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Comment by Dr. Krishna Kumari Challa on May 31, 2024 at 6:58am

How does the word 'not' affect what we understand? Scientists find negation mitigates our interpretation of phrases

When we're told "This coffee is hot" upon being served a familiar caffeinated beverage at our local diner or cafe, the message is clear. But what about when we're told "This coffee is not hot"? Does that mean we think it's cold? Or room temperature? Or just warm?

A team of scientists has now identified how our brains work to process phrases that include negation (i.e., "not"), revealing that it mitigates rather than inverts meaning—in other words, in our minds, negation merely reduces the temperature of our coffee and does not make it "cold."

We now have a firmer sense of how negation operates as we try to make sense of the phrases we process.

In identifying that negation serves as a mitigator of adjectives—bad or good, sad or happy, and cold or hot—we also have a better understanding of how the brain functions to interpret subtle changes in meaning.

In an array of communications, ranging from advertising to legal filings, negation is often used intentionally to mask a clear understanding of a phrase. In addition, large language models in AI tools have difficulty interpreting passages containing negation. The researchers say that their results show how humans process such phrases while also potentially pointing to ways to understand and improve AI functionality.

This research spotlights the complexity that goes into language comprehension, showing that this cognitive process goes above and beyond the sum of the processing of individual word meanings.

Find the full details of the experimental work here: Zuanazzi A, Ripollés P, Lin WM, Gwilliams L, King J-R, Poeppel D, Negation mitigates rather than inverts the neural representations of adjectives. PLoS Biology (2024). DOI: 10.1371/journal.pbio.3002622

Comment by Dr. Krishna Kumari Challa on May 31, 2024 at 6:51am

Reduced sulfur content in shipping fuel associated with increased maritime atmospheric warming

An 80% reduction in sulfur dioxide shipping emissions observed in early 2020 could be associated with substantial atmospheric warming over some ocean regions, according to a modeling study published in Communications Earth & Environment. The sudden decline in emissions was a result of the introduction of the International Maritime Organization's 2020 regulation (IMO 2020), which reduced the maximum sulfur content allowed in shipping fuel from 3.5% to 0.5% to help reduce air pollution.

Fuel oil used for large ships has a significantly higher percentage content of sulfur than fuels used in other vehicles. Burning this fuel produces sulfur dioxide, which reacts with water vapor in the atmosphere to produce sulfate aerosols. These aerosols cool the Earth's surface in two ways: by directly reflecting sunlight back to space; and by affecting cloud cover.

Increasing the number of aerosols increases the number of water droplets that form while reducing their size, both increasing the cloud coverage and forming brighter clouds which reflect more sunlight back to space. Marine cloud brightening is a form of geoengineering where marine clouds are deliberately seeded with aerosols to achieve this effect.

Researchers  calculated the effect of IMO 2020 on the atmospheric levels of sulfate aerosols over the ocean and how this affected cloud composition. They found substantial reductions in both the levels of atmospheric aerosols and the cloud droplet number density.

The greatest modeled aerosol reductions were in the North Atlantic, the Caribbean Sea, and the South China Sea—the regions with the busiest shipping lanes. The authors then estimated the effect of IMO 2020 on Earth's energy budget (the difference between the energy received from the sun and the energy radiated from the Earth) since 2020. They calculated that the estimated effect is equivalent to 80% of the observed increase in the heat energy retained on Earth over that period.

The authors suggest that the substantial modeled effect of IMO 2020 on Earth's energy budget demonstrates the potential effectiveness of marine cloud brightening as a strategy to temporarily cool the climate. However, they also warn that the intended reduction in sulfur dioxide emissions due to IMO 2020 potentially causing an inadvertent increase in marine atmospheric temperature is an example of a geoengineering termination shock, which could affect regional weather patterns.

Tianle Yuan, Abrupt reduction in shipping emission as an inadvertent geoengineering termination shock produces substantial radiative warming, Communications Earth & Environment (2024). DOI: 10.1038/s43247-024-01442-3. www.nature.com/articles/s43247-024-01442-3

Comment by Dr. Krishna Kumari Challa on May 31, 2024 at 6:44am

Antibiotic pollution disrupts the gut microbiome and blocks memory in aquatic snails, study finds

Antibiotics prevent snails from forming new memories by disrupting their gut microbiome—the community of beneficial bacteria found in their guts.

The new research highlights the damaging effects that human pollution could be having on aquatic wildlife.

In the study published in The ISME Journal, pond snails were given a favorite food—carrot juice—but had to quickly learn and remember that it was no longer safe to eat.

Snails in clean water did well, avoiding feeding on the carrot juice when it had been paired with a chemical they dislike. However, snails that had been exposed to high concentrations of antibiotics in the water failed to learn and form a memory, and continued to show normal feeding behavior even after training.

It's well known that a healthy gut microbiome is important to human health, and this  study is the first to show this is also the case in snails and other animals.

The researchers found the antibiotics altered the gut microbiome substantially and changed the abundance of bacteria that have been found to relate to healthy memory formation in other animals, including humans. This relationship between the bacteria found in the gut and brain function is called the microbiome-gut-brain axis. Chemicals produced by good gut bacteria when breaking down food can improve brain health and cognitive function.

Reducing the abundance of these healthy bacteria in the gut blocks the gut microbiome's otherwise beneficial effects on the brain.

Previous studies on the link between the gut microbiome and brain function have focused on terrestrial species. However, aquatic wildlife is more likely to be directly affected by antibiotic exposure in the environment.

Antibiotics are not removed effectively by waste treatment, and so they enter the freshwater environment. The antibiotic concentrations snails were exposed to in this new experiment were detected at similar levels in freshwater in the UK, Europe and globally.

Gabrielle Davidson et al, Antibiotic-altered gut microbiota explain host memory plasticity and disrupt pace-of-life trait covariation for an aquatic snail, The ISME Journal (2024). DOI: 10.1093/ismejo/wrae078

Comment by Dr. Krishna Kumari Challa on May 31, 2024 at 6:38am

Study results indicate that pitavastatin inhibits interleukin-33 to suppress skin and pancreatic cancers

A new study led by investigators from Mass General Cancer Center reveals that statins—commonly used cholesterol-lowering drugs—may block a particular pathway involved in the development of cancer that results from chronic inflammation. The findings are published in Nature Communications.

Chronic inflammation is a major cause of cancer worldwide.

Researchers investigated the mechanism by which environmental toxins drive the initiation of cancer-prone chronic inflammation in the skin and pancreas.

They also examined safe and effective therapies to block this pathway in order to suppress chronic inflammation and its cancer aftermath.

The researchers study relied on cell lines, animal models, human tissue samples and epidemiological data. The group's cell-based experiments demonstrated that environmental toxins (such as exposure to allergens and chemical irritants) activate two connected signaling pathways called the TLR3/4 and TBK1-IRF3 pathways. This activation leads to the production of the interleukin-33 (IL-33) protein, which stimulates inflammation in the skin and pancreas that can contribute to the development of cancer.

When they screened a library of U.S. Food and Drug Administration–approved drugs, the researchers found that a statin, pitavastatin, effectively suppresses IL-33 expression by blocking the activation of the TBK1-IRF3 signaling pathway. In mice, pitavastatin suppressed environmentally-induced inflammation in the skin and the pancreas and prevented the development of inflammation-related pancreatic cancers.

In human pancreas tissue samples, IL-33 was over-expressed in samples from patients with chronic pancreatitis (inflammation) and pancreatic cancer compared with normal pancreatic tissue. Also, in analyses of electronic health records data on more than 200 million people across North America and Europe, use of pitavastatin was linked to a significantly reduced risk of chronic pancreatitis and pancreatic cancer.

The findings demonstrate that blocking IL-33 production with pitavastatin may be a safe and effective preventive strategy to suppress chronic inflammation and the subsequent development of certain cancers.

Park JH et al. Statin prevents cancer development in chronic inflammation by blocking interleukin 33 expression, Nature Communications (2024). DOI: 10.1038/s41467-024-48441-8

Comment by Dr. Krishna Kumari Challa on May 31, 2024 at 6:30am

Astronomers find most distant galaxy using James Webb Space Telescope

An international team of astronomers recently announced the discovery of the two earliest and most distant galaxies ever seen, dating back to only 300 million years after the Big Bang. These results, using NASA's James Webb Space Telescope (JWST), mark a major milestone in the study of the early universe.

The discoveries were made by the JWST Advanced Deep Extragalactic Survey (JADES) team. 

Because of the expansion of the universe, the light from distant galaxies stretches to longer wavelengths as it travels. This effect is so extreme for these two galaxies that their ultraviolet light is shifted to infrared wavelengths where only JWST can see it. Because light takes time to travel, more distant galaxies are also seen as they were earlier in time.

The two record-breaking galaxies are called JADES-GS-z14-0 and JADES-GS-z14-1, the former being the more distant of the two. In addition to being the new distance record holder, JADES-GS-z14-0 is remarkable for how big and bright it is.

The size of the galaxy clearly proves that most of the light is being produced by large numbers of young stars, rather than material falling onto a supermassive blackhole in the galaxy's center, which would appear much smaller.

The combination of the extreme brightness and the fact that young stars are fueling this high luminosity makes JADES-GS-z14-0 the most striking evidence yet found for the rapid formation of large, massive galaxies in the early universe. It is stunning that the universe can make such a galaxy in only 300 million years.

The galaxy is located in a field where the JWST Mid-Infrared Instrument had conducted an ultra-deep observation. Its brightness at intermediate infrared wavelengths is a sign of emission from hydrogen and even oxygen atoms in the early universe. Despite being so young, the galaxy is already hard at work creating the elements familiar to us on Earth.

This amazing object shows that galaxy formation in the early universe is very rapid and intense.

A shining cosmic dawn: spectroscopic confirmation of two luminous galaxies at z∼14, arXiv:2405.18485 [astro-ph.GA] arxiv.org/abs/2405.18485

JWST/MIRI photometric detection at 7.7 μm of the stellar continuum and nebular emission in a galaxy at z>14, arXiv:2405.18462 [astro-ph.GA] arxiv.org/abs/2405.18462

Brant Robertson et al, Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic Star-Formation Rate Density 300 Myr after the Big Bang, arXiv (2023). DOI: 10.48550/arxiv.2312.10033

Comment by Dr. Krishna Kumari Challa on May 30, 2024 at 1:05pm

The ocular immune system protects the eye from infection and regulates healing processes following injuries. The interior of the eye lacks lymph vessels but is highly vascularized, and many immune cells reside in the uvea, including mostly macrophages, dendritic cells, and mast cells.[1] These cells fight off intraocular infections, and intraocular inflammation can manifest as uveitis (including iritis) or retinitis. The cornea of the eye is immunologically a very special tissue. Its constant exposure to the exterior world means that it is vulnerable to a wide range of microorganisms while its moist mucosal surface makes the cornea particularly susceptible to attack. At the same time, its lack of vasculature and relative immune separation from the rest of the body makes immune defense difficult. Lastly, the cornea is a multifunctional tissue. It provides a large part of the eye's refractive power, meaning it has to maintain remarkable transparency, but must also serve as a barrier to keep pathogens from reaching the rest of the eye, similar to function of the dermis and epidermis in keeping underlying tissues protected. Immune reactions within the cornea come from surrounding vascularized tissues as well as innate immune responsive cells that reside within the cornea.

https://en.wikipedia.org/wiki/Ocular_immune_system

Comment by Dr. Krishna Kumari Challa on May 30, 2024 at 1:03pm

The eye is one of a few sites in the body with something called immune privilege. That special status makes the eye an ideal environment for researching certain therapies for treating vision loss.

The body’s immune system—made up of organs, tissues and cells—works to protect us from infection and disease. When a virus or other foreign substance is detected, the immune system kicks in. It makes molecules called antibodies to attack these invading substances known as antigens. This natural defense system is called an inflammatory response, and results in swelling of tissue and a higher-than-normal temperature.

While an inflammatory response can help fight off infection or disease, it can also cause problems. For example, if someone has a donated organ transplanted in their body, their immune system may recognize the organ as foreign tissue and mount an inflammatory response. This can cause the transplant to fail.

Interestingly, certain areas of the body have something called immune privilege. This means that the body’s normal inflammatory immune response is limited here. Scientists think the purpose of immune privilege is to protect these important areas from damage that may occur with swelling and higher temperatures from the immune response. The eye is one of a few areas of the body with immune privilege. The eye limits its inflammatory immune response so that vision isn’t harmed by swelling and other tissue changes. Other sites with immune privilege include the brain, testes, placenta and fetus.

Because of this immune privilege, the eye offers an excellent location for certain kinds of research and therapy. For example, scientists can implant types of cells called stem cells in the eye to study their role in regrowing or repairing damaged tissue. Cells implanted in the immune-privileged eye are less likely to be rejected than they might be in other parts of the body. Studies of stem cell use in the eye have shown promise in treating vision loss.

Another reason the eye is a good place for researching new therapies? It is relatively easy to reach and see inside of the structure. That makes implanting cells in the eye much easier than other areas of the body.

Source: https://www.aao.org/eye-health/tips-prevention/eye-immune-privilege

Comment by Dr. Krishna Kumari Challa on May 30, 2024 at 12:41pm

Is a train's risk of derailment affected by its length?

Longer freight trains are more likely to derail compared with shorter trains, according to new research published in Risk Analysis. The increased risk held even after accounting for the need for fewer trains if more cars were on each train.

For the study, investigators assessed information on US freight train accidents between 2013–2022 from Federal Railroad Administration databases. The team found that running 100-car trains would lead to an 11% higher risk of derailment compared with running 50-car trains, even when accounting for the fact that only half as many 100-car trains would need to run. For 200-car trains, the risk was 24% higher than for 50-car trains.

he Relationship between Freight Train Length and the Risk of Derailment, Risk Analysis (2024). DOI: 10.1111/risa.14312

Comment by Dr. Krishna Kumari Challa on May 30, 2024 at 9:51am

More rogue planets discovered
The Euclid space telescope has discovered seven more rogue planets, shining a light on the dark and lonely worlds floating freely through the universe untethered to any star.

The Euclid study also offered clues to how rogue planets are created: Some could be formed in the outer part of a solar system before getting detached from their star and floating away.

But the study indicates that many rogue planets may be created as a "natural byproduct" of the star-formation process. This suggests a "really close connection between stars and planets and how they form".

Without being bound to a star, as the Earth is to the sun, there are no days or years on these planets, which languish in perpetual night. Yet scientists think there is a chance they could be able to host life—and estimate there may be trillions dotted throughout the Milky Way.

Last week the European Space Agency released the Euclid telescope's first scientific results since the mission launched in July.

Among the discoveries were seven new free-floating planets, gas giants at least four times the mass of Jupiter.

They were spotted in the Orion Nebula, the nearest star-forming region to Earth, roughly 1,500 light years away.

Euclid also confirmed the existence of dozens of other previously detected rogue planets. This is likely to be just the tip of the iceberg.

Because they do not reflect the light of a star, spotting rogue planets is like "finding a needle in a haystack".

Younger planets, such as those discovered by Euclid, are hotter, making them a little easier to see.

Some research has suggested there are around 20 rogue planets for every star, which could put their number in the trillions in our home galaxy alone.

Given there are thought to be hundreds of billions of galaxies across the universe, the potential number of free-floating worlds becomes difficult to fathom.

When NASA's Roman space telescope launches in 2027 it is expected to find many more rogue planets, possibly offering clarity about how many could be out there.

But not all rogue planets wander alone. Four of the more than 20 confirmed by Euclid are believed to be binaries—two planets orbiting each other in a single system.

If rogue planets are habitable, they could be a key target in humanity's search for extraterrestrial life.

Lacking heat from a nearby star, free-floating planets are believed to be cold, with frozen surfaces.

That means any life-supporting energy would have to come from inside the planet.

And geothermal vents allow animals to survive on Earth that have never seen the sun's rays.

But even under the best conditions, this extreme isolation would likely be able to support only bacterial and microbial life.

Advantages of being a rogue planet: Rogue planets could be thought of as traversing a lonely path through the cosmos.

But "being around a star has its downsides".

Once the sun becomes a red giant—in an estimated 7.6 billion years—it will greatly expand, swallowing the Earth.

Rogue planets do not have to worry about eventually being destroyed by a star. "These things will last forever". ( Maybe if they don't go near any other star or planet or anybody that can influence its path and structure).

"If you don't mind the cold temperatures you could survive on these planets for eternity."

The study published ‘s on arXiv.org e-Print archive Friday.

https://arxiv.org/abs/2405.13497

Comment by Dr. Krishna Kumari Challa on May 30, 2024 at 9:49am

Chocolate's tasty flavors might pose a health risk in other desserts

What makes chocolate taste and smell so delicious? Chemistry, of course. A variety of molecules work together to create that unmistakable aroma, but those same molecules might carry some unwanted health effects if there are too many around. According to research published in Journal of Agricultural and Food Chemistry, while many of the compounds appeared in chocolate in low enough concentrations to be safe, higher amounts were found in some baked sweet treats.

When making chocolate, cocoa beans are roasted to help their chocolatey flavors shine. During this process, new molecules like α,β-unsaturated carbonyls are formed when they react with other ingredients under high temperatures. This class of carbonyls is highly reactive and potentially genotoxic, or able to cause damage to DNA when consumed.

Though naturally found in many foods, these carbonyls are also used as flavoring additives, and some have been banned in some countries, including the buttery-tasting furan-2(5H)-one. To better understand how these molecules form naturally in foods, and whether or not they are present in levels that could pose a health concern, researchers tested chocolates and other sweet treats for 10 different α,β-unsaturated carbonyls—some of which have been confirmed as safe by the European Food Safety Authority, while others are still under evaluation.

The team created its own chocolates and found that α,β-unsaturated carbonyls formed during roasting and after the addition of cocoa butter; however, their concentrations remained too low to pose any health concerns from consuming the chocolates.

Next, researchers screened 22 commercially available desserts, including crepes, waffles, cakes and biscuits, either with or without chocolate. In these packaged treats, they found even lower concentrations of nine of the 10 carbonyls compared to the chocolates.

The remaining carbonyl—genotoxic furan-2(5H)-one—appeared in much higher concentrations in the crepe and cake samples, reaching up to 4.3 milligrams per kilogram. Considering that the recommended threshold for genotoxic substances is only 0.15 micrograms per person per day, consuming these desserts could exceed that limit, though additional studies are needed to accurately assess the potential health risk.

Researchers concluded that the furan-2(5H)-one molecule likely formed during the baking process and did not seem to correlate with the amount of chocolate present in the packaged desserts. The team says that this work helps to better understand where these carbonyls come from in chocolate and highlights the importance of monitoring flavorings in food to keep consumers informed and safe.

Occurrence and Synthesis Pathways of (Suspected) Genotoxic α,β-Unsaturated Carbonyls in Chocolate and Other Commercial Sweet Snacks, Journal of Agricultural and Food Chemistry (2024). DOI: 10.1021/acs.jafc.4c01043 , pubs.acs.org/doi/abs/10.1021/acs.jafc.4c01043

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