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Comment by Dr. Krishna Kumari Challa on May 22, 2026 at 9:42am

Why some antibiotics fail in the body—pH conditions can dramatically change how bacteria respond

When researchers test whether an antibiotic will work, they usually do so in a controlled laboratory environment. But when an infection happens inside the human body, things aren't so clean and tidy. New research found that even a slight change in acidity may dramatically shift how bacteria respond to treatment.
The study is centered around Klebsiella pneumoniae, a major cause of deadly infections and one of the world's most antibiotic-resistant pathogens.

Klebsiella pneumoniae exhibits up to 64-fold increased resistance to beta-lactam antibiotics under mildly acidic conditions (pH 5), due to the expression of alternative cell wall synthesis proteins (PBP2PARA, PBP3PARA, and PBP1b). Silencing these proteins reduces resistance, indicating their critical role in antibiotic survival at low pH. These findings highlight the need to assess antibiotic efficacy under physiologically relevant conditions.
Researchers set out to learn what happens to antibiotic resistance when K. pneumoniae grows in mildly acidic conditions like those found in parts of the human body during an active infection. What they found was that when grown at a pH of 5, the bacterium became up to 64 times more resistant to beta-lactam antibiotics, the most widely prescribed treatment for infections.

These beta-lactams work by shutting down the cell wall-building proteins in the bacterium known as PBPs. Without these, the bacterium can't properly construct its cell wall or divide, and it eventually dies. However, in addition to these PBPs made at neutral pH, it appears that K. pneumoniae has a reserve team ready to step up when conditions get acidic.
K. pneumoniae has a backup set of cell wall-building proteins that come online as the cell enters, in this case, an acidic environment.
PBP2PARA and PBP3PARA are duplicate copies of essential cell wall synthesis genes, and when conditions turn acidic, these alternate versions of cell building and division proteins are expressed.

This was surprising, given that past research on pathogen resistance had been done on a model organism, E. coli, which does not have a backup team of proteins. "This sets up a lot of implications for reevaluating and rethinking how we're assessing antibiotic resistance in pathogens.
Additionally, they identified another duplicate cell wall synthesis protein, PBP1b, whose activity appeared to be important for stress response during growth at low pH. These results suggest that these duplicate proteins may be important for helping the bacterium survive against antibiotic treatments under acidic conditions.
To confirm this, researchers silenced these proteins and they found that when these proteins weren't made, the cell lost much of its antibiotic resistance. PBP1b and PBP3PARA make the most impact on resistance, so their presence is most critical to the cell at low pH.

In the face of antibiotic resistance, these findings offer a warning and a potential path forward.

Sarah Beagle et al, Acid-dependent beta-lactam resistance in Klebsiella pneumoniae is mediated by paralogous class B PBPs and the class A PBP, PBP1b, mBio (2026). DOI: 10.1128/mbio.00092-26

Comment by Dr. Krishna Kumari Challa on May 22, 2026 at 9:33am

Wildlife is watching us, too—and changing behaviour in response

Analysis of GPS-tracked movements of 37 bird and mammal species across the U.S., combined with mobile phone and satellite data, shows that over 65% of species alter their behaviour in response to human presence, with effects varying by species and habitat context. Some animals reduced their range to avoid humans, while others expanded it or exploited human-associated resources. These findings indicate that both habitat alteration and direct human presence influence wildlife, suggesting conservation strategies should address not only habitat loss but also the timing and intensity of human activity.

Ruth Y. Oliver et al, Interacting effects of human presence and landscape modification on birds and mammals, Science (2026). DOI: 10.1126/science.adq3396. www.science.org/doi/10.1126/science.adq3396

Comment by Dr. Krishna Kumari Challa on May 22, 2026 at 9:28am

Decades after Chernobyl disaster, this radioactive landscape has become one of wildlife's most unlikely strongholds
Today (May 22nd) we are celebrating the International Day for Biological Diversity 2026

The Chernobyl Exclusion Zone and adjacent protected areas, with minimal human activity, exhibit the highest mammal diversity and occupancy rates, including rare and endangered species. Large, strictly protected zones provide superior refuge for wildlife compared to smaller parks or unprotected areas, highlighting the significant positive impact of reduced human disturbance on biodiversity.

There are nearly 8 million species on our planet, yet around 15,000 of them are now threatened with extinction. Even more alarming is the speed at which this is happening. Species today are disappearing at a rate estimated to be 1,000 to 10,000 times higher than the natural extinction rate—in other words, the pace at which species would have vanished if humans weren't here.

It is well documented that human activities and changes in land use for agriculture, industrialization, and urbanization have destroyed several habitats, leading to a decline in biodiversity. Establishing protected areas is a sound way to protect vulnerable species and preserve biodiversity. Compared to unprotected regions, these special zones experience far less human disturbance, reducing stressors such as hunting, habitat loss, and human-animal interactions, allowing ecosystems to recover and thrive.
Some areas are deliberate PAs, while others are devoid of human establishments due to natural or man-made disasters such as the CEZ.

The researchers in this study explored a vast area of about 60,000 km² in northern Ukraine to see how different levels of PAs—CEZs, nature reserves, national parks, and areas with no legal protection—affected where large animals live. They set up 174 motion-sensing camera traps to capture images of wildlife residents in the area and analyzed the images using mathematical tools such as Bayesian occupancy models to estimate occupancy and detection probabilities.

The results revealed that the CEZ and its nearby natural reserve have transformed into an excellent refuge for endangered and shy wildlife. The number and variety of animals in the region were much higher than in smaller parks, owing to the region's strict human-entry rules.

Svitlana Kudrenko et al, The Chornobyl Exclusion Zone as a wildlife refuge: restricted human access shaped mammal recolonization, Proceedings of the Royal Society B: Biological Sciences (2026). DOI: 10.1098/rspb.2025.3151

Comment by Dr. Krishna Kumari Challa on May 22, 2026 at 9:21am

How does gold keep its glitter? Researchers uncover why it resists tarnish

Gold has been prized for thousands of years for its enduring shine, but researchers have discovered that gold's resistance to tarnishing depends on more than its chemistry.

In a new study published in Physical Review Letters, researchers found that atoms on certain gold surfaces naturally rearrange themselves into protective patterns that dramatically suppress reactions with oxygen.

The discovery helps explain why gold jewelry and other gold objects can remain untarnished for centuries—and could also point the way toward designing more effective gold-based catalysts for industrial and energy-related applications.

Using computer simulations that predict how atoms and electrons behave, the researchers studied how oxygen molecules interact with two common gold surface structures. They found that without this atomic rearrangement, oxygen molecules could break apart and react with gold much more easily.

Instead, the rearranged surfaces suppress oxygen reactions by a factor of a billion to a trillion, essentially creating a protective atomic-scale barrier that helps gold stay shiny indefinitely.

The findings offer a new explanation for one of gold's best-known properties while also opening the door to potential advances in catalysis.

Anonymous, Role of reconstruction in the inertness of gold towards oxygen, Physical Review Letters (2026). DOI: 10.1103/g3bc-t1qv

Comment by Dr. Krishna Kumari Challa on May 22, 2026 at 9:16am

Extraterrestrial life may be slipping past space missions, astrobiologists warn

Current astrobiological detection methods risk false-negative results, potentially missing existing extraterrestrial life due to preservation issues, detection limitations, and insufficiently targeted research strategies. Overlooking such evidence may deprioritize promising environments and lead to premature resource exploitation, risking irreversible loss of undiscovered life. Improved strategies integrating laboratory, modeling, fieldwork, and AI-driven pattern recognition are needed to minimize these risks.

False negatives in the search for extraterrestrial life, Nature Astronomy (2026). DOI: 10.1038/s41550-026-02863-0

Comment by Dr. Krishna Kumari Challa on May 22, 2026 at 9:08am

Common food preservatives linked to high blood pressure and heart disease

Food preservatives are used in hundreds of thousands of industrially processed foods. Experimental studies suggest that some preservative food additives may be harmful to cardiovascular health.

Eating foods that contain common preservative food additives may increase the risks of high blood pressure and cardiovascular disease, according to research published in the European Heart Journal.

Researchers carried out detailed analyses of the ingredients of all the food and drink, including any preservatives. They also tracked the volunteers' health for an average of seven to eight years to see if they develop high blood pressure or any cardiovascular disease.

Researcher found that 99.5% of the volunteers had consumed at least one food preservative within the first two years of taking part.

Overall, they found that people who ate the largest amounts of "non-antioxidant" preservatives had a 29% higher risk of hypertension, compared to those who ate the least, and a 16% higher risk of cardiovascular disease, including heart attack, stroke, and angina. People who ate the most antioxidant preservatives had a 22% higher risk of hypertension.

Non-antioxidant preservatives are designed to stop harmful microbes, such as mold and bacteria, from growing, whereas antioxidant preservatives are designed to stop oxidation which means the food will not turn brown or become rancid.

Researchers also looked at 17 of the most commonly eaten preservatives and found that eight of these were specifically linked to high blood pressure. These were: potassium sorbate (E202), potassium metabisulphite (E224), sodium nitrite (E250), ascorbic acid (E300), sodium ascorbate (E301), sodium erythorbate (E316), citric acid (E330) and extracts of rosemary (E392). Ascorbic acid (E300) was also specifically linked to cardiovascular disease.

The findings are based on highly detailed data, and the researchers have taken account of other factors that can increase or lower the risk of cardiovascular disease. Experimental research in the literature consistently suggested that preservatives may cause oxidative stress in the body or affect the way the pancreas works.

These results suggest we need a re-evaluation of the risks and benefits of these food additives by the authorities in charge for better consumer protection.

These findings support existing recommendations to favour non-processed and minimally processed foods, and avoid unnecessary additives.

Preservative food additives, hypertension, and cardiovascular diseases: the NutriNet-Santé study, European Heart Journal (2026). DOI: 10.1093/eurheartj/ehag308

Comment by Dr. Krishna Kumari Challa on May 22, 2026 at 8:54am

Quantum supremacy just ran into an unexpected rival: An ordinary laptop armed with new math

Using a conventional computer and cutting-edge mathematical tools and code, physicists have cracked a daunting quantum physics problem previously claimed to be solvable only by quantum computers.

The technique is so ground-breaking in its efficiency that the researchers were even able to use a personal laptop to solve the problem.

By enabling scientists to squeeze extra problem-solving power from classical computers, the breakthrough methodology is opening new avenues for research on quantum dynamics and may be useful as a protocol for solving problems about finding the optimal solution amid an abundance of feasible ones.

The problem at hand involves simulating a quantum system composed of hundreds of interacting "qubits"—the quantum computing equivalent of the bits used in classical computers—arranged in square, cubic, or diamond lattices. While bits can have values of 0 or 1, qubits can exist in a superposition of multiple values, making it challenging for traditional computers to simulate their dynamics.

The research team  achieved their breakthrough by developing and implementing new tools based on tensor networks. The tensor networks made the problem feasible for classical computers. The team ran many of their simulations using relatively modest computational resources.

Despite using only modest computational hardware, the researchers demonstrated that their simulations yielded state-of-the-art accuracies. The simulations converged on solutions that matched theoretical predictions and provided accurate results when applied to smaller test problems. The results also agreed with those reported by the quantum computing researchers—but with no quantum computer required.

Joseph Tindall et al, Dynamics of disordered quantum systems with two- and three-dimensional tensor networks, Science (2026). DOI: 10.1126/science.adx2728. www.science.org/doi/10.1126/science.adx2728

Comment by Dr. Krishna Kumari Challa on May 22, 2026 at 8:40am

Astronomers have discovered the tiniest odd radio circle

Astronomers have identified a possible new member of one of astronomy's strangest classes of objects: Odd radio circles (ORCs), enormous ring-like structures visible only at radio wavelengths. The newly discovered source, J1248+4826, appears to be the most compact ORC candidate identified so far, with a ring only about 30,000 parsecs across. The paper was posted to the arXiv preprint server on May 6.

First reported in 2021, odd radio circles are faint ring-shaped radio emissions that are not detected at other wavelengths. They typically have a massive early-type galaxy with hundreds of billions of solar masses at their center, existing somewhere when the universe was roughly 8–11 billion years old. They span hundreds of kiloparsecs across.

Where they come from is still an open question. Leading ideas include remnants of magnetized plasma ejected roughly a billion years ago by a supermassive black hole, a past starburst episode, merging galaxy groups, or large-scale active galactic nuclei-driven outflows.

This newly discovered one  is a radio ring surrounded by a faint diffuse envelope, located very close to a galaxy group as seen when the universe was 11.2 billion years old.

The team's analysis revealed that the ring's radius is about 9 arcseconds, which corresponds to only 30 kiloparsecs physically. This is well below the previously reported radii of the ring-structure of ORCs, which range from 44 to 365 kiloparsecs. The surrounding diffuse envelope, extending to roughly 100 kiloparsecs, is more in line with the other members of the population.

Despite its compact size, the structure shares many of the same radio properties as previously known ORCs. However, unlike other ORCs that have their host galaxy at their center, this structure's host galaxy was found not at the center but at the edge.

M. Polletta et al, A Compact Radio Ring with a Diffuse Envelope in LOFAR: Odd Radio Circle or Distinct Phenomenon?, arXiv (2026). DOI: 10.48550/arxiv.2605.05174

Comment by Dr. Krishna Kumari Challa on May 21, 2026 at 12:12pm

Dissolved oxygen is very different from the oxygen atoms that pair with a hydrogen to form water. Dissolved oxygen is what aquatic life needs to 'breathe': that goes for animals, plants, plankton, bacteria, and anything else living underwater.

But the bonds that keep oxygen gas dissolved in water are relatively weak. Just a slight shift in temperature is enough to rip them apart, allowing the oxygen to escape.

https://www.science.org/doi/10.1126/sciadv.aef3132

Part 2

Comment by Dr. Krishna Kumari Challa on May 21, 2026 at 12:10pm

80% of Earth's Rivers Are Quickly Losing Oxygen, Study Reveals

Oxygen levels have decreased in almost 80 percent of rivers worldwide, and they're going to continue losing this precious resource unless we make some serious changes.

Satellite and climate data collected between 1985 and 2023 reveal that over 16,000 rivers across the world have been losing their dissolved oxygen.

On average, these rivers have been losing 0.045 milligrams of oxygen per liter each decade.

Without enough dissolved oxygen essential to sustain life underwater, rivers – and the communities that rely on their water and resources – are under serious threat.

By the end of the century, assuming carbon dioxide emissions continue to rise at similar rates (as opposed to some of the worst-case scenarios), rivers across most of South America, India, the Arctic, and the Eastern United States are expected to lose around 10 percent of their dissolved oxygen.

The most severe shifts so far have occurred in tropical rivers, such as the Ganges in India and the Amazon River in South America. The Ganges River in particular is losing oxygen 20 times faster than the global average.

Scientists didn't see this coming. Previously, they assumed that high-latitude rivers would experience the worst deoxygenation because these regions are climate change hotspots.
But tropical rivers had a disadvantage from the start: Since their waters were already warmer, they already had lower levels of dissolved oxygen. This means they're already closer to reaching hypoxia (insufficient oxygen to sustain most life).

Climate change driven by human activities is reducing oxygen solubility (the ability of a body of water to hold dissolved oxygen). According to the new study, oxygen solubility accounts for about 63 percent of global river deoxygenation.

Water temperature is most likely driving this change in oxygen solubility. Warmer waters hold less dissolved oxygen because the oxygen and water molecules are receiving more energy in the form of heat.
Part 1

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