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Comment by Dr. Krishna Kumari Challa on March 13, 2023 at 12:04pm

What is Plasma?

Comment by Dr. Krishna Kumari Challa on March 13, 2023 at 11:48am

Scientists identify substance that may have sparked life on Earth

A team of scientists dedicated to pinpointing the primordial origins of metabolism—a set of core chemical reactions that first powered life on Earth—has identified part of a protein that could provide scientists clues to detecting planets on the verge of producing life.

The research, published in Science Advances, has important implications in the search for extraterrestrial life because it gives researchers a new clue to look for.

Based on laboratory studies,  scientists say one of the most likely chemical candidates that kickstarted life was a simple peptide with two nickel atoms they are calling "Nickelback" not because it has anything to do with the Canadian rock band, but because its backbone nitrogen atoms bond two critical nickel atoms. A peptide is a constituent of a protein made up of a few elemental building blocks known as amino acids.

Scientists think that sometime between 3.5 and 3.8 billion years ago there was a tipping point, something that kickstarted the change from prebiotic chemistry—molecules before life—to living, biological systems. They think the change was sparked by a few small precursor proteins that performed key steps in an ancient metabolic reaction. And they think they've now found one of these 'pioneer peptides.

When scouring the universe with telescopes and probes for signs of past, present or emerging life, NASA scientists look for specific "biosignatures" known to be harbingers of life. Peptides like nickelback could become the latest biosignature employed by NASA to detect planets on the verge of producing life.

An original instigating chemical, the researchers reasoned, would need to be simple enough to be able to assemble spontaneously in a prebiotic soup. But it would have to be sufficiently chemically active to possess the potential to take energy from the environment to drive a biochemical process.

To do so, the researchers adopted a "reductionist" approach: They started by examining existing contemporary proteins known to be associated with metabolic processes. Knowing the proteins were too complex to have emerged early on, they pared them down to their basic structure.

After sequences of experiments, researchers concluded the best candidate was Nickelback. The peptide is made of 13 amino acids and binds two nickel ions.

Nickel, they reasoned, was an abundant metal in early oceans. When bound to the peptide, the nickel atoms become potent catalysts, attracting additional protons and electrons and producing hydrogen gas. Hydrogen, the researchers reasoned, was also more abundant on early Earth and would have been a critical source of energy to power metabolism.

This work shows that, not only are simple protein metabolic enzymes possible, but that they are very stable and very active—making them a plausible starting point for life.

Jennifer Timm et al, Design of a Minimal di-Nickel Hydrogenase Peptide, Science Advances (2023). DOI: 10.1126/sciadv.abq1990. www.science.org/doi/10.1126/sciadv.abq1990

Comment by Dr. Krishna Kumari Challa on March 13, 2023 at 11:37am

Estrogen receptor in the heart found to regulate obesity in postmenopausal women

Estrogen is known to play an important role in the protection of women's hearts, but once women are postmenopausal and estrogen levels drop, they are at an increased risk of a number of diseases and conditions, including heart disease, obesity and diabetes.

Published in Nature Cardiovascular Research, the study found that reduced ERα in the cells responsible for heart contraction (cardiomyocytes) led to moderate heart dysfunction and increased rates of obesity in female mice, but not in male mice.

Researchers  identified a sex hormone receptor in the heart that can regulate adiposity (obesity) in females. They were interested in trying to understand the role of this estrogen receptor in the heart for some time, to see how it provides protection to the heart.

When they blocked this estrogen receptor, they were expecting to see changes and damage largely to the heart. But rather than seeing a dramatic heart phenotype, what they saw was an adiposity phenotype. So, they observed that the female mice were heavier and had more fat mass, which they  weren't expecting at all.

Genes that are important for contractility of the heart and metabolic function of the heart were also lower in the female heart when ERα was reduced, explaining why the female study hearts did not pump as well.

Extracellular vesicles, that were released from the female hearts with reduced ERα also contained proteins that differed from both the control group and male hearts.

Researchers found that reducing ERα in heart muscle cells (cardiomyocytes) of female mice leads to transcriptional, lipidomic and metabolic dysregulation in the heart, together with metabolic dysregulation in skeletal muscle and adipose tissue. 

Furthermore, the extracellular vesicles that are released from heart cells with reduced ERα had the capacity to reprogram skeletal muscle cells in cell culture. These changes to tissues, the extracellular vesicles proteome and reprogrammed skeletal muscle cells altered the cells' molecular landscape and function. So rather than energy being expended, energy is instead stored, which explains the increased adiposity in female mice in the absence of Erα.

This important work has implications for preventing and treating heart and metabolic disease in post menopausal women, but also cardiotoxicity in premenopausal women receiving therapies that may inhibit or reduce ERα in the heart.

David Greening, Estrogen receptor alpha deficiency in cardiomyocytes reprograms the heart-derived extracellular vesicle proteome and induces obesity in female mice, Nature Cardiovascular Research (2023). DOI: 10.1038/s44161-023-00223-z. www.nature.com/articles/s44161-023-00223-z

Comment by Dr. Krishna Kumari Challa on March 11, 2023 at 2:38pm

In a study last year it was found that virtual-reality train rides seemed to last longer for passengers when the simulated trains were more crowded.

But many prior studies have focused on perception of relatively long time intervals,  and therefore tend to reveal more about how people estimate time than how they experience it directly in the moment.

To shed more light on the latter, the new study looked for links between time perception and bodily rhythms, with a focus on natural fluctuations in heart rate. While the overall cadence of a heart sounds steady, each individual beat can be slightly shorter or longer than the one before.

Research has shown that heartbeats can influence our perception of external stimuli, and the heart has long been suspected of helping the brain keep time.

The heartbeat is a rhythm that our brain is using to give us our sense of time passing.  "And that is not linear – it is constantly contracting and expanding.

While the heart may wield heavy influence on the brain's perception of time, it's a two-way street, the researchers note. Hearing a tone led subjects to focus their attention on the sound, an "orienting response" that in turn changed their heart rate and readjusted their experience of time.

Incorrectly perceiving the passage of time might sound like a bad thing, and sometimes it is. But while losing track of time can lead to trouble, there may also be adaptive benefits to the kind of temporal wrinkles identified in this study.

The heart seems to help the brain work more efficiently with limited resources, the researchers add, influencing how it experiences the passage of time on the smallest scales, and operating at time periods too brief for conscious thoughts or feelings.

"Even at these moment-to-moment intervals, our sense of time is fluctuating" . "A pure influence of the heart, from beat to beat, helps create a sense of time."

https://onlinelibrary.wiley.com/doi/epdf/10.1111/psyp.14270

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part2

Comment by Dr. Krishna Kumari Challa on March 11, 2023 at 2:34pm

Your Heartbeat Shapes Your Perception of Time, Study Finds

Right now, your brain is keeping track of the passage of time without your awareness, letting you focus on better things.

This happens automatically, but not consistently. The brain's perception of time can fluctuate, with some moments seeming to stretch or shrink relative to each objective second.

While these wrinkles in time may be distortions of reality, technically they aren't all in your head. According to a new study, some originate in your heart.

Heartbeats set the pace for time perception.Time is a dimension of the Universe and a core basis for our experience of self. This new research shows that the moment-to-moment experience of time is synchronized with, and changes with, the length of a heartbeat.

These variations in time perception – or "temporal wrinkles" – are normal, researchers say, and may be adaptive. Previous research has also explored their origins, suggesting thoughts and emotions can distort our sense of time, making some moments seem to expand or contract.

part1

Comment by Dr. Krishna Kumari Challa on March 11, 2023 at 1:01pm

Microbes can create a more peaceful world: Scientists issue call to action

Microorganisms should be 'weaponized' to stave off conflicts across the globe, according to a team of eminent microbiologists.

The paper 'Weaponising microbes for peace'  outlines the ways in which microbes and microbial technologies can be used to tackle global and local challenges that could otherwise lead to conflict, but warns that these resources have been severely underexploited to date.

Worldwide deficits and asymmetries in basic resources and services considered to be human rights, such as drinking water, sanitation, healthy nutrition, access to basic healthcare and a clean environment, can lead to competition between peoples for limited resources, tensions, and in some cases conflicts. "There is an urgent need to reduce such deficits, to level up, and to assure provision of basic resources for all peoples. This will also remove some of the causes of conflicts. There is a wide range of powerful microbial technologies that can provide or contribute to this provision of such resources and services, but deployment of such technologies is seriously underexploited.

The paper then lists a series of ways in which microbial technologies can contribute to challenges such as food supply and security, sanitation and hygiene, healthcare, pollution, energy and heating, and mass migrations and overcrowding. For example, microbes are at the core of efforts to tackle pollution by bioremediation, replacing chemical methods of treating drinking water with metalloid conversion systems, and producing biofuels from wastes. "There is now a desperate need for a determined effort by all relevant actors to widely deploy appropriate microbial technologies to reduce key deficits and asymmetries, particularly among the most vulnerable populations.

There is now a desperate need for a determined effort by all relevant actors to widely deploy appropriate microbial technologies to reduce key deficits and asymmetries, particularly among the most vulnerable populations.

Not only will this contribute to the improvement of humanitarian conditions and leveling up, and thereby to a reduction in tensions that may lead to conflicts, but also advance progress towards attainment of Sustainable Development Goals.

"We must weaponise microbes for peace."

The editorial is published in Microbial Biotechnology.

Shailly Anand et al, Weaponising microbes for peace, Microbial Biotechnology (2023). DOI: 10.1111/1751-7915.14224

Comment by Dr. Krishna Kumari Challa on March 11, 2023 at 12:42pm

You're stuck with your same old genome, but corals aren't

Some corals live to be hundreds, and even thousands, of years old. They were born with genes that were successful back in their parent's generation, so how can these old corals still be successful now? Especially in a changing climate? It's possible that the generation and the filtering of mutations that occur in different parts of a big coral act as a proving ground for adaptive genetics for the future. A new study shows a novel way that some very ancient animals might be surviving.

You got your entire set of genes—good or bad—from your parents, and those are the only genes you will have for your entire life. Those genes are also the only ones you will pass along to your children. Of course, there are a few exceptions—like mutations that happen in sperm or egg cells that you might pass along to the next generation. And a growing chorus of technologies is poised to alter harmful mutations in human genes that make life difficult, such as recent success in altering the genes in lung cells that cause cystic fibrosis.

Nearly every animal must make a living with a set of genes that remains virtually unchanged during their lifetime, but a recent study of tropical reef building corals shows something different. These very long-lived animals are constantly changing and testing their genes—and some of these changes make it into the next generation. In this way a centuries-old coral might be a cauldron of genetic innovation, and it might help prepare them for climate change.

Elora H. López-Nandam et al, Mutations in coral soma and sperm imply lifelong stem cell renewal and cell lineage selection, Proceedings of the Royal Society B: Biological Sciences (2023). DOI: 10.1098/rspb.2022.1766

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Comment by Dr. Krishna Kumari Challa on March 11, 2023 at 12:38pm

Ancient dormant viruses found in permafrost, once revived, can infect 

A team of climate scientists has found that ancient viruses dormant for tens of thousands of years in permafrost can infect modern amoeba when they are revived. For their study, reported on the open-access site Viruses, the group collected several giant virus specimens from permafrost in Siberia and tested them to see if they could still infect modern creatures.

Prior research has shown that permafrost—frozen soil—is an excellent preservative. Many carcasses of frozen extinct animals have been extracted from permafrost in the Northern Hemisphere. Prior research has also shown that plant seeds lying dormant in permafrost can be coaxed to grow once revived. And there is evidence suggesting that viruses and bacteria trapped in permafrost could infect hosts if revived. In this new effort, the researchers tested this theory.

The effort by the research team followed up on prior work in 2014 that showed a 30,000-year-old virus could be revived—and that it could be infectious. The team followed up on that effort by reviving a different virus in 2015 and allowing it to infect an amoeba. In this new effort, the team collected several virus specimens from multiple permafrost sites across Siberia for lab testing. For safety reasons, the research team collects only so-called giant viruses and only those that can infect amoeba, not humans or any other creature. In reviving the virus samples, the team found that they were still capable of infecting amoeba. They also found, via radiocarbon dating of the permafrost in which they were found, that the viruses had been in a dormant state for between 27,000 and 48,500 years.

The researchers suggest their findings hint at a much bigger problem—as the planet warms and the permafrost melts, there is a chance of viruses emerging that are capable of infecting humans. Such a threat is not science fiction, they note—prior researchers found influenza viruses in a lung sample of a woman who had died in Alaska during the flu pandemic of 1918. And another team found a virus related to smallpox in a mummified woman found in Siberia—she had been there for 300 years.

Jean-Marie Alempic et al, An Update on Eukaryotic Viruses Revived from Ancient Permafrost, Viruses (2023). DOI: 10.3390/v15020564

Comment by Dr. Krishna Kumari Challa on March 10, 2023 at 12:09pm

How wildfires shred the ozone layer

Huge wildfires that raged across Australia in 2019–20 unleashed chemicals that chewed through the ozone layer. The wildfire smoke combined with harmless remnants of now-banned chlorinated compounds, reactivating their ozone-eating form — a reaction that doesn’t usually happen in the warm air away from the poles. More-frequent wildfires resulting from climate change could expand ..., which protects Earth from harmful ultraviolet rays.

https://www.nature.com/articles/d41586-023-00687-w?utm_source=Natur...

https://www.nature.com/articles/s41586-022-05683-0.epdf?sharing_tok...

Comment by Dr. Krishna Kumari Challa on March 10, 2023 at 12:07pm

The mice with two dads: scientists create eggs from male cells

Proof-of-concept mouse experiment will have a long road before use in humans is possible.

Researchers have made eggs from the cells of male mice — and shown that, once fertilized and implanted into female mice, the eggs can develop into seemingly healthy, fertile offspring. The approach, announced yesterday at the Third International Summit on Human Genome Editing in London, has not yet been published and is a long way from being used in humans. It is an early proof-of-concept for a technique that raises the possibility of a way to treat some causes of infertility — and even allow for single-parent embryos.

https://www.nature.com/articles/d41586-023-00717-7?utm_source=Natur...

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