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Comment by Dr. Krishna Kumari Challa on March 12, 2025 at 9:37am

Microplastics may threaten global food supply by disrupting photosynthesis

A team of environmental researchers, Earth scientists and pollution specialists  has found evidence that microplastics have a negative impact on photosynthesis in terrestrial, marine, and freshwater ecosystems.

In their study, published in the Proceedings of the National Academy of Sciences, the group conducted a meta-analysis of data from more than 150 studies involving the impact of microplastics on plants.

Prior research has shown that microplastics have made their way to nearly every ecosystem on the planet, and now contaminate plants and animals, including humans. For this new study, the research team wondered if microplastics might have an unknown impact on plants living in the ocean, in fresh water or growing on land, and they conducted a study of prior research to find out.

The team suspected that microplastics might have a direct impact on the ability of plants to engage in photosynthesis. To that end, they searched the literature using an AI app and found 157 studies that mentioned both microplastics and impacts on photosynthesis, which included 3,286 observations.

Combining the results, the researchers calculated that microplastics reduced photosynthetic efficiency across all three plant types by 7% to 12% and caused reductions in production of chlorophyll. Such percentages, they suggest, result in approximately 4% to 14% harvest yield losses of maize, wheat and rice around the globe. They also suggest that microplastics account for up to 7% of losses in global aquatic net primary productivity.

The research team notes that the problem appears to be worsening, which will impact crop production even more. They further suggest that if the problem is not reversed, the result could be a major increase in the number of people at risk of starvation over the next two decades.

 Ruijie Zhu et al, A global estimate of multiecosystem photosynthesis losses under microplastic pollution, Proceedings of the National Academy of Sciences (2025). DOI: 10.1073/pnas.2423957122

Comment by Dr. Krishna Kumari Challa on March 12, 2025 at 9:28am

The same principle applies beyond neuroscience. Imagine a landscape where temperatures and rainfall vary gradually over a space. You might expect species to be spread, and also to vary, smoothly over this region. But in reality, ecosystems often form species clusters with sharp boundaries—distinct ecological "neighborhoods" that don't overlap.

The new study suggests why local competition, cooperation, and predation between species interact with the global environmental gradients to create natural separations, even when the underlying conditions change gradually. This phenomenon can be explained using peak selection and suggests that the same principle that shapes brain circuits could also be at play in forests and oceans.

One of the researchers' most striking findings is that modularity in these systems is remarkably robust. Change the size of the system, and the number of modules stays the same—they just scale up or down. That means a mouse brain and a human brain could use the same fundamental rules to form their navigation circuits, just at different sizes.

The model also makes testable predictions. If it's correct, grid cell modules should follow simple spacing ratios. In ecosystems, species distributions should form distinct clusters even without sharp environmental shifts.

The work adds another conceptual framework to biology. "Peak selection can inform future experiments, not only in grid cell research but across developmental biology.

Mikail Khona et al, Global modules robustly emerge from local interactions and smooth gradients, Nature (2025). DOI: 10.1038/s41586-024-08541-3

Part 3

Comment by Dr. Krishna Kumari Challa on March 12, 2025 at 9:26am

The authors of the research paper propose a simple mathematical principle called peak selection, showing that when a smooth gradient is paired with local interactions that are competitive, modular structures emerge naturally. In this way, biological systems can organize themselves into sharp modules without detailed top-down instruction.

The researchers tested their idea on grid cells, which play a critical role in spatial navigation as well as the storage of episodic memories. Grid cells fire in a repeating triangular pattern as animals move through space, but they don't all work at the same scale—they are organized into distinct modules, each responsible for mapping space at slightly different resolutions.

No one knows how these modules form, but the new model shows that gradual variations in cellular properties along one dimension in the brain, combined with local neural interactions, could explain the entire structure. The grid cells naturally sort themselves into distinct groups with clear boundaries, without external maps or genetic programs telling them where to go.

The new  work explains how grid cell modules could emerge. The explanation tips the balance toward the possibility of self-organization. It predicts that there might be no gene or intrinsic cell property that jumps when the grid cell scale jumps to another module.

Part 2

Comment by Dr. Krishna Kumari Challa on March 12, 2025 at 9:22am

How nature organizes itself, from brain cells to ecosystems

You'll see it everywhere: the way trees form branches, the way cities divide into neighborhoods, the way the brain organizes into regions. Nature loves modularity—a limited number of self-contained units that combine in different ways to perform many functions. But how does this organization arise?

In findings published in Nature, researchers report that a mathematical model called peak selection can explain how modules emerge without strict genetic instructions. The findings, which apply to brain systems and ecosystems, help explain how modularity occurs across nature, no matter the scale.

Scientists have debated how modular structures form. One hypothesis suggests that various genes are turned on at different locations to begin or end a structure. This explains how insect embryos develop body segments, with genes turning on or off at specific concentrations of a smooth chemical gradient in the insect egg.

Another idea, inspired by mathematician Alan Turing, suggests that a structure could emerge from competition—small-scale interactions can create repeating patterns, like the spots on a cheetah or the ripples in sand dunes.

Both ideas work well in some cases, but fail in others. The new research suggests that nature need not pick one approach over the other.

Part 1

Comment by Dr. Krishna Kumari Challa on March 12, 2025 at 9:14am

Comment by Dr. Krishna Kumari Challa on March 12, 2025 at 9:09am

Majority of the world's population breathes dirty air, report says

Most of the world has dirty air, with just 17% of cities globally meeting air pollution guidelines, a recent report found.

Switzerland-based air quality monitoring database IQAir analyzed data from 40,000 air quality monitoring stations in 138 countries and found that Chad, Congo, Bangladesh, Pakistan and India had the dirtiest air. India had six of the nine most polluted cities with the industrial town of Byrnihat in northeastern India the worst.

Experts said the real amount of air pollution might be far greater as many parts of the world lack the monitoring needed for more accurate data.

More air quality monitors are being set up to counter the issue, the report said. This year, report authors were able to incorporate data from 8,954 new locations and around a thousand new monitors as a result of efforts to better monitor air pollution.

But last week, data monitoring for air pollution was dealt a blow when the U.S. State Department announced it would no longer make public its data from its embassies and consulates around the world.

Breathing in polluted air over a long period of time can cause respiratory illness, Alzheimer's disease and cancer. The World Health Organization estimates that air pollution kills around 7 million people each year.

Experts say that much more needs to be done to cut air pollution levels. The WHO had earlier found that 99% of the world's population lives in places that do not meet recommended air quality levels.

And the problem is if you have bad water, no water, you can tell people to wait for half an hour a day, the water will come. But if you have bad air, you cannot tell people to pause breathing.

Several cities like Beijing, Seoul, South Korea, and Rybnik in Poland have successfully improved their air quality through stricter regulations on pollution from vehicles, power plants and industry. They've also promoted cleaner energy and invested in public transportation.

Source: News agencies

Comment by Dr. Krishna Kumari Challa on March 12, 2025 at 9:01am

How hand shape affects sound while clapping

New research work published in Physical Review Research,  elucidates the complex physical mechanisms and fluid dynamics involved in a handclap, with potential applications in bioacoustics and personal identification, whereby a handclap could be used to identify someone.

The researchers used high-speed cameras to track the hand motion, air flow and sound of 10 volunteers clapping, measuring the different frequencies when the size and shape of the cavity between hands changes: when clapping with cupped hands, flat hands or fingers to palm. They found the larger the cavity between palms, the lower the frequency of the clap, with the hands acting as a resonator—whereby the sound comes from the force of air through the hand's cavity and the opening between the thumb and index finger.

It's the air column pushed by this jet flow of air coming out of the hand cavity that causes the disturbance in the air, and that's the sound we hear.

The researchers compared the human data to that produced with simplified replicas, as well as theoretical projections of how air would move through a traditional resonator, called a Helmholtz resonator.

They confirmed both experimentally and computationally that the Helmholtz resonator can predict the frequency of the human handclap.

It's a confirmation of this unifying principle that may be helpful in other fields, especially bioacoustics, because that principle may help explain all kinds of bioacoustics phenomena, especially those involving soft material collision and jet flow.

Additionally, the researchers studied why claps are so short, compared to sound made through a traditional resonator, finding that the softness of the hands plays a role: the soft tissues of the hands vibrate after impact, absorbing energy and dampening the sound.

When there's more vibration in the material, the sound attenuates much more quickly. So, if you want to get the attention of another person very far from you, and you want the sound to last longer, you might want to choose a certain type of handclapping shape that makes your hand more rigid.

The research further opens the door to the idea of using a handclap as a personal identifier or signature.

The handclap is actually a very characteristic thing, because we have different sizes of hand, techniques, different skin textures and softness—that all results in different sound performances. Now that we understand the physics of it, we can use the sound to identify the person.

Yicong Fu et al, Revealing the sound, flow excitation, and collision dynamics of human handclaps, Physical Review Research (2025). DOI: 10.1103/PhysRevResearch.7.013259

Comment by Dr. Krishna Kumari Challa on March 12, 2025 at 8:53am

Scientists discover smart way to generate energy with tiny plastic beads

An international team of researchers has discovered a new method to generate electricity using small plastic beads. By placing these beads close together and bringing them into contact, they generate more electricity than usual. This process, known as triboelectrification, is similar to the static electricity produced when rubbing a balloon against hair.

Triboelectric nanogenerators (TENGs) generate electricity through friction between different materials. Typically, this occurs when two distinct materials move against each other. The research now shows that when a surface made up of closely packed small beads comes into contact with another surface containing the same beads, some beads gain a positive charge while others become negatively charged. The more efficiently these electric charges transfer, the more electricity is produced.

Tests with different types of beads reveal that size and material play a crucial role. Larger beads tend to acquire a negative charge, whereas smaller ones are more likely to become positively charged. The most significant effect occurs with melamine-formaldehyde (MF) beads.

This material has low elasticity, meaning it is less flexible and better at holding and transferring electric charge. Additionally, using beads provides a cost-effective alternative to the expensive technology typically used in TENGs to enhance performance. The dry fabrication of particles also makes the process more sustainable by eliminating the need for solvents.

Advancements in triboelectrification could enable new energy-harvesting applications without batteries or power outlets.

Ignaas S. M. Jimidar et al, Granular Interfaces in TENGs: The Role of Close‐Packed Polymer Bead Monolayers for Energy Harvesters, Small (2025). DOI: 10.1002/smll.202410155

Comment by Dr. Krishna Kumari Challa on March 12, 2025 at 8:49am

Microplastics could be fueling antibiotic resistance

Microplastics—tiny shards of plastic debris—are all over the planet. They have made their way up food chains, accumulated in oceans, clustered in clouds and on mountains, and been found inside human bodies at alarming rates. Scientists have been racing to uncover the unforeseen impacts of so much plastic in and around us.

One possible, and surprising, consequence: more drug-resistant bacteria.

In a startling discovery, a team of  researchers found that bacteria exposed to microplastics became resistant to multiple types of antibiotics commonly used to treat infections. They say this is especially concerning for people in high-density, impoverished areas like refugee settlements, where discarded plastic piles up and bacterial infections spread easily.

The study is published in Applied and Environmental Microbiology.

The fact that there are microplastics all around us, and even more so in impoverished places where sanitation may be limited, is a striking part of this observation.

There is certainly a concern that this could present a higher risk in communities that are disadvantaged, and only underscores the need for more vigilance and a deeper insight into [microplastic and bacterial] interactions.

The plastics provide a surface that the bacteria attach to and colonize. 

Once attached to any surface, bacteria create a biofilm—a sticky substance that acts like a shield, protecting the bacteria from invaders and keeping them affixed securely.

Even though bacteria can grow biofilms on any surface, researchers observed that the microplastic supercharged the bacterial biofilms so much that when antibiotics were added to the mix, the medicine was unable to penetrate the shield.

The researchers  found that the biofilms on microplastics, compared to other surfaces like glass, are much stronger and thicker, like a house with a ton of insulation.

The rate of antibiotic resistance on the microplastic was so high compared to other materials, that the researchers performed the experiments multiple times, testing different combinations of antibiotics and types of plastic material. Each time, the results remained consistent.

They conclusively demonstrated that the presence of plastics is doing a whole lot more than just providing a surface for the bacteria to stick to—they are actually leading to the development of resistant organisms.

 Effects of microplastic concentration, composition, and size on Escherichia coli biofilm- associated antimicrobial resistance, Applied and Environmental Microbiology (2025). DOI: 10.1128/aem.02282-24

Comment by Dr. Krishna Kumari Challa on March 12, 2025 at 8:37am

Beneficial genetic changes observed in regular blood donors

Researchers have identified genetic changes in blood stem cells from frequent blood donors that support the production of new, non-cancerous cells.

Understanding the differences in the mutations that accumulate in our blood stem cells as we age is important to understand how and why blood cancers develop and hopefully how to intervene before the onset of clinical symptoms.

As we age, stem cells in the bone marrow naturally accumulate mutations and with this, we see the emergence of clones, which are groups of blood cells that have a slightly different genetic makeup. Sometimes, specific clones can lead to blood cancers like leukemia.

When people donate blood, stem cells in the bone marrow make new blood cells to replace the lost blood and this stress drives the selection of certain clones.

In research published Blood, the research team analyzed blood samples taken from over 200 frequent donors—people who had donated blood three times a year over 40 years, more than 120 times in total—and sporadic control donors who had donated blood less than five times in total.

Samples from both groups showed a similar level of clonal diversity, but the makeup of the blood cell populations was different.

For instance, both sample groups contained clones with changes to a gene called DNMT3A, which is known to be mutated in people who develop leukemia. Interestingly, the changes to this gene observed in frequent donors were not in the areas known to be preleukemic.

To understand this better, the  researchers edited DNMT3A in human stem cells in the lab. They induced the genetic changes associated with leukemia and also the non-preleukemic changes observed in the frequent donor group.

They grew these cells in two environments: one containing erythropoietin (EPO), a hormone that stimulates red blood cell production which is increased after each blood donation, and another containing inflammatory chemicals to replicate an infection.

The cells with the mutations commonly seen in frequent donors responded and grew in the environment containing EPO and failed to grow in the inflammatory environment. The opposite was seen in the cells with mutations known to be preleukemic.

This suggests that the DNMT3A mutations observed in frequent donors are mainly responding to the physiological blood loss associated with blood donation.

Finally, the team transplanted the human stem cells carrying the two types of mutations into mice. Some of these mice had blood removed and then were given EPO injections to mimic the stress associated with blood donation.

The cells with the frequent donor mutations grew normally in control conditions and promoted red blood cell production under stress, without cells becoming cancerous. In sharp contrast, the preleukemic mutations drove a pronounced increase in white blood cells in both control or stress conditions.

The researchers believe that regular blood donation is one type of activity that selects for mutations that allow cells to respond well to blood loss, but does not select the preleukemic mutations associated with blood cancer.

Karpova, D. et al. Clonal Hematopoiesis Landscape in Frequent Blood Donors, Blood (2025). DOI: 10.1182/blood.2024027999

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