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Comment by Dr. Krishna Kumari Challa on December 8, 2023 at 10:41am

Those patterns signaled that some elements listed near the middle of the periodic table—such as silver and rhodium—were likely the remnants of heavy element fission. The team was able to determine that the r-process can produce atoms with an atomic mass of at least 260 before they fission.

That 260 is interesting because we haven't previously detected anything that heavy in space or naturally on Earth, even in nuclear weapon tests.

 Ian U. Roederer et al, Element abundance patterns in stars indicate fission of nuclei heavier than uranium, Science (2023). DOI: 10.1126/science.adf1341. www.science.org/doi/10.1126/science.adf1341

Part 2

Comment by Dr. Krishna Kumari Challa on December 8, 2023 at 10:40am

Ancient stars made extraordinarily heavy elements, researchers find

How heavy can an element be? An international team of researchers has found that ancient stars were capable of producing elements with atomic masses greater than 260, heavier than any element on the periodic table found naturally on Earth. The finding deepens our understanding of element formation in stars.

We are, literally, made of star stuff. Stars are element factories, where elements constantly fuse or break apart to create other lighter or heavier elements. When we refer to light or heavy elements, we're talking about their atomic mass. Broadly speaking, atomic mass is based on the number of protons and neutrons in the nucleus of one atom of that element.
The heaviest elements are only known to be created in neutron stars via the rapid neutron capture process, or r-process. Picture a single atomic nucleus floating in a soup of neutrons. Suddenly, a bunch of those neutrons get stuck to the nucleus in a very short time period—usually in less than one second—then undergo some internal neutron-to-proton changes, and voila! A heavy element, such as gold, platinum or uranium, forms.

The heaviest elements are unstable or radioactive, meaning they decay over time. One way that they do this is by splitting, a process called fission.

The r-process is necessary if you want to make elements that are heavier than, say, lead and bismuth.
You have to add many neutrons very quickly, but the catch is that you need a lot of energy and a lot of neutrons to do so. And the best place to find both are at the birth or death of a neutron star, or when neutron stars collide and produce the raw ingredients for the process.
The team took a fresh look at the amounts of heavy elements in 42 well-studied stars in the Milky Way. The stars were known to have heavy elements formed by the r-process in earlier generations of stars. By taking a broader view of the amounts of each heavy element found in these stars collectively, rather than individually as is more common, they identified previously unrecognized patterns.
Part 1

Comment by Dr. Krishna Kumari Challa on December 7, 2023 at 11:43am

Warfare ruins the environment—and not just on the front lines

On the morning of December 6, 1917, a French cargo ship called SS Mont-Blanc collided with a Norwegian vessel in the harbor of Halifax in Nova Scotia, Canada. The SS Mont-Blanc, which was laden with 3,000 tons of high explosives destined for the battlefields of the first world war, caught fire and exploded. The resulting blast released an amount of energy equivalent to roughly 2.9 kilotons of TNT, destroying a large part of the city. Although it was far from the front lines, this explosion left a lasting imprint on Halifax in a way that many regions experience environmental change as a result of war. The attention of the media is often drawn to the destructive explosions caused by bombs, drones or missiles. And the devastation we have witnessed in cities like Aleppo, Mosul, Mariupol and now Gaza certainly serve as stark reminders of the horrific impacts of military action. However, research is increasingly uncovering broader and longer-term consequences of war that extend well beyond the battlefield. Armed conflicts leave a lasting trail of environmental damage, posing challenges for restoration after the hostilities have eased.

https://theconversation.com/warfare-ruins-the-environment-and-not-j...

Comment by Dr. Krishna Kumari Challa on December 7, 2023 at 11:40am

Planet tipping points pose 'unprecedented' threat to humanity: report

Humanity faces an "unprecedented" risk from tipping points that could unleash a domino effect of irreversible catastrophes across the planet, researchers warned this week.

The most comprehensive assessment ever conducted of Earth's invisible tripwires was released as leaders meet for UN climate talks in Dubai with 2023 set to smash all heat records. While many of the 26 tipping points laid out in the report—such as melting ice sheets—are linked to global warming, other human activities like razing swathes of the Amazon rainforest could also push Earth's ecosystems to the brink. Five of these are showing signs of tipping—from melting ice sheets threatening catastrophic sea level rise, to mass die-off of tropical coral reefs—the report warned. Some may have already begun to irrecoverably transform. Once the world crosses the threshold for just one tipping point, dealing with the immediate humanitarian disaster could distract attention away from stopping the others, creating a "vicious cycle" of mass hunger, displacement and conflict, the report warned.

The risks for humanity in crossing tipping points into these unexplored states is dire, and the impact to human lives potentially horrific.

Source: News agencies

Comment by Dr. Krishna Kumari Challa on December 7, 2023 at 11:32am

Study finds climate change can cause methane to be released from the deep ocean

New research has shown that fire-ice—frozen methane which is trapped as a solid under our oceans—is vulnerable to melting due to climate change and could be released into the sea.

An international team of researchers found that as frozen methane and ice melts, methane—a potent greenhouse gas—is released and moves from the deepest parts of the continental slope to the edge of the underwater shelf. They even discovered a pocket that had moved 25 miles (40 kilometers). Publishing in the journal Nature Geoscience, the researchers say this means that much more methane could potentially be vulnerable and released into the atmosphere as a result of climate warming.

Methane hydrate, also known as fire-ice, is an ice-like structure found buried in the ocean floor that contains methane. Vast amounts of methane are stored as marine methane under oceans. It thaws when the oceans warm, releasing methane into oceans and the atmosphere—known as dissociated methane—contributing to global warming.

The scientists used advanced three-dimensional seismic imaging techniques to examine the portion of the hydrate that dissociated during climatic warming off the coast of Mauritania in Northwest Africa. They identified a specific case where dissociated methane migrated over 40 kilometers and was released through a field of underwater depressions, known as pockmarks, during past warm periods.

Long-distance migration and venting of methane after marine hydrate dissociation, Nature Geoscience (2023). DOI: 10.1038/s41561-023-01333-w. www.nature.com/articles/s41561-023-01333-w

Comment by Dr. Krishna Kumari Challa on December 7, 2023 at 10:44am

Researchers show that an influx of water and salts propel immune cells through the body

Researchers have shown that an influx of water and ions into immune cells allows them to migrate to where they're needed in the body.

Our bodies respond to illness by sending out chemical signals called chemokines, which tell immune cells called T cells where to go to fight the infection. This process had already been associated with a protein called WNK1, which activates channels on the cell surface,  allowing ions (salts like sodium or potassium) to move into cells. Until now, it was not clear why ion influx was needed for T cells to move.

Through a study published in Nature Communications, the researchers imaged mouse T cells and observed that, following a chemokine signal, WNK1 is activated at the front of the cells, called the "leading edge." The team showed that the activation of WNK1 opens channels on the leading edge, resulting in an influx of water and ions. They propose that this flow of water causes the cells to swell on the front side, creating space for the 'actin cytoskeleton'—the scaffolding inside the cell that holds its structure—to grow into. This propels the whole cell forward and the process repeats again. The researchers used gene editing to stop mice producing WNK1, or an inhibitor to prevent WNK1's activity, observing that the T cells in these mice slowed down or stopped moving completely. Importantly, they found that they could make up for the loss of WNK1 and make the cells speed up by dropping them into a watery solution, which causes the cells to take up water and swell. This shows that the uptake of water, controlled by the WNK1 protein is key for the cells to migrate.

The researchers think that the mechanism they've discovered could be involved in lots of different cell types beyond immune cells.

Leonard L. de Boer et al, T cell migration requires ion and water influx to regulate actin polymerization, Nature Communications (2023). DOI: 10.1038/s41467-023-43423-8

Comment by Dr. Krishna Kumari Challa on December 7, 2023 at 10:39am

Plant Hormone That Can Boost Plant Growth By 30%

Comment by Dr. Krishna Kumari Challa on December 7, 2023 at 10:33am

A possible way for early life on Earth to survive cosmic radiation

A team of biophysicists  has uncovered via experimentation the means by which early life might have been able to survive cosmic radiation. In their study, reported in the journal Nature Communications, the group conducted experiments with radiation-resistant manganese antioxidants.

Prior research has shown that the Earth was formed approximately 4.5 billion years ago, and that life arose approximately a half-billion years later. Prior research has also shown that the Earth's magnetic field did not start protecting life from cosmic radiation until approximately 3.5 billion years ago. This leads to questions about how life was able to begin and flourish in those early years.

A type of bacteria known as Deinococcus radiodurans has been shown to be capable of surviving levels of radiation that would kill most other living creatures. Study of this bacteria reveals that it is able to do so because of the amount of Mn(II) (manganese) ions in its body—it serves to protect the tiny creatures from the oxidative stress that would occur in other bacteria that do not have it. This finding has led to theories that suggest harboring of Mn(II) ions is the means by which early life survived on Earth.

To test this theory, the research team created models they describe as protocells—such "coacervates" were used to serve as stand-ins for early life protocells on Earth. The team used two types, one based on polyphosphate manganese, the other based on polyphosphate peptides. When exposed to high levels of gamma rays, the polyphosphate–manganese coacervates remained intact and viable. The polyphosphate–peptide coacervates, on the other hand, were destroyed. Prior research has shown that polyphosphate manganese has been present on Earth longer than life has existed, likely produced during volcanic activity—thus, it would have been available for use by protocells as a means of protection. The researchers suggest that early protocells on Earth were able to survive due to protection by material similar to polyphosphate manganese. Such protocells, they note, would have been able to survive long enough to develop into cyanobacteria and eventually eukaryotic cells, which would have been protected by the Earth's magnetic field and ozone layer.

Shang Dai et al, An inorganic mineral-based protocell with prebiotic radiation fitness, Nature Communications (2023). DOI: 10.1038/s41467-023-43272-5

Comment by Dr. Krishna Kumari Challa on December 7, 2023 at 10:29am

Study finds sleep can improve memory retention but can also imprint false memories

A team of psychologists has found via experimentation that sleeping after studying can consolidate memories. But, as they note in their paper published in the journal Royal Society Open Science, sleep can also sometimes lead to the creation of false memories.

Recent research efforts have shown that human memory is not nearly as accurate as it may feel to someone who is recalling a memory of a thing or event—findings that have called into question eyewitness accounts at criminal trials. Such results have led to more study of memory retention and recall as a way to learn more about the ways that memory works.

For this new research, 488 volunteers studied a list of related words and then to attempt to recall those words 12 hours later. To learn about the impact of sleep on retention, some of the volunteers were allowed to sleep between the time they viewed the original list and the time of the memory retention testing.

The researchers found that those people who were allowed to sleep during the interim scored better on memory retention. But they also found that they were more likely to believe falsely that some related words were on the list. As an example, when given a list such as "nurse, hospital and surgery," people who had been allowed to sleep were more likely to falsely believe the word "doctor" had also appeared on the list.

The researchers suggest this finding shows that the purpose of memory is not necessarily to give people an accurate assessment of things that have occurred, but to give them a means for retrieving the gist of things. As humans evolved, it was important that connections and associations be made as part of the learning process in order to better prepare for future threats.

The research team also found that the time of day the volunteers were questioned about the list had an impact on recall accuracy—both groups made more errors and falsely recalled more words when questioned during the evening.

Matthew H. C. Mak et al, A registered report testing the effect of sleep on Deese-Roediger-McDermott false memory: greater lure and veridical recall but fewer intrusions after sleep, Royal Society Open Science (2023). DOI: 10.1098/rsos.220595

Comment by Dr. Krishna Kumari Challa on December 7, 2023 at 10:26am

"Malaria researchers have been trying to chip away at understanding resistance and susceptibility of P. vivax infection of African people for more than 100 years," Zimmerman said. "More than 2.5 billion people may live in Africa and Southeast Asia where the parasite is found. Hundreds of thousands of people a year die from malaria. In general, malaria is one of the big three global-health infectious diseases—malaria, tuberculous and HIV/AIDS."

The team is studying a specific blood type (Fy-negative) in the blood of most people in Africa and of African origin, called "the silent Duffy blood group." Duffy-negative people have a mutation in the DNA code (GATA-1) that results in the protein not being expressed on the surface of red blood cells.

The researchers did experiments using blood cells grown in the lab and cells taken from bone marrow to study the Duffy-silent blood type.

"Surprisingly, we found that even when people are missing the GATA-1 DNA code, the Duffy protein sometimes shows up on their red blood cells," Zimmerman said. "Our findings suggest that the bone marrow and other places where blood cells are first made are important for the malaria parasite to find the red cells with the Duffy protein, to grow and cause sickness."

In other experiments in the lab, they examined the blood of people with Duffy silent blood type. They noticed the P. vivax malaria infection was often detected using a special test rather than the usual microscope test.

This means that people with Duffy-silent blood type can still have the infection, but it's not always easy to see in regular blood tests. In other words, they found that P. vivax can invade the red blood cells of people with the Duffy-silent trait. Also, if they have the infection in the bone marrow, they produce the transmissible form of the parasite. Mosquitoes can acquire it and cause infections in other people.

"This discovery raises questions about how malaria parasites cause infection and sickness, especially because some people with the infection don't show many signs in their blood," Zimmerman said. "We need to look at the blood more closely to understand better how widespread and serious this type of malaria is in people with the Duffy-silent trait."

Celia Dechavanne et al, Duffy antigen is expressed during erythropoiesis in Duffy-negative individuals, Cell Host & Microbe (2023). DOI: 10.1016/j.chom.2023.10.019

Part 2

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