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Comment by Dr. Krishna Kumari Challa on October 17, 2023 at 8:24am

Regardless of whether the system is living or nonliving, when a novel configuration works well and function improves, evolution occurs.

The authors' "Law of Increasing Functional Information" states that the system will evolve "if many different configurations of the system undergo selection for one or more functions."

In the case of biology, Darwin equated function primarily with survival—the ability to live long enough to produce fertile offspring.

The new study expands that perspective, noting that at least three kinds of function occur in nature.

The most basic function is stability—stable arrangements of atoms or molecules are selected to continue. Also chosen to persist are dynamic systems with ongoing supplies of energy.

The third and most interesting function is "novelty"—the tendency of evolving systems to explore new configurations that sometimes lead to startling new behaviors or characteristics.

Part 2

Comment by Dr. Krishna Kumari Challa on October 17, 2023 at 8:22am

Scientists identify nature's missing evolutionary law

A paper published in the Proceedings of the National Academy of Sciences describes "a missing law of nature," recognizing for the first time an important norm within the natural world's workings.

In essence, the new law states that complex natural systems evolve to states of greater patterning, diversity, and complexity. In other words, evolution is not limited to life on Earth, it also occurs in other massively complex systems, from planets and stars to atoms, minerals, and more.

"Macroscopic" laws of nature describe and explain phenomena experienced daily in the natural world. Natural laws related to forces and motion, gravity, electromagnetism, and energy, for example, were described more than 150 years ago.

The new work presents a modern addition—a macroscopic law recognizing evolution as a common feature of the natural world's complex systems, which are characterized as follows:

• They are formed from many different components, such as atoms, molecules, or cells, that can be arranged and rearranged repeatedly
• Are subject to natural processes that cause countless different arrangements to be formed
• Only a small fraction of all these configurations survive in a process called "selection for function."

Part 1

Comment by Dr. Krishna Kumari Challa on October 16, 2023 at 9:54am

A theory on how gold, platinum, and other precious metals found their way into Earth's mantle

Scientists say they've hit the jackpot with some valuable new information about the story of gold.

It's a story that begins with violent collisions of large objects in space, continues in a half-melted region of Earth's mantle, and ends with precious metals finding an unlikely resting spot much closer to the planet's surface than scientists would have predicted.

Their new theory provides possible answers to lingering questions about the way gold, platinum, and other precious metals found their way to shallow pockets within Earth's mantle rather than deep in the planet's core. More broadly, the new theory offers insights into planet formation throughout the universe.

Recent research from scientists around the world has established that precious metals such as gold and platinum came to Earth billions of years ago after the early proto-Earth collided with large, moon-sized bodies in space, which left behind deposits of materials that were folded into what is today's Earth.

Aside from being valued for their scarcity, aesthetic beauty, and use in high-tech products, gold and platinum are what is known as highly "siderophile" elements. They are drawn to the element iron to such a degree that they would be expected to collect almost entirely in Earth's metallic core—either by merging directly with the metal core on impact or by sinking quickly from the mantle into the core.

By this logic, they should not have collected at or near the Earth's surface. Yet they did.

The new theory centers around a thin, "transient" region of the mantle, where the shallow part of the mantle melts and the deeper part remains solid. The researchers found that this region has peculiar dynamic properties that can efficiently trap falling metallic components and slowly deliver them to the rest of the mantle. 

Their theory posits that this delivery is still ongoing, with the remnants of the transient region appearing as "large low-shear-velocity provinces"—well-known geophysical anomalies in the deep mantle.

This transient region almost always forms when a big impactor hits the early Earth, making this new  theory quite robust.

 Jun Korenaga et al, Vestiges of impact-driven three-phase mixing in the chemistry and structure of Earth's mantle, Proceedings of the National Academy of Sciences (2023). DOI: 10.1073/pnas.2309181120

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Comment by Dr. Krishna Kumari Challa on October 16, 2023 at 8:50am

If you are not getting enough sleep, your vascular cells may be drowning in oxidants!

Several people in the world are in the same situation of sleep deprivation and habitually get only five to six hours of sleep instead of the recommended seven to eight hours.

But even a mild chronic sleep deficit may heighten the risk of developing heart disease later in life: Surveys of thousands of people have found that people who report mild but chronic sleep deficits have more heart disease later in life than people who get adequate sleep.

Published in Scientific Reports, a study of women now shows what's happening in the body during chronic mild sleep deprivation.

After just six weeks of shortened sleep, the study found, the cells that line our blood vessels are flooded by damaging oxidants. And unlike well-rested cells, sleep-restricted cells fail to activate antioxidant responses to clear the destructive molecules.

The result: cells that are inflamed and dysfunctional, an early step in the development of cardiovascular disease. This is some of the first direct evidence to show that mild chronic sleep deficits cause heart disease.

Riddhi Shah, Vikash Kumar Shah, Memet Emin, Su Gao, Rosemary V. Sampogna, Brooke Aggarwal, Audrey Chang, Marie-Pierre St-Onge, Vikas Malik, Jianlong Wang, Ying Wei, Sanja Jelic. Mild sleep restriction increases endothelial oxidative stress in female persons. Scientific Reports, 2023; 13 (1) DOI: 10.1038/s41598-023-42758-y

Comment by Dr. Krishna Kumari Challa on October 15, 2023 at 6:32am

Flu-resistant chickens
 Birds with small alterations to one gene are highly resistant to avian flu

Scientists have created the world’s first flu-resistant chickens in an advance that could pave the way for gene-edited poultry. The birds, which had small alterations to one gene, were highly resistant to avian flu, with nine in 10 birds showing no signs of infection when exposed to a typical dose of the virus.

However, infections were not completely blocked, and scientists say this would have to be achieved before genetically engineered chickens could be introduced to farms, due to the risk of the virus evolving to become more dangerous to humans.

https://www.nature.com/articles/s41467-023-41476-3

Comment by Dr. Krishna Kumari Challa on October 14, 2023 at 8:37am

The three types of households with their typical characteristics and food waste behaviours. Credit: Trang Nguyen using Canva.com, CC BY-NC-ND

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 a fire retardant in building materials

Comment by Dr. Krishna Kumari Challa on October 14, 2023 at 8:20am

Targeting a coronavirus ion channel could yield new COVID-19 drugs

The genome of the SARS-CoV-2 virus encodes 29 proteins, one of which is an ion channel called E. This channel, which transports protons and calcium ions, induces infected cells to launch an inflammatory response that damages tissues and contributes to the symptoms of COVID-19.

MIT chemists have now discovered the structure of the "open" state of this channel, which allows ions to flow through. This structure, combined with the "closed" state structure that was reported by the same lab in 2020, could help scientists figure out what triggers the channel to open and close. These structures could also guide researchers in developing antiviral drugs that block the channel and help prevent inflammation.

When SARS-CoV-2 infects cells, the E channel embeds itself inside the membrane that surrounds a cellular organelle called the ER-Golgi intermediate compartment (ERGIC). The ERGIC interior has a high concentration of protons and calcium ions, which the E channel transports out of ERGIC and into the cell cytoplasm. That influx of protons and calcium leads to the formation of multiprotein complexes called inflammasomes, which induce inflammation.

Previous research has shown that when SARS-CoV-2 viruses are mutated so that they don't produce the E channel, the viruses generate much less inflammation and cause less damage to host cells.

So the E channel is an antiviral drug target now. If you can stop the channel from sending calcium into the cytoplasm, then you have a way to reduce the cytotoxic effects of the virus.

Joao Medeiros-Silva et al, Atomic Structure of the Open SARS-CoV-2 E Viroporin, Science Advances (2023). DOI: 10.1126/sciadv.adi9007. www.science.org/doi/10.1126/sciadv.adi9007

Comment by Dr. Krishna Kumari Challa on October 14, 2023 at 8:08am

Research shows wildfire smoke may linger in homes long after initial blaze

Newly published research on indoor air quality  shows wildfire smoke may linger in homes long after the initial blaze has been put out or winds have shifted.

The findings, published in Science Advances, show that wildfire smoke can attach to home surfaces like carpet, drapes or counters—extending the exposure for those inside and potentially causing health problems even after an initial cleaning activity by air purifiers.

However, the research also shows that  surface cleaning—like vacuuming, dusting or mopping—can reduce exposure and limit risk. The team was able to show that the amount of smoke left on surfaces was proportional to the surface area that was cleaned. That means simple cleaning and specifically addressing large but little noticed spaces that may trap harmful compounds such as cabinets and HVAC systems could be beneficial right away.

 Jienan Li et al, The persistence of smoke VOCs indoors: partitioning, surface cleaning, and air cleaning in a smoke-contaminated house, Science Advances (2023). DOI: 10.1126/sciadv.adh8263. www.science.org/doi/10.1126/sciadv.adh8263

Comment by Dr. Krishna Kumari Challa on October 13, 2023 at 12:12pm

Hair Turns Gray Due to Stuck Stem Cells

Hair-colouring stem cells must swing back and forth between their maturity states to give hair its colour.

Like human aging, stem cell maturation is considered a one-way process; once an undifferentiated stem cell goes down the path to become a specific type of cell, there is no turning back. But that does not seem to be the case with melanocyte stem cells (McSC), which give rise to cells that produce hair and skin pigments. 

In a recent study, researchers investigated McSC in hair follicles and found that depending on microenvironment cues, McSCs can fluctuate between undifferentiated and differentiated states. The researchers also found that as the hair follicle ages, a larger number of melanocyte stem cells get stuck in an undifferentiated state, losing their ability to mature and produce melanin. Published in Nature, these results not only challenge the traditional view on how stem cells differentiate, but also offer clues to why hair turns gray with aging. 

The researchers were surprised to find that McSC did not reside in an area called the bulge as previously thought, but were instead located in a compartment known as the hair germ. When the hair started to grow, the McSC transitioned to an intermediate differentiation state from which they either transformed into fully mature melanocytes at the base of the growing hair or moved up to the hair bulge where they stayed as undifferentiated cells. Then these stem cells homed back to the hair germ as the hair entered the resting phase of its growth cycle.

Once they realized that the maturation of these cells depended on their location, the team next investigated which signals within those compartments drove these changes. In the new study, the team found that nearby epithelial cells in the hair germ released Wnt ligands that mature the McSC, but these signals were suppressed in the bulge where the cells regained their undifferentiated features.

Melanocytes give hair its color, and hair pigmentation reduces with aging. So, the researchers wondered what would happen to McSC mobility in an aged hair follicle. To accelerate the aging of hair follicles, the researchers plucked mouse hair to induce regeneration of the follicles and observed McSCs over time. In aged mice, they found more of the stem cells in the bulge area rather than going back to the hair germ.

These findings suggested that as the hair follicle ages, McSC get stuck in a region where less pigment-inducing signals are present. This mechanism might explain why hair turns gray much more rapidly than it falls off.

Although scientists knew that cells could swing back and forth between their maturity states when there were tissue injuries, the study results are exciting as they reveal that dedifferentiation can also occur under a physiological condition.

Since the researchers conducted all of the experiments in mice, questions remain as to whether the same events are also seen in humans.

Sun Q, et al. Dedifferentiation maintains melanocyte stem cells in a dynamic niche. Nature. 2023;616(7958):774-782.

Rabbani P, et al. Coordinated activation of Wnt in epithelial and melanocyte stem cel.... Cell. 2011;145(6):941-955.

Comment by Dr. Krishna Kumari Challa on October 13, 2023 at 11:16am

Monkey lives with gene-edited pig kidney A macaque lived for more than two years with a kidney from a gene-edited miniature pig — one of the longest-lasting interspecies organ transplants. It raises hopes that human organ shortages could one day be alleviated by using organs from donor animals. The donor pigs received 69 gene edits to prevent immune reactions after transplantation and to keep the organ healthy. Of the 15 monkeys that received a transplant, five survived for more than one year and one of those lived for 758 days.

https://www.nature.com/articles/s41586-023-06594-4.epdf?sharing_tok...

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