Comment

Comment by Dr. Krishna Kumari Challa on September 11, 2025 at 1:00pm

'Potential biosignatures' found in ancient Mars lake

A new study suggests a habitable past and signs of ancient microbial processes on Mars. Led by NASA and featuring key analysis from Imperial College London, the work has uncovered a range of minerals and organic matter in Martian rocks that point to an ancient history of habitable conditions and potential biological processes on the Red Planet.

This is a very exciting discovery of a potential biosignature but it does not mean we have discovered life on Mars. We now need to analyze this rock sample on Earth to truly confirm if biological processes were involved or not.

While driving through the valley, called Neretva Vallis, Perseverance came across a thick succession of fine-grained mudstones and muddy conglomerates. Here, it conducted a detailed analysis of these rocks, using instruments such as the Planetary Instrument for X-ray Lithochemistry (PIXL) and Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals (SHERLOC).

By mapping the types and distributions of different sedimentary rocks, researchers were able to reconstruct the environment in which these mudstones were deposited.

Their analysis revealed a range of sedimentary structures and textures indicative of lake margin and lake bed environments, including a composition rich in minerals like silica and clays—the opposite to a river scenario, where fast-moving water would carry these tiny particles away.

This pointed to a surprising conclusion: they had found lake deposits in the bottom of a river valley.

The finding may suggest a period in the history of Jezero Crater where the valley itself was flooded, giving rise to this potentially habitable lake.

With the lake habitat scenario pinned down, the Perseverance science team turned their attention to the mudstones themselves. It was inside these rocks that they discovered a group of tiny nodules and reaction fronts, with chemical analysis revealing that these millimeter-scale structures are highly enriched in iron-phosphate and iron-sulfide minerals (likely vivianite and greigite).

These appear to have formed through redox reactions involving organic carbon, a process that could have been driven by either abiotic or—interestingly—biological chemistry. Importantly, this sets the stage for everything that happened next: the formation of this specific type of oxidized, iron- and phosphorus-rich sediment was the essential prerequisite for creating the ingredients for subsequent reactions.

Since these ingredients mirror by-products of microbial metabolism seen on Earth, it can be considered a compelling potential biosignature, raising the possibility that there was once microbial life on Mars.

Ultimately, the only way for the true origin of these structures to be determined is by returning the samples to Earth, a possibility that rests on when future missions will manage to successfully collect the samples from Mars' surface.

Joel Hurowitz, Redox-driven mineral and organic associations in Jezero Crater, Mars, Nature (2025). DOI: 10.1038/s41586-025-09413-0. www.nature.com/articles/s41586-025-09413-0

Comment by Dr. Krishna Kumari Challa on September 11, 2025 at 12:54pm

Hawking and Kerr black hole theories confirmed by gravitational wave

Scientists have confirmed two long-standing theories relating to black holes—thanks to the detection of the most clearly recorded gravitational wave signal to date.

Ten years after detecting the first gravitational wave, the LIGO-Virgo-KAGRA Collaboration has (10 Sep) announced the detection of GW250114—a ripple in spacetime which offers unprecedented insights into the nature of black holes and the fundamental laws of physics.

The study confirms Professor Stephen Hawking's 1971 prediction that when black holes collide, the total event horizon area of the resulting black hole is bigger than the sum of individual black holes—it cannot shrink.

Research also confirmed the Kerr nature of black holes—a set of equations developed in 1963 by New Zealand mathematician Roy Kerr elegantly explaining what space and time look like near a spinning black hole. The Kerr metric predicts effects such as space being 'dragged' around and light looping to make multiple copies of objects.

Publishing their findings in Physical Review Letters, the international group of researchers note that GW250114 was detected with a signal-to-noise ratio of 80. This clarity enabled precise tests of general relativity and black hole thermodynamics.

GW250114: testing Hawking's area law and the Kerr nature of black holes, Physical Review Letters (2025). DOI: 10.1103/kw5g-d732

Comment by Dr. Krishna Kumari Challa on September 11, 2025 at 12:42pm

Scientists find quasi-moon orbiting the Earth for the last 60 years

Everyone who has ever lived on Earth has been well-aware of the moon, but it turns out Earth also has some frequent temporary companions. These "quasi-moons" are small asteroids that enter into a kind of resonance with Earth's orbit, although they aren't technically orbiting Earth. In August, this small group of asteroids, called Arjunas, offered another companion to add to the list.

Astronomers at the Pan-STARRS observatory in Hawaii discovered the new quasi-moon, referred to as "2025 PN7," on August 2, 2025. Their research was recently published in Research Notes of the AAS. Using JPL's Horizons system and Python tools, they analyzed the orbital data and compared it to other Arjunas and quasi-satellites.

The team found that 2025 PN7 had been in a quasi-orbit for about 60 years already and would likely be nearby for another 60 or so years before departing. Compared to other quasi-moons, this period is relatively short. The quasi-moon Kamo'oalewa has an expected near-Earth orbit of around 381 years, while the total time for 2025 PN7 is 128 years.

Scientists have been aware of these quasi-satellites since 1991, when they first discovered 1991 VG—which some thought was an interstellar probe at the time.

Over three decades later, it is now widely accepted that such objects are natural and constitute a secondary asteroid belt that occupies the region in which the Earth–moon system orbits around the sun, defining the Arjuna dynamical class. The Arjunas with the most Earth-like orbits can experience temporary captures as mini-moons of our planet.

However, mini-moons are distinct from quasi-moons, like 2025 PN7, as mini-moons do temporarily  orbit Earth and quasi-moons only appear to do so. Currently, there are six other known quasi-moons: 164207 Cardea (2004 GU9), 469219 Kamo'oalewa (2016 HO3), 277810 (2006 FV35), 2013 LX28, 2014 OL339 and 2023 FW13.

Carlos de la Fuente Marcos et al, Meet Arjuna 2025 PN7, the Newest Quasi-satellite of Earth, Research Notes of the AAS (2025). DOI: 10.3847/2515-5172/ae028f

Comment by Dr. Krishna Kumari Challa on September 11, 2025 at 11:26am

Giant DNA discovered in people's mouths could impact oral health, immunity and even cancer risk

Researchers have made a surprising discovery hiding in people's mouths: Inocles, giant DNA elements that had previously escaped detection. These appear to play a central role in helping bacteria adapt to the constantly changing environment of the mouth.

The findings, published in the journal Nature Communications, provide fresh insight into how oral bacteria colonize and persist in humans, with potential implications for health, disease and microbiome research.

They discovered Inocles, an example of extrachromosomal DNA—chunks of DNA that exist in cells, in this case bacteria, but outside their main DNA. It's like finding a book with extra footnotes stapled to it, and  scientists are just starting to read them to find out what they do.

Detecting Inocles was not easy, as conventional sequencing methods fragment genetic data, making it impossible to reconstruct large elements.

To overcome this, the team applied advanced long-read sequencing techniques, which can capture much longer stretches of DNA.

Inocle genomes, turned out to be hosted by the bacteria Streptococcus salivarius.

The average genome size of Inocle is 350 kilobase pairs, a measure of length for genetic sequences, so it is one of the largest extrachromosomal genetic elements in the human microbiome. Plasmids, other forms of extrachromosomal DNA, are at most a few tens of kilobase pairs.

This long length endows Inocles with genes for various functions, including resistance to oxidative stress, DNA damage repair and cell wall-related genes, possibly involved in adapting to extracellular stress response.

What's remarkable is that, given the range of the human population the saliva samples represent, researchers think 74% of all human beings may possess Inocles. And even though the oral microbiome has long been studied, Inocles remained hidden all this time because of technological limitations.

Now that we know they exist, we can begin to explore how they shape the relationship between humans, their resident microbes and our oral health. And there's even some hints that Inocles might serve as markers for serious diseases like cancer, say the researchers.

 Yuya Kiguchi et al, Giant extrachromosomal element "Inocle" potentially expands the adaptive capacity of the human oral microbiome, Nature Communications (2025). DOI: 10.1038/s41467-025-62406-5

Comment by Dr. Krishna Kumari Challa on September 10, 2025 at 1:26pm

The investigations showed that a certain type of immune cell, so-called plasmacytoid dendritic cells, produce large amounts of the important antiviral messenger interferon-α (IFN-α) upon infection with influenza—regardless of the virus strain. This means that these immune cells generally respond strongly to influenza viruses without the need for the virus to productively infect them.

If this is the case, why do not all viruses cause the same severity of the disease? The research team found that other immune cells, namely myeloid dendritic cells and different types of macrophages, are infected with highly pathogenic influenza viruses and produce large amounts of IFN-α. Viral replication in these immune cells appears to be an important factor in the production of type I interferon and the development of an excessive immune response (cytokine storm).
These results provide an explanation of why some influenza viruses could be so much more dangerous than others: it might be their ability to replicate in certain immune cells and thereby trigger an extremely strong immune reaction that leads to severe inflammation and harm to health. This knowledge can help to develop targeted therapies and better identify risk groups.

Marc A. Niles et al, Influenza A virus induced interferon-alpha production by myeloid dendritic cells and macrophages requires productive infection, Emerging Microbes & Infections (2025). DOI: 10.1080/22221751.2025.2556718

Part 2

Comment by Dr. Krishna Kumari Challa on September 10, 2025 at 1:25pm

Why some influenza viruses are more dangerous than others

Serious infections with influenza A viruses are characterized by an excessive immune response, known as cytokine storm. It was previously unclear why some virus strains trigger these storms, while others do not. Researchers investigated 11 different influenza A virus strains and their effect on different human immune cells.

The results, published in Emerging Microbes & Infections, show that highly pathogenic avian influenza viruses infect specific kinds of immune cells and thus stimulate the production of type I interferon. This could explain why these viruses are particularly dangerous.

The new research results show that not only the immune cells that have always been the focus of attention regarding type I interferon production, but also other immune system cells could be decisive in whether an influenza infection triggers an excessive immune system response. This knowledge is important in order to be able to better assess the risk of dangerous virus variants.

Influenza viruses are some of the most significant respiratory disease pathogens worldwide. While most infections are relatively mild, certain virus strains can cause severe pneumonia, leading to acute respiratory failure. Highly pathogenic influenza viruses are particularly dangerous. They often spread from birds to humans and are associated with significantly higher mortality rates.

The immune system plays a crucial role in this danger: some virus strains cause the body to release an excessive amount of messenger substances known as cytokines. If a cytokine storm occurs, the immune response will end up damaging the body's tissue more than the virus itself.

But why do some influenza viruses trigger such excessive reactions, while others only cause infections with mild progression?

The researchers  tested how the flu viruses infect different immune cells and stimulate the release of messenger substances.

The aim of their research is to decipher the mechanisms behind mild and severe disease progression and to develop long-term approaches for better protection and treatment options.

Part 1

Comment by Dr. Krishna Kumari Challa on September 10, 2025 at 1:12pm

"Even after accounting for alcohol use by mothers during pregnancy, the father's drinking was still linked to lower child height, smaller head size and reduced verbal IQ. This suggests that paternal alcohol use may have its own, though limited, impact on a child's growth and development.

"Data analyses of children where both parents consumed alcohol during pregnancy had significantly negative effects on growth, head circumference, verbal intelligence and general birth defect scores than in children where neither parent consumed alcohol."

The researchers say that, while it is not yet clear whether the impact of a father's drinking on a child's growth and development stems from impaired sperm quality or other epigenetic influences (changes in how genes work that don't involve altering the DNA code itself), the father's role in the development of FASD cannot be overlooked.

Philip A. May et al, Does paternal alcohol consumption affect the severity of traits of fetal alcohol spectrum disorders?, Alcohol, Clinical and Experimental Research (2025). DOI: 10.1111/acer.70105

Part 2

Comment by Dr. Krishna Kumari Challa on September 10, 2025 at 1:11pm

Fathers' drinking plays role in fetal alcohol spectrum disorder, study shows

It's a well-known fact that fetal alcohol spectrum disorder (FASD) in children is caused by mothers who drink during pregnancy. But it turns out that the father's drinking habits could also affect a child's growth and development.

A team of international researchers found that a father's alcohol use may have a small but direct negative impact on a child's development by the age of seven. A father's drinking contributes to the harm caused by alcohol use during pregnancy.

The findings of their study were published recently in the journal Alcohol: Clinical & Experimental Research.

The researchers analyzed data from five studies on the prevalence and characteristics of FASD among Grade 1 learners in the Western Cape to explore whether a father's drinking affects children diagnosed with FASD. The children's biological mothers or legal guardians completed a questionnaire on the risk factors for FASD.

According to the researchers, there is a growing recognition that factors beyond pregnant women's drinking habits can affect their children's development. They add that increased attention is currently paid to the role of fathers, not only as a contributing factor to women's drinking habits, but also as an independent contributing factor to the growth and development of children.

The findings show that children whose fathers drank alcohol were more likely to be shorter, have smaller heads, and score lower on verbal IQ tests. It was also clear from the study that the highest risk to the child's development exists when both parents use alcohol during pregnancy. It also appeared that 'binge drinking' by the father, but especially by both parents, has the most detrimental effect on the child's development. 

Data analysis showed that between 66% and 77% of fathers of children on the FAS spectrum drank during their partner's pregnancy with the child in question. These fathers drank an average of 12 drinks per drinking day. The number of drinks that fathers drank per drinking day was significantly correlated with smaller head circumference in their children. Head circumference is used as a measure of brain development."

The researchers add that fathers who drank an average of five or more drinks per drinking day had shorter children with smaller head circumferences. These children also performed worse on measures in verbal intelligence tests.

"In general, it was found that the more fathers drank, the worse their children performed. However, it should also be noted that all these effects were observed in children whose mothers consumed alcohol during pregnancy."

They note that a father's drinking alone didn't increase the chances of a child being diagnosed with FASD. However, when the mother drank during pregnancy and the father was also a heavy drinker, the child was more likely to have the most serious symptoms of FASD.
"When looking at both parents' drinking patterns, the father's alcohol use alone didn't show a clear link to the child's physical or brain development problems. While both parents' drinking was considered, the main effects on a child's development and physical features were linked to the mother's alcohol use.
Part 1

Comment by Dr. Krishna Kumari Challa on September 10, 2025 at 11:45am

The role of telomeres in processes such as cancer development and aging, and what happens when they do not work properly, has long interested scientists. Diseases caused by disturbances in telomere maintenance are rare, but very serious, and include premature aging, blood cell deficiency called aplastic anemia and fibrosis in the lungs.

In about half of cases, the disease is explained by a known mutation that affects telomere stability, but in many cases, there is currently no known medical explanation for why the individual is sick.
Their research is also relevant to cancer research. On one hand, inappropriate "repair" of telomeres can trigger catastrophic events leading to the accumulation of mutations and cancer.

On the other hand, cancer cells are often less efficient at repairing damage to DNA compared to normal cells. This weakness is exploited in cancer treatments and many therapies kill tumor cells by causing DNA damage or inhibiting repair, or both.

In other words, knowledge of how cells regulate DNA repair and protect telomeres has a bearing on both prevention and treatment of cancer.

Increased understanding of which proteins play key roles in these cellular processes can, in the long term, contribute to more precise and targeted treatment strategies.

Patrik Eickhoff et al, Chromosome end protection by RAP1-mediated inhibition of DNA-PK, Nature (2025). DOI: 10.1038/s41586-025-08896-1

Part 2

Comment by Dr. Krishna Kumari Challa on September 10, 2025 at 11:44am

Discovery reveals how chromosome ends can be protected

Researchers have uncovered a previously unknown mechanism that safeguards the chromosome ends from being mistakenly repaired by the cell. While DNA repair is vital for survival, attempts to repair the chromosome ends—called telomeres—can have catastrophic outcomes for cells.

The research, published in Nature, increases the understanding of how cancer and certain rare diseases develop.

Cells constantly monitor their DNA. A DNA helix that ends abruptly is a signal that DNA has been severely damaged—at least in most cases. The most severe DNA damage a cell can suffer is when a DNA helix breaks up in two pieces. 

Normally, the cells would try to promptly repair all damage to DNA. The dilemma is that our chromosomes have ends that look just like broken DNA. If cells were to "repair" them, looking for another loose end to join them with, this would lead to the fusion between two or more chromosomes, making the cell susceptible to transform into a cancer cell.

Therefore, the chromosome ends—called telomeres—must be protected from the cell's DNA repair machinery.

The cells have to constantly repair DNA damage to avoid mutations, cell death, and cancer, while at the same time, they must not repair the chromosome ends by mistake, since that would result in the same catastrophic outcome. What's the difference between damaged DNA and the natural chromosome end? This problem has been known for almost a century, but some aspects are still not completely resolved.

Although the telomeres are not to be repaired as if they were broken DNA, several DNA repair proteins can be found at the chromosome ends. 

The research team has previously shown that a key repair protein, DNA Protein Kinase (called DNA-PK) helps in processing telomeres and in protecting them from degradation. But how DNA-PK at the same time is prevented from trying to repair these blunt DNA ends remained a mystery until now.

The researchers have now shown that two other proteins, called RAP1 and TRF2, have an important role to play in regulating DNA-PK.

They show genetically, biochemically and structurally how the protein RAP1, brought to telomeres by TRF2, ensure by  direct interaction that DNA-PK doesn't 'repair' the telomeres.

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