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Comment by Dr. Krishna Kumari Challa on July 21, 2023 at 10:56am

The First Dark Stars
At least three far-off objects observed by the James Webb Space Telescope (JWST) could be stellar objects called “dark stars.” These stars might not be fueled by nuclear fusion but by the self-annihilation of dark matter—the invisible stuff that is thought to make up about 85 percent of the matter in the universe. Dark stars could have formed soon after the big bang, from the collapse of helium and hydrogen clouds that annihilated the particles within.
Dark stars have never been definitively observed before–astronomers weren’t even sure they really existed. To prove these objects are indeed dark stars will take many months of observation–particularly, watching their electromagnetic spectrums for a particular isotope of helium only found in dark stars, not in galaxies.
“Finding a dark star would not only provide a new look into the early formation of the universe,” says Pearl Sandick, a theoretical particle physicist at the University of Utah, “but would also be a unique opportunity to directly observe dark matter interactions.
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In 2007, scientists proposed the idea of Dark Stars. The first phase of stellar evolution in the history of the universe may be Dark Stars (DS), powered by dark matter (DM) heating rather than by nuclear fusion. Although made almost entirely of hydrogen and helium from the Big Bang, they form at the centers of protogalaxies where there is a sufficient abundance of DM to serve as their heat source. They are very bright diffuse puffy objects and grow to be very massive. In fact, they can grow up to ten million solar masses with up to ten billion solar luminosities. In this paper, they show that the James Webb Space Telescope may have already discovered these objects.

https://www.pnas.org/doi/full/10.1073/pnas.2305762120

Comment by Dr. Krishna Kumari Challa on July 21, 2023 at 8:44am

Study shows how the brain coordinates neuronal processing and communication during sleep

Past neuroscience studies have shown that while humans are sleeping, the brain remains highly active, consolidating memories and removing toxins accumulated during waking hours. While memory consolidation during sleep is a widely documented phenomenon, the processes underpinning it are yet to be fully elucidated.

Researchers recently carried out a study investigating the neural mechanisms through which the brain facilitates neuronal processing and communication between neurons during sleep. Their paper, published in Nature Neuroscience, unveils the processes through which the sequential unfolding of specific sleep rhythms coordinates memory consolidation while humans are asleep.

A few years ago, scientists found that some of the key sleep signatures ('slow oscillations,' 'spindles' and 'ripples') coincide in the hippocampus, the brain's 'memory hub.' This was a good indication that the synchronization of these sleep rhythms may be involved in memory consolidation. What was missing, however, was evidence that they in fact impact neuronal firing rates, i.e., the 'hard currency' of learning and plasticity.

Scientists now recorded the brain activity of 10 human participants as they were asleep using a technique known as intracranial electroencephalography (iEEG). These participants were patients with epilepsy who had electrodes implanted in their brain as part of their treatment.

While the patients were sleeping, Staresina and his colleagues simultaneously recorded their sleep rhythms and neuron firing rates. The recordings they collected showed that firing rates and neural communication are indeed orchestrated by slow oscillations, spindles and ripples, as they hypothesized.

Bernhard P. Staresina et al, How coupled slow oscillations, spindles and ripples coordinate neuronal processing and communication during human sleep, Nature Neuroscience (2023). DOI: 10.1038/s41593-023-01381-w

Comment by Dr. Krishna Kumari Challa on July 20, 2023 at 12:51pm

People With Complete Color Blindness Given Their First Sight of Color
A small selection of volunteers who were completely color blind can now faintly detect a splash of color following retinal gene therapy.

Following the trial by researchers in Israel, three adults and one child who could only sense brightness of light found that after gene therapy they were able to tell a red object apart from its darker background.
Achromatopsia is caused by defects in genes that control cone cells, our eyes' color-sensors. The approximately 1 in 30,000 people affected see all the vibrant colors of the world as blurry shades of gray.

A single gene mutation caused the congenital condition in the volunteers, and the researchers hoped that inserting functional copies of the gene into cone cells would allow them to see color.
The researchers used a viral vector to transport a functional copy of the gene into the retina which houses cone cells, in one of each participant's eyes.
Researchers found treated 'achromats' can perceive red color, albeit in a very limited way, and differently than normally sighted controls.
But the different shades of gray were not replaced by a range of rainbow colors.

Nevertheless, color detection was evident in all patients' treated eyes.

https://www.cell.com/current-biology/fulltext/S0960-9822(23)00826-6?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0960982223008266%3Fshowall%3Dtrue

Comment by Dr. Krishna Kumari Challa on July 20, 2023 at 12:03pm

Lasting Brain Effects
Researchers recently examined the brains of patients born with congenital blindness who had their vision restored surgically. Despite many years of having their sight back, these individuals had a visual cortex that more closely resembled the corresponding visual areas of individuals with permanent blindness.

Why this matters: These findings suggest that harsh experiences or environments early in life can result in irreversible structural changes in multiple regions of the brain. Poverty and adversity (abuse or neglect) have often been found to have a widespread effect across the brain, and extrapolating from this vision study, experts expect permanent neurological changes resulting from harsh early experiences, write Cordula Hölig, Brigitte Röder and Ramesh Kekunnaya, cognitive neuroscientists and an ophthalmologist, respectively, who are the study’s lead authors.

What the experts say: “Poverty and adversity can cause changes in brain development. …Ensuring access to safe environments, affordable health care, healthy food and appropriate education gives children the opportunity to develop and stay physically and mentally healthy,” write the study authors.

Comment by Dr. Krishna Kumari Challa on July 20, 2023 at 12:02pm

The true cost of science’s language barrier
Researchers whose first language is not English can spend around twice as long reading an English-language scientific journal article as native speakers. In a survey of more than 900 environmental scientists from 8 countries, non-native speakers also reported needing more time to prepare conference presentations in English — and many avoid this type of commitment. Conservation scientist and co-author Tatsuya Amano has felt the impact first-hand as a Japanese researcher who has adapted to working in the United Kingdom and Australia. “Behind the scenes, I have to spend so much time to reach that level.”

https://journals.plos.org/plosbiology/article?id=10.1371/journal.pb...

https://www.nature.com/articles/d41586-023-02320-2?utm_source=Natur...

Comment by Dr. Krishna Kumari Challa on July 20, 2023 at 11:59am

Can India's new billion-dollar funding agency boost research?

India’s proposed National Research Foundation will shake up the scientific landscape to encourage a culture of research.

India is planning to set up a national agency to increase research across the nation’s thousands of universities, colleges, institutes and laboratories. Legislation to establish the fund is expected to be introduced into the Indian Parliament in the next three weeks.

The National Research Foundation (NRF) will have a budget of roughly US$6 billion over five years. Some 70% of these funds is intended to come from investors in the private sector, and the remaining portion will be covered by the government.

The NRF’s goal is to “seed, grow and promote” research across the country’s institutions by strengthening ties between academia, industry and the government, according to a statement from the Ministry of Science and Technology.

https://www.nature.com/articles/d41586-023-02336-8?utm_source=Natur...

Comment by Dr. Krishna Kumari Challa on July 20, 2023 at 11:51am

Bacterial protein found in the urogenital tract may contribute to reduced fertility, birth defects

A   study, published on July 17 in the Proceedings of the National Academy of Sciences (PNAS), established a new link between genomic instability and a protein from Mycoplasma fermentans, a kind of bacterium that commonly colonizes the urogenital tract. This bacterial protein also reduced fertility in mother mice and resulted in more birth defects in their newborn pups.

The study results not only broaden our understanding of the interplay between the urogenital tract microbiota and human reproductive health, but also shed light on the previously unidentified contribution of the human microbiota to genetic abnormalities.

For this latest study, researchers created mice that make the DnaK protein normally produced by the bacterium Mycoplasma fermentans. These mice with exposure to DnaK accrued genomic instability in which entire sections of the genome were duplicated or deleted, resulting in mice with varying numbers of copies of certain genes.

The team noticed that some of these mice from three to five weeks of age had problems with movement and coordination. They found that these mice have a deletion in the Grid2 gene, which in humans leads to the rare genetic disease known as spinocerebellar ataxia-18 (SCAR18) that causes delayed development of skilled movements and intellectual disabilities.

Remarkably, this instance marks the first time a mouse model successfully recapitulated a human genetic disease de novo, showcasing this model's potential for further cancer biology research.

More than a third of the female mice that made the DnaK protein were unable to get pregnant. Additionally, more than 20% of the pups born from moms with the DnaK protein had some sort of birth defect/deformity.

"The occurrences of genomic instability, in the form of increased number of copy number variations, could explain the decreased fertility and the increased instances of abnormally developed fetuses we observed upon DnaK exposure.

https://www.pnas.org/doi/10.1073/pnas.2219897120

Comment by Dr. Krishna Kumari Challa on July 20, 2023 at 11:39am

Can two exoplanet siblings share a single orbit?

Using the Atacama Large Millimeter/submillimeter Array (ALMA), astronomers have found the possible "sibling" of a planet orbiting a distant star. The team has detected a cloud of debris that might be sharing this planet's orbit, which they think  could be the building blocks of a new planet or the remnants of one already formed. If confirmed, this discovery would be the strongest evidence yet that two exoplanets can share one orbit.

Two decades ago it was predicted in theory that pairs of planets of similar mass may share the same orbit around their star, the so-called Trojan or co-orbital planets. For the first time, scientists have found evidence in favour of that idea.

Trojans, rocky bodies in the same orbit as a planet, are common in our own solar system, the most famous example being the Trojan asteroids of Jupiter—more than 12,000 rocky bodies that are in the same orbit around the sun as the gas giant. Astronomers have predicted that Trojans, in particular Trojan planets, could also exist around a star other than our sun, but evidence for them is scant.

"Exotrojans [Trojan planets outside the solar system] have so far been like unicorns: They are allowed to exist by theory but no one has ever detected them.

Now, an international team of scientists have used ALMA, in which ESO is a partner, to find the strongest observational evidence yet that Trojan planets could exist—in the PDS 70 system. This young star is known to host two giant Jupiter-like planets, PDS 70b and PDS 70c. By analyzing archival ALMA observations of this system, the team spotted a cloud of debris at the location in PDS 70b's orbit where Trojans are expected to exist.

Trojans occupy the so-called Lagrangian zones, two extended regions in a planet's orbit where the combined gravitational pull of the star and the planet can trap material. Studying these two regions of PDS 70b's orbit, astronomers detected a faint signal from one of them, indicating that a cloud of debris with a mass up to roughly two times that of our moon might reside there.

The scientists think  this cloud of debris could point to an existing Trojan world in this system, or a planet in the process of forming.

O. Balsalobre-Ruza et al, Tentative co-orbital submillimeter emission within the Lagrangian region L5 of the protoplanet PDS 70 b, Astronomy & Astrophysics (2023). DOI: 10.1051/0004-6361/202346493

Comment by Dr. Krishna Kumari Challa on July 20, 2023 at 10:14am

Magnetic fields around cosmic bodies tend to be asymmetric, or stronger on one side. Magnetic fields can prevent the mixing of materials. So, if the magnetic field is stronger on one side, then that side would have less mixing and thus more hydrogen.

Another theory proposed by the scientists to explain the two faces also depends on magnetic fields. But in this scenario, the fields are thought to change the pressure and density of the atmospheric gases.

The magnetic fields may lead to lower gas pressures in the atmosphere, and this may allow a hydrogen 'ocean' to form where the magnetic fields are strongest.

At present scientists don't know which of these two theories is correct. so further work in this regard is being planned.

Ilaria Caiazzo, A rotating white dwarf shows different compositions on its opposite faces, Nature (2023). DOI: 10.1038/s41586-023-06171-9. www.nature.com/articles/s41586-023-06171-9

Part 2

Comment by Dr. Krishna Kumari Challa on July 20, 2023 at 10:10am

Two-faced star : Unusual white dwarf with a hydrogen side and a helium side

In a first for white dwarfs, the burnt-out cores of dead stars, astronomers have discovered that at least one member of this cosmic family is two faced. One side of the white dwarf is composed of hydrogen, while the other is made up of helium.

The surface of the white dwarf completely changes from one side to the other.

Part 1

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