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Comment by Dr. Krishna Kumari Challa on March 31, 2021 at 8:16am

Physicists flip particle accelerator setup to gain a clearer view of atomic nuclei

Physicists at MIT and elsewhere are blasting beams of ions at clouds of protons —like throwing nuclear darts at the speed of light—to map the structure of an atom's nucleus.

The experiment is an inversion of the usual particle accelerators, which hurl electrons at atomic nuclei to probe their structures. The team used this "inverse kinematics" approach to sift out the messy, quantum mechanical influences within a nucleus, to provide a clear view of a nucleus' protons and neutrons, as well as its short-range correlated (SRC) pairs. These are pairs of protons or neutrons that briefly bind to form super-dense droplets of nuclear matter and that are thought to dominate the ultradense environments in neutron stars.

The results, published today in Nature Physics, demonstrate that inverse kinematics may be used to characterize the structure of more unstable nuclei—essential ingredients scientists can use to understand the dynamics of neutron stars and the processes by which they generate heavy elements.

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Particle accelerators typically probe nuclear structures through electron scattering, in which high-energy electrons are beamed at a stationary cloud of target nuclei. When an electron hits a nucleus, it knocks out protons and neutrons, and the electron loses energy in the process. Researchers measure the energy of the electron beam before and after this interaction to calculate the original energies of the protons and neutrons that were kicked away.

While electron scattering is a precise way to reconstruct a nucleus' structure, it is also a game of chance. The probability that an electron will hit a nucleus is relatively low, given that a single electron is vanishingly small in comparison to an entire nucleus. To increase this probability, beams are loaded with ever-higher electron densities.

Scientists also use beams of protons instead of electrons to probe nuclei, as protons are comparably larger and more likely to hit their target. But protons are also more complex, and made of quarks and gluons, the interactions of which can muddy the final interpretation of the nucleus itself.

To get a clearer picture, physicists in recent years have inverted the traditional setup: By aiming a beam of nuclei, or ions, at a target of protons, scientists can not only directly measure the knocked out protons and neutrons, but also compare the original nucleus with the residual nucleus, or nuclear fragment, after it has interacted with a target proton.

"With inverted kinematics, we know exactly what happens to a nucleus when we remove its protons and neutrons.

Unperturbed inverse kinematics nucleon knockout measurements with a carbon beam, Nature Physics (2021). DOI: 10.1038/s41567-021-01193-4

https://phys.org/news/2021-03-physicists-flip-particle-setup-gain.h...

Comment by Dr. Krishna Kumari Challa on March 30, 2021 at 10:11am

Self healing robots

Comment by Dr. Krishna Kumari Challa on March 30, 2021 at 10:00am

New drug to regenerate lost teeth

Antibody for USAG-1 shown to stimulate tooth growth

A new study by scientists at Kyoto University and the University of Fukui, however, may offer some hope. The team reports that an antibody for one gene -- uterine sensitization associated gene-1 or USAG-1 -- can stimulate tooth growth in mice suffering from tooth agenesis, a congenital condition. The paper was published in Science Advances.

Although the normal adult mouth has 32 teeth, about 1% of the population has more or fewer due to congenital conditions. Scientists have explored the genetic causes for cases having too many teeth as clues for regenerating teeth in adults.

According to researchers the fundamental molecules responsible for tooth development have already been identified. The morphogenesis of individual teeth depends on the interactions of several molecules including BMP, or bone morphogenetic protein, and Wnt signaling.

The paper "Anti-USAG-1 therapy for tooth regeneration through enhanced BMP signaling" appeared 12 February 2021 in the journal Science Advances, with doi: 10.1126/sciadv.abf1798

https://www.eurekalert.org/pub_releases/2021-03/ku-ndt032921.php

Comment by Dr. Krishna Kumari Challa on March 30, 2021 at 9:50am

A third of global farmland at 'high' pesticide pollution risk

A third of the planet's agricultural land is at "high risk" of pesticide pollution from the lingering residue of chemical ingredients that can leach into water supplies and threaten biodiversity, according to research published recently.

The use of pesticides has soared globally as agricultural production has expanded, prompting growing fears over environmental damage and calls to cut hazardous chemical use.

Researchers in Australia modelled pollution risk across 168 countries with data on the usage of 92 active pesticide ingredients and found "widespread global pesticide pollution risk".

They highlighted several acutely vulnerable ecosystems in South Africa, China, India, Australia and Argentina, at the nexus of high pollution risk, high water scarcity and high biodiversity.

The study, published in Nature Geoscience, found that overall 64 percent of global agricultural land —approximately 24.5 million square kilometres (9.4 million sq miles)—was at risk of pesticide pollution from more than one active ingredient, and 31 percent is at high risk.

It is significant because the potential pollution is widespread and some regions at risk also bear high biodiversity and suffer from water scarcity.

Risk of pesticide pollution at the global scale, Nature Geoscience (2021). DOI: 10.1038/s41561-021-00712-5

https://phys.org/news/2021-03-global-farmland-high-pesticide-pollut...

Comment by Dr. Krishna Kumari Challa on March 30, 2021 at 9:17am

Scientists create simple synthetic cell that grows and divides normally

Five years ago, scientists created a single-celled synthetic organism that, with only 473 genes, was the simplest living cell ever known. However, this bacteria-like organism behaved strangely when growing and dividing, producing cells with wildly different shapes and sizes.

Now, scientists have identified seven genes that can be added to tame the cells' unruly nature, causing them to neatly divide into uniform orbs. This achievement

was described in the journal Cell.

Identifying these genes is an important step toward engineering synthetic cells that do useful things. Such cells could act as small factories that produce drugs, foods and fuels; detect disease and produce drugs to treat it while living inside the body; and function as tiny computers.

But to design and build a cell that does exactly what you want it to do, it helps to have a list of essential parts and know how they fit together.

Cell (2021). DOI: 10.1016/j.cell.2021.03.008

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Scientists at JCVI constructed the first cell with a synthetic genome in 2010. They didn't build that cell completely from scratch. Instead, they started with cells from a very simple type of bacteria called a mycoplasma. They destroyed the DNA in those cells and replaced it with DNA that was designed on a computer and synthesized in a lab. This was the first organism in the history of life on Earth to have an entirely synthetic genome. They called it JCVI-syn1.0.

Since then, scientists have been working to strip that organism down to its minimum genetic components. The super-simple cell they created five years ago, dubbed JCVI-syn3.0, was perhaps too minimalist. The researchers have now added 19 genes back to this cell, including the seven needed for normal cell division, to create the new variant, JCVI-syn3A. This variant has fewer than 500 genes. To put that number in perspective, the E. coli bacteria that live in your gut have about 4,000 genes. A human cell has around 30,000.

https://phys.org/news/2021-03-scientists-simple-synthetic-cell.html...

Comment by Dr. Krishna Kumari Challa on March 29, 2021 at 10:08am

Study confirms evolutionary link between social structure and selfishness

Researchers revealed that less selfish behavior evolved under living conditions that forced individuals to interact more frequently with siblings. More selfishness makes you not to interact with your siblings. While the finding was verified with insect experiments,  the evolutionary principle could be applied to study any species, including humans.

In laboratory tests, researchers showed they could predictably increase or decrease rates of cannibalism in Indian meal moths by decreasing how far individuals could roam from one another, and thus increasing the likelihood of "local" interactions between sibling larvae. In habitats where caterpillars were forced to interact more often with siblings, less selfish behavior evolved within 10 generations.

In societies or cultures that live in big family groups among close relatives, for example, you might expect to see less selfish behavior, on average, than in societies or cultures where people are more isolated from their families and more likely to be surrounded by strangers because they have to move often for jobs or other reasons.

Mike Boots et al, Experimental evidence that local interactions select against selfish behaviour, Ecology Letters (2021). DOI: 10.1111/ele.13734

https://phys.org/news/2021-03-evolutionary-link-social-selfishness....

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Comment by Dr. Krishna Kumari Challa on March 28, 2021 at 10:00am

Scientists Discover Deep-Sea Microbes That Are Invisible to Our Immune System

Bacteria collected from more than a mile below the surface of the Pacific Ocean may have just blown one of immunology's longest-held assumptions clean out of the water.

The bacteria are so alien to humans that our immune cells do not even register that they exist, making them completely invisible to our immune systems.

This totally contradicts one of the classic tenets of immunology – that the human immune system evolved to be able to sense every single microbe so it could catch the infectious ones.

"The idea was that the immune system is a generalist, it doesn't care if something was a threat or not, it just got rid of it. But no one had really pressure tested that assumption until now.

To test this, the researchers had to find bacteria that were unlikely to have ever had previous contact with mammalian immune systems. They chose a spot deep in the central Pacific Ocean, in the Phoenix Islands Protected Area in Kiribati, 1,650 miles (2,655 kilometers) southwest of Hawaii.

"It's not just the deep ocean, but the most deep, ancient, remote, and protected part of the ocean. It's 4,000 meters (13,100 feet) deep; there are no resident mammals; and it's on the equatorial space where there wouldn't even be any whales for there to be any whale falls. 

Once there, researchers used a remote submarine to collect marine bacteria from samples of water, sponge, sea star, and sediment, before growing them into 117 culturable species.

After identifying the features of their bacteria, the researchers introduced 50 of the strains to mouse and human immune cells. To their surprise, they found that 80 percent of the microbes, mostly belonging to the genus Moritella, escaped detection. The receptors on the mammalian bone marrow immune cells used in the study were incapable of seeing them.

To try to narrow down which features of the marine bacteria made them invisible to our immune receptors, the team also exposed the mouse and human cells to just one specific part of the bacterial cell wall, called the lipopolysaccharide (LPS). Mammalian immune systems are known to use this outermost part of the bacterial cell wall to recognize so-called gram-negative bacteria and put up a fight.

The researchers found that the mammal cells' receptors were blind to the LPS on its own, too.

"The LPS molecules looked similar to what you'd find in bacteria on land, but many of them were completely silent," Kagan said. "This is because the lipid chains on the LPS turned out to be much longer than the ones we're used to on land, but we still don't know why that means they can go undetected."

Despite their spooky ability to evade detection, the researchers said that deep-sea bacteria don't pose any risk of infecting people. 

Firstly, they haven't evolved to evade mammalian immune systems, so if there was any pathogenicity it would be accidental. The second reason it's highly unlikely is that the temperatures, pressures, and the chemical environments inside our bodies are so different to what you'd find at the bottom of the ocean. These bacteria aren't happy for more than a few minutes outside of their normal habitat.

https://immunology.sciencemag.org/content/6/57/eabe0531

https://www.sciencealert.com/scientists-discover-deep-sea-microbes-...

Comment by Dr. Krishna Kumari Challa on March 28, 2021 at 9:53am

Corals may need their predators' poop

How Scientists Are Restoring The Great Barrier Reef

Comment by Dr. Krishna Kumari Challa on March 27, 2021 at 12:58pm

First Report of Horizontal Gene Transfer Between Plant and Animal

Whiteflies overcome a toxin in plants they eat through the use of the plant’s own genetic protection, likely ferried from plant to insect millions of years ago by a virus.

In the first known example of horizontal gene transfer between a plant and an animal, a common pest known as the whitefly (Bemisia tabaci) acquired a gene from the one of the various plants it feeds on, researchers reported today (March 25) in Cell. The gene, BtPMaT1, protects the insects from phenolic glycosides, toxins that many plants produce to defend themselves against such pests, thus allowing the whiteflies to feast.

J. Xia et al., “Whitefly hijacks a plant detoxification gene that neutralizes plant toxins,” Cell, doi:10.1016/j.cell.2021.02.014, 2021.

Comment by Dr. Krishna Kumari Challa on March 27, 2021 at 12:49pm

It's snowing plastic

The snow may be melting, but it is leaving pollution behind in the form of micro- and nano-plastics according to a McGill study that was recently published in Environmental Pollution. The pollution is largely due to the relatively soluble plastics found in antifreeze products (polyethylene glycols) that can become airborne and picked up by the snow.

The researchers used a new technique that they have developed to analyze snow samples collected in April 2019 in Montreal for both micro- and nano-sized particles of various plastics. The McGill technique is orders of magnitude more sensitive than any of the other current methods used for tracing plastic in the environment. It allows scientists to detect ultra-trace quantities of many of the most common soluble and insoluble plastics in snow, water, rainfall, and even in soil samples once they have been separated – down to the level of a picogram (or one trillionth of a gram). It is based on using nano-structured mass spectrometry and, unlike other techniques currently in use, the new technique is both recyclable and based on sustainable practices.

https://researchnews.cc/news/5835/It-s-snowing-plastic#.YF7xN68zbIU

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