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Comment by Dr. Krishna Kumari Challa on February 26, 2025 at 11:27am

Street dogs like yellow colour: 

Indian street dogs show strong preference for yellow bowls, even empty ones

A team of animal behaviorists at the Indian Institute of Science Education & Research in India has found that street dogs living in that country prefer eating from yellow bowls to those of other colors. Their paper is published in the journal Animal Cognition.

Prior research has shown that dogs have just two types of cone photoreceptors in their eyes compared to the three in humans. This means that they don't see colors the same way. Dogs see the difference between blue and yellow, for example, but other colors such as green, orange and red appear to them as muted shades of gray or yellow. This means that for dogs, the color yellow stands out.

In this new effort, the research team wondered if the prominence of yellow in dog photoreception made the color more important to dogs. To find out, they carried out experiments on free-range dogs living in rural, semi-urban and urban areas in or near the city of Kolkata in India. The team coaxed 458 of the dogs to take part in experiments involving choosing between colored bowls.
In India, free-range street dogs are common—they survive through the generosity of people feeding them, generally from a bowl of some type. Thus, they are accustomed to being presented with bowls, which they expect will be filled with food.

In the first experiment, involving 134 dogs, each was given a single chance to choose one of three food-filled bowls placed a short distance apart on the ground as the researchers watched and recorded their choices. They found that 72 of the dogs chose the yellow bowl. They repeated the experiment with empty bowls and found much the same result.

Part 1

Comment by Dr. Krishna Kumari Challa on February 26, 2025 at 10:34am

Why Mars is red: New insights

Mars is easily identifiable in the night sky by its prominent red hue. Thanks to the fleet of spacecraft that have studied the planet over the last decades, we know that this red color is due to rusted iron minerals in the dust. That is, iron bound up in Mars's rocks has at some point reacted with liquid water, or water and oxygen in the air, similar to how rust forms on Earth.

Over billions of years, this rusty material—iron oxide—has been broken down into dust and spread all around the planet by winds, a process that continues today.

But iron oxides come in many flavors, and the exact chemistry of Martian rust has been intensely debated because how it formed is a window into the planet's environmental conditions at the time. And closely linked to that is the question of whether Mars has ever been habitable.

Previous studies of the iron oxide component of the Martian dust based on spacecraft observations alone did not find evidence of water contained within it. Researchers had therefore concluded that this particular type of iron oxide must be hematite, formed under dry surface conditions through reactions with the Martian atmosphere over billions of years after Mars's early wet period.

However, new analysis of spacecraft observations in combination with novel laboratory techniques shows that Mars's red color is better matched by iron oxides containing water, known as ferrihydrite.

The work is published in Nature Communications.

Ferrihydrite typically forms quickly in the presence of cool water, and so must have formed when Mars still had water on its surface. The ferrihydrite has kept its watery signature to the present day, despite being ground down and spread around the planet since its formation.

Detection of ferrihydrite in Martian red dust records ancient cold and wet conditions on Mars, Nature Communications (2025). DOI: 10.1038/s41467-025-56970-z. www.nature.com/articles/s41467-025-56970-z

Comment by Dr. Krishna Kumari Challa on February 26, 2025 at 10:29am

A completely new type of microscopy based on quantum sensors

Researchers  have invented an entirely new field of microscopy called nuclear spin microscopy. The team can visualize magnetic signals of nuclear magnetic resonance with a microscope. Quantum sensors convert the signals into light, enabling extremely high-resolution optical imaging.

Magnetic resonance imaging (MRI) scanners are known for their ability to look deep into the human body and create images of organs and tissues. The new method, published in the journal Nature Communications, extends this technique to the realm of microscopic detail.

The quantum sensors used make it possible to convert magnetic resonance signals into optical signals. These signals are captured by a camera and displayed as images.

The resolution of the new MRI microscope reaches ten-millionths of a meter—that is so fine that even the structures of individual cells can be made visible in the future. At the heart of the new microscope is a tiny diamond chip.

This diamond, specially prepared at the atomic level, serves as a highly sensitive quantum sensor for MRI magnetic fields. When irradiated with laser light, it generates a fluorescent signal containing the MRI signal's information. This signal is recorded with a high-speed camera and enables images with a significantly higher resolution down to the microscopic level.

The potential applications of magnetic resonance microscopy are up-and-coming: In cancer research, individual cells could be examined in detail to gain new insights into tumor growth and spread. In pharmaceutical research, the technology could be used to efficiently test and optimize active ingredients at a molecular level. It also offers excellent potential in materials science, such as analyzing the chemical composition of thin-film materials or catalysts.

 Karl D. Briegel et al, Optical widefield nuclear magnetic resonance microscopy, Nature Communications (2025). DOI: 10.1038/s41467-024-55003-5

Comment by Dr. Krishna Kumari Challa on February 26, 2025 at 10:01am

The scientists identified long, twisting fossil filaments within the Algerian gypsum, which have previously been interpreted as benthic algae or cyanobacteria, and are now thought to be sulfur-oxidizing bacteria like Beggiatoa. These were embedded in gypsum, and surrounded by dolomite, clay minerals, and pyrite.

The presence of these minerals signals the presence of organic life, because prokaryotes—cells without a nucleus—supply elements which clay needs to form. They also facilitate dolomite formation in an acidic environment like Mars by increasing the alkalinity around them and concentrating ions in their cell envelopes.

For dolomite to form within gypsum without the presence of organic life, high temperatures and pressures would be needed that would have dehydrated the gypsum, and which aren't consistent with our knowledge of the Martian environment.

If mass spectrometers identify the presence of clay and dolomite in Martian gypsum in addition to other biosignatures, this could be a key signal of fossilized life, which could be reinforced by analyzing other chemical minerals present and by looking for similar organically formed filaments.
While these findings strongly support the biogenicity of the fossil filament in gypsum, distinguishing true biosignatures from abiotic mineral formations remains a challenge.
An additional independent detection method would improve the confidence in life detection. Additionally, Mars has unique environmental conditions which could affect biosignature preservation over geological periods. Further studies are needed.

The search for ancient life on Mars using morphological and mass spectrometric analysis: an analog study in detecting microfossils in Messinian gypsum, Frontiers in Astronomy and Space Sciences (2025). DOI: 10.3389/fspas.2025.1503042

Part 2

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Comment by Dr. Krishna Kumari Challa on February 26, 2025 at 9:59am

Laser-powered device tested on Earth could help detect microbial fossils on Mars

The first life on Earth formed four billion years ago, as microbes living in pools and seas: what if the same thing happened on Mars? If it did, how would we prove it? Scientists hoping to identify fossil evidence of ancient Martian microbial life have now found a way to test their hypothesis, proving they can detect the fossils of microbes in gypsum samples that are a close analogy to sulfate rocks on Mars.

The findings provide a methodological framework for detecting biosignatures in Martian sulfate minerals, potentially guiding future Mars exploration missions.

The new  laser ablation ionization mass spectrometer, a spaceflight-prototype instrument, can effectively detect biosignatures in sulfate minerals. This technology could be integrated into future Mars rovers or landers for in-situ analysis.

Billions of years ago, the water on Mars dried up. Gypsum and other sulfates formed when pools evaporated, leaving behind minerals that precipitated out of the water and potentially fossilizing any organic life left behind. This means that if microbes such as bacteria lived there, traces of their presence could be preserved as fossils.

Gypsum has been widely detected on the Martian surface and is known for its exceptional fossilization potential. It forms rapidly, trapping microorganisms before decomposition occurs, and preserves biological structures and chemical biosignatures.

But to identify these microbial fossils we first need to prove we can identify similar fossils in places where we know such microbes existed—such as Mediterranean gypsum formations that developed during the Messinian Salinity Crisis.

The Messinian Salinity Crisis occurred when the Mediterranean Sea was cut off from the Atlantic Ocean. This led to rapid evaporation, causing the sea to become hypersaline and depositing thick layers of evaporites, including gypsum. These deposits provide an excellent terrestrial analog for Martian sulfate deposits.

The scientists selected an instrument that could be used on a spaceflight: a miniature laser-powered mass spectrometer, which can analyze the chemical composition of a sample in detail as fine as a micrometer.

They sampled gypsum from Sidi Boutbal quarry, Algeria, and analyzed it using the mass spectrometer and an optical microscope, guided by criteria which can help distinguish between potential microbial fossils and natural rock formations. These include morphology which is irregular, sinuous, and potentially hollow, as well as the presence of chemical elements necessary for life, carbonaceous material, and minerals like clay or dolomite which can be influenced by the presence of bacteria.

Part 1

Comment by Dr. Krishna Kumari Challa on February 26, 2025 at 9:53am

Before treatment, all children exhibited visual acuity limited to light perception. By the final follow-up, treated eyes showed a mean visual acuity improvement to 0.9 logMAR (range 0.8–1.0) from a baseline equivalent of 2.7 logMAR.

Untreated eyes of the children showed no improvement in visual acuity and either deteriorated to unmeasurable levels or lost light perception by the final follow-up.

Objective testing in two older children using the PopCSF touchscreen assay and steady-state visually evoked potentials (ssVEPs) confirmed significant enhancements in visual function and cortical response specific to treated eyes. Retinal imaging revealed better-preserved thickness and lamination in three treated eyes compared to untreated counterparts.
Gene therapy with rAAV8.hRKp.AIPL1 resulted in sustained visual improvements without serious adverse effects, supporting early intervention for AIPL1-associated retinal dystrophy.

 Michel Michaelides et al, Gene therapy in children with AIPL1-associated severe retinal dystrophy: an open-label, first-in-human interventional study, The Lancet (2025). DOI: 10.1016/S0140-6736(24)02812-5

Part 2

Comment by Dr. Krishna Kumari Challa on February 26, 2025 at 9:52am

Gene therapy can improve vision in young children with AIPL1-associated retinal dystrophy

Researchers  have found that gene therapy improved visual acuity and preserved retinal structure in young children with AIPL1-associated severe retinal dystrophy. This is the first human trial of gene supplementation therapy targeting this condition.

Retinal dystrophy caused by biallelic variants in the AIPL1 gene leads to severe visual impairment from birth, with progressive degeneration and limited treatment options. Previous studies of early-onset rod-cone dystrophies, including AIPL1-related forms, highlighted a critical window for intervention during early childhood, when some photoreceptor structure remains intact. Prior research using Aipl1-deficient mouse models and human retinal organoids demonstrated partial restoration of photoreceptor function through gene therapy.

In the study, "Gene therapy in children with AIPL1-associated severe retinal dystrophy: an open-label, first-in-human interventional study," published in The Lancet, researchers administered a single subretinal injection of a recombinant adeno-associated viral vector (rAAV8.hRKp.AIPL1) carrying the AIPL1 gene to one eye of each child to assess the safety and efficacy of gene supplementation therapy in improving visual function and preserving retinal structure.
Four children aged 1.0 to 2.8 years with confirmed AIPL1 mutations received a subretinal injection of rAAV8.hRKp.AIPL1 in one eye. The gene therapy vector, produced under UK regulatory approval, delivered the AIPL1 coding sequence using a human rhodopsin kinase promoter. Oral prednisolone was administered perioperatively to mitigate inflammation. Visual acuity, functional vision, retinal structure, and cortical responses were evaluated over a mean follow-up of 3.5 years.
Part 1

Comment by Dr. Krishna Kumari Challa on February 26, 2025 at 9:43am

Galloping Bubbles

Bubbles that break rules: A fluid discovery that defies logic

Researchers  have made an extraordinary discovery that is reshaping our understanding of bubbles and their movement. Picture tiny air bubbles inside a container filled with liquid. When the container is shaken up and down, these bubbles engage in an unexpected, rhythmic "galloping" motion—bouncing like playful horses and moving horizontally, even though the shaking occurs vertically.

This counterintuitive phenomenon, revealed in a new study published in Nature, has significant implications for technology from cleaning surfaces to improving heat transfer in microchips and even advancing space applications.  

These galloping bubbles are already garnering significant attention: their impact in the field of fluid dynamics has been recognized with an award for their video entry at the most recent Gallery of Fluid Motion, organized by the American Physical Society.

The newly discovered self-propulsion mechanism allows bubbles to travel distances and gives them an unprecedented capacity to navigate intricate fluid networks. This could offer solutions to long-standing challenges in heat transfer, surface cleaning, and even inspire new soft robotic systems.

Jian H. Guan et al, Galloping Bubbles, Nature Communications (2025). DOI: 10.1038/s41467-025-56611-5

Comment by Dr. Krishna Kumari Challa on February 25, 2025 at 11:15am

How AI is revealing the language of the birds

Comment by Dr. Krishna Kumari Challa on February 25, 2025 at 10:51am

An unknown illness kills over 50 people in part of Congo with hours between symptoms and death

An unknown illness has killed over 50 people in northwestern Congo, according to doctors on the ground and the World Health Organization this week.

The interval between the onset of symptoms and death has been 48 hours in the majority of cases, and that's what's really worrying.

The outbreak began on Jan. 21, and 419 cases have been recorded including 53 deaths.
According to the WHO's Africa office, the first outbreak in the town of Boloko began after three children ate a bat and died within 48 hours following hemorrhagic fever symptoms.

There have long been concerns about diseases jumping from animals to humans in places where wild animals are popularly eaten. The number of such outbreaks in Africa has surged by more than 60% in the last decade, the WHO said in 2022.

After the second outbreak of the current mystery disease began in the town of Bomate on Feb. 9, samples from 13 cases have been sent to the National Institute for Biomedical Research in Congo's capital, Kinshasa, for testing, the WHO said.

All samples have been negative for Ebola or other common hemorrhagic fever diseases like Marburg. Some tested positive for malaria.
Source: News agencies

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