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Comment by Dr. Krishna Kumari Challa on February 6, 2025 at 11:23am

Antibiotic resistance can spread unpredictably into the environment, living on mineral surfaces

Imagine one of world's many picturesque beaches, the waves lapping against the shore, the golden sand and the smooth pebbles. That sounds like a beautiful moment in time. But under the surface, there is more to the story.

A new study, published in Science of The Total Environment,  shows that the sand on that beach may contain antibiotic resistant DNA. Flow and currents in rivers, lakes, streams and the sea, suspend and move mineral particles making it possible for suspended DNA to attach and travel long distances.

The DNA that codes for antibiotic resistance may have been carried into the environment by wastewater from hospitals or farming. If left alone in the water column, the DNA will degrade fast, but if it binds to bypassing mineral surfaces the DNA can be stabilized and survive. Deposited minerals can thus act as a sort of gene library carrying genes from one environment to another, and this may cause antibiotic resistance to spread.

Even though the DNA is bound to the particles, local bacteria can incorporate the DNA and become resistant. Once incorporated, the resistance can spread rapidly to neighboring bacteria and to offspring. In this way, antibiotic resistance can spread unpredictably to new environments—even though these bacteria have never seen a high-resistance environment.

According to the new study, the type of mineral plays a large role for how fast bacteria can incorporate mineral-bound DNA and how fast the obtained trait is disseminated throughout a community. In addition, some mineral grains can both up-concentrate and preserve DNA, while others can only carry a few molecules.

The researchers hope to be able to find an antidote of sorts, a mineral compound that can prevent bacteria from incorporating the DNA or the DNA from spreading in biofilm.

Saghar Hendiani et al, Reconciling the role of mineral surfaces for bacterial evolution: Importance of minerals in the dissemination of antibiotic resistance, Science of The Total Environment (2025). DOI: 10.1016/j.scitotenv.2024.178301

Comment by Dr. Krishna Kumari Challa on February 6, 2025 at 11:16am

Active agent against cancer metastasis discovered: Adhibin prevents migration and attachment to other cells

Every cell in the body normally has its fixed place as part of a tissue structure. Except for a few cell types, such as blood or immune cells. But cancer cells also cross established boundaries, grow into the surrounding tissue and multiply. And they can detach from the cell structure and spread via the blood or lymphatic vessels to other areas of the body, where they attach to new cells and form metastases.

The changes that cancer cells undergo to metastasize are not yet fully understood. Rho (Ras-homologous) GTPases apparently play an important role. These proteins process signals within cells and regulate, among other things, growth, differentiation into the genetically predetermined cell type and cell migration.

Rho GTPases are molecular switches that switch between an active and an inactive state by binding to the phosphate compounds GTP and GDP. GTP corresponds to the 'on' position of the switch and starts the molecular biological processes, while GDP corresponds to the 'off' position and stops them.

A balancing act for the cell: if these Rho proteins are too numerous or too active due to genetic changes, they can cause serious damage to cellular growth and differentiation processes and trigger cancer, for example.

A research team has now found a substance that intervenes in a specific step of the complex Rho signaling pathways and not only prevents tumor cells from forming solid cell clusters but also from actively migrating.

This intervention can be used to prevent the formation of metastases. The results of the research have been published in Nature Communications.

Despoina Kyriazi et al, An allosteric inhibitor of RhoGAP class-IX myosins suppresses the metastatic features of cancer cells, Nature Communications (2024). DOI: 10.1038/s41467-024-54181-6

Comment by Dr. Krishna Kumari Challa on February 6, 2025 at 10:36am

 How RNA travels between cells to control genes across generations

RNA-based medicines are one of the most promising ways to fight human disease, as demonstrated by the recent successes of RNA vaccines and double-stranded RNA (dsRNA) therapies. But while health care providers can now successfully develop drugs that use dsRNA to accurately target and silence disease-causing genes, a major challenge remains: getting these potentially life-saving RNA molecules into cells efficiently.

A new study published in the journal eLife on February 4, 2025, may lead to breakthroughs in RNA-based drug development.

Researchers used microscopic roundworms as a model to investigate how dsRNA molecules naturally enter cells and influence many future generations. The team discovered multiple pathways for dsRNA to enter the worms' cells—a finding that could help improve drug delivery methods in humans.

Researchers learned that RNA molecules can carry specific instructions not just between cells but across many generations, which adds a new layer to our current understanding of how inheritance works.

The researchers  found that a protein called SID-1, which acts as a gatekeeper for the transfer of information using dsRNA, also has a role in regulating genes across generations.

When researchers removed the SID-1 protein, they observed that the worms unexpectedly became better at passing changes in gene expression to their offspring. In fact, these changes persisted for over 100 generations—even after SID-1 was restored to the worms.

Interestingly, you can find proteins similar to SID-1 in other animals, including humans. Understanding SID-1 and its role has significant implications for human medicine. If we can learn how this protein controls RNA transfer between cells, we could potentially develop better targeted treatments for human diseases and perhaps even control the inheritance of certain disease states.

The research team also discovered a gene called sdg-1 that helps regulate "jumping genes"—DNA sequences that tend to move or copy themselves to different locations on a chromosome. While jumping genes can introduce new genetic variations that may be beneficial, they are more likely to disrupt existing sequences and cause disease.

The researchers found that sdg-1 is located within a jumping gene but produces proteins that are used to control jumping genes, creating a self-regulating loop that could prevent unwanted movements and changes.

It's fascinating how these cellular mechanisms maintain this delicate balance, like a thermostat keeping a house at just the right temperature so it isn't too warm or too cold. The system needs to be flexible enough to allow some 'jumping' activity while preventing excessive movements that could harm the organism.

These findings  provide valuable insights into how animals regulate their own genes and maintain stable gene expression across generations. Studying these mechanisms could potentially pave the way for innovative future treatments for heritable diseases in humans.

 Nathan M Shugarts Devanapally et al, Intergenerational transport of double-stranded RNA in C. elegans can limit heritable epigenetic changes, eLife (2025). DOI: 10.7554/eLife.99149.3

Comment by Dr. Krishna Kumari Challa on February 6, 2025 at 10:06am

Why antibiotics can fail even against non-resistant bacteria

Antibiotics are indispensable for treating bacterial infections. But why are they sometimes ineffective, even when the bacteria are not resistant? In their latest study published in the journal Nature, researchers challenge the conventional view that a small subset of particularly resilient bacteria are responsible for the failure of antibiotic therapies.

In certain infectious diseases caused by bacteria, antibiotics are less effective than expected. One example is infections caused by Salmonella bacteria, which can lead to illnesses such as typhoid fever. For many years, researchers believed that a small subset of dormant bacteria was the main problem in fighting infections.

These so-called persisters can survive antibiotic treatment and cause relapses later. Researchers worldwide have been working on new therapies aimed at targeting and eliminating these "sleeping" bacteria.

In a new study,  scientists challenge the prevailing concept that persisters are the cause of antibiotic ineffectiveness.

Contrary to widespread belief, antibiotic failure is not caused by a small subset of persisters. In fact, the majority of Salmonella in infected tissues are difficult to kill. Scientists have been able to demonstrate that standard laboratory tests of antimicrobial clearance produce misleading results, giving a false impression of a small group of particularly resilient persisters.

Nutrient starvation increases Salmonella resilience

The researchers investigated antimicrobial clearance in both Salmonella-infected mice and tissue-mimicking laboratory models. The body's defense mechanisms against bacteria often include reducing the availability of nutrients. The researchers have now revealed that, in fact, this nutrient starvation is the main reason for Salmonella bacteria surviving treatments with antibiotics. The researchers assume that the same applies to other bacterial pathogens.

Under nutrient-scarce conditions, bacteria grow very slowly. This may seem good at first, but it is actually a problem because most antibiotics only gradually kill slowly growing bacteria. As a result, the drugs are much less effective, and relapses can occur even after prolonged therapy.

The scientists used an innovative method to monitor antibiotic action in single bacteria in real time. They demonstrated that nearly the entire Salmonella population survives antibiotic treatment for extended periods, not just a small subset of hyper-resilient persisters.

Joseph Fanous et al, Limited impact of Salmonella stress and persisters on antibiotic clearance, Nature (2025). DOI: 10.1038/s41586-024-08506-6. www.nature.com/articles/s41586-024-08506-6

Comment by Dr. Krishna Kumari Challa on February 6, 2025 at 9:56am

AI bias shapes everything from hiring to health care

Generative AI tools like ChatGPT, DeepSeek, Google's Gemini and Microsoft's Copilot are transforming industries at a rapid pace. However, as these large language models become less expensive and more widely used for critical decision-making, their built-in biases can distort outcomes and erode public trust.

Researchers published a study emphasizing the urgent need to address bias by developing and deploying ethical, explainable AI. This includes methods and policies that ensure fairness and transparency and reduce stereotypes and discrimination in LLM applications.

Xiahua Wei et al, Addressing bias in generative AI: Challenges and research opportunities in information management, Information & Management (2025). DOI: 10.1016/j.im.2025.104103

Comment by Dr. Krishna Kumari Challa on February 6, 2025 at 9:52am

Electric vehicle batteries can last almost 40% longer in the real world than in lab tests

When we see "tested under laboratory conditions," we often assume real-world conditions will lead to faster degradation of a product.

But experts from Stanford University have found the opposite is true for electric vehicle (EV) batteries. Their new research shows traditional laboratory testing leads to faster degradation, while real-world use gives substantially more battery life, extending the lifespan of the entire EV. Researchers found the stop-start way we drive and the variable rate the battery discharges power actually prolongs battery life by up to 38% compared to traditional tests.

This is good news for EV drivers—and for efforts to electrify transport. This extra battery life would translate to more than 300,000 more kilometers an EV could drive before needing battery replacement, the researchers say.

Longer-lasting batteries would reduce the total cost of EV ownership—and benefit the environment by getting more use out of each battery.

https://www.nature.com/articles/s41560-024-01675-8

Comment by Dr. Krishna Kumari Challa on February 6, 2025 at 9:26am

Top climate scientists declare 2C climate goal 'dead'

Pathetic! The world is failing to recognize this catastrophe, acting on the warning of climate scientists and stopping it. 

Holding long-term global warming to two degrees Celsius—the fallback target of the Paris climate accord—is now "impossible," according to a stark new analysis published by leading scientists.

Led by renowned climatologist James Hansen, the paper appears in the journal Environment: Science and Policy for Sustainable Development and concludes that Earth's climate is more sensitive to rising green house gas emissions than previously thought.

Compounding the crisis, Hansen and colleagues argued, is a recent decline in sunlight-blocking aerosol pollution from the shipping industry, which had been mitigating some of the warming.

An ambitious climate change scenario outlined by the UN's climate panel, which gives the planet a 50 percent chance of keeping warming under 2C by the year 2100, "is an implausible scenario," the scientists say.

"That scenario is now impossible, the two degree target is dead."

Instead, the scientists argued, the amount of greenhouse gases already pumped into the atmosphere by burning fossil fuels meant increased warming is now guaranteed.

Temperatures will stay at or above 1.5C in the coming years—devastating coral reefs and fueling more intense storms—before rising to around 2.0C by 2045, they forecast.

They estimated polar ice melt and freshwater injection into the North Atlantic will trigger the shutdown of the Atlantic Meridional Overturning Circulation (AMOC) within the next 20-30 years.

The current brings warmth to various parts of the globe and also carries nutrients necessary to sustain ocean life.

Its end "will lock in major problems including sea level rise of several meters—thus, we describe AMOC shutdown as the 'point of no return,'" the scientists argued in their paper.

The world's nations agreed during the landmark Paris climate accord of 2015 to try to hold end-of-century warming to 1.5C above pre-industrial levels.

Scientists identified the threshold as critical to preventing the breakdown of major ocean circulation systems, the abrupt thawing of boreal permafrost, and the collapse of tropical coral reefs.

The 1.5C target has already been breached over the past two years, according to data from the EU's climate monitoring system Copernicus, though the Paris Agreement referred to a long-term trend over decades.

At 2C, the impacts would be even greater, including irreversible loss to Earth's ice sheets, mountain glaciers and snow, sea ice and permafrost.

The authors acknowledged the findings appeared grim, but argued that honesty is a necessary ingredient for change.

Failure to be realistic in climate assessment and failure to call out the fecklessness of current policies to stem global warming is not helpful to young people," they said.

But is the world listening?

James E. Hansen et al, Global Warming Has Accelerated: Are the United Nations and the Public Well-Informed?, Environment: Science and Policy for Sustainable Development (2025). DOI: 10.1080/00139157.2025.2434494

Comment by Dr. Krishna Kumari Challa on February 6, 2025 at 8:27am

Compact camera can identify objects at the speed of light

Researchers recently  have produced some eye-popping research, including shrinking a camera down to the size of a grain of salt while still capturing crisp, clear images.

Building on this work they, published a paper in Science Advances that describes a new kind of compact camera engineered for computer vision—a type of artificial intelligence that allows computers to recognize objects in images and video.

Their research prototype uses optics for computing, significantly reducing power consumption and enabling the camera to identify objects at the speed of light. Their device also represents a new approach to the field of computer vision.

Instead of using a traditional camera lens made out of glass or plastic, the optics in this camera relies on layers of 50 meta-lenses—flat, lightweight optical components that use microscopic nanostructures to manipulate light. The meta-lenses also function as an optical neural network, which is a computer system that is a form of artificial intelligence modeled on the human brain.

This unique approach has a couple of key advantages. First, it's fast. Because much of the computation takes place at the speed of light, the system can identify and classify images more than 200 times faster than neural networks that use conventional computer hardware, and with comparable accuracy. Second, because the optics in the camera rely on incoming light to operate, rather than electricity, the power consumption is greatly reduced.

Kaixuan Wei et al, Spatially varying nanophotonic neural networks, Science Advances (2024). DOI: 10.1126/sciadv.adp0391

Comment by Dr. Krishna Kumari Challa on February 6, 2025 at 7:15am

Kids use different math skills at work vs. school, India study shows

In India, many kids who work in retail markets have good math skills. They can quickly perform a range of calculations to complete transactions. But as a new study shows, these kids often perform much worse on the same kinds of problems as they are taught in the classroom. This happens even though many of these students still attend school or attended school through 7th or 8th grades.

Conversely, the study also finds, Indian students who are still enrolled in school and don't have jobs do better on school-type math problems, but they often fare poorly at the kinds of problems that occur in marketplaces.

Overall, both the "market kids" and the "school kids" struggle with the approach the other group is proficient in, raising questions about how to help both groups learn math more comprehensively.

For the school kids, they do worse when you go from an abstract problem to a concrete problem. For the market kids, it's the opposite.

Indeed, the kids with jobs who are also in school "underperform despite being extraordinarily good at mental math".

The paper, "Children's arithmetic skills do not transfer between applied and ac...," is published in Nature.

So why might the performance of the nonworking students decline when given a problem in market conditions?

"They learned an algorithm but didn't understand it!"

Meanwhile, the market kids seemed to use certain tactics to handle retail transactions. For one thing, they appear to use rounding well. Take a problem like 43 times 11. To handle that intuitively, you might multiply 43 times 10, and then add 43, for the final answer of 473. This appears to be what they are doing.

The market kids are able to exploit base 10, so they do better on base 10 problems.

The school kids have no idea. It makes no difference to them. The market kids may have additional tricks of this sort.

 On the other hand, the school kids had a better grasp of formal written methods of division, subtraction, and more.

Finding a way to cross the divide between informal and formal ways of tackling math problems, then, could notably help some Indian children.

The fact that such a divide exists, meanwhile, suggests some new approaches could be tried in the classroom, say the researchers.These findings highlight the importance of educational curricula that bridge the gap between intuitive and formal mathematics.

Now I know why I  get confused with calculations when I visit the markets.

Esther Duflo, Children's arithmetic skills do not transfer between applied and academic mathematics, Nature (2025). DOI: 10.1038/s41586-024-08502-w. www.nature.com/articles/s41586-024-08502-w

Comment by Dr. Krishna Kumari Challa on February 6, 2025 at 7:06am

Generally, things really do seem better in the morning, large study suggests

Generally, things really do seem better in the morning, with clear differences in self-reported mental health and well-being across the day, suggest the findings of a large study published in the open access journal BMJ Mental Health.

People generally wake up feeling in the best frame of mind in the morning, but in the worst around midnight, the findings indicate, with day of the week and season of the year also playing their part.

Mental health and well-being are dynamic in nature, and subject to change over both short and extended periods, note the researchers. But relatively few studies have looked at how these might change over the course of the day, and those studies that have, have included particular, or only small, groups.

The researchers therefore wanted to explore whether time of day was associated with variations in mental health (depressive and/or anxiety symptoms), happiness (hedonic well-being), life satisfaction, sense of life being worthwhile (eudemonic well-being) and loneliness (social well-being). They also wanted to find out if these associations varied by day, season, and year. They analyzed data from the University College London COVID-19 Social Study, which began in March 2020, and involved regular monitoring until November 2021, and then additional monitoring up to March 2022.

All studied aspects were measured via questionnaires using validated assessment tools or through single direct questions.

Analysis of the data revealed a clear pattern in self-reported mental health and well-being across the day, with people generally waking up in the morning feeling best—lowest depressive/anxiety symptoms and loneliness and highest happiness, life satisfaction, and worthwhile ratings—and feeling worst around midnight.

The influence of day of the week was less clear-cut, with more variation in mental health and well-being during weekends than on weekdays.

Happiness, life satisfaction, and worthwhile ratings were all higher on Mondays and Fridays than on Sundays, and happiness was also higher on Tuesdays. But there was no evidence that loneliness differed across days of the week.

There was clear evidence of a seasonal influence on mood, however. Compared with winter, people tended to have lower levels of depressive and anxiety symptoms and loneliness, and higher levels of happiness, life satisfaction, and feeling that life was worthwhile in other seasons.

And mental health was best in the summer across all outcomes. But the season didn't affect the associations observed across the day, however.

Mental health and well-being also steadily improved from 2020, the first year of the COVID-19 pandemic.

This is an observational study, and as such, can't establish cause. 

Will things feel better in the morning? A time-of-day analysis of mental health and wellbeing from nearly 1 million observations, BMJ Mental Health (2025). DOI: 10.1136/bmjment-2024-301418

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