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Comment by Dr. Krishna Kumari Challa on January 17, 2025 at 9:34am

Damage to RNA, not DNA, found to be main cause of acute sunburn

We have all been told to avoid direct sunlight between 12 noon and 3 p.m., seek out shade and put on sunscreen and a hat. Nevertheless, most of us have experienced sunburn at least once. The skin turns bright red, feels irritated and needs cooling.

You may also have been told that sunburn damages the DNA. But that is not the full truth, according to researchers responsible for a new study conducted . The findings are published in the journal Molecular Cell.

Sunburn damages the DNA, leading to cell death and inflammation. So the textbooks say. But in this study researchers were surprised to learn that this is a result of damage to the RNA, not the DNA that causes the acute effects of sunburn!

RNA is similar to DNA, but whereas DNA is long lived, RNA is a more transient molecule. A type of RNA, known as messenger RNA (mRNA), functions as the intermediate 'messenger' that carries information from DNA to make proteins—the basic building blocks of cellular components.

DNA damage is serious as the mutations will get passed down to progenies of the cells, RNA damage happens all the time and does not cause permanent mutations. Therefore, we used to think that the RNA is less important, as long as the DNA is intact. But in fact, damages to the RNA are the first to trigger a response to UV radiation.

The new study was conducted on mice as well as human skin cells, and the objective was to describe the impact of UV radiation on the skin and what causes these damages. The researchers found the same skin response to UV radiation exists in both mice and human cells.

mRNA damage triggers a response in ribosomes (protein complexes that "read" the mRNA to synthesize protein), orchestrated by a protein known as ZAK-alpha—the so-called ribotoxic stress response—the new study shows. The response can be described as a surveillance system within the cells, which registers the RNA damage, leading to inflammatory signaling and recruitment of immune cells, which then leads to inflammation of the skin.

Researchers  found that the first thing the cells respond to after being exposed to UV radiation is damage to the RNA, and that this is what triggers cell death and inflammation of the skin. In mice exposed to UV radiation they found responses such as inflammation and cell death, but when they removed the ZAK gene, these responses disappeared, which means that ZAK plays a key role in the skin's response to UV-induced damage.

So you could say that everything depends on this one response, which monitors all protein translations occurring. The cells respond to the RNA damage, realizing that something is wrong, and this is what leads to cell death.

Part 1

Comment by Dr. Krishna Kumari Challa on January 17, 2025 at 9:19am

India achieves 'historic' space docking mission

India docked two satellites in space Thursday, a key milestone for the country's dreams of a space station and a manned moon mission, the space agency said.

The satellites, weighing 220 kilograms (485 pounds) each, blasted off in December on a single rocket from India's Sriharikota launch site. Later they separated.

The two satellites were maneuvered back together on Thursday in a "precision" process resulting in a "successful spacecraft capture", the Indian Space Research Organisation (ISRO) said, calling it a "historic moment".

India became the fourth country to achieve the feat—dubbed as SpaDeX, or Space Docking Experiment—after Russia, the United States and China.

The aim of the mission was to "develop and demonstrate the technology needed for rendezvous, docking, and undocking of two small spacecraft", ISRO said.

ISRO said the technology is "essential" for India's moon mission.

Source: ISRO

Comment by Dr. Krishna Kumari Challa on January 16, 2025 at 12:04pm

Mosquitoes defy droughts by drinking blood, ensuring survival and disease spread

Mosquitoes are able to survive prolonged droughts by drinking blood, which helps to explain how their populations quickly rebound when it finally rains, biologists found. 

A study examined how two species of mosquito known for infecting people with diseases such as malaria were able to survive nearly three weeks without rain.

The findings could help explain why the incidence of infection from mosquito-borne illness does not always decline during droughts. While there may be fewer mosquitoes, those that survive bite more often.

And mosquitoes appear to be benefiting from climate change as winters get warmer by biting people more!

 Christopher J. Holmes et al, Multiple blood feeding bouts in mosquitoes allow for prolonged survival and are predicted to increase viral transmission during dry periods, iScience (2025). DOI: 10.1016/j.isci.2025.111760

Comment by Dr. Krishna Kumari Challa on January 16, 2025 at 11:43am

AI-designed proteins neutralize toxins found in snake venom

A study by this year's Nobel Laureate in Chemistry reveals a possible game-changer in snakebite treatment. Researchers have created new proteins that neutralize lethal toxins found in snake venom, potentially offering a safer and more effective alternative to traditional antivenoms.

According to the WHO, venomous snakebites affect between 1.8 and 2.7 million people each year, leading to roughly 100,000 annual deaths and three times as many permanent disabilities, including lost limbs. Most injuries happen in Africa, Asia, and Latin America, where weak health systems aggravate the issue.

Currently, the only antivenoms used to treat snakebite victims are derived from animal plasma and often come with high costs, limited efficacy, and adverse side effects. Venoms also differ widely across snake species, necessitating custom treatments in different parts of the world.

In recent years, however, scientists have gained a deeper understanding of snake toxins and developed new ways to combat their effects. One such development was published on 15 January in Nature.

A team led by 2024 Nobel Laureate in Chemistry David Baker from the University of Washington School of Medicine and Timothy Patrick Jenkins from DTU (the Technical University of Denmark) used deep learning tools to design new proteins that bind to and neutralize toxins from deadly cobras.

The study focuses on an important class of snake proteins called three-finger toxins, which are often the reason antivenoms based on immunized animals fail. While not yet protecting against full snake venom—which is a complex mixture of different toxins unique to each snake species—the AI-generated molecules provide full protection from lethal doses of three-finger toxins in mice: 80–100% survival rate, depending on the exact dose, toxin and designed protein.

These toxins tend to evade the immune system, rendering plasma-derived treatments ineffective. This research thus demonstrates that AI-accelerated protein design can be used to neutralize harmful proteins that have otherwise proven difficult to combat.

David Baker, De novo designed proteins neutralize lethal snake venom toxins, Nature (2025). DOI: 10.1038/s41586-024-08393-x. www.nature.com/articles/s41586-024-08393-x

Comment by Dr. Krishna Kumari Challa on January 16, 2025 at 11:33am

Marine animals consume microplastic particles and excrete them in feces, posing risks to marine environment

A new  study has uncovered alarming findings about the spread of microplastic particles in the marine food web. In recent years, numerous studies have examined the dangers of marine animals and more specifically, filter-feeding organisms, ingesting non-degradable microplastic particles.

In the current study, the research team sought to understand how the biological filtration by filter-feeding organisms affects the microplastics in their environment. The findings indicate that the particles are excreted in the feces of marine animals, causing them to be unidentifiable as plastic to the marine environment, but potentially as other organic matter suitable for consumption.

Additionally, the presence of microplastic within feces affects feces dispersal, which causes the accumulation of feces and plastic particles. This may increase carbon and nitrogen levels on the seafloor and lead to algal blooms, which have a critical impact on the balance of the marine food web.

Eden Harel et al, Effects of biological filtration by ascidians on microplastic composition in the water column, Chemosphere (2024). DOI: 10.1016/j.chemosphere.2024.143589

Comment by Dr. Krishna Kumari Challa on January 16, 2025 at 10:03am

Nerves for the suckers also exited from the ANC through these septa, systematically connecting to the outer edge of each sucker. This indicates that the nervous system sets up a spatial, or topographical, map of each sucker.

Octopuses can move and change the shape of their suckers independently. The suckers are also packed with sensory receptors that allow the octopus to taste and smell things that they touch—like combining a hand with a tongue and a nose. The researchers think the "suckeroptopy," as they called the map, facilitates this complex sensory-motor ability.

 Neuronal segmentation in cephalopod arms, Nature Communications (2025). DOI: 10.1038/s41467-024-55475-5

Part 2

Comment by Dr. Krishna Kumari Challa on January 16, 2025 at 10:02am

Octopus arms have segmented nervous systems to power extraordinary movements

Octopus arms move with incredible dexterity, bending, twisting, and curling with nearly infinite degrees of freedom. New research revealed that the nervous system circuitry that controls arm movement in octopuses is segmented, giving these extraordinary creatures precise control across all eight arms and hundreds of suckers to explore their environment, grasp objects, and capture prey.

Octopus arms move with incredible dexterity, bending, twisting, and curling with nearly infinite degrees of freedom. Credit: Cassady Olson

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Using cellular markers and imaging tools to trace the structure and connections from the ANC, the researchers  saw that neuronal cell bodies were packed into columns that formed segments, like a corrugated pipe. These segments are separated by gaps called septa, where nerves and blood vessels exit to nearby muscles. Nerves from multiple segments connect to different regions of muscles, suggesting the segments work together to control movement.

The best way to set up a control system for this very long, flexible arm would be to divide it into segments.

Part 1

Comment by Dr. Krishna Kumari Challa on January 16, 2025 at 9:41am

Archaeologists reveal 8,000-year-old bone powder cooking practice in ancient China

A new study by archaeologists published in the International Journal of Osteoarchaeology, provides insights into some of the earliest forms of humans processing bones into powder for cooking, dating back nearly 8,000 years (6,085 and 6,369 BC).

The finding was made at the Xielaozhuang (XLZ) site in the Henan province of North China. The site belonged to the Peiligang culture (ca. 9,000–7,000 BP), which was one of North China's most significant Neolithic cultures. It was known for being among the earliest producers of fermented beverages, creators of the oldest tonal flutes, basic textile weavers and sewers, and possibly one of the earliest users of the Chinese script.

Using a multidisciplinary approach that combined Scanning Electron Microscopy with Energy-Dispersive X-ray (SEM-EDS), Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), and starch analysis, the researchers were able to analyze the chemical, mineral, and microscopic composition of the crust-residue.

More specifically, the research team found certain compounds and minerals, including hydroxyapatite, magnesium whitlockite, phosphate (PO₄^3-), and carbonate (CO₃^2-) groups, as well as key elements, including carbon, oxygen, phosphorus, calcium, and magnesium, all of which are typical components found in bone.

They concluded that bone powder was likely ground up and cooked together with various wild plants, including acorns and Job's tears.

This was particularly interesting because, despite agriculture having been developed in China around 10,000 years ago, the Peiligang culture made limited use of cultivated crops and animals, including foxtail millet, common millet, rice, and pigs. In fact, no domesticated crops were found in the crust-residue at XLZ, and from previous zooarchaeological analyses, it was known that domesticated animals, such as pigs, only made up around 10% of all remains.

The researchers speculate that bone powder processing at XLZ represented an important survival strategy during the transition from hunting-gathering to farming. It has long been hypothesized that various Paleolithic societies used bone grease extraction methods to extract extra fat (grease) and nutrients from otherwise inedible resources.

This research contributes to a growing body of evidence showing how early Neolithic societies developed sophisticated subsistence strategies during the transition from hunter-gatherer to farm-based societies.

 Xingtao Wei et al, Bone Powder and Wild Plants: Subsistence Strategies of Early Neolithic Settlers in North China, International Journal of Osteoarchaeology (2024). DOI: 10.1002/oa.3376

Comment by Dr. Krishna Kumari Challa on January 16, 2025 at 9:22am

Dopamine acts on motivation and reinforcement learning via distinct cellular processes

Dopamine is a key neurotransmitter known to modulate motivation and reinforcement learning. While the role of dopamine in these reward-related processes is well-established, the cellular and neural circuit-level mechanisms underpinning its involvement in these processes is not yet fully understood.

So researchers  carried out a study investigating the cellular processes via which dopamine supports motivation and the reinforcement of specific behaviours.

Their findings, published in Nature Neuroscience, suggest that different aspects of reward-related behaviour are supported by two distinct dopamine receptors, namely D3 and D1.

The previous literature clearly showed that dopamine is important for motivation and reinforcement. 

This is an important topic since deficits in motivation or excessive motivation are cardinal symptoms in many mental disorders. The nucleus accumbens, a brain region where dopamine is thought to exert its effects, is uniquely enriched with a molecule that recognizes dopamine, the D3 receptor.

As an initial step in addressing the role of D3,the researchers developed a new mouse strain that enables cell-type-selective deletion of D3 receptors, including in the nucleus accumbens.

The results show that specifically, D3 receptors were found to regulate motivation, while D1 receptors appeared to regulate reinforcement.

These  findings provide the first evidence that dopamine exerts its actions on motivation and reinforcement through separable cellular processes in neurons that are part of the brain's reward circuitry.

There are important implications because medications that act on D3 receptors are used for the treatment of mood disorders.

Juan Enriquez-Traba et al, Dissociable control of motivation and reinforcement by distinct ventral striatal dopamine receptors, Nature Neuroscience (2024). DOI: 10.1038/s41593-024-01819-9

Nicolas X. Tritsch, Motivating interest in D3 dopamine receptors, Nature Neuroscience (2024). DOI: 10.1038/s41593-024-01820-2

Comment by Dr. Krishna Kumari Challa on January 15, 2025 at 11:01am

Even though the glass looks clean when cleaned with detergent, its ability to transmit light is significantly impaired. Therefore, a clean-looking end result does not guarantee optimal performance.
The study provides information on solar panel maintenance for users of solar power.

 Aapo Poskela et al, Impact of Textured Surfaces and Cleaning on Solar Panel Glass Transmittance, (2024). DOI: 10.4229/eupvsec2024/3av.1.17

Part 2

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