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Comment by Dr. Krishna Kumari Challa on October 25, 2022 at 9:37am

During sleep, one brain region teaches another, converting novel data into enduring memories

What role do the stages of sleep play in forming memories?

We've known for a long time that useful learning happens during sleep. You encode new experiences while you're awake, you go to sleep, and when you wake up your memory has somehow been transformed.

Yet precisely how new experiences get processed during sleep has remained mostly a mystery. Using a neural network computational model they built, researchers now have new insight into the process.

In research published in the Proceedings of the National Academy of Sciences, they show that as the brain cycles through slow-wave and rapid-eye movement (REM) sleep, which happens about five times a night, the hippocampus teaches the neocortex what it learned, transforming novel, fleeting information into enduring memory. This is not just a model of learning in local circuits in the brain. It's how one brain region can teach another brain region during sleep, a time when there is no guidance from the external world.

The team ran several sleep simulations using a brain-inspired learning algorithm they built. The simulations revealed that during slow-wave sleep, the brain mostly revisits recent incidents and data, guided by the hippocampus, and during REM sleep, it mostly reruns what happened previously, guided by memory storage in the neocortical regions. As the two brain regions connect during non-REM sleep, that's when the hippocampus is actually teaching the neocortex. Then, during the REM phase, the neocortex reactivates and can replay what it already knows, solidifying the data's hold in long-term memory.

When the neocortex doesn't have a chance to replay its own information, we see that the information there gets overwritten. Scientists think you need to have alternating REM and non-REM sleep for strong memory formation to occur.

This needs to be tested further to confirm, though. 

Singh, Dhairyya et al, A model of autonomous interactions between hippocampus and neocortex driving sleep-dependent memory consolidation, Proceedings of the National Academy of Sciences (2022). DOI: 10.1073/pnas.2123432119. doi.org/10.1073/pnas.2123432119

Comment by Dr. Krishna Kumari Challa on October 24, 2022 at 11:31am

NEOWISE: Revealing Changes in the Universe

Comment by Dr. Krishna Kumari Challa on October 24, 2022 at 11:16am

Particle Physics Could Reduce The 'Collateral Damage' of Cancer Treatments

Researchers at Europe's science lab CERN, who regularly use particle physics to challenge our understanding of the universe, are also applying their craft to upend the limits to cancer treatment.

The physicists here are working with giant particle accelerators in search of ways to expand the reach of cancer radiation therapy, and take on hard-to-reach tumors that would otherwise have been fatal.

In one CERN lab, called CLEAR, the research is aimed at creating very high energy beams of electrons – the negatively charged particles in the atom – that eventually could help to combat cancerous cells more effectively. They are researching a "technology to accelerate electrons to the energies that are needed to treat deep-seated tumors, which is above 100 million electron volts" (MeV)

The idea is to use these very high-energy electrons (VHEE) in combination with a new and promising treatment method called FLASH.

This method entails delivering the radiation dose in a few hundred milliseconds, instead of minutes as is the current approach.

This has been shown to have the same destructive effect on the targeted tumor but causes far less damage to the surrounding healthy tissue. The effect of the brief but intense FLASH treatment is to "reduce the toxicity to healthy tissue while still properly damaging cancer cells".

At such low energy though, the beams cannot penetrate deeply, meaning the highly-effective treatment has so far only been used on superficial tumors, found with skin cancer.

But the CERN physicists are now collaborating with the Lausanne University Hospital (CHUV) to build a machine for FLASH delivery that can accelerate electrons to 100 to 200 MeV, making it possible to use the method for much more hard-to-reach tumors.

source: new agencies

Comment by Dr. Krishna Kumari Challa on October 24, 2022 at 9:49am

Breaking the sound barriers without the sonic boom

Seventy-five years ago, a sonic boom thundered for the first time over the high desert of California.

It was Oct. 14, 1947, and the joint X-1 team of NACA, Air Force (newly formed that year), and Bell engineers and pilots had broken the sound barrier —an imaginary wall in the sky some said was impossible to penetrate.

Now, aeronautical innovators with NASA's Quesst mission are poised to break the sound barrier again, only this time in a very different way that could make it possible for all of us to one day travel by air just as fast as any of the X-1 pilots who flew supersonic. With X-59.

Through Quesst, NASA plans to demonstrate the X-59 can fly faster than sound without generating the typically loud sonic booms.

Researchers gained a greater understanding of how aircraft create sonic booms and turned their attention the idea of lowering the intensity of the sonic booms by manipulating the shape of the airplane.

That idea was tested in flight by NASA's Shaped Sonic Boom Demonstration program during 2003–2004. It used a Northrop F-5E jet whose fuselage was modified to give it a shape designed to produce quieter sonic booms.

And it worked now. First flight of the X-59 is targeted for early 2023.

Source: NASA

Comment by Dr. Krishna Kumari Challa on October 23, 2022 at 9:57am

Why NASA is trying to crash land on Mars

 Like a car’s crumple zone, the experimental SHIELD lander is designed to absorb a hard impact.

NASA has successfully touched down on Mars nine times, relying on cutting-edge parachutes, massive airbags, and jetpacks to set spacecraft safely on the surface. Now engineers are testing whether or not the easiest way to get to the Martian surface is to crash.

Rather than slow a spacecraft’s high-speed descent, an experimental lander design called SHIELD (Simplified High Impact Energy Landing Device) would use an accordion-like, collapsible base that acts like the crumple zone of a car and absorbs the energy of a hard impact.

The new design could drastically reduce the cost of landing on Mars by simplifying the harrowing entry, descent, and landing process and expanding options for possible landing sites.

https://researchnews.cc/news/15986/Why-NASA-is-trying-to-crash-land...

Comment by Dr. Krishna Kumari Challa on October 22, 2022 at 11:26am

Increased thermogenesis in fat cells during active period of circadian rhythm limits weight gain in mice

A team of researchers has found that an increase in thermogenesis in fat cells during active periods of the daily circadian rhythm can limit weight gain in mice.

Prior research has shown that overeating during the inactive phase of the circadian rhythm in mice and humans can lead to higher levels of weight gain. Likewise, adhering to time-restricted feeding (TRF) can lead to less weight gain. But until now, why this happens has not been fully understood. To learn more about the effects of a high-fat diet on mice over phases of the circadian rhythm, the researchers fed two groups of mice a high-fat diet. One group was fed during their active phase (when it was dark out) and the other was fed during their inactive phase (when it was light out.) They then took a close look at what was occurring in the fat cells of both groups. The researchers found that the mice fed during their inactive phase gained more weight, as expected. But they also learned more about the factors behind such a weight gain. One of the biggest was thermogenesis, the process by which heat is generated in the body. They found that an increase in thermogenesis in fat cells during the active phase of the circadian rhythm (due to a boost in creatine in fat cells) was at least partly responsible for restricting weight gain. They also found that a zinc finger protein can block the genes responsible for producing the chemicals that regulate thermogenesis by controlling production of adenosine triphosphate. They conclude that their work has helped to explain why TRF can play such an important role in weight management.

Chelsea Hepler et al, Time-restricted feeding mitigates obesity through adipocyte thermogenesis, Science (2022). DOI: 10.1126/science.abl8007

Damien Lagarde et al, The timing of eating controls energy use, Science (2022). DOI: 10.1126/science.ade6720

Comment by Dr. Krishna Kumari Challa on October 22, 2022 at 8:43am

Disruption of gut microbial balance is associated with increased mortality after kidney, liver transplants

Disruptions in the gut microbiome have been linked to lower survival rates for people who have undergone kidney and liver transplants, a finding that highlights the critical importance of the vast and complex microbial communities that dwell within us.

Scientists studied  faecal samples from more than 1,000 recipients of kidney and liver transplants to learn how the balance of microbes in the gut microbiome impact post-transplant survival. Gut microbiome dysbiosis—disruptions in microbial diversity—is associated with increased mortality after solid organ transplantation, researchers found.

The gut microbiome is made up of both "good" and "bad" microbes: bacteria, viruses and fungi. Health benefits throughout the body are derived from the healthy balance of these microbial communities in the gut. However, the living communities are not static; they fluctuate in response to diet, emotions, exercise, surgery, and exposure to medications.

Past studies demonstrated that recipients of stem cell transplants had a higher mortality risk when faced with disruptions in their gut microbiome. It has taken until now to pose the same question, based on a large sample size, whether microbiota disruption negatively impacts recipients of solid organ transplants.

They were aware that the health of the microbiome influenced the fate of patients who had undergone stem cell transplants, infusions that are sometimes referred to as bone marrow transplants. The procedure provides the recipient with a donor's healthy progenitor cells to generate a new blood supply. But scientists also were aware that a successful stem cell transplant wasn't enough unless the gut microbiome was also flourishing with a diverse population of beneficial microbes.

The researchers reported  on the need for microbial variety to ensure a healthy transplant outcome.

J. Casper Swarte et al, Gut microbiome dysbiosis is associated with increased mortality after solid organ transplantation, Science Translational Medicine (2022). DOI: 10.1126/scitranslmed.abn7566

Comment by Dr. Krishna Kumari Challa on October 21, 2022 at 9:37am

Metallic water prepared for first time under terrestrial conditions

Inside a vacuum chamber, the researchers expose a drop of sodium-potassium alloy to a small amount of water vapor, which begins to condense on its surface. The electrons liberated from the alkali metal dissolve in the layer of water on the surface faster than the chemical reaction that results in the explosion. There are a sufficient number of them to overcome the critical limit for the formation of a conduction band and thus give rise to a metallic water solution.

https://www.sciencealert.com/scientists-transformed-pure-water-into...

Comment by Dr. Krishna Kumari Challa on October 21, 2022 at 8:58am

Alligators exposed to PFAS show autoimmune effects

A recent study of alligators  found the animals had elevated levels of 14 different per- and polyfluoroalkyl (PFAS) chemicals in their blood serum, as well as clinical and genetic indicators of immune system effects. The work adds to the body of evidence connecting PFAS exposure with adverse immune system effects.

Researchers took blood samples and did health evaluations on 49 alligators living along the Cape Fear River between 2018 and 2019. They compared these results to a reference population of 26 alligators from Lake Waccamaw, located in the adjoining Lumber River basin.

They  looked at 23 different PFAS and saw clear differences between both types and levels of PFAS in the two populations. The most unusual observation the team made was that alligators in the Cape Fear River which had high concentration of PFAS also had a number of unhealed or infected lesions.

Alligators rarely suffer from infections. They do get wounds, but they normally heal quickly. Seeing infected lesions that weren't healing properly was concerning and led the scientists  to look more closely at the connections between PFAS exposure and changes in the immune systems of the alligators.

A qRT-PCR genetic analysis revealed significantly elevated levels of interferon-alpha (INF-α) responsive genes in the Cape Fear River alligators: their levels were 400 times higher than those of the low level PFAS containing alligators, 

INF-α is a secreted immune protein involved in stimulating immune response.The set of INF-α responsive genes we analyzed are normally involved with viral infections. In humans, chronic (or long-term) high expression of this set of genes is an important indicator of autoimmune diseases, especially lupus. Additionally, some PFAS exposures in humans are linked with chronic autoimmune disorders like ulcerative colitis and thyroid disease. 

The elevated expression of INF-α in these alligators tells us that something in these alligators' immune responses is being disrupted.

Blood Concentrations of Per- and Polyfluoroalkyl Substances are Associated with Autoimmune-like Effects in American Alligators from Wilmington, North Carolina, Frontiers in Toxicology (2022). DOI: 10.3389/ftox.2022.1010185

Comment by Dr. Krishna Kumari Challa on October 21, 2022 at 8:10am

Injecting extracellular vesicles from young mice into older mice found to reduce some signs of aging

A team of researchers has found that injecting older mice with extracellular vesicles (EVs) from young mice reduced some signs of aging. 

EVs, which are also known as exosomes, are structures produced in eukaryotic cells that are involved in signaling between cells and also used for transporting mRNA. Suspecting that aspects of the aging process might be related to degeneration in communication between cells, the researchers wondered what would happen if they injected older mice with EVs. To find out, they extracted stem cells from fatty tissue in young test mice. Next, they collected EVs that were produced by the cells they had collected. They then injected the EVs into the tails of older mice—once at the outset of the test and again a week later.

The researchers then began studying the mice to see what impact the injections might have. They found that after just two weeks, the mice showed improvements in physical strength, suggesting reductions in age-related muscle degeneration. They also found the mice tired less easily and tended to be better coordinated—and their fur grew back more quickly. The team noted that the improvements peaked at approximately 30 days after the initial injection and disappeared after approximately 60 days.

The researchers also dissected some of the test mice and found reductions in degeneration of kidney tissue and an increase in cell production. They also found reductions in inflammatory biomarkers and that some tissue appeared to be epigenetically younger.

Jorge Sanz-Ros et al, Small extracellular vesicles from young adipose-derived stem cells prevent frailty, improve health span, and decrease epigenetic age in old mice, Science Advances (2022). DOI: 10.1126/sciadv.abq2226

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