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Comment by Dr. Krishna Kumari Challa on November 25, 2021 at 8:24am

they eventually determined the structure to be a new complex of proteins that binds RNA. The complex is likely involved in splicing, an important cellular event that enables the translation of genes to proteins, and helps determine which genes are activated at which times.

The insides of cells—and the many proteins found there—are typically studied using one of two techniques: microscope imaging or biophysical association. With imaging, researchers add florescent tags of various colors to proteins of interest and track their movements and associations across the microscope's field of view. To look at biophysical associations, researchers might use an antibody specific to a protein to pull it out of the cell and see what else is attached to it.

The team has been interested in mapping the inner workings of cells for many years. What's different about this study  is the use of deep learning to map the cell directly from cellular microscopy images. The combination of these technologies is unique and powerful because it's the first time measurements at vastly different scales have been brought together.

part 2

Comment by Dr. Krishna Kumari Challa on November 25, 2021 at 8:23am

We might not know half of what's in our cells, new AI technique reveals

Most human diseases can be traced to malfunctioning parts of a cell—a tumor is able to grow because a gene wasn't accurately translated into a particular protein or a metabolic disease arises because mitochondria aren't firing properly, for example. But to understand what parts of a cell can go wrong in a disease, scientists first need to have a complete list of parts.

By combining microscopy, biochemistry techniques and artificial intelligence, researchers have taken what they think may turn out to be a significant leap forward in the understanding of human cells. The technique, known as Multi-Scale Integrated Cell (MuSIC), is described November 24, 2021 in Nature.

Scientists have long realized there's more that we don't know than we know, but now we finally have a way to look deeper. In the pilot study, MuSIC revealed approximately 70 components contained within a human kidney cell line, half of which had never been seen before. In one example, the researchers spotted a group of proteins forming an unfamiliar structure.

Part 1

Comment by Dr. Krishna Kumari Challa on November 24, 2021 at 1:42pm

CITATIONS

C. Sanner et al. Pauli blocking of atom-light scattering. Science. Vol. 374, November, 19 2021, p. 979. doi: 10.1126/science.abh3483.

A.B. Deb and N. Kjærgaard. Observation of Pauli blocking in light scattering from quantum dege.... Science. Vol. 374, November 19, 2021, p. 972. doi: 10.1126/science.abh3470.

Y. Margalit et al. Pauli blocking of light scattering in degenerate fermions. Science. Vol. 374, November 19, 2021, p. 976. doi: 10.1126/science.abi6153

Part 3

Comment by Dr. Krishna Kumari Challa on November 24, 2021 at 1:42pm

To observe the effect, Margalit and colleagues beamed light through a cloud of lithium atoms, measuring the amount of light it scattered. Then, the team decreased the temperature to make the atoms fill up the lowest energy states, suppressing the scattering of light. As the temperature dropped, the atoms scattered 37 percent less light, indicating that many atoms were prevented from scattering light. (Some atoms can still scatter light, for example if they get kicked into higher-energy quantum states that are unoccupied.)

In another experiment, physicist Christian Sanner of the research institute JILA in Boulder, Colo., and colleagues studied a cloud of ultracold strontium atoms. The researchers measured how much light was scattered at small angles, for which the atoms are jostled less by the light and therefore are even less likely to be able to find an unoccupied quantum state. At lower temperatures, the atoms scattered half as much light as at higher temperatures.

The third experiment, performed by Deb and physicist Niels Kjærgaard, also of the University of Otago, measured a similar scattering drop in an ultracold potassium atom cloud and a corresponding increase in how much light was transmitted through the cloud.

Because the Pauli exclusion principle also governs how electrons, protons and neutrons behave, it is responsible for the structure of atoms and matter as we know it. These new results reveal the wide-ranging principle in a new context, says Sanner. “It’s fascinating because it shows a very fundamental principle in nature at work.”

The work also suggests new ways to control light and atoms. “One could imagine a lot of interesting applications,” says theoretical physicist Peter Zoller of the University of Innsbruck in Austria, who was not involved with the research. In particular, light scattering is closely related to a process called spontaneous emission, in which an atom in a high-energy state decays to a lower energy by emitting light. The results suggest that decay could be blocked, increasing the lifetime of the energetic state. Such a technique might be useful for storing quantum information for a lengthier period of time than is normally possible, for example in a quantum computer.

So far, these applications are still theoretical, Zoller says. “How realistic they are is something to be explored in the future.”

https://www.sciencenews.org/article/quantum-physics-atom-light-paul...

Part 2

Comment by Dr. Krishna Kumari Challa on November 24, 2021 at 1:41pm

Scientists finally detected a quantum effect that blocks atoms from scattering light

When all available quantum states are full, ultracold atom clouds become more transparent

A cloud of ultracold atoms is like a motel with a neon “no vacancy” sign.

If a guest at the motel wants to switch rooms, they’re out of luck. No vacant rooms means there’s no choice but to stay put. Likewise, in new experiments, atoms boxed in by crowded conditions have no way to switch up their quantum states. That constraint means the atoms don’t scatter light as they normally would, three teams of researchers report in the Nov. 19 Science. Predicted more than three decades ago, this effect has now been seen for the first time.

Under normal circumstances, atoms interact readily with light. Shine a beam of light on a cloud of atoms, and they’ll scatter some of that light in all directions. This type of light scattering is a common phenomenon: It happens in Earth’s atmosphere. “We see the sky as blue because of scattered radiation from the sun,” says Yair Margalit, who was part of the team at MIT that performed one of the experiments.

But quantum physics comes to the fore in ultracold, dense atom clouds. “The way they interact with light or scatter light is different.

According to a rule called the Pauli exclusion principle, atoms in the experiments can’t take on the same quantum state — namely, they can’t have the same momentum as another atom in the experiment (SN: 5/19/20). If atoms are packed together in a dense cloud and cooled to near absolute zero, they’ll settle into the lowest-energy quantum states. Those low-energy states will be entirely filled, like a motel with no open rooms.

When an atom scatters light, it gets a kick of momentum, changing its quantum state, as it sends light off in another direction. But if the atom can’t change its state due to the crowded conditions, it won’t scatter the light. The atom cloud becomes more transparent, letting light through instead of scattering it.  

Part 1

Comment by Dr. Krishna Kumari Challa on November 24, 2021 at 11:31am

How bacteria makes copper into an antibiotic

Copper in small quantities is an essential nutrient but can also be toxic. Human immune cells use copper to fight invading pathogens. Some microorganisms, in turn, have evolved ways to take up copper and incorporate it into biological molecules, either as a way to absorb copper for nutrition or to neutralize its toxic effects.

One of these organisms is the soil bacterium Pseudomonas aeruginosa, which can cause infections in hospital patients. A new study from researchers published Nov. 19 in Science, shows how P. aeruginosa uses copper to make an antibiotic called fluopsin C.

This finding helps us understand how this pathogenic bacterium resists copper and out competes our natural microbiota during infection and will drive the discovery of new treatments. Fluopsin C was discovered in 1970. It is a broad-spectrum antibiotic that kills a wide range of bacteria and fungi, including strains resistant to other drugs.

The researchers followed the uptake of copper by cultured P. aeruginosa and showed that the copper atoms were incorporated into fluopsin C. 

The researchers found that two small sulfur-containing molecules bind to each copper atom in a mix of cis and trans isomers.

The study shows how Fluopsin C could be synthesized by an enzymatic process instead of using hazardous chemicals. Repurposing copper  into an antibiotic in this way is a different response from processes in most organisms, which either sequester or export the metal from the cell.

Jon B. Patteson et al, Biosynthesis of fluopsin C, a copper-containing antibiotic from Pseudomonas aeruginosa, Science (2021). DOI: 10.1126/science.abj6749

https://phys.org/news/2021-11-bacteria-copper-antibiotic.html?utm_s...

Comment by Dr. Krishna Kumari Challa on November 24, 2021 at 9:54am

When bees get a taste for dead things: Meat-eating 'vulture bees'

A little-known species of tropical bee has evolved an extra tooth for biting flesh and a gut that more closely resembles that of vultures rather than other bees.

Bees don't eat meat. However, a species of stingless bee in the tropics has evolved the ability to do so, presumably due to intense competition for nectar.

These are the only bees in the world that have evolved to use food sources not produced by plants, which is a pretty remarkable change in dietary habits.

Honeybees, bumblebees, and stingless bees have guts that are colonized by the same five core microbes. Unlike humans, whose guts change with every meal, most bee species have retained these same bacteria over roughly 80 million years of evolution. Given their radical change in food choice, a team of UCR scientists wondered whether the vulture bees'  gut bacteria differed from those of a typical vegetarian bee. They differed quite dramatically, according to a study the team published today in the American Society of Microbiologists' journal mBio.

To track these changes, the researchers went to Costa Rica, where these bees are known to reside. They set up baits—fresh pieces of raw chicken suspended from branches and smeared with petroleum jelly to deter ants.

The baits successfully attracted vulture bees and related species that opportunistically feed on meat for their protein. Normally, stingless bees have baskets on their hind legs for collecting pollen. However, the team observed carrion-feeding bees using those same structures to collect the bait.

For comparison, the team also collected stingless bees that feed both on meat and flowers, and some that feed only on pollen. On analyzing the microbiomes of all three bee types, they found the most extreme changes among exclusive meat-feeders.

The vulture bee microbiome is enriched in acid-loving bacteria, which are novel bacteria that their relatives don't have. These bacteria are similar to ones found in actual vultures, as well as hyenas and other carrion-feeders, presumably to help protect them from pathogens that show up on carrion.

Laura L. Figueroa et al, Why Did the Bee Eat the Chicken? Symbiont Gain, Loss, and Retention in the Vulture Bee Microbiome, mBio (2021). DOI: 10.1128/mBio.02317-21

https://phys.org/news/2021-11-bees-dead-meat-eating-vulture-sport.h...

Comment by Dr. Krishna Kumari Challa on November 23, 2021 at 12:12pm

COVIDisAirborne: Multiscale ComputationalMicroscopy of Delta SARS-CoV-2 in a Respiratory Aerosol

Comment by Dr. Krishna Kumari Challa on November 23, 2021 at 12:02pm

Crazy plan  to give Mars an artificial magnetosphere

Terraforming Mars is one of the great dreams of humanity. Mars has a lot going for it. Its day is about the same length as Earth's, it has plenty of frozen water just under its surface, and it likely could be given a reasonably breathable atmosphere in time. But one of the things it lacks is a strong magnetic field. So if we want to make Mars a second Earth, we'll have to give it an artificial one.

The reason magnetic fields are so important is that they shield a planet from solar wind and ionizing particles. Earth's magnetic field prevents most high-energy charged particles from reaching the surface. Instead, they are deflected from Earth, keeping us safe. The magnetic field also prevents solar winds from stripping Earth's atmosphere over time. Early Mars had a thick, water-rich atmosphere, but it was gradually depleted without the protection of a strong magnetic field.

Unfortunately, we can't just recreate Earth's magnetic field on Mars. Our field is generated by a dynamo effect in Earth's core, where the convection of iron alloys generates Earth's geomagnetic field. The interior of Mars is smaller and cooler, and we can't simply "start it up" to create a magnetic dynamo. But there are a few ways we can create an artificial magnetic field, as a recent study shows.

As the study points out, if you want a good planetary magnetic field, what you really need is a strong flow of charged particles, either within the planet or around the planet. Since the former isn't a great option for Mars, the team looks at the latter. It turns out you can create a ring of charged particles around Mars, thanks to its moon Phobos.

Phobos is the larger of the two Martian moons, and it orbits the planet quite closely—so closely that it makes a trip around Mars every eight hours. So the team proposes using Phobos by ionizing particles from its surface, then accelerating them so they create a plasma torus along the orbit of Phobos. This would create a magnetic field strong enough to protect a terraformed Mars.

It's a bold plan, and while it seems achievable, the engineering hurdles would be significant. But as the authors point out, this is the time for ideas. Start thinking about the problems we need to solve, and how we can solve them, so when humanity does reach Mars, we will be ready to put the best ideas to the test.

R.A. Bamford et al, How to create an artificial magnetosphere for Mars, Acta Astronautica (2021). DOI: 10.1016/j.actaastro.2021.09.023

https://phys.org/news/2021-11-absolutely-bonkers-mars-artificial-ma...

Comment by Dr. Krishna Kumari Challa on November 23, 2021 at 11:54am

 How longer lives are tied to physical activity: evolutionary explanation for why lack of physical activity as humans age increases disease risk and reduces longevity.

You know exercise is good for you. Some people can even rattle off reasons it keeps your muscles and joints strong, and how it fights off certain diseases. But  can  you tell the story of why and how physical activity was built into human biology?

A team of evolutionary biologists and biomedical researchers from Harvard are taking a run at it (sometimes literally) in a new study published in PNAS. The work lays out evolutionary and biomedical evidence showing that humans, who evolved to live many decades after they stopped reproducing, also evolved to be relatively active in their later years.

The researchers say that physical activity later in life shifts energy away from processes that can compromise health and toward mechanisms in the body that extend it. They hypothesize that humans evolved to remain physically active as they age—and in doing so to allocate energy to physiological processes that slow the body's gradual deterioration over the years. This guards against chronic illnesses such as cardiovascular disease, type 2 diabetes, and even some cancers.

Researchers examined two pathways by which lifelong physical activity reallocates energy to improve health. The first involves dealing excess energy away from potentially harmful mechanisms, like excess fat storage. The team also identified how physical activity allocates energy to repair and maintenance processes. The paper shows that besides burning calories, physical activity is physiologically stressful, causing damage to the body at the molecular, cellular, and tissue levels. The body's response to this damage, however, is essentially to build back stronger.

This includes repairing tears in muscle fibers, repairing cartilage damage, and healing microfractures. The response also causes the release of exercise-related antioxidants and anti-inflammatories, and enhances blood flow. In the absence of physical activity, these responses are activated less. The cellular and DNA repair processes have been shown to lower the risk of diabetes, obesity, cancer, osteoporosis, Alzheimer's, and depression.

The key take-home point is that because we evolved to be active throughout our lives, our bodies need physical activity to age well. In the past, daily physical activity was necessary in order to survive, but today we have to choose to exercise, that is do voluntary physical activity for the sake of health and fitness.

The active grandparent hypothesis: Physical activity and the evolution of extended human healthspans and lifespans, PNAS (2021). DOI: 10.1073/pnas.2107621118

https://phys.org/news/2021-11-outlines-longer-tied-physical.html?ut...

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