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Comment by Dr. Krishna Kumari Challa on September 22, 2021 at 1:20pm

Salty Diet Helps Gut Bugs Fight Cancer in Mice: Study

A high-salt diet suppressed the growth of tumors in a mouse model of melanoma, apparently because of an interplay between the gut microbiome and natural killer cells.

Salt may not be good for your BP, but .....

In mice, a diet high in salt suppresses tumor growth—but only when gut microbes are there to stimulate immune cells, a September 10 study in Science Advances reports. The findings raise tantalizing questions about the role of diet and gut microbes in human cancers, and may point to new avenues for therapeutic development.

While the study isn’t the first to connect a high-salt diet to shrinking tumors, the authors have shown a unique mechanistic role of high salt induced gut microbiome changes as the central phenomenon behind their observed anti-cancer effect.

The researchers  pursued this line of inquiry because previous research had linked high salt intake with autoimmune diseases, suggesting that increased salt stimulates immune cells. Meanwhile, tumors are well known to grow in immune-suppressive environments. So they thought, “If we put salt in the mice’s diet, maybe [the immune system in] the tumor environment becomes activated,” suppressing cancerous growth.

a 2019 Frontiers in Immunology study from a European team led by Hasselt University immunologist Markus Kleinewietfeld reported that high-salt diets inhibited tumor growth in mice. No researchers carried out similar experiments, implanting mice with B16F10 skin melanoma cells and then feeding the tumor transplant mice diets with different salt levels, they got similar results: tumors grew slower in mice who were fed a high-salt diet.

https://www.science.org/doi/10.1126/sciadv.abg5016

https://www.the-scientist.com/news-opinion/a-salty-diet-helps-gut-b...

Comment by Dr. Krishna Kumari Challa on September 22, 2021 at 12:57pm

the researchers computed how many satellites will be in the sky at different times of year, at different hours of the night and from different positions on Earth’s surface. They also estimated how bright the satellites were likely to be at different hours of the day and times of the year.

The simulations showed that “the way the night sky is going to change will not affect all places equally,” Lawler says. The places where naked-eye stargazing will be most affected are at latitudes 50° N and 50° S, regions that cross lower Canada, much of Europe, Kazakhstan and Mongolia, and the southern tips of Chile and Argentina, the researchers found.

The geometry of sunlight in the summer means there will be hundreds of visible satellites all night long. It’s bad everywhere, but it’s worse there.

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A few visible satellites can be a fun spectacle. Astronomers have been meeting with representatives from private companies, as well as space lawyers and government officials, to work out compromises and mitigation strategies. Companies have been testing ways to reduce reflectivity, like shading the satellites with a “visor.” Other proposed strategies include limiting the satellites to lower orbits, where they move faster across the sky and leave a fainter streak in telescope images. Counterintuitively, lower satellites may be better for some astronomy research. “They move out of the way quick.”

But that lower altitude strategy will mean more visible satellites for other parts of the world, and more that are visible to the naked eye.

There are some latitudes on Earth where no matter what altitude you put your satellites at, they’re going to be all over the darn place. The only way out of this is fewer satellites.

There are currently no regulations concerning how bright a satellite can be or how many satellites a private company can launch. Scientists are grateful that companies are willing to work with them, but think that their cooperation is voluntary. Efforts are under way to bring the issue to the attention of the United Nations and to try to use existing environmental regulations to place limits on satellite launches.

S. Lawler, A. Boley and H. Rein. Visibility predictions for near-future satellite megaconstellations.... arXiv:2109.04328. Posted September 9, 2021.

https://www.sciencenews.org/article/satellite-mega-constellations-n...

Comment by Dr. Krishna Kumari Challa on September 22, 2021 at 12:43pm

Satellite swarms may outshine the night sky’s natural constellations

“Mega-constellations” from those satellites will be visible to the naked eye, simulations suggest

A few years back  somebody asked me from the art field, "If You 're asked to make a science-art installation, what would it be?" My instant answer was, "Groups of satellites in the night sky that shine like star constellations and also help the mankind". 

"Wow!" was that person's reaction.

But,  now that reply of mine is going to be revisited. Why? Companies like SpaceX and Amazon have launched hundreds of satellites into low orbits since 2019, with plans to launch thousands more in the works — a trend that’s alarming astronomers. The goal of these satellite “mega-constellations” is to bring high-speed internet around the globe, but these bright objects threaten to disrupt astronomers’ ability to observe the cosmos.

 Now, a new simulation of the potential positions and brightness of these satellites shows that, contrary to earlier predictions, casual sky watchers will have their view disrupted, too. And parts of the world will be affected more than others.

Flat, smooth surfaces on satellites can reflect sunlight depending on their position in the sky. Earlier research had suggested that most of the new satellites would not be visible with the naked eye.

There are currently about 7,890 objects in Earth orbit, about half of which are operational satellites, according to the U.N. Office for Outer Space Affairs. But that number is increasing fast as companies launch more and more satellites . In August 2020, there were only about 2,890 operational satellites.

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Comment by Dr. Krishna Kumari Challa on September 22, 2021 at 10:11am

Rock shape should be given greater consideration in rockfall risk assessments

The shape of rocks is a key factor in assessing rockfall hazard. This is the conclusion of a new study from the Institute for Snow and Avalanche Research.

Rockfall is a very real threat in an Alpine country like Switzerland. In order to assess the hazard at a given location and plan protective measures, engineering firms use computer models to calculate how far falling rocks can roll. However, the models are not yet able to adequately take into account the extent to which the mass, size or shape of a rock influences its movement. This would require real-world measurement data to be fed into the models, but until now such data were only available sporadically, since no systematic rockfall studies had been conducted.

First comprehensive experiments

That has now changed after researchers  spent over four years carrying out rockfall experiments. This has allowed them to compile the largest set of measurement data to date.

The researchers used artificial rocks in the form of concrete blocks fitted with sensors, which they rolled down a slope near the Flüela Pass in the Swiss canton of Grisons. They compared different shapes and masses, reconstructed the complete trajectories and determined speeds, jump heights and runout zones (see info box). They have just published their results in the scientific journal Nature Communications.

The most significant finding is that the direction a rock rolls in depends much more on its shape than on its mass. While cube-shaped boulders plunge straight down the line of greatest slope, wheel-shaped rocks often pull away to one side and so may threaten a much wider area at the base of the slope. "This needs to be taken into consideration when assessing danger zones, but also when determining the location and dimensions of rockfall nets.

Because wheel-like rocks hit rockfall nets with their narrow side, their energy is concentrated on a much smaller area than is the case with cube-like rocks—so protective nets need to be stronger.

The data set is also available on the EnviDat platform, where it is freely accessible to other research groups. They can use it to calibrate their own algorithms or to develop new, more accurate models providing enhanced protection against rockfall.

Andrin Caviezel et al, The relevance of rock shape over mass—implications for rockfall hazard assessments, Nature Communications (2021). DOI: 10.1038/s41467-021-25794-y

https://phys.org/news/2021-09-greater-consideration-rockfall.html?u...

Comment by Dr. Krishna Kumari Challa on September 22, 2021 at 10:04am

Inhibiting targets of SARS-CoV-2 proteases can block infection, study shows

Researchers  have shown how SARS-CoV-2 viral proteases attack the host cell, and how this can be targeted to stop virus replication in cell culture using existing drugs.

The new findings, published today in Nature Communications, offer a powerful resource to understand proteolysis in the context of viral infection, and to inform the development of targeted strategies to inhibit the virus that causes COVID-19.

Both viral and cellular proteases play a crucial role in SARS-CoV-2 replication, and inhibitors targeting proteases have already shown success at inhibiting SARS-CoV-2 in cell culture models. 

In this study, researchers used a mass spectrometry approach to study proteolytic cleavage events during SARS-CoV-2 infection.

The team found previously unknown cleavage sites in multiple viral proteins, including major antigenic proteins S and N, which are the main targets for vaccine and antibody testing efforts.

They discovered significant increases in cellular cleavage events consistent with cleavage by SARS-CoV-2 main protease (Mpro) and identified 14 potential high-confidence substrates of the main and papain-like proteases, validating a subset with in vitro assays.

They went on to show that siRNA depletion of these cellular proteins inhibits SARS-CoV-2 replication, and that drugs targeting two of these proteins: the tyrosine kinase SRC and Ser/Thr kinase MYLK, showed a dose-dependent reduction in SARS CoV-2 titres.

Both Bafetinib (an experimental cancer drug) and Sorafenib (an approved drug used to treat kidney and liver cancer) showed SARS-CoV-2 inhibition at concentrations that did not result in cytotoxicity in a human cell line model of infection.

Characterising proteolysis during SARS-CoV-2 infection identifies viral cleavage sites and cellular targets with therapeutic potential, Nature Communications (2021). DOI: 10.1038/s41467-021-25796-w

https://phys.org/news/2021-09-inhibiting-sars-cov-proteases-block-i...

Comment by Dr. Krishna Kumari Challa on September 21, 2021 at 6:10am

Serious Infections Linked to Autism: Study

In both a mouse model and the hospital records of more than 3 million children, researchers found a connection between strong immune activation in males and later symptoms of autism spectrum disorder.

While researchers have found plenty of gene variants that seem to increase the risk of an autism diagnosis, it’s not clear why some people carrying these mutations develop autism spectrum disorders and some do not. In a study published today (September 17) in Science Advances, researchers point to a potential answer: severe infections during early childhood. After an early immune challenge, male mice with a mutated copy of the tuberous sclerosis complex 2 (Tsc2) gene developed deficits in social behavior linked to changes in microglia, the immune cells of the brain. And an analysis of the hospital records of more than 3 million children showed that children, particularly boys, who were hospitalized for infections between ages 18 months and four years were more likely that healthy peers to receive a future autism spectrum disorder (ASD) diagnosis.

https://www.science.org/doi/10.1126/sciadv.abf2073

https://www.the-scientist.com/news-opinion/serious-infections-linke...

Comment by Dr. Krishna Kumari Challa on September 21, 2021 at 6:05am

The Placebo Effect Is an Amazing Illusion, But That Doesn't Mean It's Medicine

Placebo is a beneficial effect produced by a placebo drug or treatment, which cannot be attributed to the properties of the placebo itself, and must therefore be due to the patient's belief in that treatment.

The placebo is one of science's greatest mysteries. The pill that isn't a pill. The medical illusion that somehow becomes real.

The mind-boggling weirdness of the placebo effect is certainly a strange thing, nobody doubts that.

But just because the placebo effect occasionally delivers unexpected outcomes doesn't mean we should overestimate how powerful it is – nor try to find a place for it in the medical care of patients, scientists are now warning.

In a new perspective article, researchers argue that recent suggestions placebos could play a role in clinical care are unfounded, and are based on flawed evidence.

Much of the current discourse on placebo seems to focus more on enshrining placebos as mysterious and highly effective and less on making a practical difference to patient care and outcomes.

Observations of the placebo effect can be traced back to the 18th century, and the reputation of the placebo has grown ever since: the idea that an inert, sham treatment, taken unknowingly by a patient, can sometimes deliver therapeutic effects like the real thing.

That reputation is mostly underserved. A Cochrane review of placebos considered 234 trials and concluded that, in general, placebos do not produce major health benefits, except for some small and inconsistent effects on self-reported outcomes such as pain or nausea," the researchers explain.

Placebos remain important for clinical trials because they help achieve blinding and, thus, control of bias," the team writes.

"When administered in a blinded fashion, a placebo will provide a small effect, but the real treatment will normally provide better outcomes for the patient… It may be better to dismiss placebos and instead manage patients with evidence-based treatments., they conclude.

https://onlinelibrary.wiley.com/doi/10.5694/mja2.51230

https://www.sciencealert.com/the-placebo-effect-is-an-amazing-illus...

Comment by Dr. Krishna Kumari Challa on September 21, 2021 at 5:39am

Science of Concrete & the Surfside Condo Collapse

Comment by Dr. Krishna Kumari Challa on September 21, 2021 at 5:35am

Yeast and bacteria together biosynthesize plant hormones for weed control

Plants regulate their growth and development using hormones, including a group called strigolactones that prevent excessive budding and branching. For the first time, scientists  have synthesized strigolactones from microbes.

Strigolactones also help plant roots form symbiotic relationships with microorganisms that allow the plant to absorb nutrients from the soil. These two factors have led to agricultural interest in using strigolactones to control the growth of weeds and root parasites, as well as improving nutrient uptake.

These root-extruding compounds don't come without risks. They also stimulate germination of witchweeds and broomrapes, which can cause entire crops of grain to fail, making thorough research essential prior to commercial development. Scientists are still learning about the physiological roles played by this diverse group of hormones in plants. Until recently, manufacturing pure strigolactones for scientific study has been difficult and too costly for agricultural use.

The new  work provides a unique platform to investigate strigolactone biosynthesis and evolution, and it lays the foundation for developing strigolactone microbial bioproduction processes as alternative sourcing.

Researchers directed a group that inserted plant genes associated with strigolactone production into ordinary baker's yeast and nonpathogenic Escherichia coli bacteria that together produced a range of strigolactones.

Sheng Wu et al, Establishment of strigolactone-producing bacterium-yeast consortium, Science Advances (2021). DOI: 10.1126/sciadv.abh4048

https://phys.org/news/2021-09-yeast-bacteria-biosynthesize-hormones...

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Comment by Dr. Krishna Kumari Challa on September 21, 2021 at 5:27am

Nano-scale discovery could help to cool down overheating in electronics

A team of physicists  solved the mystery behind a perplexing phenomenon in the nano realm: why some ultra-small heat sources cool down faster if you pack them closer together. The findings  could one day help the tech industry design faster electronic devices that overheat less.

Often, heat is a challenging consideration in designing electronics. You build a device then discover that it's heating up faster than desired.

In 2015, physicists  were experimenting with bars of metal that were many times thinner than the width of a human hair on a silicon base. When they heated those bars up with a laser, something strange occurred.

They behaved very counterintuitively. These nano-scale heat sources do not usually dissipate heat efficiently. But if you pack them close together, they cool down much more quickly.

Now, the researchers know why it happens.

In the new study, they used computer-based simulations to track the passage of heat from their nano-sized bars. They discovered that when they placed the heat sources close together, the vibrations of energy they produced began to bounce off each other, scattering heat away and cooling the bars down.

The group's results highlight a major challenge in designing the next generation of tiny devices, such as microprocessors or quantum computer chips: When you shrink down to very small scales, heat does not always behave the way you think it should.

 Directional thermal channeling: A phenomenon triggered by tight packing of heat sources, Proceedings of the National Academy of Sciences (2021). DOI: 10.1073/pnas.2109056118

https://phys.org/news/2021-09-nano-scale-discovery-cool-overheating...

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