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Comment by Dr. Krishna Kumari Challa on June 22, 2023 at 10:51am

Scientists discover critical factors that determine the survival of airborne viruses

Critical insights into why airborne viruses lose their infectivity have been uncovered by scientists.

The findings, published in the Journal of the Royal Society Interface today, reveal how cleaner air kills the virus significantly quicker and why opening a window may be more important than originally thought. The research could shape future mitigation strategies for new viruses.

In the first study to measure differences in airborne stability of different variants of SARS-CoV-2 in inhalable particles, researchers show that the virus has become less capable of surviving in the air as it has evolved from the original strain through to the delta variant.

There are numerous factors that affect the transmission of airborne viruses, and these are often confounded with physical and environmental parameters that can affect viral longevity in the aerosol phase such as temperature, RH, air movement and UV light.

Through manipulating the gaseous content of the air, the researchers confirmed that the aerostability of the virus is controlled by the alkaline pH of the aerosol droplets containing the virus. Importantly, they describe how each of the SARS-CoV-2 variants has different stabilities while airborne, and that this stability is correlated with their sensitivities to alkaline pH conditions.

The high pH of exhaled SARS-CoV-2 virus droplets is likely a major driver of the loss of infectiousness, so the less acid in the air, the more alkaline the droplet, the faster the virus dies. Opening a window may be more important than originally thought as fresh air with lower carbon dioxide, reduces acid content in the atmosphere and means the virus dies significantly quicker.

Differences in Airborne Stability of SARS-CoV-2 Variants of Concern is Impacted by Alkalinity of Surrogates of Respiratory Aerosol, Journal of the Royal Society Interface (2023). DOI: 10.1098/rsif.2023.0062. royalsocietypublishing.org/doi … .1098/rsif.2023.0062

Comment by Dr. Krishna Kumari Challa on June 22, 2023 at 9:26am

Next, the researchers rubbed flower pollen on a bumblebee so that it could exhibit a natural electric charge. Once close to these bees, worms stood on their tails, then jumped aboard. Some worms even piled on top of each other and jumped in a single column, transferring 80 worms at once across the gap.

"Worms stand on their tail to reduce the surface energy between their body and the substrate, thus making it easier for themselves to attach to other passing objects. In a column, one worm lifts multiple worms, and this worm takes off to transfer across the electric field while carrying all the column worms.

C. elegans is known to attach to bugs and snails for a ride, but because these animals don't carry electric fields well, they must make direct contact to do so. C. elegans is also known to jump on winged insects, but it was not clear how the worms were traversing such a significant distance for their microscopic size. This research makes the connection that winged insects naturally accumulate charge as they fly, producing an electric field that C. elegans can travel along.

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It's unclear exactly how C. elegans performs this behavior. The worms' genetics might play a role. Researchers observed jumping in other worm species closely related to C. elegans, and they noted that mutants who are unable to sense electric fields jump less than their normal counterparts. However, more work is needed to determine exactly what genes are involved in making these jumps and whether other microorganisms can use electricity to jump as well.

Takuma Sugi, Caenorhabditis elegans transfers across a gap under an electric field as dispersal behavior, Current Biology (2023). DOI: 10.1016/j.cub.2023.05.042. www.cell.com/current-biology/f … 0960-9822(23)00674-7

Part 2

Comment by Dr. Krishna Kumari Challa on June 22, 2023 at 9:23am

Researchers discover that worms use electricity to jump

In nature, smaller animals often attach themselves to larger ones to "hitch a ride" and save energy migrating large distances. In paper published on June 21 in the journal Current Biology, researchers show how microscopic Caenorhabditis elegans worms can use electric fields to "jump" across Petri plates or onto insects, allowing them to glide through the air and attach themselves, for example, onto naturally charged bumblebee chauffeurs.

Pollinators, such as insects and hummingbirds, are known to be electrically charged, and it is thought that pollen is attracted by the electric field formed by the pollinator and the plant. However, it was not completely clear earlier whether electric fields are utilized for interactions between different terrestrial animals.

The researchers first began investigating this project when they noticed that the worms they cultivated often ended up on the lids of Petri dishes, opposite to the agar they were placed on. When the team attached a camera to observe this behavior, they found that it was not just because worms were climbing up the walls of the dish. Instead, they were leaping from the floor of the plate to the ceiling.

Suspecting travel by electric field, the researchers placed worms on a glass electrode and found that they only leaped to another electrode once charge was applied. Worms jumped at an average speed of .86 meters per second (close to a human's walking speed), which increased with electric field intensity.

Part 1

Comment by Dr. Krishna Kumari Challa on June 21, 2023 at 11:43am

Scientists Reveal That Jupiter Is Not What We're Being Told

Comment by Dr. Krishna Kumari Challa on June 21, 2023 at 11:40am

"Predatory bacteria" provide hope for chlorine-free drinking water

 In a unique study carried out in drinking water pipes in Sweden, researchers  tested what would happen if chlorine was omitted from drinking water. The result? An increase in bacteria, of course, but after a while something surprising happened: a harmless predatory bacteria grew in numbers and ate most of the other bacteria. The study suggests that chlorine is not always needed if the filtration is efficient - and that predatory bacteria could perhaps be used to purify water in the future.

Just as human intestines contain a rich bacterial flora, many types of bacteria thrive in our drinking water and the pipes that transport them. On the inside of pipe walls is a thin, slippery coating, called a biofilm, which protects and supports bacteria. These bacteria have adapted to life in the presence of chlorine, which otherwise has the primary task to kill bacteria, particularity bacteria that can make humans sick.

An ordinary glass of drinking water contains a lot of harmless bacteria. Chlorine, however, which in the studied piping system was added in the form of monochloramine, is not wholly unproblematic.

Chlorine is an effective way to minimize growth of bacteria, but there is a risk of potential health impacts from byproducts that form with the chlorine. Chlorine has been linked to cancer and foetal damage and studying whether chlorine could be replaced by other methods is therefore relevant.

Our drinking water is currently purified in several stages. Depending on the type of water, companies use various kinds of filters, and UV light but the last stage is almost always the addition of chlorine.

In the present experiment, when the chlorine disappeared, certain types of bacteria starved while others grew and thrived. The biggest surprise for the researchers came in the third chlorine-free month when it was observed that certain bacteria had drastically decreased in number. And one special type of bacteria had increased: namely the predatory bacteria Bdellovibrio.

Researchers have not seen this exact type of bacteria in previous studies of this drinking water network. It has probably been lying concealed in the biofilm but was now given an opportunity. It’s totally harmless for us humans.

Each method of water treatmetn has its advantages and disadvantages. UV light is an effective method, but one disadvantage is that the lamps use a lot of energy. Biofilters often don’t require any energy at all but take up a considerable amount of space. Ultrafilters are expensive. Many drinking water treatment plants in Sweden purify water using a combination of methods. However, thsi study shows that harmful chlorine is not essential if you have other strategies to deal with, and monitor, bacteria.

Tage Rosenqvist et al, Succession of bacterial biofilm communities following removal of chloramine from a full-scale drinking water distribution system, npj Clean Water (2023). DOI: 10.1038/s41545-023-00253-x

Comment by Dr. Krishna Kumari Challa on June 21, 2023 at 10:49am

Air conditioning in India and Europe poses risk for dramatic rise in emissions, says study

Between now and 2050 the use of air conditioners to cope with rising temperatures risks generating an increase in emissions in the order of 10 million metric tons of carbon dioxide in Europe and as much as 120 million metric tons in India.

These figures were revealed in a study published in the journal Scientific Reports by environmental economists Francesco Colelli and Enrica De Cian of Ca' Foscari University of Venice, CMCC (Euro-Mediterranean Center on Climate Change) and RFF-CMCC European Institute on Economics and the Environment and Ian Sue Wing of Boston University. The study is the first to illustrate the impacts of climate change on the demand for air conditioners and electricity for cooling in Europe and India: between now and 2050, with the current fuel mix, there is a risk of a mismatch between what is done for adaptation and mitigation, with increased emissions as a result. The rush to buy new air conditioners in the residential sector and the resulting increased use of electricity associated will characterize both relatively richer but more temperate European countries, and relatively poorer but warmer Indian states. The study estimates that by 2050, under a +2/-3 °C warming forecast, air-conditioning uptake could double in Europe and grow fourfold in India, reaching about 40% of homes in both regions. On the one hand, more air conditioning will bring benefits to the population by reducing the heat exposure connected to global warming. Researchers have estimated that cooling technologies will lead the population being exposed to 40% less heat in Europe and 35% less in India by 2050.

On the other hand, this will have a strong impact on emissions. Between now and 2050 the energy production required by the increased use of air conditioners will cause a rise in annual CO₂ emissions between 7 and 17 million tons in Europe, and between 38 and 160 million tons in India.

Francesco Pietro Colelli et al, Air-conditioning adoption and electricity demand highlight climate change mitigation–adaptation tradeoffs, Scientific Reports (2023). DOI: 10.1038/s41598-023-31469-z

Comment by Dr. Krishna Kumari Challa on June 21, 2023 at 10:35am

Penguin propulsion: The physics behind the world's fastest swimming birds

Penguins aren't just cute: they're also speedy. Gentoo penguins are the fastest swimming birds in the world, and that ability comes from their unique and sophisticated wings.

Researchers  developed a model to explore the forces and flow structures created by penguin wings underwater. They determined that wing feathering is the main factor for generating thrust. Their findings have been published in the journal Physics of Fluids.

Penguin wings, aka flippers, bear some resemblance to airplane wings covered with scaly feathers. To maximize efficiency underwater instead of in the air, penguin wings are shorter and flatter than those of flying birds.

The animals can adjust swimming posture by active wing feathering (changing the angle of their wings to reduce resistance), pitching, and flapping. Their dense, short feathers can also lock air between the skin and water to reduce friction and turbulence.

Penguins' superior swimming ability to start/brake, accelerate/decelerate, and turn swiftly is due to their freely waving wings. They allow penguins to propel and maneuver in the water and maintain balance on land.

Hydrodynamic performance of a penguin wing: Effect of feathering and flapping, Physics of Fluids (2023). DOI: 10.1063/5.0147776

Comment by Dr. Krishna Kumari Challa on June 20, 2023 at 11:50am

Phase transitions are very common. The term refers to how a material changes from one state to another. A solid melts into a liquid, a liquid boils into a gas. A metal transitions from a normal state to a superconducting one. Each of these has a tipping point at which an equilibrium state undergoes a profound shift into another state.

Their results showed that we're not necessarily headed for certain climate doom. We might follow quite a regular and predictable trajectory, the endpoint of which is a climate stabilization at a higher average temperature point than what we have now. That's… still not great, given the deadly effects we're already seeing on humans and other animals.

But at the more extreme end, Earth runs into havoc. This means that the Earth's system evolves into chaotic behavior – extreme seasonal fluctuations and weather events – that precludes prediction of the future behavior of the system, making it impossible to mitigate. That means it would be extremely difficult, if not impossible, to claw our way back to a stable climate.

Even for this simple case, we observed the emergence of chaotic behavior in the equilibrium points of the Earth system. This leads to potentially important consequences if at least some components of the human activities actually follow logistic maps, which is a quite reasonable hypothesis, given the physical limitations of the planet-wide system we live in."

This outcome isn't inevitable, which is something of a relief. But, the researchers say we need to consider it a real possibility for designing strategies to mitigate climate change and manage the Earth system in the future.

https://arxiv.org/abs/2204.08955

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Part 2

Comment by Dr. Krishna Kumari Challa on June 20, 2023 at 11:48am

Earth Could Feasibly Descend Into Chaos, Physicists Warn

The impact of human activity on the Earth system could result in unpredictable chaos from which there is no return, physicists have calculated.

Using a theory conceived to model superconductivity, a team of physicists showed that, after a certain point, we will not be able to restore equilibrium to Earth's climate. A finite amount of human activity could result in a Hothouse Earth from which there is no return. They detailed their work in a paper made available in April 2022 on the preprint server arXiv that remains to be peer-reviewed.

If the Earth System gets into the region of chaotic behavior, we will lose all hope of somehow fixing the problem, they warn.

For some years now, extreme weather events seem to be occurring more regularly. Wildfires blaze, storms rage, temperatures reach new records. Climate scientists have warned that this is a consequence of human activity, such as the burning of fossil fuels, deforestation, and increases in farming.

This has led to the proposal of a new geological epoch: the Anthropocene, a period in which human activity has led to a significant and marked impact on the entire Earth system, comprised of the geosphere, biosphere, hydrosphere, and atmosphere.

The Anthropocene would follow the Holocene, which started around 11,700 years ago, and scientists propose its beginning around the middle of the 20th century – the peak of the nuclear era.

Part 1

Comment by Dr. Krishna Kumari Challa on June 20, 2023 at 11:40am

Special Nasal Drops Could Help The Brain Recover After A Stroke

Scientists have demonstrated how nasal drops containing a particular molecule can help mice recover from the damaging biological consequences of a stroke – and the hope is that the treatment could eventually be transferred to humans.

Crucially, the treatment isn't applied straight away but is initiated seven days after the stroke. That means those who are unable to be assisted immediately after a stroke could still be protected against the worst effects of the condition.

The key molecule in the drops is the complement peptide (a chain of amino acids) C3a, which we already know plays an important role in the body's immune system, as well as in the development and plasticity of the brain.

If the treatment is used in clinical practice, all stroke patients could receive it, even those who arrive at the hospital too late for thrombolysis or thrombectomy. Those who have remaining disability after the clot is removed could improve with this treatment too.

The delay is actually deliberate. Applied too early, the C3a peptide can increase the number of inflammatory cells in the brain, where they would start doing more harm than good.

Scientists induced an artificial ischemic stroke, the most common type of stroke there is, in mice. After a week, however, the nasal drops proved to help mice recover motor function faster and more completely, compared to a placebo group.

The new study also gives us a better idea of the effect of C3a on the brain. MRI scans revealed that the peptide helped to increase the number of connections between nerve cells in the brains of the mice.

The results show that the C3a peptide affects the function of astrocytes – that is, cells that control many of the nerve cells' functions in both the healthy and the diseased brain – and which signals astrocytes send to nerve cells.

https://www.jci.org/articles/view/162253

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