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Comment by Dr. Krishna Kumari Challa on April 2, 2021 at 9:58am

Hubble Shows Torrential Outflows from Infant Stars May Not Stop Them from Growing

Comment by Dr. Krishna Kumari Challa on April 2, 2021 at 8:59am

Physicists observe new phase in Bose-Einstein condensate of light pa...

About 10 years ago, researchers at the University of Bonn produced an extreme aggregate photon state, a single "super-photon" made up of many thousands of individual light particles, and presented a completely new light source. The state is called an optical Bose-Einstein condensate and has captivated many physicists ever since, because this exotic world of light particles is home to its very own physical phenomena. Researchers led by Prof. Dr. Martin Weitz, who discovered the super photon, and theoretical physicist Prof. Dr. Johann Kroha now report a new observation: a so-called overdamped phase, a previously unknown phase transition within the optical Bose-Einstein condensate. The study has been published in the journal Science.

Comment by Dr. Krishna Kumari Challa on April 2, 2021 at 8:54am

How brain cells repair their DNA reveals 'hot spots' of aging and disease

Neurons lack the ability to replicate their DNA, so they're constantly working to repair damage to their genome. Now, a new study by Salk scientists finds that these repairs are not random, but instead focus on protecting certain genetic "hot spots" that appear to play a critical role in neural identity and function.

The findings, published in the April 2, 2021, issue of Science, give novel insights into the genetic structures involved in aging and neurodegeneration, and could point to the development of potential new therapies for diseases such Alzheimer's, Parkinson's and other age-related dementia disorders.

"This research shows for the first time that there are sections of genome that neurons prioritize when it comes to repair.

Unlike other cells, neurons generally don't replace themselves over time, making them among the longest-living cells in the human body. Their longevity makes it even more important that they repair lesions in their DNA as they age, in order to maintain their function over the decades of a human life span. As they get older, neurons' ability to make these genetic repairs declines, which could explain why people develop age-related neurodegenerative diseases like Alzheimer's and Parkinson's.

To investigate how neurons maintain genome health, the study authors developed a new technique they term Repair-seq. The team produced neurons from stem cells and fed them synthetic nucleosides—molecules that serve as building blocks for DNA. These artificial nucleosides could be found via DNA sequencing and imaged, showing where the neurons used them to make repairs to DNA that was damaged by normal cellular processes. While the scientists expected to see some prioritization, they were surprised by just how focused the neurons were on protecting certain sections of the genome.

"Incorporation of a nucleoside analog maps genome repair sites in postmitotic human neurons" Science (2021). science.sciencemag.org/cgi/doi … 1126/science.abb9032

https://medicalxpress.com/news/2021-04-brain-cells-dna-reveals-hot....

Comment by Dr. Krishna Kumari Challa on April 2, 2021 at 7:37am

DNA can be collected from air, scientists show for first time

Scientists have shown for the first time that DNA can be collected from the air. The finding could provide new techniques for forensics researchers, anthropologists, and even help in the understanding of the transmission of airborne diseases like COVID-19, they say.

The team looked at whether environmental DNA (eDNA) could be collected from air samples and used to identify animal species. Most similar studies to date have focused on the collection of eDNA from water.

But the new proof-of-concept study, published in the journal PeerJ, showed that airDNA sampling could successfully detect naked mole rat DNA and human DNA in the air.

They first took air samples from a room which had housed naked mole-rats, and then used existing techniques to check for DNA sequences within the sampled air.

Using this approach, the research team showed that airDNA sampling could successfully detect mole rat DNA within the animals’ housing and from the room itself. They also found human DNA in the air samples, suggesting a potential use of this sampling technique for forensic applications.

https://peerj.com/articles/11030/

https://www.sciencefocus.com/news/dna-can-be-collected-from-air-sci...

Comment by Dr. Krishna Kumari Challa on April 1, 2021 at 10:08am

Here’s why humans chose particular groups of stars as constellations

Scientists simulate how humans trace patterns in the night sky

Stargazers can easily pick out the shape of a constellation. Now, scientists have shown that three factors can explain why certain groups of stars form such recognizable patterns.

To replicate how humans perceive the celestial sphere, a team of researchers considered how the eye might travel randomly across this night sky. Human eyes tend to move in discrete jumps, called saccades (SN: 10/31/11), from one point of interest to another. Scientists created a simulation that incorporated the distribution of lengths of those saccades, combined that with basic details of the night sky as seen from Earth — namely the apparent distances between neighboring stars and their brightnesses. The technique could reproduce individual constellations.

Ancient people from various cultures connected similar groupings of stars independently of each other. this indicates that there are some fundamental aspects of human learning … that influence the ways in which we organize information.

S. David et al. Free energy model of the human perception of a starry sky. American Physical Society March Meeting. March 18, 2021.

Comment by Dr. Krishna Kumari Challa on April 1, 2021 at 9:29am

Neuroscientists have identified a brain circuit that stops mice from mating with others that appear to be sick

When someone is sick, it's natural to want to stay as far from them as possible. It turns out this is also true for mice, according to an MIT study that also identified the brain circuit responsible for this distancing behaviour.

In a study that explores how otherwise powerful instincts can be overridden in some situations, researchers from MIT's Picower Institute for Learning and Memory found that when male mice encountered a female mouse showing signs of illness, the males interacted very little with the females and made no attempts to mate with them as they normally would. The researchers also showed that this behavior is controlled by a circuit in the amygdala, which detects distinctive odors from sick animals and triggers a warning signal to stay away.

Earlier  studies have shown that mice can distinguish between healthy mice and mice that have been injected with a bacterial component called LPS, which induces mild inflammation when given at a low dose. These studies suggested that mice use odor, processed by their vomeronasal organ, to identify sick individuals.

To explore whether mice would change their innate behavior when exposed to sick animals, the researchers placed male mice in the same cage with either a healthy female or a female that was showing LPS-induced signs of illness. They found that the males engaged much less with the sick females and made no effort to mount them.

The researchers then tried to identify the brain circuit underlying this behavior. The vomeronasal organ, which processes pheromones, feeds into a part of the amygdala called the COApm, and the MIT team found that this region is activated by the presence of LPS-injected animals.

Further experiments revealed that activity in the COApm is necessary to suppress the males' mating behavior in the presence of sick females. When COApm activity was turned off, males would try to mate with sick females. Additionally, artificially stimulating the COApm suppressed mating behavior in males even when they were around healthy females.

 An amygdala circuit that suppresses social engagement, Nature (2021). DOI: 10.1038/s41586-021-03413-6

https://phys.org/news/2021-03-neuroscientists-brain-circuit-mice-si...

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Comment by Dr. Krishna Kumari Challa on March 31, 2021 at 10:54am

 A rapid, sensitive test for detection of antibodies against SARS-CoV-2

Comment by Dr. Krishna Kumari Challa on March 31, 2021 at 9:17am

New physics at the Large Hadron Collider? Scientists are excited, but it's too soon to be sure

https://theconversation.com/new-physics-at-the-large-hadron-collide...

https://sciencex.com/news/2021-03-physics-large-hadron-collider-sci...

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Oil-eating bacteria could help to tackle spills

A team of scientists from Heriot-Watt University has created an underwater observatory in the Faroe-Shetland Channel—and found its waters are teeming with oil-eating bacteria that could help deal with future oil spills.

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How to talk to people about climate change

As our planet warms, seas rise and catastrophic weather events become more frequent, action on climate change has never been more important. But how do you convince people who still don't believe that humans contribute to the warming climate?

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Satellite light pollution is everywhere

There seems to be nowhere left on Earth to view the stars without encountering light pollution from space stuff. After analysing light scattered off the collective cloud of satellites and debris above Earth, researchers found that human-made objects cast a background glow on the night sky even whe.... Stargazers might not be able to notice the difference with the naked eye, but astronomers worry that the pervasive glare of debris orbiting Earth could obscure our view of distant galaxies. “As space gets more crowded, the magnitude of this effect will only be more, not less,” says astronomer John Barentine.

Comment by Dr. Krishna Kumari Challa on March 31, 2021 at 9:13am

Scientists identify molecular pathway that helps moving cells avoid aimless wandering

Working with fruit flies, scientists  have identified a new molecular pathway that helps steer moving cells in specific directions. The set of interconnected proteins and enzymes in the pathway act as steering and rudder components that drive cells toward an "intended" rather than random destination.

These same molecular pathways, according to the scientists, may drive cancer cells to metastasize or travel to distant areas of the body and may also be important for understanding how cells assemble and migrate in an embryo to form organs and other structures.

Scientists more specifically pin pointed gene called Tre1 and its role. 

In experiments with fruit fly embryos carrying an intact Tre1 gene, cells that produce future generations of the organism, called germ cells, migrate correctly to the sex organ, known as the gonad.

Without the Tre1 gene, however, most of the germ cells failed to meet up with other nongerm cells, or somatic cells, of the gonad.

Ji Hoon Kim et al, Hedgehog signaling and Tre1 regulate actin dynamics through PI(4,5)P2 to direct migration of Drosophila embryonic germ cells, Cell Reports (2021). DOI: 10.1016/j.celrep.2021.108799

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This is not the first time that scientists noted Tre1's importance in germ cell navigation. Two research teams from Indiana University and the Massachusetts Institute of Technology had previously made the link.

It was already known that the Tre1 gene encodes a protein that spans the cell membrane multiple times and pokes out onto the cell's surface. It's a member of a large family of proteins called G protein-coupled receptors, which enable cells to communicate and respond to signals from other cells and light and odor cues. Nearly 35% of  approved medicines target G protein-coupled receptors.

https://phys.org/news/2021-03-scientists-molecular-pathway-cells-ai...

Comment by Dr. Krishna Kumari Challa on March 31, 2021 at 8:28am

Researchers discover how animals grow their pointy body parts

An interdisciplinary research team  discovered a new universal rule of biological growth that explains surprising similarities in the shapes of sharp structures across the tree of life, including teeth, horns, claws, beaks, animal shells, and even the thorns and prickles of plants.

Animals and plants often grow in specific patterns, like logarithmic spirals following the golden ratio. There are very simple processes that generate these patterns—a logarithmic spiral is produced when one side of a structure grows faster than another at a constant ratio. We can call these 'rules of growth', and they help us understand why organisms are certain shapes.

In the new study published today in BMC Biology, the research team demonstrates a new rule called the 'power cascade' based on how the shape 'cascades' down a tooth following a power law.

When an elephant tusk grows longer, it grows wider at a very specific rate following a 'power law'—a mathematical pattern where there is a straight-line relationship between the logarithm of the tooth's width and length. Power laws are found throughout nature, such as in the magnitudes of earthquakes, the sizes of cities, and the movement of the stock market.

This pattern applies across many animals, in the teeth of giant sharks, Tyrannosaurus rex, mammoths, and even humans. Remarkably, this power law works for claws, hooves, horns, spider fangs, snail shells, antlers, and the beaks of mammals, birds, and dinosaurs. Beyond animals, the team also observed it in the thorns of the rose bush and lemon tree. This was found   almost everywhere researchers looked across the kingdoms of life—in living animals and those extinct for millions of years.

The new study shows that shells and other shapes such as teeth and horns are in fact the power cascade shape (called a 'power cone').

Because so many structures follow this growth pattern, we can use it to predict the likely pattern of evolution. Whenever animals evolve teeth, horns, or claws, it seems most likely that they will be this shape. It even allows us to predict what mythical animals would look like if they follow the same patterns of nature.

BMC Biology (2021). DOI: 10.1186/s12915-021-00990-w

https://phys.org/news/2021-03-animals-pointy-body.html?utm_source=n...

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