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Comment by Dr. Krishna Kumari Challa on December 14, 2020 at 12:05pm

Expandable Foam Supersizes 3D-Printed Objects - Headline Science

Comment by Dr. Krishna Kumari Challa on December 14, 2020 at 11:42am

Physicists use antiferromagnetic rust to carry information over lon... Be it with smartphones, laptops, or mainframes: The transmission, processing, and storage of information is currently based on a single class of material—as it was in the early days of computer science about 60 years ago. A new class of magnetic materials, however, could raise information technology to a new level. Antiferromagnetic insulators enable computing speeds that are a thousand times faster than conventional electronics, with significantly less heating. Components could be packed closer together and logic modules could thus become smaller, which has so far been limited due to the increased heating of current components.

Asteroid Ryugu dust delivered to Earth; NASA astrobiologists prepar... On Dec. 6 local time (Dec. 5 in the United States), Japanese spacecraft Hayabusa2 dropped a capsule to the ground of the Australian Outback from about 120 miles (or 200 kilometers) above Earth's surface. Inside that capsule is some of the most precious cargo in the solar system: dust that the spacecraft collected earlier this year from the surface of asteroid Ryugu.

Comment by Dr. Krishna Kumari Challa on December 14, 2020 at 11:15am

Charles Darwin was right about why insects are losing the ability to fly

Most insects can fly.

Yet scores of species have lost that extraordinary ability, particularly on islands.

On the small islands that lie halfway between Antarctica and continents like Australia, almost all the insects have done so.

Flies walk, moths crawl.

Of course, Charles Darwin knew about this wing loss habit of island insects. He and the famous botanist Joseph Hooker had a substantial argument about why this happens. Darwin's position was deceptively simple. If you fly, you get blown out to sea. Those left on land to produce the next generation are those most reluctant to fly, and eventually evolution does the rest. 

But since Hooker expressed his doubt, many other scientists have too.

In short, they have simply said Darwin got it wrong.

Yet almost all of these discussions have ignored the place that is the epitome of flight loss—those 'sub-Antarctic' islands. Lying in the 'roaring forties' and 'furious fifties', they're some of the windiest places on Earth.

If Darwin really got it wrong, then wind would not in any way explain why so many insects have lost their ability to fly on these islands.

Using a large, new dataset on insects from sub-Antarctic and Arctic islands, Monash University researchers examined every idea proposed to account for flight loss in insects, including Darwin's wind idea.

Reporting today in Proceedings of the Royal Society B, they show that Darwin was right for this 'most windy of places'. None of the usual ideas (such as those proposed by Hooker) explain the extent of flight loss in sub-Antarctic insects, but Darwin's idea does. Although in a slightly varied form, in keeping with modern ideas on how flight loss actually evolves.

Windy conditions make insect flight more difficult and energetically costly. Thus, insects stop investing in flight and its expensive underlying machinery (wings, wing muscles) and redirect the resources to reproduction.

Wind plays a major but not exclusive role in the prevalence of insect flight loss on remote islands.

 Proceedings of the Royal Society B, rspb.royalsocietypublishing.or … .1098/rspb.2020.2121

https://phys.org/news/2020-12-charles-darwin-insects-ability.html?u...

Comment by Dr. Krishna Kumari Challa on December 13, 2020 at 12:17pm

Study sheds light on diabetes and COVID interaction
NASHVILLE, TN.- COVID-19 has been linked to cases of new-onset diabetes, diabetes-related emergencies and a higher death rate among diabetes patients. While this suggests that SARS-CoV-2, the virus that causes COVID-19, may infect and damage the insulin-producing beta cells of the pancreas, that does not appear to be the case, according to a report by researchers at Vanderbilt University Medical Center published Dec. 1 in the journal Cell Metabolism. “This is important information in terms of understanding the interaction of diabetes and SARS-CoV-2 and COVID-19,” said Katie Coate, PhD, who led the study with Jeeyeon Cha, MD, PhD. “There are other potential pathways for how SARS-CoV-2 infects cells, and these are just beginning to be described or are as yet undiscovered

Comment by Dr. Krishna Kumari Challa on December 12, 2020 at 10:28am

Researchers find why 'lab-made' proteins have unusually high temperature stability

Bioengineers have found why proteins that are designed from scratch tend to be more tolerant to high temperatures than proteins found in nature.

Rie Koga et al, Robust folding of a de novo designed ideal protein even with most of the core mutated to valine, Proceedings of the National Academy of Sciences (2020). DOI: 10.1073/pnas.2002120117

https://phys.org/news/2020-12-lab-made-proteins-unusually-high-temp...

Comment by Dr. Krishna Kumari Challa on December 12, 2020 at 10:24am

How epigenetic switches control gene expression

Scientists at Tokyo Institute of Technology have deciphered how to quantitatively assess the effects of specific epigenetic changes on the rate of transcription by developing a mathematical model. Using their method, they successfully generated reconstituted chromatin-bearing histone modifications in vitro. Their study published in Nucleic Acids Research provides an accurate quantitative approach for understanding how site-specific changes to histone proteins impact the accessibility of chromatin and gene expression levels.

Masatoshi Wakamori et al, Quantification of the effect of site-specific histone acetylation on chromatin transcription rate, Nucleic Acids Research (2020). DOI: 10.1093/nar/gkaa1050

https://phys.org/news/2020-12-epigenetic-gene.html?utm_source=nwlet...

Comment by Dr. Krishna Kumari Challa on December 12, 2020 at 10:21am

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Black holes gain new powers when they spin fast enough

General relativity is a profoundly complex mathematical theory, but its description of black holes is amazingly simple. A stable black hole can be described by just three properties: its mass, its electric charge and its rotation or spin. Since black holes aren't likely to have much charge, it really takes just two properties. If you know a black hole's mass and spin, you know all there is to know about the black hole.

This property is often summarized as the no-hair theorem. Specifically, the theorem asserts that once matter falls into a black hole, the only characteristic that remains is mass. You could make a black hole out of a sun's worth of hydrogen, chairs or those old copies of National Geographic from Grandma's attic, and there would be no difference. Mass is mass as far as general relativity is concerned. In every case, the event horizon of a black hole is perfectly smooth, with no extra features. "The balck holes have no hair."

But with all its predictive power, general relativity has a problem with quantum theory. This is particularly true with black holes. If the no-hair theorem is correct, the information within an object is destroyed when it crosses the event horizon. Quantum theory says that information can never be destroyed. So the valid theory of gravity is contradicted by the valid theory of the quanta. This leads to problems such as the firewall paradox, which can't decide whether an event horizon should be hot or cold.

Several theories have been proposed to solve this contradiction, often involving extensions to relativity. The difference between standard relativity and these modified theories can only be seen in extreme situations, making them difficult to study observationally. But a new paper in Physical Review Letters shows how they might be studied through the spin of a black hole.

Many modified relativity theories have an extra parameter not seen in the standard theory. Known as a massless scalar field, it allows Einstein's model to connect with quantum theory  in a way that isn't contradictory. In this new work, the team looked at how such a scalar field connects to the rotation of a black hole. They found that at low spins, a modified black hole is indistinguishable from the standard model, but at high rotations, the scalar field allows a black hole to have extra features. In other words, in these alternative models, rapidly rotating black holes can have hair.

The hairy aspects of rotating black holes would only be seen near the event horizon itself, but they would also affect merging black holes. As the authors point out, future gravitational wave observatories should be able to use rapidly rotating black holes to determine whether an alternative to general relativity is valid.

Einstein's theory of general relativity has passed every observational challenge so far, but it will likely break down in the most extreme environments of the universe. Studies such as this show how we might be able to discover the theory that comes next.

 Alexandru Dima et al. Spin-Induced Black Hole Spontaneous Scalarization, Physical Review Letters (2020). DOI: 10.1103/PhysRevLett.125.231101

https://phys.org/news/2020-12-black-holes-gain-powers-fast.html?utm...

Comment by Dr. Krishna Kumari Challa on December 12, 2020 at 10:06am

Some droughts during the Indian monsoon are due to unique North Atl...

A team of researchers from the Indian Institute of Science and Cotton University has found that some droughts during monsoon season in India are due to unique North Atlantic disturbances. In their paper published in the journal Science, the group describes their study of weather patterns in South Asia over the past century and what it showed about monsoon season droughts.

P. J. Borah et al. Indian monsoon derailed by a North Atlantic wavetrain, Science (2020). DOI: 10.1126/science.aay6043

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Current pace of action on climate change is "unthinkable" state ex ...

Justifiable pride can be taken in the incremental accomplishments of international climate change cooperation, but it is "unthinkable" to continue at the current pace. The global response to climate change is completely insufficient and leaves the world on a "road to hell".

Climate Policy (2020). DOI: 10.1080/14693062.2020.1860567

Comment by Dr. Krishna Kumari Challa on December 12, 2020 at 10:01am

Scientists build whole functioning thymus from human cells

Researchers at the Francis Crick Institute and University College London have rebuilt a human thymus, an essential organ in the immune system, using human stem cells and a bioengineered scaffold. Their work is an important step towards being able to build artificial thymi which could be used as transplants.

The thymus is an organ in the chest where T lymphocytes, which play a vital role in the immune system, mature. If the thymus does not work properly or does not form during foetal development in the womb, this can lead to diseases such as severe immunodeficiency, where the body cannot fight infectious diseases or cancerous cells, or autoimmunity, where the immune system mistakenly attacks the patient's own healthy tissue.

In their proof-of-concept study, published in Nature Communications today, the scientists rebuilt thymi using stem cells taken from patients who had to have the organ removed during surgery. When transplanted into mice, the bioengineered thymi were able to support the development of mature and functional human T lymphocytes.

While researchers have previously rebuilt other organs or sections of organs, this is the first-time scientists have successfully rebuilt a whole working human thymus. 

Campinoti, S et al. (2020). Reconstitution of a functional human thymus by postnatal stromal progenitor cells and natural whole-organ scaffolds. Nature Communications, DOI: 10.1038/s41467-020-20082-7

https://medicalxpress.com/news/2020-12-scientists-functioning-thymu...

Comment by Dr. Krishna Kumari Challa on December 12, 2020 at 9:21am

Since its completion in November 1963, the Telescope had been used for radar astronomy and radio astronomy, and had been part of the Search for extraterrestrial intelligence (SETI) program. It was also used by NASA for Near-Earth object detection.
Arecibo joins with telescopes in Europe and with the Russian Radio Astron satellite to form the largest telescope ever – 20 times the size of the Earth. Arecibo continues to obtain orbit refinement of potentially hazardous near-Earth asteroids (PHAs) to identify possible future Earth impactors.
It has several acheivements since it started working
http://www.naic.edu/about/accomplishments.html#:~:text=Arecibo%20jo....

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