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Comment by Dr. Krishna Kumari Challa 16 hours ago

What puts the ‘cable’ in cable bacteria
The ‘wires’ that cable bacteria use to conduct electricity seem to be made of repeating units of a compound that contains nickel and sulfur. Researchers found that these units make up ‘nanoribbons’, which are woven together like a plait to form the larger wires. The work has yet to be peer reviewed, but if confirmed, the finding could be the first known example of a biologically produced metal–organic framework. “If it holds true, this is a major step in our understanding of what cable bacteria can accomplish,” says electromicrobiologist Lars Peter Nielsen, who co-discovered the microorganisms in 2009.

https://www.biorxiv.org/content/10.1101/2025.10.10.681601v1

https://www.science.org/content/article/metal-scaffolds-turn-bacter...

Comment by Dr. Krishna Kumari Challa 16 hours ago

The new review is based on 13 randomized trials presented in 26 articles containing more than 1,400 separate statistical analyses. Only one of the 13 randomized trials demonstrated the effect it was designed to detect—and that trial was stopped early and was considered unsuccessful by the researchers themselves.

The review showed that only about 7% of the many hypotheses tested by the researchers could be expected to be correct. Notably, this did not apply to the researchers' own primary hypotheses—these were not supported by the corrected results.

In 23 out of 25 articles, the researchers highlighted secondary findings as support for their theories, but in 22 of these cases the evidence disappeared after proper statistical handling. Overall, the researchers' interpretation did not take into account how many analyses they had conducted, and they did not focus on the main outcomes of the trials.
The researchers stress that the purpose was not to determine whether non-specific vaccine effects exist, but to examine Benn and Aaby's research practices.

"We hope that others in the field will now re-evaluate the evidence—what do we actually know about non-specific vaccine effects? Although Benn and Aaby have contributed about one-third of all research in the area, others have also studied the question, and this should be included to form a complete picture.

 Henrik Støvring et al, What is actually the emerging evidence about non-specific vaccine effects in randomized trials from the Bandim Health Project?, Vaccine (2025). DOI: 10.1016/j.vaccine.2025.127937

Part 2

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Comment by Dr. Krishna Kumari Challa 16 hours ago

Randomized trials show no evidence of non-specific vaccine effects

Researchers  have conducted randomized trials involving thousands of children in Guinea-Bissau and Denmark to demonstrate so-called non-specific vaccine effects—that is, whether vaccines also protect against diseases other than the one they are designed to prevent.

A new comprehensive Danish review now shows that the trials have been unable to demonstrate non-specific effects for the widely used vaccinations against measles, tuberculosis, diphtheria, tetanus, and whooping cough. The study has just been published in the journal Vaccine.

It is concerning that such a prominent research group has conducted so many randomized trials over such a long period without finding real results. Randomized trials are normally considered the gold standard in medical research, so if they do not show anything, one should be very cautious about presenting it as convincing evidence.

The new study is the first to systematically analyze all of Benn and Aaby's randomized trials. While others have previously criticized individual studies, the researchers behind the new review examined the full body of work.

Researchers find indications that the researchers systematically selected and highlighted results that supported their theories, while downplaying the fact that they did not confirm the primary hypothesis the trials were actually designed to test. When you look at the overall picture, there are almost no real findings left.

The results meant it was time to change the global approach to vaccination—all new vaccines should routinely be assessed for non-specific effects, and vaccination programs should be revised worldwide.

Part 1

Comment by Dr. Krishna Kumari Challa 17 hours ago

Hitler's DNA reveals possible genetic disorder tied to sexual and social behaviour

Adolf Hitler most likely suffered from the genetic condition Kallmann Syndrome that can manifest itself in undescended testicles and a micropenis, researchers  said this week, following DNA testing of the Nazi dictator's blood.

The new research also quashes the suggestion that Hitler had Jewish ancestry.

Popular World War II songs often mocked Hitler's anatomy but lacked any scientific basis.

The findings by an international team of scientists and historians now appear to confirm longstanding suspicions around his sexual development.

No one has ever really been able to explain why Hitler was so uncomfortable around women throughout his life, or why he probably never entered into intimate relations with women.

But now we know that he had Kallmann Syndrome, this could be the answer we've been looking for, say the researchers.

The research findings are featured in a new documentary, "Hitler's DNA: Blueprint of a Dictator." 

The testing found a "high likelihood" that Hitler had Kallmann Syndrome and "very high" scores—in the top one percent—for a predisposition to autism, schizophrenia and biopolar disorder. 

The research team stressed that such conditions, however, could not explain or excuse Hitler's warmongering or racist policies.

The testing was made possible after researchers obtained a sample of Hitler's blood from a piece of material taken from the sofa on which he shot himself.

The DNA results additionally rule out the possibility that Hitler had a Jewish grandfather via his grandmother.

Source: AFP

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Comment by Dr. Krishna Kumari Challa 17 hours ago

Testosterone in body odor linked to perceptions of social status 

As humans, we are constantly navigating social status, using subconscious strategies to assert either our dominance or prestige.

We often use voice or  body language to communicate this. Imagine a politician with a slow, booming voice, expanding their chest and extending their arms, quickly asserting authority over their audience.

We also use our sense of smell, according to new research from the University of Victoria (UVic), published in Evolution and Human Behaviour.

This study examines the role of body odor in people's perceptions of others' social status. 

Researchers examined whether scent cues associated with levels of circulating testosterone impact people's social status judgments. They found that both male and female participants in their study perceived men with higher levels of testosterone to be more dominant than men with lower testosterone levels.

Chemical signaling is the most widespread form of communication on Earth. Many animals will use scent to express and understand social status within their group. Mice, for example, scent-mark their territory to assert their dominance.

Previous research shows that humans use two different strategies to assert and maintain social status: dominance and prestige. Dominance is coercive, using tactics to force compliance. Prestige, on the other hand, involves showing valuable skills and traits that lead others to show deference voluntarily.

Research also reveals that scent plays an important role in human communication—of fear, sickness, safety, attraction, and personality traits such as dominance and neuroticism.

This is the first study to directly examine whether humans use scent cues related to circulating testosterone levels in the formation of social status judgments.

No significant relationship was found in the study between testosterone levels and perceived prestige. Perceptions of dominance, on the other hand, were associated with higher testosterone levels.

This study contributes to a growing body of work seeking to understand how social communication occurs through scent. 

However, the findings should be interpreted with caution. The study involved a relatively small and uniform sample, and replication with larger and more diverse groups will be important to confirm whether these patterns hold.

Marlise K. Hofer et al, The role of testosterone in odor-based perceptions of social status, Evolution and Human Behavior (2025). DOI: 10.1016/j.evolhumbehav.2025.106752

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Comment by Dr. Krishna Kumari Challa 17 hours ago

How chromosomes separate accurately: Molecular 'scissors' caught in action

Cell division is a process of remarkable precision: during each cycle, the genetic material must be evenly distributed between the two daughter cells. To achieve this, duplicated chromosomes, known as sister chromatids, are temporarily linked by cohesin—a ring-shaped protein complex that holds them together until separation.

Researchers have uncovered the mechanism by which separase—the molecular ''scissors'' responsible for this cleavage—recognizes and cuts cohesin.

Their findings, published in Science Advances, shed new light on chromosome segregation errors that can lead to certain forms of cancer.

Before a cell divides, its chromosomes are duplicated. These identical copies, called sister chromatids, are held together by cohesin—a ring-like structure composed of several proteins that prevents premature separation.

When the cell is ready to divide, separase, a specialized enzyme, cleaves one of the cohesin subunits, the protein SCC1, allowing the chromatids to separate and the genetic material to be evenly distributed between the two daughter cells. Any malfunction in this process can compromise genome stability, potentially resulting in severe diseases, including cancer.

Using cryo-electron microscopy (cryo-EM)—a cutting-edge technique that enables biological samples to be visualized in their native state at near-atomic resolution—the team captured the interaction between separase and SCC1 and identified the precise cleavage sites on the protein.

Biochemical and structural analyses also revealed multiple "docking sites" on the surface of separase, ensuring high-affinity binding of SCC1 to separase prior to cleavage. These contact points include five phosphate-binding sites that recognize phosphorylated residues on SCC1.

These affinity experiments showed that these phosphate–separase interactions stabilize the complex and accelerate SCC1 cleavage, ensuring fast and precise separation of chromosomes.

The work provides an extensive functional and structural framework to understand how separase is regulated and how it recognizes its substrates.

Jun Yu et al, Substrate recognition by human separase, Science Advances (2025). DOI: 10.1126/sciadv.ady9807

Comment by Dr. Krishna Kumari Challa 18 hours ago

This durability makes iron biosignatures particularly attractive for planetary exploration. Unlike fragile organic molecules that degrade under radiation and harsh chemistry, mineralized iron structures can survive. Researchers have identified these biosignatures in environments ranging from hydrothermal vents on the ocean floor to terrestrial soils, from acidic mine drainage to neutral freshwater springs. Wherever liquid water contacts iron-bearing rocks, iron-metabolizing bacteria typically establish themselves.

Mars presents an obvious target. The planet's distinctive red color comes from oxidized iron in surface dust and rocks. Ancient Mars hosted liquid water, and spacecraft have documented iron-rich minerals throughout the geological record. If microbial life ever evolved on Mars, iron metabolism would have provided an accessible energy source. The minerals these hypothetical organisms produced could still exist, locked in ancient sediments awaiting discovery by rovers equipped with the right instruments.

The icy moons Europa and Enceladus offer different but equally compelling possibilities. Both harbor subsurface oceans beneath frozen shells. Europa's ocean likely contacts a rocky seafloor, where water and rock interactions would release dissolved iron. Enceladus actively vents ocean material through ice geysers at its south pole. Mission concepts propose sampling these plumes or landing near the vents, analyzing ejected particles for iron minerals that might betray biological origins.

The review emphasizes that recognizing biogenic iron minerals requires understanding how they form, what textures they create, and how they differ from abiotic iron precipitates. Mission planners must equip spacecraft with instruments capable of detecting not just iron minerals generally, but the specific morphological and chemical signatures that distinguish biology from geology.

The stakes are high. Finding iron biosignatures on another world wouldn't just confirm life exists elsewhere, it would reveal that the same fundamental chemistry supporting Earth's deep biosphere operates throughout the solar system.

Laura I. Tenelanda-Osorio et al, Terrestrial iron biosignatures and their potential in solar system exploration for astrobiology, Earth-Science Reviews (2025). DOI: 10.1016/j.earscirev.2025.105318

Part 2

Comment by Dr. Krishna Kumari Challa 18 hours ago

The rust that could reveal alien life

Iron rusts. On Earth, this common chemical reaction often signals the presence of something far more interesting than just corroding metal—for example, living microorganisms that make their living by manipulating iron atoms. Now researchers argue these microbial rust makers could provide some of the most promising biosignatures for detecting life on Mars and the icy moons of the outer solar system.

Researchers now have compiled a comprehensive review of how iron metabolizing bacteria leave distinctive fingerprints in rocks and minerals, and why these signatures matter for astrobiology. The research, published in Earth-Science Reviews, bridges decades of terrestrial microbiology with the practical challenges of searching for life beyond Earth.

Iron ranks among the most abundant elements in the solar system, and Earth's microorganisms have evolved remarkably diverse ways to exploit it. Some bacteria oxidize ferrous iron to generate energy, essentially breathing iron the way humans breathe oxygen. Others reduce ferric iron, using it as the final electron acceptor in their metabolism. These processes don't happen in isolation. Iron metabolizing microbes link their element of choice to the carbon and nitrogen cycles, coupling iron transformations to carbon dioxide fixation, organic matter degradation, and even photosynthesis.

The byproducts of these microbial reactions create what researchers call biogenic iron oxyhydroxide minerals. These aren't subtle traces. Organisms that thrive in neutral pH environments and oxidize iron produce distinctive structures such as twisted stalks, tubular sheaths, and filamentous networks of iron minerals mixed with organic compounds. The minerals precipitate as the bacteria work, forming rusty deposits that can persist in the geological record for billions of years.

Part 1

Comment by Dr. Krishna Kumari Challa 18 hours ago

The microrobots also contain the active ingredient they need to deliver. The researchers successfully loaded the microrobots with common drugs for a variety of applications—in this case, a thrombus-dissolving agent, an antibiotic or tumor medication.

These drugs were released by a high-frequency magnetic field that heats the magnetic nanoparticles, dissolving the gel shell and the microrobot.

The researchers used a two-step strategy to bring the microrobot close to its target: first, they injected the microrobot into the blood or cerebrospinal fluid via a catheter. They went on to use an electromagnetic navigation system to guide the magnetic microrobot to the target location.

The catheter's design is based on a commercially available model with an internal guidewire connected to a flexible polymer gripper. When pushed beyond the external guide, the polymer gripper opens and releases the microrobot.
To precisely steer the microrobots, the researchers developed a modular electromagnetic navigation system suitable for use in the operating theater.

 Fabian C. Landers et al, Clinically ready magnetic microrobots for targeted therapies, Science (2025). DOI: 10.1126/science.adx1708. www.science.org/doi/10.1126/science.adx1708

Part 2

Comment by Dr. Krishna Kumari Challa 18 hours ago

Magnetic nanoparticles that successfully navigate complex blood vessels may be ready for clinical trials
Magnetic microrobots with iron oxide and tantalum nanoparticles can be precisely guided through complex blood vessels using modular electromagnetic navigation, delivering drugs directly to target sites such as thrombi. These microrobots achieve over 95% delivery accuracy in realistic vessel models and animal tests, supporting readiness for clinical trials and potential applications beyond vascular occlusions.

Every year, 12 million people worldwide suffer a stroke; many die or are permanently impaired. Currently, drugs are administered to dissolve the thrombus that blocks the blood vessel. These drugs spread throughout the entire body, meaning a high dose must be administered to ensure that the necessary amount reaches the thrombus. This can cause serious side effects, such as internal bleeding.

Since medicines are often only needed in specific areas of the body, medical research has long been searching for a way to use microrobots to deliver pharmaceuticals to where they need to be: in the case of a stroke, directly to the stroke-related thrombus.

Now, a team of researchers at ETH Zurich has made major breakthroughs on several levels. They have published their findings in Science.

The microrobot the researchers use comprises a proprietary spherical capsule made of a soluble gel shell that they can control with magnets and guide through the body to its destination. Iron oxide nanoparticles in the capsule provide the magnetic properties.

Because the vessels in the human brain are so small, there is a limit to how big the capsule can be. The technical challenge is to ensure that a capsule this small also has sufficient magnetic properties.

The microrobot also needs a contrast agent to enable doctors to track via X-ray how it is moving through the vessels. The researchers focused on tantalum nanoparticles, which are commonly used in medicine but are more challenging to control due to their greater density and weight.

Combining magnetic functionality, imaging visibility and precise control in a single microrobot required perfect synergy between materials science and robotics engineering, which has taken the researchers many years to successfully achieve.

They developed precision iron oxide nanoparticles that enable this delicate balancing act.

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