores the importance of considering sex-specific effects when examining the neurobiological underpinnings of social behaviour.

 Boaz R. Cherki et al, Intranasal oxytocin interacts with testosterone reactivity to modulate parochial altruism, Communications Psychology (2024). DOI: 10.1038/s44271-024-00066-9

Part 3

**

A physicist uses X-rays to rescue old music recordings

Researchers are developing a technique that uses the special synchrotron X-ray light from the Swiss Light Source SLS to non-destructively digitize recordings from high-value historic audio tapes—including treasures from the Montreux Jazz Festival archive, such as a rare recording of the King of the Blues, B.B. King.

Magnetic tapes have almost completely disappeared from our lives and now only enjoy a nostalgic niche existence. However, significant quantities of these analog magnetic media are still stored in the archives of sound studios, radio and TV stations, museums, and private collections worldwide. Digitizing these tapes is an ongoing challenge as well as a race against time, as the tapes degrade and eventually become unplayable. Physicists and experts in nanomagnetism, are developing a method to non-destructively digitize degraded audio tapes in the highest quality using X-ray light. To achieve this goal, they have been collaborating with the Swiss National Sound Archives, which has produced custom-made reference recordings and provided audio engineering know-how. Now, a partnership with the Montreux Jazz Digital Project will help to further develop and test the method.
The remaining members of the famous rock band Queen recently faced a big challenge. In their studio, the musicians found a tape from 1988 containing a song with the voice of their legendary singer Freddie Mercury, who died in 1991. However, the tape was badly damaged. At first, no one believed they would be able to save this special piece. With great effort, the sound engineers managed to succeed after all.
Part 1

While it is possible to painstakingly reassemble and restore such tapes, these researchers are pursuing a completely new approach. They use synchrotron radiation : With X-ray light from a synchrotron, they can reconstruct even heavily damaged tape fragments without even touching them.

Audio tapes store information in a layer of tiny magnetic particles—like little compass needles pointing either north or south. When the tape is recorded, their magnetic orientation is changed—the tape becomes magnetized, and the audio information is now physically stored in the orientation pattern. To play back this pattern, the tape is moved past a play head. As the magnetic field constantly changes through the pattern, a voltage is induced in the play head and an electrical signal is generated. This signal is amplified and converted into an acoustic signal.

With his new X-ray method, researchers do not rely on the magnetic field, but on the individual compass needles that generate this field. The magnetization states of these tiny particles, whose size is smaller than a tenth of the diameter of a human hair, can be read out almost individually using the X-ray light of the SLS and converted into a high-quality audio signal.

Since the synchrotron light can measure almost every single magnetic compass needle on the tape, it can achieve unprecedented resolution.

https://www.psi.ch/en/media/our-research/rescuing-music-with-x-rays

Part 2

Write it down, then throw it away: Research confirms a simple method for reducing anger

A research group  has discovered that writing down one's reaction to a negative incident on a piece of paper and then shredding it or throwing it away reduces feelings of anger.

This research is important because controlling anger at home and in the workplace can reduce negative consequences in our jobs and personal lives. Unfortunately, many anger management techniques proposed by specialists lack empirical research support. They can also be difficult to recall when angry.

The results of this study, published in Scientific Reports, are the culmination of years of previous research on the association between the written word and anger reduction. It builds on work showing how interactions with physical objects can control a person's mood.

Yuta Kanaya et al, Anger is eliminated with the disposal of a paper written because of provocation, Scientific Reports (2024). DOI: 10.1038/s41598-024-57916-z , doi.org/10.1038/s41598-024-57916-z

First ever measurement of qubits with ultrasensitive thermal detectors, evading Heisenberg uncertainty principle

Chasing ever-higher qubit counts in near-term quantum computers constantly demands new feats of engineering.

Among the troublesome hurdles of this scaling-up race is refining how qubits are measured. Devices called parametric amplifiers are traditionally used to do these measurements. But as the name suggests, the device amplifies weak signals picked up from the qubits to conduct the readout, which causes unwanted noise and can lead to decoherence of the qubits if not protected by additional large components. More importantly, the bulky size of the amplification chain becomes technically challenging to work around as qubit counts increase in size-limited refrigerators. Researchers have now demonstrated in a Nature Electronics paper that bolometer measurements can be accurate enough for single-shot qubit readout.
To the chagrin of many physicists, the Heisenberg uncertainty principle determines that one cannot simultaneously know a signal's position and momentum, or voltage and current, with accuracy. So it goes with qubit measurements conducted with parametric voltage-current amplifiers.

But bolometric energy sensing is a fundamentally different kind of measurement—serving as a means of evading Heisenberg's infamous rule. Since a bolometer measures power, or photon number, it is not bound to add quantum noise stemming from the Heisenberg uncertainty principle in the way that parametric amplifiers are.
Part1

Unlike amplifiers, bolometers very subtly sense microwave photons emitted from the qubit via a minimally invasive detection interface. This form factor is roughly 100 times smaller than its amplifier counterpart, making it extremely attractive as a measurement device.
In their very first experiments, they found these bolometers accurate enough for single-shot readout, free of added quantum noise, and they consume 10,000 times less power than the typical amplifiers—all in a tiny bolometer, the temperature-sensitive part of which can fit inside of a single bacterium.
Single-shot fidelity is an important metric physicists use to determine how accurately a device can detect a qubit's state in just one measurement as opposed to an average of multiple measurements. In the case of the QCD group's experiments, they were able to obtain a single-shot fidelity of 61.8% with a readout duration of roughly 14 microseconds. When correcting for the qubit's energy relaxation time, the fidelity jumps up to 92.7%.

With minor modifications, they could expect to see bolometers approaching the desired 99.9% single-shot fidelity in 200 nanoseconds. For example, they can swap the bolometer material from metal to graphene, which has a lower heat capacity and can detect very small changes in its energy quickly. And by removing other unnecessary components between the bolometer and the chip itself, they can not only make even greater improvements on the readout fidelity, but they can achieve a smaller and simpler measurement device that makes scaling-up to higher qubit counts more feasible.

András M. Gunyhó, Single-Shot Readout of a Superconducting Qubit Using a Thermal Detector, Nature Electronics (2024). DOI: 10.1038/s41928-024-01147-7

Physicists discover a novel quantum state in an elemental solid

Physicists have observed a novel quantum effect termed "hybrid topology" in a crystalline material. This finding opens up a new range of possibilities for the development of efficient materials and technologies for next-generation quantum science and engineering.

The finding, published in Nature, came when  scientists discovered that an elemental solid crystal made of arsenic (As) atoms hosts a never-before-observed form of topological quantum behaviour. They were able to explore and image this novel quantum state using a scanning tunneling microscope (STM) and photoemission spectroscopy, the latter a technique used to determine the relative energy of electrons in molecules and atoms.

This state combines, or "hybridizes," two forms of topological quantum behavior—edge states and surface states, which are two types of quantum two-dimensional electron systems. These have been observed in previous experiments, but never simultaneously in the same material where they mix to form a new state of matter.

M. Zahid Hasan, A hybrid topological quantum state in an elemental solid, Nature (2024). DOI: 10.1038/s41586-024-07203-8. www.nature.com/articles/s41586-024-07203-8

AI makes retinal imaging 100 times faster, compared to manual method

Researchers  have applied artificial intelligence (AI) to a technique that produces high-resolution images of cells in the eye. They report that with AI, imaging is 100 times faster and improves image contrast 3.5-fold. The advance, they say, will provide researchers with a better tool to evaluate age-related macular degeneration (AMD) and other retinal diseases.

 Vineeta Das, Furu Zhang, Andrew Bower, et al. Revealing speckle obscured living human retinal cells with artificial intelligence assisted adaptive optics optical coherence tomography, Communications Medicine (2024). DOI: 10.1038/s43856-024-00483-1

Witness the awe-inspiring spectacle of explosive solar phenomena during the April 8 total eclipse! Expert analysis delves into solar flares, coronal mass ejections, and mesmerizing sunspots

Scientists discover first nitrogen-fixing organelle

Biology textbooks have to be re-written now. Because  they assert that only bacteria can take nitrogen from the atmosphere and convert it into a form that is usable for life. Plants that fix nitrogen, such as legumes, do so by harbouring symbiotic bacteria in root nodules. But a recent discovery upends that rule.

In two recent papers, an international team of scientists describes the first known nitrogen-fixing organelle within a eukaryotic cell. The organelle is the fourth example in history of primary endosymbiosis—the process by which a prokaryotic cell is engulfed by a eukaryotic cell and evolves beyond symbiosis into an organelle.

It's very rare that organelles arise from these types of things. 

The first time we think it happened, it gave rise to all complex life. Everything more complicated than a bacterial cell owes its existence to that event leading  to the origins of the mitochondria. A billion years ago or so, it happened again with the chloroplast, and that gave us plants.

The third known instance involves a microbe similar to a chloroplast.

The newest discovery is the first example of a nitrogen-fixing organelle, which the researchers are calling a "nitroplast".
Part 1

In a paper published in Cell in March 2024,  researchers show that the size ratio between UCYN-A (a short DNA sequence of what appeared to be from an unknown nitrogen-fixing cyanobacterium in Pacific Ocean seawater) and their algal hosts is similar across different species of the marine haptophyte algae Braarudosphaera bigelowii.

The researchers use a model to demonstrate that the growth of the host cell and UCYN-A are controlled by the exchange of nutrients. Their metabolisms are linked. This synchronization in growth rates led the researchers to call UCYN-A "organelle-like."

That's exactly what happens with organelles. If you look at the mitochondria and the chloroplast, it's the same thing: they scale with the cell.

But the scientists did not confidently call UCYN-A an organelle until confirming other lines of evidence. In the cover article of the journal Science, published recently, researchers show that UCYN-A imports proteins from its host cells.

That's one of the hallmarks of something moving from an endosymbiont to an organelle. They start throwing away pieces of DNA, and their genomes get smaller and smaller, and they start depending on the mother cell for those gene products—or the protein itself—to be transported into the cell.

These independent lines of evidence leave little doubt that UCYN-A has surpassed the role of a symbiont. And while mitochondria and chloroplasts evolved billions of years ago, the nitroplast appears to have evolved about 100 million years ago, providing scientists with a new, more recent perspective on organellogenesis.

The organelle also provides insight into ocean ecosystems. All organisms need nitrogen in a biologically usable form, and UCYN-A is globally important for its ability to fix nitrogen from the atmosphere. Researchers have found it everywhere from the tropics to the Arctic Ocean, and it fixes a significant amount of nitrogen.

 Tyler H. Coale et al, Nitrogen-fixing organelle in a marine alga, Science (2024). DOI: 10.1126/science.adk1075

Francisco M. Cornejo-Castillo et al, Metabolic trade-offs constrain the cell size ratio in a nitrogen-fixing symbiosis, Cell (2024). DOI: 10.1016/j.cell.2024.02.016

Part 2

Plant more native trees to reduce landslide risk, control erosion, say researchers

Landslides typically occur under heavy rain. With the potential for increased precipitation due to climate change and a possible return to La Niña reinforcing slopes with native trees and shrubs could be an effective, economical and sustainable solution.

Homeowners, councils and state governments looking to build houses and infrastructure on or near slopes should reconsider cutting down trees or using artificial slope reinforcement to buttress vertical terrain against landslides and slips.

They should plant native trees and shrubs instead, according to scientists. Plants provide a sustainable, natural approach to slope reinforcement, compared to artificial methods, such as steel mesh or sprayed concrete. They also create and maintain crucial habitat.

Jiale Zhu et al, An experimental study on root-reinforced soil strength via a steel root analogue in unsaturated silty soil, Acta Geotechnica (2023). DOI: 10.1007/s11440-023-01918-0

Don't depend on old Biology text books and theories for knowledge. Why Biology, all science is changing rapidly and progressing with rocket speed.

Each day I read a large amount of stories that are rewriting the old science textbooks. If you don't get updated, you remain a creature living under the big rock - very ancient, half-blind, half-mute and half-minded!

Science is not wine. It doesn't get better as it ages, it gets stale instead.

Science is like a running river, if you don't move as speedily as it does, you rot like an old log and decay!

(This ‘s my reply to a person who complained that my reports are contradicting Biology text books!)

Tiny AI-trained robots demonstrate soccer skills

How the inflamed brain becomes disconnected after a stroke

Whether reeling from a sudden stroke or buckling under the sustained assault of Alzheimer's, the brain becomes inflamed, leading to cognitive problems and even death.

Scientists have known for many years that severe inflammation can kill the brain's neurons. Now, researchers  have discovered that even subtle inflammation damages the brain.

Instead of killing neurons outright, however, relatively mild inflammation only destroys the arm-like projections, called neurites, that wire neurons together. These connections are vital for everything the brain does, including learning and memory.

The findings, published last month in Cell Reports, describe in detail a new degenerative pathway that scientists can now try to disrupt. This could help stem the damage from common neurological diseases.

There are several exciting drugs now entering clinical use that interrupt these inflammatory processes, and now we know to look at their effects on neurites.

Not too far off, this could have a big impact on helping patients.

Inflammation is the body's first line of defense when something goes wrong. It rushes blood to an injured area, bathing it with immune cells that release chemicals to kill pathogens.

Scientists wanted to know how this inflammatory process was damaging the brain. They Researchers were particularly interested in molecular aggregates, called cofilactin rods (CARs), that appear after a stroke. CARs form when two proteins, called cofilin and actin, that normally maintain neurites, break loose, forming messy clumps.

CARs are known to form in response to a chemical called superoxide, which immune cells release when the brain is inflamed.

To get a closer look at this process, the researchers stimulated inflammation in a part of the mouse brain that controls movement. They expected that neurons would die and the mice would have trouble moving.

The mice did struggle to move, but when the researchers looked at their brain tissue under a microscope, they were surprised to see that only the neurites had withered away, leaving the neurons isolated like stars in the night sky. The loss of these connections was enough to rob the mice of some of their motor coordination.

The scientists then tried reducing the amount of either superoxide or cofilin, and treated the brain with the same inflammatory substance. Under these conditions, fewer CARs formed, and the neurites survived. The mice also retained their coordination.

They had discovered a new pathway: inflammation caused immune cells to release superoxide, pulling cofilin and actin out of neurites and making CARs. Neurites died, and the disconnected brain malfunctioned.

Many neurological diseases involve inflammation, including multiple sclerosis, traumatic brain injury, and amyotrophic lateral sclerosis (ALS).

Now that scientists understand it better, they can design therapies to interrupt this inflammatory pathway. Stroke patients, for example, could be treated early on with anti-inflammatory agents to shield neurites from damage and preserve cognition.

Gökhan Uruk et al, Cofilactin rod formation mediates inflammation-induced neurite degeneration, Cell Reports (2024). DOI: 10.1016/j.celrep.2024.113914

Part 2

Scientists uncover a missing link between poor diet and higher cancer risk

A research team has unearthed new findings that may help explain the connection between cancer risk and poor diet, as well as common diseases like diabetes, which arise from poor diet. The insights gained from this study hold promise for advancing cancer prevention strategies aimed at promoting healthy aging.

Cancer is caused by the interaction between our genes and factors in our environment, such as diet, exercise, and pollution. How such environmental factors increase cancer risk is not yet very clear, but it is vital to understand the connection if we are to take preventive measures that help us stay healthy longer.

A chemical linked to diabetes, obesity, and poor diet can heighten cancer risk

The research team first studied patients who are at a high risk of developing breast or ovarian cancers because they inherit a faulty copy of the cancer gene—BRCA2—from their parents. They demonstrated that cells from such patients were particularly sensitive to the effects of methylglyoxal, which is a chemical produced when our cells break down glucose to create energy.

The study showed that this chemical can cause faults in our DNA that are early warning signs of cancer development.

The team's research also suggested that people who do not inherit a faulty copy of BRCA2 but could experience higher-than-normal levels of methylglyoxal—such as patients with diabetes or pre-diabetes, which are connected with obesity or poor diet—can accumulate similar warning signs indicating a higher risk of developing cancer.

This research suggests that patients with high methylglyoxal levels may have higher cancer risk. Methylglyoxal can be easily detected by a blood test for HbA1C, which could potentially be used as a marker. Furthermore, high methylglyoxal levels can usually be controlled with medicines and a good diet, creating avenues for proactive measures against the initiation of cancer.

Interestingly, the research team's work also revised a longstanding theory about certain cancer-preventing genes. This theory—called the Knudson's 'two-hit' paradigm—was first formulated in 1971, and it was proposed that these genes must be inactivated permanently in our cells before cancer can arise.

The NUS team has now found that methylglyoxal can temporarily inactivate such cancer-preventing genes, suggesting that repeated episodes of poor diet or uncontrolled diabetes can 'add up' over time to increase cancer risk. This new knowledge is likely to be influential in changing the direction of future research in this area.

Li Ren Kong et al, A glycolytic metabolite bypasses "two-hit" tumor suppression by BRCA2, Cell (2024). DOI: 10.1016/j.cell.2024.03.006

Study of data from thousands of women suggests ovarian cycle is regulated by circadian rhythm

A team of reproductive researchers affiliated with several institutions in France and the U.S. has found that the timing of monthly ovarian cycles in women is mostly likely attributable to the circadian rhythm. In their paper published in the journal Science Advances, the group describes their study of thousands of ovarian cycles as reported by thousands of women in Europe and the U.S. and what they found.

The timing mechanism behind the ovarian cycle has mystified scientists for centuries, though one of the strongest theories has been that it is tied to the lunar cycle*. Charles Darwin suggested that the two became linked back when humans lived near the seashore, where the tides heavily impacted daily scheduling.

And three years ago a team led by Würzburg chronobiologist Charlotte Förster found evidence for women's menstrual cycles temporarily synchronizing with cycles of the moon.

In this new effort, the research team has found little evidence of a lunar impact—they suggest the mechanism most likely controlling the ovarian cycle is the circadian rhythm.

* C. Helfrich-Förster el al., "Women temporarily synchronize their menstrual cycles with the luminance and gravimetric cycles of the Moon," Science

advances (2021). advances.sciencemag.org/lookup … .1126/sciadv.abe1358

Part 1

The circadian rhythm is defined as physical, mental, and behavioral changes that organisms, such as humans, experience over 24-hour cycles. One of the most famous behaviors impacted by the circadian rhythm is sleep—people tend to feel sleepy at the same time every night. However, it has also been noted that the circadian rhythm can be impacted by the lunar cycle—people have been found to go to bed later and sleep less, for example, on nights before a full moon.

To learn more about the ovarian cycle-controlling mechanism, the research team obtained medical records for over 3,000 women living in Europe and North America, which held data relating to 27,000 ovarian cycles. The team tracked the first day of each cycle for all the women under study. In doing so, they found little correlation between cycle start time and lunar cycling.

The researchers did find something else, though. Many examples of what they describe as phase jumps—where something disturbs the timing of a cycle for a given woman, and the body responds by changing the clock rhythm over several months to bring the cycle back to its original norm. They compare it to how the circadian rhythm reacts to people experiencing jet lag. This, they suggest, indicates that the circadian rhythm is much more likely the mechanism that controls ovarian cycling.

 René Ecochard et al, Evidence that the woman's ovarian cycle is driven by an internal circamonthly timing system, Science Advances (2024). DOI: 10.1126/sciadv.adg9646

Part 2

Paper straws contain more potentially toxic ‘forever chemicals’ than plastic. Should you give them up?

Many paper straws tested by scientists contain significant amounts of chemicals that don't biodegrade.

If you have been following the scientific debate on the effect of different types of straw on the environment and human health, you’ll know that the decision whether to use a straw or not  is not an easy one.

Pictures of plastic straws causing the death of turtles and other aquatic life were published in national newspapers. Governments scrambled to justify they had let plastic pollution reach such an appalling state of affairs – they singled out plastic straws as something that they could ban. And so they did, ignoring those of us who warned about the unexpected consequences.

A study by a European research group showed there are significant health and environmental risks associated with the pape... that have replaced plastic straws.

Scientists observing the performance of the new paper straws found themselves puzzled by their ability to repel liquids and resist getting soggy. Could there be an additive, they wondered, that might be allowing paper straws to perform so well?

Part 1

They studied plastic, paper and plant-based straws obtained in the USA. It showed that paper and plant-based straws contain PFAS (Per- and polyfluoroalkyl substances).

These are fluorine-based chemicals that have remarkable properties in repelling water, grease and pretty much anything. They are widely used in products designed to resist water and oil such as raincoats, furniture, cookware and food packaging.

PFAS are chemically and thermally very stable which means that almost nothing reacts or degrades them. This means they persist in the environment and will do so for thousands of years. For this reason, they have been dubbed ‘forever chemicals’.

They have been found literally everywhere from the Arctic ice to the Amazon rainforest. They also make it into the human body by migrating from packaging into our food and drink.

Once PFAS are in our blood they are associated with a number of health effects such as liver and kidney disease. There is also evidence that PFAS may lead to increased risk of high blood pressure in pregnant ..., and decreased immune response. Some studies show an association of PFAS exposure with kidney and testicular cancer. They have been shown to harm wildlife too.

All the evidence points to paper and plant-based straws having significant PFAS in them. PFAS have also been found in plastic straws but at lower levels. The only material determined to be free of PFAS was stainless steel.

Stainless steel straws  are reusable and easy to clean. So I use only them.

Please use only steel straws.

**

Discovery of the first fractal molecule in nature

An international team of researchers has stumbled upon the first regular molecular fractal in nature. They discovered a microbial enzyme—citrate synthase from a cyanobacterium—that spontaneously assembles into a pattern known as the Sierpinski triangle. Electron microscopy and evolutionary biochemistry studies indicate that this fractal may represent an evolutionary accident.

The study is published in Nature.

Snowflakes, fern leaves, romanesco cauliflower heads: many structures in nature have a certain regularity. Their individual parts resemble the shape of the whole structure. Such shapes, which repeat from the largest to the smallest, are called fractals. But regular fractals that match almost exactly across scales, as in the examples above, are very rare in nature.

Molecules also have a certain regularity. But if you look at them from a great distance, you can no longer see any signs of this. Then you see smooth matter whose features no longer match those of the individual molecules. The degree of fine structure we see depends on our magnification—in contrast to fractals, where self-similarity persists at all scales. In fact, regular fractals at the molecular level are completely unknown in nature till now.

This is somewhat surprising. After all, molecules can assemble themselves into all sorts of wonderful shapes. Scientists have extensive catalogues of self-assembled complex molecular structures. However, there has never been a regular fractal among them. It turns out that almost all regular-looking self-assemblies lead to the kind of regularity that becomes smooth on large scales.

Researchers now discovered a microbial enzyme—citrate synthase from a cyanobacterium—that spontaneously assembles into a regular fractal pattern known as the Sierpiński triangle. This is an infinitely repeating series of triangles made up of smaller triangles.

The protein makes these beautiful triangles and as the fractal grows, we see these larger and larger triangular voids in the middle of them, which is totally unlike any protein assembly we've ever seen before.

Part 1

How did this unusual exception emerge? What distinguishes the enzyme from all others, causing it to form a fractal shape? Teaming up with structural biologist at the university of Marburg, the team eventually managed to determine the molecular structure of this assembly using electron microscopy, which illuminated how it achieves its fractal geometry.
It now became clear how exactly this protein manages to assemble into a fractal: Normally, when proteins self-assemble, the pattern is highly symmetrical: each individual protein chain adopts the same arrangement relative to its neighbors. Such symmetrical interactions always lead to patterns that become smooth on large scales.

The key to the fractal protein was that its assembly violated this rule of symmetry. Different protein chains made slightly different interactions at different positions in the fractal. This was the basis for forming the Sierpiński triangle, with its large internal voids, rather than a regular lattice of molecules.

Self-assembly is often used by evolution to regulate enzymes, but in this case the cyanobacterium that this enzyme is found in does not seem to care much whether or not its citrate synthase can assemble into a fractal.
When the team genetically manipulated the bacterium to prevent its citrate synthase from assembling into the fractal triangles, the cells grew just as well under a variety of conditions. This prompted them to wonder whether this might just be a harmless accident of evolution. Such accidents can happen when the structure in question isn't too difficult to construct.
To test their theory, the team recreated the evolutionary development of the fractal arrangement in the laboratory. To do this, they used a statistical method to back-calculate the protein sequence of the fractal protein as it was millions of years ago.

By then producing these ancient proteins biochemically they were able to show that the arrangement arose quite suddenly through a very small number of mutations and was then immediately lost again in several cyanobacterial lineages, so that it only remained intact in this single bacterial species.
The fact that something so complex-looking as a molecular fractal could emerge so easily in evolution suggests that more surprises and much beauty may still lie hidden in so far undiscovered molecular assemblies of many biomolecules.

Franziska L. Sendker et al, Emergence of fractal geometries in the evolution of a metabolic enzyme, Nature (2024). DOI: 10.1038/s41586-024-07287-2

Part 2

Tropical forests can't recover naturally without fruit eating birds, carbon recovery study shows

New research illustrates a critical barrier to natural regeneration of tropical forests. Their models—from ground-based data gathered in the Atlantic Forest of Brazil—show that when wild tropical birds move freely across forest landscapes, they can increase the carbon storage of regenerating tropical forests by up to 38%.

Fruit eating birds such as the Red-Legged Honeycreeper, Palm Tanager, or the Rufous-Bellied Thrush play a vital role in forest ecosystems by consuming, excreting, and spreading seeds as they move throughout a forested landscape.

Between 70% to 90% of the tree species in tropical forests are dependent on animal seed dispersal. This initial process is essential for allowing forests to grow and function. While earlier studies have established that birds are important for forest biodiversity, researchers now have a quantitative understanding of how they contribute to forest restoration. The new study, published in the journal Nature Climate Change provides evidence of the important contribution of wild birds (frugivores) in forest regeneration. Researchers compared the carbon storage potential that could be recovered in landscapes with limited fragmentation, with that of highly fragmented landscapes. Their data shows that highly fragmented landscapes restrict the movement of birds, thereby reducing the potential of carbon recovery by up to 38%.
Across the Atlantic Forest region in Brazil, the researchers found that it is critical to maintain a minimum of 40% forest cover. They also find that a distance of 133 meters (approximately 435 feet) or less between forested areas ensures that birds can continue to move throughout the landscape and facilitate ecological recovery.

Part 1

The study also found that different bird species have different impacts in terms of seed dispersal. Smaller birds disperse more seeds, but they can only spread small seeds from trees with lower carbon storage potential. In contrast, larger birds such as the Toco toucan or the Curl-crested jay disperse the seeds of trees with a higher carbon storage potential. The problem is that the larger birds are less likely to move across highly fragmented landscapes.
This crucial information enables us to pinpoint active restoration efforts—like tree planting—in landscapes falling below this forest cover threshold, where assisted restoration is most urgent and effective.
Allowing larger frugivores to move freely across forest landscapes is critical for healthy tropical forest recovery.
This study demonstrates that especially in tropical ecosystems seed dispersal mediated by birds, plays a fundamental role in determining the species that can regenerate.

Frugivores enhance potential carbon recovery in fragmented landscapes, Nature Climate Change (2024). DOI: 10.1038/s41558-024-01989-1

Evolution's recipe book: How 'copy paste' errors led to insect flight, octopus camouflage and human cognition

Seven hundred million years ago, a remarkable creature emerged for the first time. Though it may not have been much to look at by today's standards, the animal had a front and a back, a top and a bottom. This was a groundbreaking adaptation at the time, and one which laid down the basic body plan which most complex animals, including humans, would eventually inherit.

The inconspicuous animal resided in the ancient seas of Earth, likely crawling along the seafloor. This was the last common ancestor of bilaterians, a vast supergroup of animals including vertebrates (fish, amphibians, reptiles, birds, and mammals), and invertebrates (insects, arthropods, mollusks, worms, echinoderms and many more).

To this day, more than 7,000 groups of genes can be traced back to the last common ancestor of bilaterians, according to a study of 20 different bilaterian species including humans, sharks, mayflies, centipedes and octopuses. The findings were made by researchers at the Centre for Genomic Regulation (CRG) in Barcelona and are published today in the journal Nature Ecology & Evolution.

Remarkably, the study found that around half of these ancestral genes have since been repurposed by animals for use in specific parts of the body, particularly in the brain and reproductive tissues. The findings are surprising because ancient, conserved genes usually have fundamental, important jobs that are needed in many parts of the body.

When the researchers took a closer look, they found a series of serendipitous "copy paste" errors during bilaterian evolution were to blame. For example, there was a significant moment early in the history of vertebrates. A bunch of tissue-specific genes first appeared coinciding with two whole genome duplication events.

Animals could keep one copy for fundamental functions, while the second copy could be used as raw material for evolutionary innovation. Events like these, at varying degrees of scale, occurred constantly throughout the bilaterian evolutionary tree.

The authors of the study found many examples of new, tissue-specific functions made possible by the specialization of these ancestral genes.

The specialization of ancestral genes also laid some foundations for the development of complex nervous systems

Evolution of tissue-specific expression of ancestral genes across vertebrates and insects, Nature Ecology & Evolution (2024). DOI: 10.1038/s41559-024-02398-5

Human muscle map reveals how we try to fight effects of aging at cellular and molecular levels

How muscle changes with aging and tries to fight its effects is now better understood at the cellular and molecular level with the first comprehensive atlas of aging muscles in humans.

Researchers applied single-cell technologies and advanced imaging to analyze human skeletal muscle samples from 17 individuals across the adult lifespan. By comparing the results, they shed new light on the many complex processes underlying age-related muscle changes.

The atlas, published April 15 in Nature Aging, uncovers new cell populations that may explain why some muscle fibres age faster than others. It also identifies compensatory mechanisms the muscles employ to combat aging.

The findings offer avenues for future therapies and interventions to improve muscle health and quality of life as we age.

This study is part of the international Human Cell Atlas initiative to map every cell type in the human body, to transform understanding of health and disease.

As we age, our muscles progressively weaken. This can affect our ability to perform everyday activities like standing up and walking. For some people, muscle loss worsens, leading to falls, immobility, a loss of autonomy and a condition called sarcopenia. The reasons why our muscles weaken over time have remained poorly understood till now.

Part 1

In this new study, scientists  used both single-cell and single-nucleus sequencing techniques along with advanced imaging to analyze human muscle samples from 17 individuals aged 20 to 75.

They discovered that genes controlling ribosomes, responsible for producing proteins, were less active in muscle stem cells from aged samples. This impairs the cells' ability to repair and regenerate muscle fibers as we age. Further, non-muscle cell populations within these skeletal muscle samples produced more of a pro-inflammatory molecule called CCL2, attracting immune cells to the muscle and exacerbating age-related muscle deterioration.

Age-related loss of a specific fast-twitch muscle fiber subtype, key for explosive muscle performance, was also observed. However, they discovered for the first time several compensatory mechanisms from the muscles appearing to make up for the loss. These included a shift in slow-twitch muscle fibers to express genes characteristic of the lost fast-twitch subtype, and increased regeneration of remaining fast-twitch fiber subtypes.

The researchers  also identified specialized nuclei populations within the muscle fibers that help rebuild the connections between nerves and muscles that decline with age. Knockout experiments in lab-grown human muscle cells by the team confirmed the importance of these nuclei in maintaining muscle function.

With these new insights into healthy skeletal muscle aging, researchers all over the world can now explore ways to combat inflammation, boost muscle regeneration, preserve nerve connectivity, and more. Discoveries from research like this have huge potential for developing therapeutic strategies that promote healthier aging for future generations.

 Human skeletal muscle aging atlas, Nature Aging (2024). DOI: 10.1038/s43587-024-00613-3

Part 2

Scientists observe mechanical waves in bacterial communities

A new study by researchers  has reported the emergence of mechanical spiral waves in bacterial matter.

Spiral waves are commonly seen in artificial and natural systems (such as the heart). These emerge from interactions of neighboring elements, such as cardiac cells in the case of the heart. These spiral waves can have varying effects, sometimes leading to life-threatening conditions like fibrillation in the heart.

The new study, published in Nature Physics, explores spiral waves in bacteria—something that has not been observed before. In particular, the researchers' focus was on the species Pseudomonas aeruginosa. These are commonly found in soil and water and are also known to colonize hospitals.

The research is a continuation of their previous work where the authors studied long-range material transport in bacterial communities via open fluid channels.

Part 1

These spiral waves as observed by the researchers in bacteria are an emergent phenomenon. Emergent phenomena are a crucial aspect of complex systems, which are systems where the interaction of individual entities leads to phenomena that otherwise can't be observed.

This means we need to understand what is happening at the level of each entity, which in this case is a Pseudomonas aeruginosa bacterium. These bacteria have pilus motors, which are the key to the spiral waves.

Pilus motors are molecular motors, which are attached to pili—thin, hair-like appendages present on the bacterial cell surface. These motors play an important role in various processes for the bacterium, such as movement and surface attachment.

The propagating spiral waves resulted from the coordinated activity of the pilus motor, a grappling-hook-like motile organelle found in many bacterial species.

The mechanical movements of the pilus motors in many bacteria result in these spiral waves, which are like ripples on the bacterial surface.

The researchers found that the spiral waves resulted from the coordinated activity of pilus motors. They also observed that the waves were self-sustaining and stable, with nearly stationary spiral cores.

This stability is a characteristic shared by certain types of electrical and chemical spiral waves found in other living systems. However, the spiral waves observed in the bacteria are distinct from the other spiral waves.

Part 2

The findings shed light on bacterial populations and behavior, such as the formation of biofilms.

When bacteria adhere to a surface, it does so by producing extracellular polymeric substances (EPS). This substance forms a structured community known as biofilm, such that the bacteria is embedded in a matrix of EPS, protecting the bacteria from environmental stresses like antibiotics and host immune responses.

This entire process, known as the formation of biofilms, is essential for the survival of bacterial colonies. The opposite of this phenomenon—dispersal—is equally important.

When bacteria within a biofilm detach and spread to new locations, it is known as dispersal. Dispersal can occur in response to environmental cues, nutrient availability, or as part of the life cycle of the bacteria.

This mechanism can help bacteria colonize new surfaces or host environments and can influence the spread of infectious diseases or the formation of microbial communities in various ecosystems.

Part 3

The researchers think that the pilus motors not only serve as mechanical actuators but also as sensors. This means that they can detect mechanical stimuli in the environment in the environment, which allows for synchronized movements within bacterial populations.

Shiqi Liu et al, Emergence of large-scale mechanical spiral waves in bacterial living matter, Nature Physics (2024). DOI: 10.1038/s41567-024-02457-5

Part 4

In search for alien life, purple may be the new green

From house plants and gardens to fields and forests, green is the color we most associate with surface life on Earth, where conditions favored the evolution of organisms that perform oxygen-producing photosynthesis using the green pigment chlorophyll a.

But an Earth-like planet orbiting another star might look very different, potentially covered by bacteria that receive little or no visible light or oxygen, as in some environments on Earth, and instead use invisible infrared radiation to power photosynthesis.

Instead of green, many such bacteria on Earth contain purple pigments, and purple worlds on which they are dominant would produce a distinctive "light fingerprint" detectable by next-generation ground- and space-based telescopes, scientists report in new research.

Purple bacteria can thrive under a wide range of conditions, making it one of the primary contenders for life that could dominate a variety of worlds.

This is the gist of the paper titled "Purple is the New Green: Biopigments and Spectra of Earth-like Purple Worlds," published in Monthly Notices of the Royal Astronomical Society.

So we need to create a database for signs of life to make sure our telescopes don't miss life if it happens not to look exactly like what we encounter around us every day, the researchers say.

Purple bacteria can survive and thrive under such a variety of conditions that it is easy to imagine that on many different worlds, purple may just be the new green.

Lígia Fonseca Coelho et al, Purple is the new green: biopigments and spectra of Earth-like purple worlds, Monthly Notices of the Royal Astronomical Society (2024). DOI: 10.1093/mnras/stae601

Can animals count? Neuroscientists identify a sense of numeracy among rodents

A discovery that appears to confirm the existence of discrete number sense in rats has been announced by a joint research team from City University of Hong Kong (CityUHK) and The Chinese University of Hong Kong (CUHK).

The findings offer a crucial animal model for investigating the neural basis of numerical ability and disability in humans, the Hong Kong-based researchers say.

This innovative study deployed a numerical learning task, brain manipulation techniques and AI modeling to tackle an ongoing debate about whether rats can count.

Their study, published in Science Advances, sheds light on the mechanisms underlying numerical ability, a cognitive ability fundamental to mathematical aptitude, which is a hallmark of human intelligence. The article is titled "Disparate processing of numerosity and associated continuous magnit...".

The team found that rats without any previous knowledge of numbers could develop a sense of numbers when trained with sounds representing two or three numbers. Despite the influence of continuous magnitudes, the rats consistently focused on the number of sounds when making choices for food rewards.

In addition, the study helps dissect the relationship between magnitude and numerosity processing.

The researchers discovered that when they blocked a specific part of the rats' brains, called the posterior parietal cortex, the rats' ability to understand numbers was affected but not their sense of magnitude. "This suggests that the brain has a specific area for dealing with numbers".

The study not only solves a long-standing mystery about how brains handle numbers but also offers new insights into studying the specific neural circuits involved in number processing in animals and how genes are associated with mathematical ability. The findings from neural network modeling could have practical applications in the field of AI.

Tuo Liang et al, Disparate processing of numerosity and associated continuous magnitudes in rats, Science Advances (2024). DOI: 10.1126/sciadv.adj2566

Biodiversity is key to the mental health benefits of nature, new study finds

New research has found that spaces with a diverse range of natural features are associated with stronger improvements in our mental well-being compared to spaces with less natural diversity.

Published in Scientific Reports, this citizen science study used the smartphone application Urban Mind to collect real-time reports on mental well-being and natural diversity from nearly 2,000 participants.

Researchers found that environments with a larger number of natural features, such as trees, birds, plants and waterways, were associated with greater mental well-being than environments with fewer features, and that these benefits can last for up to eight hours.

Further analysis found that nearly a quarter of the positive impact of nature on mental health could be explained by the diversity of features present. These findings highlight that policies and practices that support richness of nature and species are beneficial both for environment and for public mental health.

Smartphone-based ecological momentary assessment reveals an incremental association between natural diversity and mental wellbeing', Scientific Reports (2024). DOI: 10.1038/s41598-024-55940-7

A single atom layer of gold—researchers create goldene

For the first time, scientists have managed to create sheets of gold only a single atom layer thick. The material has been termed goldene. According to researchers , this has given the gold new properties that can make it suitable for use in applications such as carbon dioxide conversion, hydrogen production, and production of value-added chemicals. Their findings are published in the journal Nature Synthesis.

Scientists have long tried to make single-atom-thick sheets of gold but failed because the metal's tendency to lump together.

But researchers  have now succeeded thanks to a hundred-year-old method used by Japanese smiths.

If you make a material extremely thin, something extraordinary happens—as with graphene. The same thing happens with gold. As you know, gold is usually a metal, but if single-atom-layer thick, the gold can become a semiconductor instead.

To create goldene, the researchers used a three-dimensional base material where gold is embedded between layers of titanium and carbon. But coming up with goldene proved to be a challenge. According to the researchers,  part of the progress is due to serendipity.

They had created the base material with completely different applications in mind. They started with an electrically conductive ceramics called titanium silicon carbide, where silicon is in thin layers. Then the idea was to coat the material with gold to make a contact. But when they exposed the component to high temperature, the silicon layer was replaced by gold inside the base material.

This phenomenon is called intercalation and what the researchers had discovered was titanium gold carbide. For several years, the researchers have had titanium gold carbide without knowing how the gold can be exfoliated or panned out.

Then the researchers found a method that has been used in Japanese forging art for over a hundred years. It is called Murakami's reagent, which etches away carbon residue and changes the color of steel in knife making, for example. But it was not possible to use the exact same recipe as the smiths did. Scientists had to look at modifications.

Part 1

They tried different concentrations of Murakami's reagent and different time spans for etching. One day, one week, one month, several months. What they noticed was that the lower the concentration and the longer the etching process, the better. But it still wasn't enough.

The etching must also be carried out in the dark as cyanide develops in the reaction when it is struck by light, and it dissolves gold. The last step was to get the gold sheets stable. To prevent the exposed two-dimensional sheets from curling up, a surfactant was added. In this case, a long molecule that separates and stabilizes the sheets, i.e. a tenside.

The goldene sheets are in a solution, a bit like cornflakes in milk. Using a type of 'sieve,' the researchers can collect the gold and examine it using an electron microscope to confirm that they have succeeded. Which they have!

The new properties of goldene are due to the fact that the gold has two free bonds when two-dimensional. Thanks to this, future applications could include carbon dioxide conversion, hydrogen-generating catalysis, selective production of value-added chemicals, hydrogen production, water purification, communication, and much more. Moreover, the amount of gold used in applications today can be much reduced.

Synthesis of goldene comprising single-atom layer gold, Nature Synthesis (2024). DOI: 10.1038/s44160-024-00518-4

Part 2