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Comment by Dr. Krishna Kumari Challa on April 16, 2021 at 12:16pm

Starving tuberculosis of sugars may be a new way to fight it

Tuberculosis is a devastating disease that claims over 1.5 million lives each year. The increase in TB cases that are resistant to the current antibiotics means that novel drugs to kill Mycobacterium tuberculosis (Mtb) are urgently needed. Researchers now have successfully discovered how Mycobacterium tuberculosis uses an essential sugar called trehalose, which provides a platform to design new and improved TB drugs and diagnostic agents.

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Tuberculosis (TB), caused by the bacterial pathogen Mycobacterium tuberculosis (Mtb) is the leading cause of death from a single infectious agent world-wide claiming over 1.5 million lives each year.

Mycobacterium tuberculosis (Mtb) is a very unique pathogen and is able to survive in the human body for decades. One way that Mtb survives is by 'eating' scarce energy sources for nutrition, whilst at the same time the human host attempts to limit the food that is available.

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However, we need a better understanding of Mtb's intracellular diet because inhibiting the pathways that allow Mtb to access and use essential food sources could be good targets for the development of new anti-tubercular agents.

One source of energy that Mtb uses is a sugar that is found in its own cell wall, called trehalose. It appears that Mtb has evolved a unique strategy to recycle and reuse this sugar to ensure that it does not waste any potential energy sources, which are in short supply.

The transport protein, which is responsible for the uptake of trehalose, called LpqY, is essential for Mtb to establish infection. If the LpqY protein is deleted and no longer able to function then Mtb can no longer supply itself with trehalose and becomes less pathogenic.

In the paper, "Structural basis of trehalose recognition by the mycobacterial LpqY-SugABC transporter," published in the Journal of Biological Chemistry, researchers from the School of Life Sciences at the University of Warwick, have unraveled the molecular basis of how Mtb uses and transports trehalose, a process which is specific to Mtb and does not occur in humans.

The team used X-ray crystallography to determine the 3-dimensional structure of LpqY and analyzed how this important transport protein is able to bind and recognize trehalose. They then went on to use a number of experimental techniques which showed that LpqY is highly specific for trehalose, is also able to recognize sugars that are similar to trehalose with small modifications and map key recognition features.

 Christopher M. Furze et al. Structural basis of trehalose recognition by the mycobacterial LpqY-SugABC transporter, Journal of Biological Chemistry (2021). DOI: 10.1016/j.jbc.2021.100307

https://phys.org/news/2021-04-starving-tuberculosis-sugars.html?utm...

Comment by Dr. Krishna Kumari Challa on April 15, 2021 at 7:33am

Plastic Is Falling From the Sky. But Where’s It Coming From?

plastic rain is the new acid rain. But where is it all coming from?

New modeling published yesterday in the Proceedings of the National Academy of Sciences shows that 84 percent of airborne microplastics in the American West actually comes from the roads outside of major cities. Another 11 percent could be blowing all the way in from the ocean. (The researchers who built the model reckon that microplastic particles stay airborne for nearly a week, and that’s more than enough time for them to cross continents and oceans.)

Microplastics—particles smaller than 5 millimeters—come from a number of sources. Plastic bags and bottles released into the environment break down into smaller and smaller bits. Your washing machine is another major source: When you launder synthetic clothing, tiny microfibers slough off and get flushed to a wastewater treatment plant. That facility filters out some of the microfibers, trapping them in “sludge,” the treated human waste that’s then applied to agricultural fields as fertilizer. That loads the soil with microplastic. A wastewater plant will then flush the remaining microfibers out to sea in the treated water. This has been happening for decades, and because plastics disintegrate but don’t ever really disappear, the amount in the ocean has been skyrocketing.

In fact, this new research shows there may now be more microplastic blowing out of the ocean at any given time than there is going into it. Put another way: So much has accumulated in the ocean that the land may now be a net importer of microplastic from the sea. These microplastics aren’t just washing ashore and accumulating on beaches. When waves crash and winds scour the ocean, they launch seawater droplets into the air. These obviously contain salt, but also organic matter and microplastics. Then the water evaporates, and you're left just with the aerosols or tiny floating bits of particulate matter.  last year, a group of researchers demonstrated this phenomenon with microplastics, showing that they turn up in sea breezes.

https://www.wired.com/story/plastic-is-falling-from-the-sky/?utm_so...

Comment by Dr. Krishna Kumari Challa on April 15, 2021 at 7:24am

Microplastics rain from the sky

The atmosphere is laden with tiny plastic fragments. Researchers modelled the air above the western United States and found that it contains almost 1,000 tonnes of microplastic. Most — 84% — comes from roads, much of it from car tyres that constantly produce microplastics as they wear down. And 11% blows in from the ocean — which has so much plastic in it that most continents receive more from the marine environment than they put in.

https://www.pnas.org/content/118/16/e2020719118

Comment by Dr. Krishna Kumari Challa on April 15, 2021 at 6:57am

3D-printed material to replace ivory for restoration of artifacts

For centuries, ivory was often used to make art objects. But to protect elephant populations, the ivory trade was banned internationally in 1989. To restore ivory parts of old art objects, one must therefore resort to substitute materials—such as bones, shells or plastic. However, there has not been a really satisfactory solution so far.

Researchers have now developed a high-tech substitute:  the novel material "Digory" consists of synthetic resin and calcium phosphate particles. It is processed in a hot, liquid state and hardened in the 3D printer with UV rays, exactly in the desired shape. It can then be polished and color-matched to create a deceptively authentic-looking ivory substitute.

 With the new material "Digory," not only is a better, more beautiful and easier to work with substitute for ivory available than before, the 3D technology also makes it possible to reproduce the finest details automatically. Instead of painstakingly carving them out of ivory substitute material, objects can now be printed in a matter of hours.

Thaddäa Rath et al. Developing an ivory-like material for stereolithography-based additive manufacturing, Applied Materials Today (2021). DOI: 10.1016/j.apmt.2021.101016

https://phys.org/news/2021-04-3d-printed-material-ivory-artifacts.h...

Comment by Dr. Krishna Kumari Challa on April 15, 2021 at 6:50am

Climate change makes Indian monsoon stronger, more erratic: study

Climate change is making India's monsoon stronger and more chaotic, scientists said recently, warning of potential severe consequences for food, farming and the economy affecting nearly a fifth of the world's population.

A new analysis comparing more than 30 climate models from around the world predicts more extremely wet rainy seasons, which sweep in from the sea from roughly June to September each year.

Researchers at the Potsdam-Institute for Climate Impact Research (PIK) found strong evidence that every degree Celsius of warming would likely increase monsoon rainfall by about five percent.

The study not only confirmed trends seen in previous research, but found "global warming is increasing monsoon rainfall in India even more than previously thought.

This raises the possibility that key crops—including rice—could be swamped during crucial growing stages.

Moreover, the monsoon is likely to become more erratic as warming increases, according to the study, published in the journal Earth System Dynamics.

Anja Katzenberger, Jacob Schewe, Julia Pongratz, Anders Levermann: Robust increase of Indian monsoon rainfall and its variability under future warming in CMIP-6 models. Earth System Dynamics. DOI: 10.5194/esd-2020-80.

https://phys.org/news/2021-04-climate-indian-monsoon-seasons-chaoti...

Comment by Dr. Krishna Kumari Challa on April 15, 2021 at 6:16am

Power of light and oxygen clears Alzheimer's disease protein in live mice

A small, light-activated molecule recently tested in mice represents a new approach to eliminating clumps of amyloid protein found in the brains of Alzheimer's disease patients. If perfected in humans, the technique could be used as an alternative approach to immunotherapy and used to treat other diseases caused by similar amyloids.

Researchers injected the molecule directly into the brains of live mice with Alzheimer's disease and then used a specialized probe to shine light into their brains for 30 minutes each day for one week. Chemical analysis of the mouse brain tissue showed that the treatment significantly reduced amyloid protein. Results from additional experiments using human brain samples donated by Alzheimer's disease patients supported the possibility of future use in humans.

The importance of this study is developing the technique to target the amyloid protein to enhance clearance of it by the immune system.

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The small molecule that the research team developed is known as a photo-oxygenation catalyst. It appears to treat Alzheimer's disease via a two-step process.

First, the catalyst destabilizes the amyloid plaques. Oxygenation, or adding oxygen atoms, can make a molecule unstable by changing the chemical bonds holding it together. Laundry detergents or other cleaners known as oxygen bleach use a similar chemical principle.

The catalyst is designed to target the folded structure of amyloid and likely works by cross-linking specific portions called histidine residues. The catalyst is inert until it is activated with near-infrared light, so in the future, researchers imagine that the catalyst could be delivered throughout the body by injection into the bloodstream and targeted to specific areas using light.

Second, the destabilized amyloid is then removed by microglia, immune cells of the brain that clear away damaged cells and debris outside healthy cells.

Photo-oxygenation by a biocompatible catalyst reduces amyloid-β levels in Alzheimer's disease model, Brain (2021). DOI: 10.1093/brain/awab058

https://medicalxpress.com/news/2021-04-power-oxygen-alzheimer-disea...

Comment by Dr. Krishna Kumari Challa on April 15, 2021 at 6:09am

Social wasps lose face recognition abilities in isolation

Just as humans are challenged from the social isolation caused by the coronavirus pandemic, a new study finds that a solitary lifestyle has profound effects on the brains of a social insect: paper wasps.

Paper wasps (Polistes fuscatus) recognize the brightly colored faces of other paper wasps, an ability they lose when reared in isolation. The wasps' ability to remember faces is similar to primates and humans, but unlike other social insects.

The study revealed that when adult wasps are housed in solitude, visual areas of their brains—especially those involved with identifying nuanced color patterns and shapes—are smaller and less developed than their peers who lived with other wasps.

Christopher M. Jernigan et al. Age and social experience induced plasticity across brain regions of the paper wasp Polistes fuscatus, Biology Letters (2021). DOI: 10.1098/rsbl.2021.0073

https://phys.org/news/2021-04-social-wasps-recognition-abilities-is...

Comment by Dr. Krishna Kumari Challa on April 15, 2021 at 6:04am

part 2

The scientists used a quantum antiferromagnet, known in the field as SCBO (from its chemical composition: SrCu₂(BO₃)₂). Quantum antiferromagnets are especially useful for understanding how the quantum aspects of a material's structure affect its overall properties—for example, how the spins of its electrons interact to give its magnetic properties. SCBO is also a "frustrated" magnet, meaning that its electron spins can't stabilize in some orderly structure, and instead they adopt some uniquely quantum fluctuating states.

In a complex experiment, the researchers controlled both the pressure and the magnetic field applied to milligram pieces of SCBO. "This allowed us to look all around the discontinuous quantum phase transition and that way we found critical-point physics in a pure spin system.

Researchers 

performed high-precision measurements of the specific heat of SCBO, which showed its readiness to absorb energy. For example, water absorbs only small amounts of energy at -10 degrees C, but at 0 degrees C and 100 degrees C, it can take up huge amounts as every molecule is driven across the transitions from ice to liquid and liquid to gas. Just like water, the pressure-temperature relationship of SCBO forms a phase diagram showing a discontinuous transition line separating two quantum magnetic phases, with the line ending at a critical point.

Now, when a magnetic field is applied, the problem becomes richer than water. Neither magnetic phase is strongly affected by a small field, so the line becomes a wall of discontinuities in a three-dimensional phase diagram—but then one of the phases becomes unstable and the field helps push it towards a third phase."

A quantum magnetic analogue to the critical point of water, Nature (2021). DOI: 10.1038/s41586-021-03411-8

https://phys.org/news/2021-04-quantum-magnets-critical-physics.html...

Comment by Dr. Krishna Kumari Challa on April 15, 2021 at 6:02am

Water and quantum magnets share critical physics

In physics, things exist in phases, such as solid, liquid and gas states. When something crosses from one phase to another, we talk about a phase transition—like water boiling into steam, turning from liquid to gas.

Water boils at 100 degrees C, and its density changes dramatically, making a discontinuous jump from liquid to gas. However, if we turn up the pressure, the boiling point of water also increases, until a pressure of 221 atmospheres where it boils at 374 degrees C. Here, something strange happens: the liquid and gas merge into a single phase. Above this "critical point," there is no longer a phase transition at all, and so by controlling its pressure, water can be steered from liquid to gas without ever crossing one.

Is there a quantum version of a water-like phase transition? The current directions in quantum magnetism and spintronics require highly spin-anisotropic interactions to produce the physics of topological phases and protected qubits, but these interactions also favor discontinuous quantum phase transitions.

Previous studies have focused on smooth, continuous phase transitions in quantum magnetic materials. Now researchers have studied a discontinuous phase transition to observe the first ever critical point in a quantum magnet, similar to that of water. The work is now published in Nature.

Comment by Dr. Krishna Kumari Challa on April 14, 2021 at 12:45pm

Wildfires launch microbes into the air. How big of a health risk is that?

Now that they know bacteria and fungi can survive in wildfire smoke, a small group of researchers is trying to figure out the implications

https://www.sciencenews.org/article/wildfire-smoke-microbes-air-hea...

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