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Comment by Dr. Krishna Kumari Challa on September 21, 2023 at 8:57am

• In winter, the new coating was slightly warmer than the passive radiative cooling system, though both maintained similar temperatures in warmer conditions.
• In summer, the new coating was significantly cooler than the white paint and steel tiles.
• During spring and fall, the new coating was the only system that could adapt to the widely fluctuating temperatures changes, switching from heating to cooling throughout the day.

The researchers say that this color-changing system could save a considerable amount of energy for regions that experience multiple seasons, while still being inexpensive and easy to manufacture.

"Warm in Winter and Cool in Summer" Scalable Biochameleons Inspired Temperature Adaptive Coating with Easy Preparation and Construction, Nano Letters (2023). DOI: 10.1021/acs.nanolett.3c02733

Part 2

Comment by Dr. Krishna Kumari Challa on September 21, 2023 at 8:56am

Chameleon-inspired coating could cool and warm buildings through the seasons

As summer turns to fall, many people will be turning off the air conditioning and firing up heaters instead. But traditional heating and cooling systems are energy-intensive, and because they typically run on fossil fuels, they aren't sustainable. Now, by mimicking a desert-dwelling chameleon, a research team reporting in Nano Letters has developed an energy-efficient, cost-effective coating. The material could keep buildings cool in the summers—or warm in the winters—without additional energy.

Many desert creatures have specialized adaptations to allow them to survive in harsh environments with large daily temperature shifts. For example, the Namaqua chameleon of southwestern Africa alters its color to regulate its body temperature as conditions change. The critters appear light gray in hot temperatures to reflect sunlight and keep cool, then turn a dark brown once they cool down to absorb heat instead.

This unique ability is a naturally occurring example of passive temperature control—a phenomenon that could be adapted to create more energy-efficient buildings. But many systems, such as cooling paints or colored steel tiles, are only designed to keep buildings either cool or warm, and can't switch between "modes."

Inspired by the Namaqua chameleon, researchers wanted to create a color-shifting coating that would adapt as outside temperatures fluctuate. To make the coating, researchers mixed thermochromic microcapsules, specialized microparticles and binders to form a suspension, which they sprayed or brushed onto a metal surface. When heated to 68 degrees Fahrenheit, the surface began to change from dark to light gray. Once it reached 86 degrees, the light-colored film reflected up to 93% of solar radiation. Even when heated above 175 degrees for an entire day, the material showed no signs of damage. Next, the team tested it alongside three conventional coatings—regular white paint, a passive radiative cooling paint and blue steel tiles—in outdoor tests on miniature, doghouse-sized buildings throughout all four seasons.

Part 1

Comment by Dr. Krishna Kumari Challa on September 21, 2023 at 8:48am

How bats evolved to avoid cancer

A new paper titled "Long-read sequencing reveals rapid evolution of immunity and cancer-related genes in bats" in Genome Biology and Evolution shows that rapid evolution in bats may account for the animals' extraordinary ability to both host and survive infections as well as avoid cancer.

Bats are exceptional among mammals for not only their ability to fly, but also for their long lives, low cancer rates, and robust immune systems. The ability of bats to tolerate viral infections may stem from unusual features of their innate immune response.

These characteristics make bats an interesting animal to investigate, because they may have implications for human health. For example, by better understanding the mechanisms of the bat immune system that allow bats to tolerate viral infections, researchers may be better able to prevent disease outbreaks from animals to people. Comparative genomic analyses of bats and cancer-susceptible mammals may eventually provide new information on the causes of cancer and the links between cancer and immunity.

Studies of bats and other organisms complement studies based on mouse models; mice are more amenable than bats to experimental manipulation but exhibit fewer characteristics with implications for human disease.

So researchers sequenced the genomes of two bat species, the Jamaican fruit bat and the Mesoamerican mustached bat, and carried out a comprehensive comparative genomic analysis with a diverse collection of bats and other mammals.

The researchers found genetic adaptations in six DNA repair-related proteins and 46 proteins in bats that were cancer-related, meaning that researchers have previously found that such proteins suppress cancer. Notably, the study found that these altered cancer-related genes were enriched more than two-fold in the bat group compared to other mammals.

By generating these new bat genomes and comparing them to other mammals scientists continue to find extraordinary new adaptations in antiviral and anticancer genes. These investigations are the first step towards translating research on the unique biology of bats into insights relevant to understanding and treating aging and diseases, such as cancer, in humans.

Armin Scheben et al, Long-read sequencing reveals rapid evolution of immunity and cancer-related genes in bats, Genome Biology and Evolution (2023). DOI: 10.1093/gbe/evad148

Comment by Dr. Krishna Kumari Challa on September 21, 2023 at 8:32am

Researchers make sand that flows uphill

Engineering researchers  have discovered that sand can actually flow uphill.

The team's findings were published recently in the journal Nature Communications. A corresponding video shows what happens when torque and an attractive force  is applied to each grain—the grains flow uphill, up walls, and up and down stairs.

"After using equations that describe the flow of granular materials,"  say the authors of the paper, "we were able to conclusively show that these particles were indeed moving like a granular material, except they were flowing uphill."

The researchers say the highly unusual discovery could unlock many more lines of inquiry that could lead to a vast range of applications, from health care to material transport and agriculture.

Uphill granular flow of microrobotic microrollers

But to understand how these grains are flowing uphill, the researchers calculated what the stresses are that cause them to move in that direction. If you have a negative angle of repose, then you must have cohesion to give a negative coefficient of friction. These granular flow equations were never derived to consider these things, but after calculating it, what came out is an apparent coefficient of friction that is negative.

Increasing the magnetic force increases the cohesion, which gives the grains more traction and the ability to move faster. The collective motion of all those grains, and their ability to stick to each other, allows a pile of sand particles to essentially work together to do counterintuitive things—like flow up walls, and climb stairs. The team is now using a laser cutter to build tiny staircases, and is taking videos of the material ascending one side and descending the other. A single microroller couldn't overcome the height of each step. But working together, they can.

 Samuel R. Wilson-Whitford et al, Microrollers flow uphill as granular media, Nature Communications (2023). DOI: 10.1038/s41467-023-41327-1

Comment by Dr. Krishna Kumari Challa on September 21, 2023 at 8:20am

Spider silk is spun by silkworms for the first time, offering a green alternative to synthetic fibers

Scientists  have synthesized spider silk from genetically modified silkworms, producing fibers six times tougher than the Kevlar used in bulletproof vests.

The study, published September 20 in the journal Matter, is the first to successfully produce full-length spider silk proteins using silkworms. The findings demonstrate a technique that could be used to manufacture an environmentally friendly alternative to synthetic commercial fibers such as nylon.

Silkworm silk is presently the only animal silk fiber commercialized on a large scale, with well-established rearing techniques. Consequently, employing genetically modified silkworms to produce spider silk fiber enables low-cost, large-scale commercialization.

Scientists have eyed spider silk as an enticingly sustainable alternative to synthetic fibres, which can release harmful microplastics into the environment and are often produced from fossil fuels that generate greenhouse gas emissions. But turning to nature for alternatives isn't without challenges.

Previously developed processes for spinning artificial spider silk have struggled to apply a surface layer of glycoproteins and lipids to the silk to help it withstand humidity and exposure to sunlight—an anti-aging "skin layer" that spiders apply to their webs.

Genetically modified silkworms offer a solution to this problem, say the researchers  since silkworms coat their own fibers with a similar protective layer.

The exceptionally high mechanical performance of the fibers produced in this study holds significant promise in this field. This type of fiber can be utilized as surgical sutures, addressing a global demand exceeding 300 million procedures annually.

The spider silk fibers could also be used to create more comfortable garments and innovative types of bulletproof vests and they may have applications in smart materials, the military, aerospace technology, and biomedical engineering.

 Qing Meng, High-strength and ultra-tough whole spider silk fibers spun from transgenic silkworms, Matter (2023). DOI: 10.1016/j.matt.2023.08.013. www.cell.com/matter/fulltext/S2590-2385(23)00421-6

Comment by Dr. Krishna Kumari Challa on September 20, 2023 at 9:22am

This rate is 35 times higher than previous genus-level extinctions.

Without human influence, it would have taken 18,000 years for the same number of genera to have met their end. Other studies have also found similarly high extinction rates for plant, fungi, and invertebrate life as well.

"[The sixth mass extinction] is causing rapid mutilation of the tree of life, where entire branches (collections of species, genera, families, and so on) and the functions they perform are being lost," explain the researchers.

The biosphere we live within is extremely interconnected, so loss of species groups that play particular functions within their interconnected-living web can have severe cascading consequences.

What's more, this rate of genera loss is set to increase, they calculate. If we continue on our current trajectory and all current endangered genera are snuffed from existence by 2100, the equivalent 300-year-loss since 1800 would have taken 106,000 years at normal background levels of extinction.

The most vulnerable species are usually the most unique, yet overlooked on the planet. Along with them we'll lose millions of years of evolutionary history, which can never be repeated, as well as the loss of critical functions they performed that helped keep all the surrounding biological cycles chugging on like a well oiled machine.

Climate change alone is creating a massive destabilization across these systems, scattering critical timing of ecosystem services like pollination, reducing the types of species and allowing new ones to invade more easily.

From plastics, to pesticides, habitat loss and poaching, we're not allowing the life around us to catch a break.

"Immediate political, economic, and social efforts of an unprecedented scale are essential if we are to prevent these extinctions and their societal impacts. What happens in the next two decades will very likely define the future of biodiversity

https://www.pnas.org/doi/10.1073/pnas.2306987120

Part 2

Comment by Dr. Krishna Kumari Challa on September 20, 2023 at 9:22am

Entire Branches on Tree of Life Are Dying, Scientists Warn

Like the comet striking the dinosaurs – in slower motion, but just as deadly – human activity is hacking off entire branches from the tree of life, a new study confirms.

"It is changing the trajectory of evolution globally and destroying the conditions that make human life possible," ecologists warn in their new paper.

"It is an irreversible threat to the persistence of civilization and the livability of future environments for Homo sapiens."

Over the past few months the sixth mass extinction has become devastatingly visible.

We've witnessed mass seabird deaths, shores have been littered with droves of dead fish, and sea lions poisoned by heat-induced algal blooms. Last year entire populations of penguins failed to breed and for years now researchers have been investigating an alarming reduction in insect life.

Ecologists assessed species extinctions since 1500 CE and compared those through the past 500 million years. They found we've driven 73 genera of back-boned animals to extinction during the last 500 years.

Genus is the taxonomic classification just above species, grouping together the most closely related organisms, much like siblings, in a family tree.

Part 1

Comment by Dr. Krishna Kumari Challa on September 20, 2023 at 6:59am

How brain cells die in Alzheimer’s

It has been a mystery and a source of scientific debate for decades.

But scientists, writing in the journal Science, connect the abnormal proteins that build up in the brain with "necroptosis" - a form of cellular suicide.

It is the loss of brain cells, called neurons, that lead to the symptoms of Alzheimer's, including memory loss.

And if you look inside the brains of people with the disease you'd see the build-up of abnormal proteins called amyloid and tau. But scientists have not been able to join the dots between these key traits of the disease until recently. 

The new work shows that abnormal amyloid starts to build up in the spaces between neurons, leading to brain inflammation, which the neurons do not like. This starts to change their internal chemistry.

Tangles of tau appear and the brain cells start producing a specific molecule (it's called MEG3) that triggers death by necroptosis. Necroptosis is one of the methods our bodies normally use to purge unwanted cells as fresh ones are made.

The brain cells survived when the researchers were able to block MEG3.

It really provides strong evidence it's this specific suicide pathway.

The answers came from experiments where human brain cells were transplanted into the brains of genetically modified mice. The animals were programmed to produce large quantities of abnormal amyloid.

There has been recent success in developing drugs that strip amyloid out of the brain and they mark the first treatments to slow the destruction of brain cells.

https://www.science.org/doi/10.1126/science.abp9556

Comment by Dr. Krishna Kumari Challa on September 20, 2023 at 6:43am

Yogurt may be the next go-to garlic breath remedy

It turns out yogurt may have a previously unknown benefit: eliminating garlic odors.

A new study conducted in a lab—with follow-up human breath tests being planned—showed that whole milk plain yogurt prevented almost all of the volatile compounds responsible for garlic's pungent scent from escaping into the air.

Researchers tested the garlic deodorizing capacity of yogurt and its individual components of water, fat and protein to see how each stood up to the stink. Both fat and protein were effective at trapping garlic odors, leading the scientists to suggest high-protein foods may one day be formulated specifically to fight garlic breath.

For each treatment experiment, the researchers placed equal amounts of raw garlic in glass bottles and confirmed the cluster of offending sulfur-based volatiles were released in concentrations that would be detected by the human nose. They used mass spectrometry to measure levels of the volatile molecules in gaseous form present before and after each treatment.

Results showed that yogurt alone reduced 99% of the major odor-producing raw garlic volatiles. When introduced separately, the fat, water and protein components of yogurt also had a deodorizing effect on raw garlic, but fat and protein performed better than water.

In the case of fat, a higher quantity of butter fat was more effective at deodorization. The proteins studied included different forms of whey, casein and milk proteins, all of which were effective at deodorizing garlic—likely because of their ability to trap the volatile molecules before they were emitted into the air. A casein micelle-whey protein complex performed the best.

Additional experiments involving changing the pH of the yogurt to make it less acidic—from 4.4 pH to 7 pH—reduced the yogurt's deodorization effect on the garlic. Changing the pH of water, on the other hand, did not make any difference in water's deodorization effect.

Manpreet Kaur et al, Effect of Yogurt and Its Components on the Deodorization of Raw and Fried Garlic Volatiles, Molecules (2023). DOI: 10.3390/molecules28155714

Comment by Dr. Krishna Kumari Challa on September 20, 2023 at 6:32am

The researchers found that when water was stratified (a layer of warm water sitting on top of cold bottom waters), methane built up and led to overall higher emissions than when water was mixed by wind or sudden cooling. That's because micro-organisms on the pond bed that produce methane require low-oxygen conditions that is disrupted by mixing.

When the results from the all the present studies are considered together, ponds are net emitters of greenhouse gases, due to methane release overwhelming the amount of carbon stored in the sediments. But the findings also offer the possibility of reducing methane emissions with bubblers or underwater circulators. If we could reduce that methane number, we could potentially flip these ponds from being net emitters to net sinks, but we have to get a handle on that methane.

Meredith A. Holgerson et al, High rates of carbon burial linked to autochthonous production in artificial ponds, Limnology and Oceanography Letters (2023). DOI: 10.1002/lol2.10351

Nicholas E. Ray et al, High Intra‐Seasonal Variability in Greenhouse Gas Emissions From Temperate Constructed Ponds, Geophysical Research Letters (2023). DOI: 10.1029/2023GL104235

Part 2

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