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Comment by Dr. Krishna Kumari Challa on April 24, 2025 at 9:17am

Scientists have found a way to 'tattoo' tardigrades

Tardigrades are clumsy, eight-legged creatures, nicknamed water bears, are about half a millimeter long and can survive practically anything: freezing temperatures, near starvation, high pressure, radiation exposure, outer space and more. Researchers reporting in the journal Nano Letters took advantage of the tardigrade's nearly indestructible nature and gave the critters tiny "tattoos" to test a microfabrication technique to build microscopic, biocompatible devices.

Through this technology,scientists are not just creating micro-tattoos on tardigrades—they are extending this capability to various living organisms, including bacteria.

Microfabrication has revolutionized electronics and photonics, creating micro- and nanoscale devices ranging from microprocessors and solar cells to biosensors that detect food contamination or cancerous cells. But the technology could also advance medicine and biomedical engineering, if researchers can adapt microfabrication techniques to make them compatible with the biological realm.

Researchers employed a process that carves a pattern with an electron beam into a thin layer of ice coating living tissue, called ice lithography, leaving behind a design when the remaining ice sublimates. And what creature is better suited to being frozen, coated in ice, and then exposed to an electron beam than the nearly indestructible tardigrade?

The team put tardigrades into a cryptobiotic state (a sort of half-dead, suspended animation) by slowly dehydrating the microscopic animals. Then, the researchers placed an individual tardigrade onto a carbon-composite paper, cooled the sheet below -226°F (-143°C), and covered the water bear with a protective layer of anisole—an organic compound that smells like anise. The frozen anisole protected the tardigrade's surface from the focused electron beam as it drew the pattern.  

When exposed to the beam, the anisole reacted and formed a new biocompatible chemical compound that stuck to the tardigrade's surface at higher temperatures. As the tardigrade warmed to room temperature under vacuum, any unreacted frozen anisole sublimated and left behind the pattern of reacted anisole. Finally, the researchers rehydrated and revived the tardigrade, which then sported a new tattoo.

The precision of this technique allowed the team to create a variety of micropatterns: squares, dots, and lines as small as 72 nanometers wide, and even the university's logo. About 40% of the tardigrades survived the procedure, and the researchers say that could be improved with further fine tuning. Most importantly, the tardigrades didn't seem to mind their new tattoos: Once rehydrated, they showed no changes in behavior. These results indicate that this technique could be suitable for printing micro-electronics or sensors onto living tissue.

It is challenging to pattern living matter, and this advance portends a new generation of biomaterial devices and biophysical sensors that were previously only present in science fiction. This work could enable advancements such as microbial cyborgs and other biomedical applications in the future.

Zhirong Yang et al, Patterning on Living Tardigrades, Nano Letters (2025). DOI: 10.1021/acs.nanolett.5c00378

Comment by Dr. Krishna Kumari Challa on April 23, 2025 at 11:03am

Antibiotic pollution in rivers follows 65% increase in human consumption, study shows

Human consumption of antibiotics increased by 65% between 2000 and 2015. These drugs are not completely metabolized while passing through the body, nor completely destroyed or removed by most wastewater treatment facilities.

Published in PNAS Nexus,  researchers calculate that worldwide humans consume around 29,200 tonnes of the 40 most used antibiotics. After metabolism and wastewater treatment, an estimated 8,500 tonnes (29% of consumption) may reach the world's river systems, and 3,300 tonnes (11%) may arrive at the world's oceans or inland sinks (such as lakes or reservoirs).

The authors calculate these figures using a model validated by data on measured concentrations of 21 antibiotics at 877 locations globally. While the total amounts of antibiotic residues translate into only very small concentrations in most rivers, which makes the drugs very difficult to detect, chronic environmental exposure to these substances can still pose a risk.

Antibiotics in rivers and lakes can reduce microbial diversity, increase the presence of antibiotic-resistant genes, and possibly impact the health of fish and algae. The authors calculate that levels of antibiotics are high enough to create a potential risk for aquatic ecosystems and antibiotic resistance during low-flow conditions (i.e., at times of less dilution) on 6 million kilometers of rivers.

Waterways with high concentrations are found across all continents, with the most impacted regions located in Southeast Asia. Amoxicillin is the antibiotic most often predicted to be found at high-risk concentrations and is the most-consumed antibiotic around the world.

The authors note that this version of their model does not include antibiotics given to livestock, which include many of the same drugs, or pharmaceutical manufacturing waste. However, the results show that antibiotic pollution in rivers arising from human consumption alone is a critical issue, which would likely be exacerbated by veterinary or industry sources of related compounds.

According to the authors, monitoring programs and strategies to manage antibiotic contamination of waterways, especially in areas at risk, are warranted.

Heloisa Ehalt Macedo et al, Antibiotics in the global river system arising from human consumption, PNAS Nexus (2025). DOI: 10.1093/pnasnexus/pgaf096

Comment by Dr. Krishna Kumari Challa on April 22, 2025 at 11:26am

Himalayan snow at 23-year low, threatening 2 billion people: report

Snowfall in Asia's Hindu Kush-Himalayan mountain range has reached a 23-year low, threatening nearly two billion people dependent on snowmelt for water, scientists warned in a report this week.

The Hindu Kush-Himalayan range, which stretches from Afghanistan to Myanmar, holds the largest reserves of ice and snow outside the Arctic and Antarctica and is a vital source of fresh water for about two billion people.

Researchers found "a significant decline in seasonal snow across the Hindu Kush Himalaya region, with snow persistence (the time snow remains on the ground) 23.6% below normal — the lowest in 23 years," the International Center for Integrated Mountain Development (ICIMOD) said.

"This trend, now in its third consecutive year, threatens water security for nearly two billion people," it said in its Snow Update Report.

The study also warned of "potential lower river flows, increased groundwater reliance, and heightened drought risk."

Several countries in the region have already issued drought warnings, with upcoming harvests and access to water at risk for populations already facing longer, hotter, and more frequent heatwaves.

The inter-governmental ICIMOD organization is made up of member countries Afghanistan, Bangladesh, Bhutan, China, India, Myanmar, Nepal and Pakistan.

It urged countries that rely on the 12 major river basins in the region to develop "improved water amangement, stronger drought preparedness, better early warning systems, and greater regional cooperation."

The Mekong and Salween basins -- the two longest rivers in Southeast Asia supplying water to China and Myanmar -- had lost around half of their snow cover, it noted.

Source: News Agencies

Comment by Dr. Krishna Kumari Challa on April 22, 2025 at 11:19am

Microplastics still slip through wastewater treatment plants, carrying pollutants and threatening long-term health

Despite advances in wastewater treatment, tiny plastic particles called microplastics are still slipping through, posing potential health and environmental hazards, according to new research.

Because plastic is inexpensive to produce yet lightweight and sturdy, manufacturers have found it ideal for use in nearly every consumer good, from food and beverage packaging to clothing and beauty products. The downside is that when a plastic item reaches the end of its useful life, it never truly disappears. Instead, it breaks down into smaller and smaller pieces called microplastics—particles five millimeters or less, about the width of a pencil eraser—that end up in our soil and water.

 Systematic literature review found  that while most waste water treatment facilities significantly reduce microplastics loads, complete removal remains unattainable with current technologies. The study is  published in Science of the Total Environment.

As a result, many microplastics are being reintroduced into the environment, likely transporting other residual harmful pollutants in wastewater, such the chemicals Bisphenols, PFAS and antibiotics. These microplastics and organic pollutants would exist in trace levels, but we can get exposure through simple actions like drinking water, doing laundry or watering plants, leading to potential long-term serious human health impacts such as cardiovascular disease and cancer.

The researchers  found that the effectiveness of treatments varies depending on the technology communities use and how microplastics are measured to calculate the removal rates.

Jenny Kim Nguyen et al, A review on microplastic fibers and beads in wastewater: The current knowledge on their occurrence, analysis, treatment, and insights on human exposure impact, Science of The Total Environment (2025). DOI: 10.1016/j.scitotenv.2025.178818

Comment by Dr. Krishna Kumari Challa on April 22, 2025 at 10:56am

New quantum-based navigation system 50 times more accurate than traditional GPS

A team of researchers has announced the successful demonstration of its newly developed quantum navigation system called "Ironstone Opal."

The group has written a paper describing how their system works and how well it tested against currently available backup GPS systems and has posted it on the arXiv preprint server.

With the advent and subsequent reliance on GPS by private and military vehicles and aircraft for navigation, governments have come to understand how vulnerable such systems can be. Outages can lead to drivers being stranded, pilots scrambling to use outdated systems and difficulties deploying military assets. I myself have faced these difficulties when I was stranded in the middle of roads and also wilderness.

Because of that, scientists around the world have been looking for reasonable backup systems, or even possible alternatives to GPS.

In this new effort, the team at Q-CTRL has developed such a backup system and is claiming that it is 50 times more accurate than any other backup GPS currently available under some scenarios.

The new system, Ironstone Opal, uses quantum sensors that are so sensitive they can be used to precisely self-locate an object using the Earth's magnetic field. The team at Q-CTRL noted that the magnetic field varies depending on location relative to the Earth. To take advantage of that, they built sensors that can precisely read the field and then use AI-based software to give X and Y geographic coordinates in the same fashion as GPS.

The researchers note that their system is passive, which means it does not emit signals that could be "heard" by other devices and cannot be jammed. They also note that their software system can filter out noise generated by vehicles or planes carrying the sensors. They point out that the system is small enough to be installed in any car, truck, or other land vehicle, as well as in drones and other aircraft.

Testing of the system on the ground, the researchers claim, showed it to be 50 times as accurate as any other GPS backup system. In the air, it was found to be 11 times more accurate than other backup systems..

 Murat Muradoglu et al, Quantum-assured magnetic navigation achieves positioning accuracy better than a strategic-grade INS in airborne and ground-based field trials, arXiv (2025). DOI: 10.48550/arxiv.2504.08167

Comment by Dr. Krishna Kumari Challa on April 21, 2025 at 10:06am

Cold welding is a solid-state welding process where metals bond without the need for heat, and it's a significant concern in space due to the vacuum environment. This phenomenon can cause malfunctions and even failures in spacecraft mechanisms, such as deployment issues and stuck mechanisms.
What it is:
Cold welding occurs when clean metal surfaces of the same material are brought into close contact under high pressure, even without heat or external agents.
In space, the vacuum environment removes the air that would normally form an oxide layer on the metal surface, allowing for a stronger bond to form.
This process can be problematic because it can lead to the formation of undesired bonds between moving parts, causing them to become stuck or malfunction.
How it affects space missions:
Deployment Issues:
Cold welding can cause mechanisms designed to deploy antennas, solar panels, or other structures to fail to deploy properly.
Stuck Mechanisms:
It can also lead to mechanisms becoming stuck in a closed or folded position, preventing them from functioning as intended.
Galileo High-Gain Antenna:
A notable example is the 1991 Galileo spacecraft, where the high-gain antenna failed to deploy fully due to cold welding, which caused the umbrella-shaped antenna ribs to bond in their folded configuration.
Wire Harnesses:
Cold welding can also affect wire harnesses, causing individual wires to bond together and increasing harness stiffness, potentially leading to wire breakage or electrical overload.
Mitigation Strategies:
Material Selection:
Using dissimilar metals or metals with low contact adhesion can help prevent cold welding.
Coatings:
Applying coatings that reduce the adhesion of surfaces can also be effective.
Lubrication:
Using appropriate lubricants can reduce friction and prevent the formation of cold welds.
Reduced Contact Area:
Reducing the contact area between moving parts can minimize the potential for cold welding.
Cleanliness:
Maintaining cleanliness and preventing contamination of surfaces can also help prevent cold welding.

Comment by Dr. Krishna Kumari Challa on April 21, 2025 at 10:04am

Cold welding, also known as cold pressure welding or contact welding, is a solid-state joining process that creates strong bonds between metals without heat. It relies on high pressure to deform the surfaces of the metals, bringing them into intimate contact and forming a strong metallurgical bond.
Here's a more detailed explanation:
How it works:
No Heat:
Unlike traditional welding, cold welding doesn't involve melting or heating the metals.
Pressure:
The process relies on applying high pressure to the joined surfaces, causing plastic deformation and forming a bond.
Solid State:
The metals remain in a solid state throughout the process.
Clean Surfaces:
The surfaces of the metals must be very clean and free of oxides or other contaminants for a strong bond to form.
Advantages:
No Heat Affected Zone (HAZ):
Because no heat is involved, there's no heat affected zone, which can alter the properties of the metal.
Strong Bonds:
Cold welding can create strong bonds that are often as strong as the parent metal.
Dissimilar Metals:
It can be used to join dissimilar metals.
Suitable for Sensitive Materials:
It's ideal for joining metals that are heat-sensitive, such as aluminum and copper, where traditional welding could compromise their properties.
Disadvantages:
Surface Preparation: Requires meticulous surface preparation to remove oxides and contaminants.
Limited to Ductile Metals: Best suited for ductile metals like aluminum, copper, and brass alloys.
High Pressure: Requires high pressure to create the bond, which can be expensive and challenging.
Not for Irregular Surfaces: Less effective on irregular surfaces.
Applications:
Joining Aluminum and Copper:
Widely used for joining these metals, especially in applications where heat is undesirable.
Aerospace and Electronics:
Important in industries where avoiding heat distortion is crucial, such as in aerospace and electronics.
Wire Joining:
Used for joining wires together.
Space Applications:
Can be used in space for joining parts in environments with no heat sources.

Comment by Dr. Krishna Kumari Challa on April 19, 2025 at 10:18am

Having this in mind, the researchers collected 205 samples of over 80 Rosa species, covering 84% of what is documented in the "Flora of China."

The samples were then analyzed using genomic sequencing, population genetics, and other methods to trace back their ancestral traits. They studied 707 single-copy genes uncovered as a set of conserved genetic markers like single-nucleotide polymorphisms—the most common type of genetic variation found in DNA—which helped them chart the evolutionary and geographical history and connections between the rose species.

Ancestral trait reconstruction showed that the shared ancestor of the studied samples was a yellow flower with a single row of petals and leaves divided into seven leaflets. As roses evolved and were domesticated, they developed new colors, distinct petal markings, and the ability to bloom in clusters.
The study also brought new insight to the widely accepted notion that the Rosa genus originated in Central Asia. The genetic evidence pointed to two major centers of rose diversity in China—one in the dry northwest, where yellow roses with small leaves grow, and another in the warm and humid southwest, where the white, fragrant variety thrives.

 Bixuan Cheng et al, Phenotypic and genomic signatures across wild Rosa species open new horizons for modern rose breeding, Nature Plants (2025). DOI: 10.1038/s41477-025-01955-5

Valéry Malécot, An evolutionary bouquet for roses, Nature Plants (2025). DOI: 10.1038/s41477-025-01971-5

Part 2

Comment by Dr. Krishna Kumari Challa on April 19, 2025 at 10:13am

Red, pink or white, all roses were once yellow says genomic analysis

Red roses, the symbol of love, were likely yellow in the past, indicates a large genomic analysis by researchers.

Roses of all colors, including white, red, pink, and peach, belong to the genus Rosa, which is a member of the Rosaceae family.

Reconstructing the ancestral traits through genomic analysis revealed that all the roads trace back to a common ancestor—a single-petal flower with yellow color and seven leaflets.

The findings are published in Nature Plants.

Accounting for almost 30% of the cut flower market sales, roses are the most widely cultivated ornamental plants and have been successfully domesticated to reflect the aesthetic preferences of each era.

It all began with the rose breeding renaissance in the 1700s, marked by the crossing of ancient wild Chinese roses and old European cultivars—plants selectively bred through human intervention to develop a desirable characteristic.

Currently, we have over 150 to 200 species of roses and more than 35,000 cultivars, displaying a wide range of blooming frequencies, fragrances, and colors. However, global climate change has prompted rose breeders to shift their focus from purely cosmetic traits to breeding rose varieties that are more resistant to stress factors like drought, disease and easier to care for.

Borrowing genetic resources from wild rose varieties, which offer valuable traits such as fragrance and disease resistance, presents a promising strategy for breeding resilient, low-maintenance rose cultivars.

A clear understanding of the origin and evolution of the Rosa genus, both wild and cultivated varieties, can not only advance the breeding efforts but also aid in the conservation of near-threatened rose varieties.

Part 1

Comment by Dr. Krishna Kumari Challa on April 18, 2025 at 10:15am

A PFO is usually harmless yet is known to increase the odds of stroke. The study aimed to determine which risk factors contribute the most to unexplained strokes.

The analysis found:

Traditional risk factors were more strongly associated with stroke in men and women without a PFO.
In contrast, nontraditional risk factors, such as blood clots in the veins, migraine with aura, chronic kidney disease, chronic liver disease or cancer, were more strongly associated with stroke among study participants with a PFO.
In those without a PFO, each additional traditional risk factor increased stroke risk by 41%, while each nontraditional risk factor increased stroke risk by 70%.
Risk factors related to women also increased stroke risk by 70% independent of traditional and nontraditional risk factors.
Among participants with a PFO, each traditional risk factor increased the risk of stroke by 18%. However, after considering individual demographic factors, such as age, sex and level of education, nontraditional risk factors more than doubled the odds of having an ischemic stroke.
Researchers also analyzed the study population's attributable risk (determining how a disease would be impacted if a certain risk factor were eliminated). To calculate population-attributable risk, researchers analyzed each risk factor and their contribution to the increased risk separately and found:

For strokes that occur without a PFO, traditional risk factors accounted for about 65% of the cases, nontraditional risk factors contributed 27% and risk factors specific to women made up nearly 19% of the cases.
In contrast, for strokes associated with a PFO, traditional risk factors contributed about 34%, nontraditional risk factors accounted for 49% and female-specific risk factors represented about 22%.
Notably, migraine with aura was the leading nontraditional risk factor associated with strokes of unknown origin, with a population-attributable risk of about 46% for strokes among people with a PFO and about 23% for those without a PFO, indicating a higher risk for people with PFO.
The role of non-traditional risk factors, especially migraine headaches, which seems to be one of the leading risk factors in the development of strokes in younger adults, is a new revelation.

Burden of Modifiable Risk Factors in YoungOnset Cryptogenic Ischemic Stroke by High-Risk Patent Foramen Ovale, Stroke (2025). DOI: 10.1161/STROKEAHA.124.049855

Part 2

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