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Comment by Dr. Krishna Kumari Challa on September 24, 2024 at 10:04am

COVID origin at Wuhan market, says study
The hunt for the origins of COVID-19 has circled back to an animal market in Wuhan, China that was linked to many of the earliest cases of the disease. Researchers reanalysed genomes collected from the market shortly after it was shut down on 1 January 2020. They identified several animal species that could have passed SARS-CoV-2, the coronavirus that causes COVID-19, to people. The study establishes the presence of animals and the virus at the market, although it does not confirm whether the animals themselves were infected with the virus. The researchers argue that their reanalysis adds weight to the market being the site of the first spillover events, in which animals infected humans.

https://www.cell.com/cell/fulltext/S0092-8674(24)00901-2?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0092867424009012%3Fshowall%3Dtrue

https://www.nature.com/articles/d41586-024-03026-9?utm_source=Live+...

Comment by Dr. Krishna Kumari Challa on September 24, 2024 at 9:20am

Acidic water damages corals, shellfish and the phytoplankton that feeds a host of marine species.

This means it also disrupts food supplies for billions of people, as well as limiting the oceans' capacity to absorb more CO2 and thus help limit global warming.

The only one of the nine planetary boundaries that is not close to being crossed concerns the state of the planet's protective ozone layer.

Man-made chemicals have damaged this shield, causing acid rain, but it has started recovering since a number of these chemicals were banned in 1987.

A ninth threshold—concerning concentrations of minute particles in the atmosphere that can cause heart and lung diseases -– is close to the danger limit.

But the researchers said the risk showed signs of receding slightly due to efforts by several countries to improve air quality, such as banning the most pollutant petrol and diesel cars.
They warned, however, that concentrations of fine particles could still soar in countries that are rapidly industrializing.

The PIK set these nine planetary danger levels to warn humans against tipping Earth's natural systems past points of no return.

"These tipping points... if crossed, would lead to irreversible and catastrophic outcomes for billions of people and many future generations on Earth", experts say.
All nine planetary boundaries are "interconnected" so breaching one crucial limit can destabilize Earth's entire life system.

Source: AFP and other news agencies

Part 2

Comment by Dr. Krishna Kumari Challa on September 24, 2024 at 9:19am

World's oceans near critical acidification level: Report

The world's oceans are close to becoming too acidic to properly sustain marine life or help stabilize the climate, a new report said this week.

The report by the Potsdam Institute for Climate Impact Research (PIK) details nine factors that are crucial for regulating the planet's ability to sustain life.

In six of these areas, the safe limit has already been exceeded in recent years as a result of human activity.

The crucial threshold for ocean acidification could soon become the seventh to be breached, according to the PIK's first Planetary Health Check.

The safe boundaries that have already been crossed concern crucial—and related—factors including climate change; the loss of natural species, natural habitat and freshwater; and a rise in pollutants, including plastics and chemical fertilizers used in agriculture.

The sustainable level of ocean acidification is now also set to be exceeded, largely as a result of ever-increasing emissions of carbon dioxide (CO2) created by burning fossil fuels like oil, coal and gas.

As CO2 emissions increase, more of it dissolves in sea water... making the oceans more acidic.

Even with rapid emission cuts, some level of continued acidification may be unavoidable due to the CO₂ already emitted and the time it takes for the ocean system to respond.

Therefore, breaching the ocean acidification boundary appears inevitable within the coming years.

Part 1

Comment by Dr. Krishna Kumari Challa on September 24, 2024 at 8:55am

High-pressure reactions can turn nonporous rocks into sponges

In deep Earth, rocks take up and release water all the time, and the effects can be wide reaching. Dehydration can cause rocks to crack and trigger earthquakes, and over geologic timescales, this water cycling can influence plate tectonics and move continents.

Researchers asked how water can move through impermeable rocks, such as those found in mantle wedges, the deep lithosphere, and the lower crust. They hypothesize that certain reactions can cause temporary porosity in these rocks. By mathematically modeling the hydration and dehydration of rock at high pressure, they derived equations to estimate how the porosity of rock changes as water cycles through it. 

The research is published in the journal Geochemistry, Geophysics, Geosystems.

Previous work suggested that at very high temperatures, minerals can react with each other to form denser minerals, squeezing water out of the minerals and generating less dense, more porous rocks in the process.

As the reaction progresses, a "dehydration front" moves through the rock. On the other hand, some reactions cause rocks to act like dry sponges, soaking up surrounding water and becoming denser. The progression of this reaction is known as a hydration front.

In the study, the researchers presented 1D simulations for three scenarios (one for a hydration front and two for dehydration fronts) in which a rock with no porosity becomes temporarily porous.

Stefan M. Schmalholz et al, (De)hydration Front Propagation Into Zero‐Permeability Rock, Geochemistry, Geophysics, Geosystems (2024). DOI: 10.1029/2023GC011422

Comment by Dr. Krishna Kumari Challa on September 24, 2024 at 8:51am

Throughout the evolution of the universe, the behavior of neutrinos impacted the growth of large-scale structures, such as clusters of galaxies across vast reaches of space that we see today. Neutrinos are one of the most abundant subatomic particles in the universe, but they're as mysterious as they are ubiquitous. One reason physicists want to know the mass scale of neutrinos is that it can help them get a better understanding of how matter clustered as the universe evolved.

Cosmologists—those who study the origin and development of the universe—have long thought that massive neutrinos kept matter in the universe from clustering as much as it otherwise might have over 13.8 billion years of cosmic evolution.

But rather than the expected suppression of matter clustering, the data instead favors enhanced matter clustering, meaning matter in the cosmos is more clumped than one would expect.

Explaining this enhancement may point toward some problem with the measurements, or it could require some new physics not included in the Standard Model of particle physics and cosmology.

The Standard Model of particle physics—the one that students likely learned in physics class—has long been scientists' best theory to explain how the basic building blocks of matter interact. This finding of neutrinos is the latest measurement, similar to what's referred to as "the Hubble tension," to hint that we might not know our universe as well as we think we do, say these experts.

In their study, Meyers and his colleagues looked into scenarios where physicists might need to tweak the Standard Model, but not throw it out entirely. They also examined introducing new concepts of physics. And they also explored whether systematic errors of key measures could account for the surprising DESI finding.

It will likely take years to know which of the researchers' theories is correct. But the study gives a blueprint for future research.

Nathaniel Craig et al, No νs is Good News, arXiv (2024). DOI: 10.48550/arxiv.2405.00836

Part 2

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Comment by Dr. Krishna Kumari Challa on September 24, 2024 at 8:49am

 Experts suggest possibility of updating fundamental physics concepts

An unexpected finding about how our universe formed is again raising the question: do we need new physics? The answer could fundamentally change what physics students are taught in classes around the world.

A study from SMU and three other universities, available on the arXiv preprint server, delved into the possibility of updating fundamental physics concepts.

SMU played a significant part in the analysis, using the university's high-performance computing capabilities to explore different scenarios that could explain the findings.

The data from what's known as DESI, or Dark Energy Spectroscopic Instrument, combined with what we already had, is the most precise data we've seen so far, and it is hinting at something unlike what we would have expected.

DESI is creating the largest, most accurate 3D map of our universe, providing a key measurement that enables cosmologists to calculate what they call the absolute mass scale of neutrinos. This absolute mass scale was determined based on new measurements from the so-called baryonic acoustic oscillations from DESI, plus information physicists already had from the "afterglow" of the Big Bang—when the universe was created—known as the cosmic microwave background.

Part 1

Comment by Dr. Krishna Kumari Challa on September 24, 2024 at 8:43am

Researchers discover the deadly genetics of cholera, which could be key to its prevention

Experts have used a cutting-edge computational approach to discover the genetic factors that make the bacteria behind cholera so dangerous—which could be key to preventing this deadly disease.

The innovative research combines machine learning, genomics, genome-scale metabolic modeling (GSMM), and 3D structural analysis to uncover the genetic secrets of Vibrio cholerae—the bacteria behind cholera.

Cholera is a deadly diarrheal disease that continues to threaten millions worldwide, with up to 4 million cases and as many as 143,000 deaths each year.

Vibrio cholerae, is evolving in ways that make the disease more severe and harder to control.

There is even less knowledge about the genomic traits responsible for the severity of cholera resulting from these lineages. About 1 in 5 people with cholera will experience a severe condition owing to a combination of symptoms (primarily diarrhea, vomiting, and dehydration).

In this new study the  research team analyzed bacterial samples from cholera patients across six regions in Bangladesh, collected between 2015 and 2021. They identified a set of unique genes and mutations in the most recent and dominant strain of Vibrio cholerae responsible for the devastating 2022 outbreak.

These genetic traits are linked to the bacteria's ability to cause severe symptoms like prolonged diarrhea, intense abdominal pain, vomiting, and dehydration—symptoms that can lead to death in severe cases.

The findings of the study also revealed that some of these disease-causing traits overlap with those that help the bacteria spread more easily. The findings show how these genetic factors enable Vibrio cholerae to survive in the human gut, making it more resilient to environmental stress and more efficient at causing disease. This research highlights the complex interactions between the bacteria's genetic makeup and its ability to cause severe illness.

This new computational framework is a major step forward in the fight against cholera. By identifying the key genetic factors that make Vibrio cholerae more dangerous, scientists can develop better treatments and more targeted strategies to control and prevent future outbreaks.

 Nature Communications (2024). DOI: 10.1038/s41467-024-52238-0. www.nature.com/articles/s41467-024-52238-0

Comment by Dr. Krishna Kumari Challa on September 21, 2024 at 11:31am

Microplastics in coral skeletons

Researchers investigating microplastics in coral have found that all three parts of the coral anatomy—surface mucus, tissue, and skeleton—contain microplastics. The findings were made possible thanks to a new microplastic detection technique developed by the team and applied to coral for the first time.

These findings may also explain the "missing plastic problem" that has puzzled scientists, where about 70% of the plastic litter that has entered the oceans cannot be found. The team hypothesizes that coral may be acting as a "sink" for microplastics by absorbing it from the oceans. Their findings were published in the journal Science of the Total Environment.

 Suppakarn Jandang et al, Possible sink of missing ocean plastic: Accumulation patterns in reef-building corals in the Gulf of Thailand, Science of The Total Environment (2024). DOI: 10.1016/j.scitotenv.2024.176210

Comment by Dr. Krishna Kumari Challa on September 21, 2024 at 11:16am

The first known outbreak of rabies in seals

Scientists in South Africa say they have identified an outbreak of rabies in seals that is thought to be the first time the virus has spread in sea mammals.

At least 24 Cape fur seals that were found dead or euthanized in various locations on South Africa's west and south coast had rabies.

Rabies, which affects mammals and can be passed to people, is almost always fatal once symptoms appear. Rabies spreads via saliva, usually through bites but also sometimes when animals lick and groom each other.

The virus has long been seen in wild animals such as raccoons, coyotes, foxes, jackals and in domestic dogs. But it had never been recorded spreading among marine mammals until now.

The only other known case of rabies in a sea mammal was in a ringed seal in Norway's Svalbard islands in the early 1980s. That seal had likely been infected by a rabid arctic fox, researchers said, and there was no evidence of rabies spreading among seals there.

Authorities in South Africa first discovered rabies in Cape fur seals in June after a dog was bitten by a seal on a Cape Town beach. The dog became infected with rabies, prompting rabies tests on brain samples from 135 seal carcasses that researchers had already collected since 2021. Around 20 new samples also were collected and more positives have come back on subsequent tests.

Scientists are trying to work out how rabies was passed to the seals, whether it is spreading widely among their large colonies and what can be done to contain it.

Source : NEWS agencies

Comment by Dr. Krishna Kumari Challa on September 21, 2024 at 11:06am

The molecular events of the cell response to fever temperatures: The researchers found that heat rapidly impaired electron transport chain complex 1 (ETC1), a mitochondrial protein complex that generates energy. ETC1 impairment set off signaling mechanisms that led to DNA damage and activation of the tumor suppressor protein p53, which aids DNA repair or triggers cell death to maintain genome integrity. Th1 cells were more sensitive to impaired ETC1 than other T cell subtypes.

The researchers found Th1 cells with similar changes in sequencing databases for samples from patients with Crohn's disease and rheumatoid arthritis, adding support to the molecular signaling pathway they defined.
Scientists think this response is a fundamental way that cells can sense heat and respond to stress.
The findings suggest that heat can be mutagenic—when cells that respond to mitochondrial stress don't properly repair the DNA damage or die.
Chronic inflammation with sustained periods of elevated tissue temperatures could explain how some cells become tumorigenic and that 's why up to 25% of cancers are linked to chronic inflammation.
'Is fever good or bad?'The short answer is: A little bit of fever is good, but a lot of fever is bad. We already knew that, but now we have a mechanism for why it's bad."

Darren Heintzman et al, Subset-specific mitochondrial stress and DNA damage shape T cell responses to fever and inflammation, Science Immunology (2024). DOI: 10.1126/sciimmunol.adp3475. www.science.org/doi/10.1126/sciimmunol.adp3475

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