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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

Part 2

Comment by Dr. Krishna Kumari Challa on September 21, 2024 at 11:01am

Fever drives enhanced activity and mitochondrial damage in a subset of T cells, study finds

Fever temperatures rev up immune cell metabolism, proliferation and activity, but they also—in a particular subset of T cells—cause mitochondrial stress, DNA damage and cell death,  researchers have discovered.

The findings, published in the journal Science Immunology, offer a mechanistic understanding of how cells respond to heat and could explain how chronic inflammation contributes to the development of cancer.

Researchers' cultured immune system T cells at 39 degrees Celsius (about 102 degrees Fahrenheit). showed  that heat increased helper T cell metabolism, proliferation and inflammatory effector activity and decreased regulatory T cell suppressive capacity.

 The researchers also made an unexpected discovery—that a certain subset of helper T cells, called Th1 cells, developed mitochondrial stress and DNA damage, and some of them died. The finding was confusing, the researchers said, because Th1 cells are involved in settings where there is often fever, like viral infections. Why would the cells that are needed to fight the infection die?

The researchers discovered that only a portion of the Th1 cells die, and that the rest undergo an adaptation, change their mitochondria, and become more resistant to stress.

There's a wave of stress, and some of the cells die, but the ones that adapt and survive are better—they proliferate more and make more cytokine (immune signaling molecules).

Par t1

Comment by Dr. Krishna Kumari Challa on September 21, 2024 at 10:16am

Oceanic life found to be thriving thanks to Saharan dust blown from thousands of kilometers away

Iron is a micronutrient indispensable for life, enabling processes such as respiration, photosynthesis, and DNA synthesis. Iron availability is often a limiting resource in today's oceans, which means that increasing the flow of iron into them can increase the amount of carbon fixed by phytoplankton, with consequences for the global climate.

Iron ends up in oceans and terrestrial ecosystems through rivers, melting glaciers, hydrothermal activity, and especially wind. But not all its chemical forms are "bioreactive," that is, available for organisms to take up from their environment.

Researchers have now shown that iron bound to dust from the Sahara blown westward over the Atlantic has properties that change with the distance traveled: the greater this distance, the more bioreactive the iron.

This relationship suggests that chemical processes in the atmosphere convert less bioreactive iron to more accessible forms.

 The results suggest that during long distance atmospheric transport, the mineral properties of originally non-bioreactive dust-bound iron change, making it more bioreactive. This iron then gets taken up by phytoplankton, before it can reach the bottom of the oceans.

The researchers conclude that dust that reaches regions like the Amazonian basin and the Bahamas may contain iron that is particularly soluble and available to life, thanks to the great distance from North Africa, and thus a longer exposure to atmospheric chemical processes.

The transported iron seems to be stimulating biological processes much in the same way that iron fertilization can impact life in the oceans and on continents. This study is a proof of concept confirming that iron-bound dust can have a major impact on life at vast distances from its source.

 Long-range transport of dust enhances oceanic iron bioavailability, Frontiers in Marine Science (2024). DOI: 10.3389/fmars.2024.1428621. www.frontiersin.org/journals/m … rs.2024.1428621/full

Comment by Dr. Krishna Kumari Challa on September 21, 2024 at 10:05am

Anti-vaxxers: Even ants take precautions. Why can't some human beings?

Black garden ants modify the structure of their nests to mitigate fungal infection spread

A small team of biologists  has found that black garden ants modify the physical structure of their nests to mitigate infection spread. The group has written a paper describing the experiments they conducted with black garden ants and fungal infections in their lab and posted it on the bioRxiv preprint server.

Prior research has shown that some animals change their behaviour to avoid spreading infections, whether they be viral, bacterial or fungal. Among those, only humans have been found to alter their surroundings as a way to further protect themselves— smart people might close off parts of their house, for example, or establish quarantine zones within hospital areas.

In this new study, the research team found an instance of an insect altering its nest to deter the spread of an infecting fungus.

To learn more about how insects, such as ants, attempt to prevent the spread of an infection among members of a nest, the research team went into the field and collected black garden ants—enough to set up 20 colonies in their lab, each in its own glass enclosure. After giving the ants a single day to acclimate themselves to their new environment, the researchers added 20 more ants to each colony—half of which were infected with a fungus known to spread among the ants. The research team then set up cameras to record the behavior of the ants and micro-CT scanners to study the nature of the nest tunnels that the ants dug beneath the soil.

The team found that in the colonies with the infected ants, new tunnels were dug faster than in those not infected. After six days, the spacing between the tunnels was farther apart in the infected nest as well.

The ants in the exposed colonies also placed their queen, food and brooding area in a less central location. And finally, those ants that were infected tended to spend most of their time on the surface, rather than underground with their nestmates.

The researchers next used disease transmission simulations to speed up the process of disease spread and found that the techniques used by the ants did indeed reduce the fungal load in the colony, helping the nest survive.

Luke Leckie et al, Architectural Immunity: ants alter their nest networks to fight epidemics, bioRxiv (2024). DOI: 10.1101/2024.08.30.610481. www.biorxiv.org/content/10.110 … /2024.08.30.610481v1

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