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Comment by Dr. Krishna Kumari Challa on November 14, 2025 at 8:41am

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 on November 14, 2025 at 8:30am

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 on November 14, 2025 at 8:16am

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 on November 14, 2025 at 8:15am

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 on November 14, 2025 at 7:30am

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 on November 14, 2025 at 7:29am

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.

Part 1

Comment by Dr. Krishna Kumari Challa on November 14, 2025 at 7:20am

Chinese team finds a fern that makes rare earth elements

Scientists have discovered a fern from South China that naturally forms tiny crystals containing rare earth elements (REEs). This breakthrough opens the door to a promising new way of "green mining" of these minerals called phytomining.

REEs are a group of 17 elements, all metals with similar properties that are essential for everything from wind turbines and electric car batteries to smartphones and medical scanners.

Extracting them is expensive and normally involves large-scale conventional mining operations that rely on harsh chemicals and cause significant pollution and land damage. That's why researchers are exploring cleaner, sustainable plant-based alternatives to collect REEs.

According to a paper published in the journal Environmental Science & Technology, the researchers studied the Blechnum orientale fern, which had been collected from REE-rich areas in South China. It was already known to be a hyperaccumulator, which is a plant that can grow in soil and water with high concentrations of metals and absorb them through its roots. But what they didn't know was the chemical form the REEs take when inside the plant. This knowledge is vital for designing the most efficient extraction process.

Using high-powered imaging technology and chemical analysis, the team discovered that the fern was forming nanoscale crystals of the REE-rich mineral monazite within its tissues, particularly in the cell walls and spaces between cells. Monazite is one of the main sources of rare earth elements in geological ore deposits worldwide.

The study authors also observed the crystal form, noting that it grows in a highly complex self-organizing pattern of tiny branches, likening it to a microscopic "chemical garden." This is the first time scientists have seen a living plant create a rare earth element crystal.

While we might not be going out to garden for REEs in the immediate future, the research is further proof that phytomining is feasible. The discovery, even with just one fern, strengthens the case that plants could one day provide a valuable, cheaper, and less destructive method for extracting much-needed rare earth elements.

 Liuqing He et al, Discovery and Implications of a Nanoscale Rare Earth Mineral in a Hyperaccumulator Plant, Environmental Science & Technology (2025). DOI: 10.1021/acs.est.5c09617

Comment by Dr. Krishna Kumari Challa on November 14, 2025 at 7:14am

Our solar system is moving faster than expected

How fast and in which direction is our solar system moving through the universe? This seemingly simple question is one of the key tests of our cosmological understanding. A research team of astrophysicists has now found new answers, ones that challenge the established standard model of cosmology.

The study's findings have just been published in the journal Physical Review Letters.

Their analysis shows that the solar system is moving more than three times faster than current models predict. This result clearly contradicts expectations based on standard cosmology and forces us to reconsider our previous assumptions. 

To determine the motion of the solar system, the team analyzed the distribution of so-called radio galaxies, distant galaxies that emit particularly strong radio waves, a form of electromagnetic radiation with very long wavelengths similar to those used for radio signals. Because radio waves can penetrate dust and gas that obscure visible light, radio telescopes can observe galaxies invisible to optical instruments.

As the solar system moves through the universe, this motion produces a subtle "headwind": slightly more radio galaxies appear in the direction of travel. The difference is tiny and can only be detected with extremely sensitive measurements.

Using data from the LOFAR (Low Frequency Array) telescope, a Europe-wide radio telescope network, combined with data from two additional radio observatories, the researchers were able to make an especially precise count of such radio galaxies for the first time. They applied a new statistical method that accounts for the fact that many radio galaxies consist of multiple components. This improved analysis yielded larger but also more realistic measurement uncertainties.

Despite this, the combination of data from all three radio telescopes revealed a deviation exceeding five sigma, a statistically very strong signal considered in science as evidence for a significant result.

The measurement shows an anisotropy ("dipole") in the distribution of radio galaxies that is 3.7 times stronger than what the standard model of the universe predicts. This model describes the origin and evolution of the cosmos since the Big Bang and assumes a largely uniform distribution of matter.

If our solar system is indeed moving this fast, we need to question fundamental assumptions about the large-scale structure of the universe, say the cosmologists. 

Alternatively, the distribution of radio galaxies itself may be less uniform than we have thought. In either case, the current models are being put to the test.

The new results confirm earlier observations in which researchers studied quasars, the extremely bright centers of distant galaxies where supermassive black holes consume matter and emit enormous amounts of energy. The same unusual effect appeared in these infrared data, suggesting that it is not a measurement error but a genuine feature of the universe.

Lukas Böhme et al, Overdispersed Radio Source Counts and Excess Radio Dipole Detection, Physical Review Letters (2025). DOI: 10.1103/6z32-3zf4

Comment by Dr. Krishna Kumari Challa on November 13, 2025 at 9:53am

How much protein you really need

Most official guidelines recommend a bare minimum of close to one gram of protein per kilogram of body weight per day. But many scientists object to suggestions flying around social media that people need m.... Here’s what experts advise:

• Protein needs can vary from person to person and can change throughout a lifetime. “For older adults, 1.2 grams per kilogram is just giving them a little extra protection,” says nutrition and exercise researcher Nicholas Burd.
• Meeting your protein needs with plants rather than meat is better for your heart and the planet, but it might require a greater variety of foods (and maybe supplements).
• If you’re getting enough calories and eating a varied diet, you’re probably getting enough protein.
• For most people, unless you have kidney disease, too much protein won’t hurt you.

https://www.nature.com/articles/d41586-025-03632-1?utm_source=Live+...

Comment by Dr. Krishna Kumari Challa on November 13, 2025 at 9:45am

How Lung and Breast Cells Fight Cancer Differently

The study findings can help develop early-stage cancer prevention strategies.

Researchers have discovered why a specific mutation leads to tumorous growth in human lungs. The same mutation, however, fails to develop a tumor in human breasts, reducing the chances of a cancer.

They focused on the human epithelial tissues, the thin sheets of cells that line our vital organs. That’s because eighty percent of all human cancers begin in epithelial tissues. 

epithelial cells act as the body’s first barrier and are constantly exposed to stress, damage, and mutations. In fact, both the lung and the breast epithelial tissues display ‘epithelial defense against cancer’ — the epithelium’s natural act against tumorous cells. That’s why the group tested a specific cancerous mutation that occurs in both breast and lung epithelial tissues.

Researchers have long recognized that breast and lung epithelial tissues exhibit distinct differences. Breast epithelium is relatively stable and compact — the cells are tightly packed with stronger junctions. On the other hand, lung epithelium expands and relaxes with each breath, which is why its cells are more flexible, elongated, and loosely connected.

The group, through a combination of live imaging and computer models, has determined how these differences directly lead to the lung epithelium being more prone to growing tumors compared to the breast.

Once a cancerous mutation sets in the breast tissue, single mutant cells are pushed out, and groups of cells get stuck together. In lung tissue, the same mutant cells spread easily and make finger-like shapes.

The team found that the “tug-of-war” forces between normal and mutant cells decide whether cancerous cells are removed, trapped, or allowed to grow. Thus, cell mechanics help explain tissue-specific cancer risk. The surprise was how directly those mechanics determine whether mutant cells are restrained or allowed to spread.

A belt forms around the tumor in the breast epithelia, raises tension, jams the mutant cluster, and often forces out single mutants. Thus, this belt restrains the tumor.

In the lung epithelia, the cells are more elongated, motile, and weakly connected. So, no such belt forms, allowing the mutant cells to survive, grow longer, and spread into the tissue.

The group’s work demonstrates a pathway to resisting the growth of mutations into tumors, and eventually, into cancers. 

https://elifesciences.org/reviewed-preprints/106893v1

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