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Comment by Dr. Krishna Kumari Challa on September 17, 2024 at 10:01am

Scientists mix sky's splendid hues to reset circadian clocks

Like sunrise, colours rest circadian rhythms

Those mesmerizing blue and orange hues in the sky at the start and end of a sunny day might have an essential role in setting humans' internal clocks.

In new research , a novel LED light that emits alternating wavelengths of orange and blue outpaced two other light devices in advancing melatonin levels in a small group of study participants.

Published in the Journal of Biological Rhythms, the finding appears to establish a new benchmark in humans' ability to influence their circadian rhythms, and reflects an effective new approach to counteract seasonal affective disorder (SAD).

Alexandra Neitz et al, Toward an Indoor Lighting Solution for Social Jet Lag, Journal of Biological Rhythms (2024). DOI: 10.1177/07487304241262918

Comment by Dr. Krishna Kumari Challa on September 17, 2024 at 9:54am

Researchers discover new blood group system

The discovery of a new blood group, MAL, has solved a 50-year-old mystery. Researchers from NHS Blood and Transplant (Bristol), NHSBT's International Blood Group Reference Laboratory (IBGRL) and the University of Bristol identified the genetic background of the previously known but mysterious AnWj blood group antigen. The findings allow identification and treatment of rare patients lacking this blood group.

Some people can lack this blood group due to the effect of illness, but the rare inherited form of the AnWj-negative phenotype has only been found in a handful of individuals—though due to this discovery it will now be easier to find others in the future.

The two best known blood group systems are ABO and Rh but blood is more complex, and matching across the other groups can be lifesaving.

If people who are AnWj-negative receive AnWj-positive blood they could have a transfusion reaction, and this research allows development of new genotyping tests for detecting such rare individuals and reducing the risk of transfusion-associated complications.

The AnWj antigen—an antigen is a surface marker—was discovered in 1972 but its genetic background was unknown until now. The new research, published in Blood, establishes a new blood group system (MAL), the 47th ever to be discovered, as home to the AnWj antigen.

The research team established that AnWj is carried on the Mal protein. More than 99.9% of people are AnWj-positive, and such individuals were shown to express full-length Mal protein on their red cells, which was not present on the cells of AnWj-negative individuals. The team identified homozygous deletions in the MAL gene associated with the inherited AnWj-negative phenotype.

The most common reason for being AnWj-negative is due to suffering from a hematological disorder or some types of cancer which suppress antigen expression. Only a very small number of people are AnWj-negative due to a genetic cause. There were five genetically AnWj negative individuals in the study including a family of Arab-Israelis. The blood tested included a sample given by a lady in 2015 who was the first AnWj negative person to be discovered in the 1970s.

The research team used whole exome sequencing—the genetic sequencing of all DNA that encodes proteins—to show that these rare inherited cases were caused by homozygous DNA sequence deletions in the MAL gene, which codes for Mal protein.

Proof that Mal is responsible for binding of AnWj antibodies isolated from these rare patients was provided by experiments showing the appearance of specific reactivity with cells in which researchers introduced the normal MAL gene but not the mutant gene.

Louise A Tilley et al, Deletions in the MAL gene result in loss of Mal protein, defining the rare inherited AnWj-negative blood group phenotype, Blood (2024). DOI: 10.1182/blood.2024025099.

Comment by Dr. Krishna Kumari Challa on September 17, 2024 at 9:50am

This allowed them to explain much better how our brain enables us to perceive the objects in our environment and understand their meaning.
The researchers looked at the data of three study participants whose brain activity was measured in the MRI scanner over 15 sessions while they looked at more than 8,000 different images of 720 objects.

When the participants saw a rocket, for example, the researchers were able to measure from the brain activity that their visual system not only recognized that it was a rocket or that a rocket is a vehicle, but also that it is gray and elongated, has to do with fire, can fly, or sparkles.
All processing stages of our perceptual system are therefore involved in capturing a broad spectrum of behaviorally relevant properties that together make up our perception, say the researchers.
This work reveals a multidimensional framework that is consistent with the rich and diverse behavioral relevance of objects. This ultimately explains our broad range of human behaviors better than the categorization-focused approach, and this in turn is crucial for understanding how we perceive and interact with our visual world in a meaningful way.

Oliver Contier et al, Distributed representations of behaviour-derived object dimensions in the human visual system, Nature Human Behaviour (2024). DOI: 10.1038/s41562-024-01980-y

Part 2

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Comment by Dr. Krishna Kumari Challa on September 17, 2024 at 9:47am

People think in many dimensions at a time

Until now the dominant view  has been that a central goal of human perception is to recognize objects and assign them to different categories—for example, this observed object is a dog and dogs belong to the category of animals.

But researchers  have now shown that this view is incomplete.

In a recent study published in the journal Nature Human Behaviour, they demonstrate that brain activity when seeing objects can be much better explained by a variety of behaviorally relevant dimensions.

Until now, it was thought that our brain's visual system breaks down the objects we see into very basic features and then gradually reassembles them with the aim of enabling their recognition.

The research  results have shown that recognition and categorization are important goals of our vision, but by no means the only ones.

In fact, the researchers found behaviorally relevant signals at all processing stages in the visual system. they were able to show this based on the behaviorally relevant dimensions they had previously discovered.

The researchers used a computer model to identify 66 object dimensions from behavioral data of more than 12,000 study participants. These dimensions not only explain categorization, i.e., whether a dog is an animal, but also cover other characteristics, such as colors and shapes, as well as gradual values, for example, how typical a dog is of an animal.

Part 1

Comment by Dr. Krishna Kumari Challa on September 17, 2024 at 8:47am

More than 39 million deaths from antibiotic-resistant infections estimated between now and 2050, suggests analysis

More than 39 million people around the world could die from antibiotic-resistant infections over the next 25 years, according to a study published in The Lancet.

The new study by the Global Research on Antimicrobial Resistance (GRAM) Project is the first global analysis of antimicrobial resistance (AMR) trends over time.

It reveals that more than one million people died each year as a result of AMR between 1990 and 2021. The study also estimates 1.91 million people could potentially die as a direct result of AMR in 2050, an increase of almost 70% per year compared to 2022. Over the same period, the number of deaths in which AMR bacteria play a role will increase by almost 75% from 4.71 million to 8.22 million per year.

Between 1990 and 2021, AMR deaths among children under five years old declined by 50%, while those among people aged 70 years and older increased by more than 80%. These trends are predicted to continue in the coming decades, with AMR deaths among children under five projected to halve by 2050 globally, as deaths among people 70 years and older more than double.

The findings highlight a vital need for interventions that incorporate infection prevention, vaccination, minimizing inappropriate antibiotic use, and research into new antibiotics to mitigate the number of AMR deaths that are forecasted for 2050.

Antimicrobial medicines are one of the cornerstones of modern health care, and increasing resistance to them is a major cause for concern. These findings highlight that AMR has been a significant global health threat for decades and that this threat is growing. Understanding how trends in AMR deaths have changed over time, and how they are likely to shift in future, is vital to make informed decisions to help save lives, say the authors of the study.

Global burden of bacterial antimicrobial resistance 1990–2021: a systematic analysis with forecasts to 2050, The Lancet (2024). DOI: 10.1016/S0140-6736(24)01867-1

Comment by Dr. Krishna Kumari Challa on September 17, 2024 at 8:41am

AI is 'accelerating the climate crisis,' experts warn

If you care about the environment, think twice about using AI. Generative artificial intelligence uses 30 times more energy than a traditional search engine, warn researchers.

The language models on which the programs are based require enormous computing capacities to train on billions of data points, necessitating powerful servers.

Then there's the energy used to respond to each individual user's requests.

Instead of simply extracting information, "like a search engine would do to find the capital of a country, for example," AI programs "generate new information," making the whole thing "much more energy-intensive," they explain.

According to the International Energy Agency, the combined AI and the cryptocurrency sectors consumed nearly 460 terawatt hours of electricity in 2022—two percent of total global production.

Although Microsoft and Google have committed to achieving carbon neutrality by the end of the decade, the US tech giants saw their greenhouse gas emissions soar in 2023 because of AI: up 48 percent for Google compared to 2019 and 29 percent for Microsoft compared to 2020.

"We are accelerating the climate crisis," say the experts, calling for more transparency from tech companies.

The solution, they say, could come from governments that, for the moment, are "flying blindly," without knowing what is "in the data sets or how the algorithms are trained."

"Once we have transparency, we can start legislating".

It is also necessary to explain to people what generative AI can and cannot do, and at what cost.

 The researchers demonstrated that producing a high-definition image using artificial intelligence consumes as much energy as fully recharging the battery of your cell phone.

The idea here is not to oppose AI, they emphasize, but rather to choose the right tools—and use them judiciously.

Source: AFP and other news agencies

Comment by Dr. Krishna Kumari Challa on September 17, 2024 at 8:34am

Scientists discover key features of language sites that could help preserve function after brain surgery

When surgeons perform brain surgery on people with brain tumors or epilepsy, they need to remove the tumor or abnormal tissue while preserving parts of the brain that control language and movement.

A new Medicine study may better inform doctors' decisions about which brain areas to preserve, thereby improving patients' language function after brain surgery. The study expands the understanding of how language is encoded in the brain and identifies key features of critical sites in the cerebral cortex that work together to produce language.

If you think of the brain's language network as a social network, scientists have essentially found the person who is the link between lots of subnetworks of people. They wouldn't know each other if not for this single person. In the brain, these "connectors" serve the same function for language. If the connector sites were removed, the patient would make more language errors after surgery—such as difficulty naming objects—because the subnetworks couldn't work together.

https://news.northwestern.edu/stories/2024/september/vital-language...

https://www.nature.com/articles/s41467-024-51839-zNature Communications (2024).

Comment by Dr. Krishna Kumari Challa on September 17, 2024 at 8:24am

Astronomers detect black hole 'starving' its host galaxy to death

Astronomers have used the NASA/ESA James Webb Space Telescope to confirm that supermassive black holes can starve their host galaxies of the fuel they need to form new stars. The results are reported in the journal Nature Astronomy.

The astronomers used Webb to observe a galaxy roughly the size of the Milky Way in the early universe, about two billion years after the Big Bang. Like most large galaxies, it has a supermassive black hole at its center. However, this galaxy is essentially 'dead': it has mostly stopped forming new stars.

This galaxy  is massive for such an early period in the universe: its total mass is about 200 billion times the mass of our sun, and most of its stars formed between 12.5 and 11.5 billion years ago.

In the early universe, most galaxies are forming lots of stars, so it's interesting to see such a massive dead galaxy at this period in time. If it had enough time to get to this massive size, whatever process that stopped star formation likely happened relatively quickly.

Using Webb, the researchers detected that this galaxy is expelling large amounts of gas at speeds of about 1,000 kilometers per second, which is fast enough to escape the galaxy's gravitational pull. These fast-moving winds are being 'pushed' out of the galaxy by the black hole.

Like other galaxies with accreting black holes, "Pablo's Galaxy" has fast outflowing winds of hot gas, but these gas clouds are tenuous and have little mass. Webb detected the presence of a new wind component, which could not be seen with earlier telescopes. This gas is colder, which means it's denser and—crucially—does not emit any light. Webb, with its superior sensitivity, can see these dark gas clouds because they block some of the light from the galaxy behind them.

The mass of gas being ejected from the galaxy is greater than what the galaxy would require to keep forming new stars. In essence, the black hole is starving the galaxy to death.

 A fast-rotator post-starburst galaxy quenched by supermassive black-hole feedback at z=3, Nature Astronomy (2024). DOI: 10.1038/s41550-024-02345-1. www.nature.com/articles/s41550-024-02345-1

Comment by Dr. Krishna Kumari Challa on September 15, 2024 at 1:52pm

The researchers  successfully performed a liver organ transplant in a rat using their fortified blood system.

These results highlight the immense potential of silicified erythrocytes [red blood cells] as a safe and efficient transfusion alternative, which effectively meets the growing clinical demand for blood," the researchers conclude.

Of course, this new blood technology is still in its infancy so it has many more challenges to endure before it can be determined safe for humans.

Meanwhile, for those of us in good health, donating blood remains a valuable way to help address current shortages and potentially save lives.

https://www.pnas.org/doi/10.1073/pnas.2322418121

Part 2

Comment by Dr. Krishna Kumari Challa on September 15, 2024 at 1:52pm

New Blood Cell 'Coats' Could Allow Cross-Species Transfusions

Chronic blood shortages are driving a search for a universal blood system that would allow doctors to save more lives. Researchers may have just brought us a step closer, by creating miniscule silicon coats for donated blood cells to wear. Incredibly, the new nanotechnology allowed biomedical engineers to successfully transfuse blood between species.

Silicified red blood cells not only escape immune activation in different species, but also function perfectly for oxygen transport," the research team writes in their paper.

By building a silicon coating for blood cells, Lei and team were able to cover the surface proteins that our bodies use to recognize blood types. This allows a different blood type to be safely used, including blood from another species.

The team successfully transfused these silicon clothed human blood cells into mice.

The best part: in every test so far, the cloaked cells otherwise act just like naked red blood cells. Their membrane remains intact, they can still float through blood plasma, produce their usual cellular fuel, and carry vital oxygen to where it's needed.

"The silicified blood retains all essential functions of red blood cells, has superior mechanical properties, is resistant to adverse environmental conditions, can be stored for extended periods, and is highly effective in preventing immune system activation," the research team explains.

The authors have identified an opportunity to reduce blood usage by providing an alternative fluid to store donor organs in.

Artificially pumping blood through these organs keeps them alive for long enough to be transplanted, but it uses a lot of blood. With the silicon coat strategy, it might be possible to tap into animal sources instead of using limited human blood supplies.

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