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Comment by Dr. Krishna Kumari Challa on May 4, 2023 at 9:39am

Scientists find link between photosynthesis and 'fifth state of matter'

Inside a lab, scientists marvel at a strange state that forms when they cool down atoms to nearly absolute zero. Outside their window, trees gather sunlight and turn them into new leaves. The two seem unrelated—but a new study suggests that these processes aren't so different as they might appear on the surface.

The study, published in PRX Energy on April 28, found links at the atomic level between photosynthesis and exciton condensates—a strange state of physics that allows energy to flow frictionlessly through a material. The finding is scientifically intriguing and may suggest new ways to think about designing electronics, the researchers say.

Modeling the complicated interactions of atoms and molecules as they display interesting properties is not possible to see  with the naked eye, so computer modeling can give scientists a window into why the behaviour happens—and can also provide a foundation for designing future technology.

When a photon from the sun strikes a leaf, it sparks a change in a specially designed molecule. The energy knocks loose an electron. The electron, and the "hole" where it once was, can now travel around the leaf, carrying the energy of the sun to another area where it triggers a chemical reaction to make sugars for the plant.

Together, that traveling electron-and-hole-pair is referred to as an "exciton." When the researchers took a birds-eye view and modeled how multiple excitons move around, they noticed something odd. They saw patterns in the paths of the excitons that looked remarkably familiar.

In fact, it looked very much like the behavior in a material that is known as a Bose-Einstein condensate, sometimes known as "the fifth state of matter." In this material, excitons can link up into the same quantum state—kind of like a set of bells all ringing perfectly in tune. This allows energy to move around the material with zero friction. (These sorts of strange behaviors intrigue scientists because they can be the seeds for remarkable technology—for example, a similar state called superconductivity is the basis for MRI machines). According to the models created by the researchers, the excitons in a leaf can sometimes link up in ways similar to exciton condensate behaviour.

Photosynthetic light harvesting is taking place in a system that is at room temperature and what's more, its structure is disordered—very unlike the pristine crystallized materials and cold temperatures that you use to make exciton condensates.

This effect isn't total—it's more akin to "islands" of condensates forming, the scientists say. But that's still enough to enhance energy transfer in the system.

 Anna O. Schouten et al, Exciton-Condensate-Like Amplification of Energy Transport in Light Harvesting, PRX Energy (2023). DOI: 10.1103/PRXEnergy.2.023002

Comment by Dr. Krishna Kumari Challa on May 4, 2023 at 9:20am

How to solve the biggest climate challenges

In a special issue dedicated to climate solutions, The New Yorker explores the breakthroughs that can make the most difference.

• Satellites in development aim to pinpoint the illicit sources of the potent greenhouse gas methane and map carbon in the atmosphere in unprecedented detail. (16 min read)
• People hoping to reduce the carbon emissions from cargo ships — which is on par with the aviation industry — are turning to a time-tested technology: sails. (17 min read)
• Pavagada Ultra Mega Solar Park in southern India is one of the largest solar-generating solar farms in the world — but the people whose livelihoods relied on the land it covers say that not everyone receives a fair share in the fruits of a cleaner economy. (18 min read)

Comment by Dr. Krishna Kumari Challa on May 4, 2023 at 9:18am

Oestrogen does a lot for the brain: it stimulates glucose uptake and energy production. Once the transition to menopause is complete, neurons grow accustomed to its absence. But in the perimenopausal period, levels of the hormone can crash one week only to soar the next. The result can be a period of neuronal discord in which brain cells are periodically deprived of oestrogen, but not for long enough to forge the pathways needed to adapt to life without it.

Perimenopause is also when many of the characteristic symptoms of menopause occur. Hot flushes are the hallmark of perimenopause; other symptoms include irregular periods, anxiety, high blood pressure and the dreaded ‘brain fog’ that impedes concentration. 

It could also be a key time to intervene using treatments that ease the transition into menopause, and which could slow the pace of age-related diseases that seem to accelerate afterwards.

But perimenopause does not have a clear start and end, making it difficult to study. Large clinical trials of treatments such as hormone-replacement therapy have often focused on women who are post-menopausal, sometimes years beyond their last period.

Some women have a short duration of perimenopausal symptoms, and others continue to be symptomatic for years or decades.

Now researchers are taking these changes in the brain seriously and are working to find solutions.

https://www.nature.com/articles/d41586-023-01474-3?utm_source=Natur...

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Comment by Dr. Krishna Kumari Challa on May 4, 2023 at 9:10am

How menopause reshapes the brain

Researchers are starting to learn how the early stages of menopause affect brain health — and what that could mean for treatment.

In studies of post-mortem brains, researchers had found neurons in a region called the hypothalamus that roughly doubled in size in women after menopause. This 's changing so much in postmenopausal women, It had to be important.

Now  a drug called fezolinetant, based on these above discoveries, is being evaluated by the US Food and Drug Administration, with an approval decision expected in the first half of this year. If approved, fezolinetant could be a landmark: the first non-hormonal therapy to treat the source of hot flushes, a symptom that has become nearly synonymous with menopause and one that is experienced by about 80% of women going through the transition.

According to scientists working in the field,  pre-menopause means years of fluctuating hormones that no longer rise and fall in their once-predictable patterns. During this time of perimenopause, circuits in the brain that previously relied on oestrogen signalling can be left floundering.

Part 1

Comment by Dr. Krishna Kumari Challa on May 4, 2023 at 9:04am

‘Remarkable’ AI tool designs mRNA vaccines

An artificial-intelligence (AI) software tool optimizes the gene sequences found in mRNA vaccines. The new methodology was developed by the California branch of Baidu Research, the AI-research arm of Beijing-based search-engine behemoth Baidu. It could help to create jabs that are more potent and stable than standard ones. The software borrows techniques from computational linguistics to design mRNA sequences with more-intricate shapes and structures than those used in current vaccines. Already, the tool has been used to optimize at least one authorized vaccine: a COVID-19 shot called SW-BIC-213.

https://www.nature.com/articles/s41586-023-06127-z?utm_source=Natur...

Comment by Dr. Krishna Kumari Challa on May 3, 2023 at 9:19am

Cybersickness more likely to affect women

 Researchers in psychology and engineering found women experience cybersickness with virtual reality headsets more often than men. Their ongoing work explores why this difference exists and options to help individuals adapt.

Gender discrepancies in cybersickness may not seem that important when it's related to video games and other forms of entertainment.

But it's still a problem, and when VR gets to the point where it's a bigger part of job training or education in a classroom, it's even more important to make sure people can access this technology. If not, a lot of people are going to get left out, and there could be a backlash.

Like motion sickness, cybersickness can occur when there's a mismatch between visual motion and body motion. Symptoms, including nausea, dizziness, headaches and eye fatigue, usually resolve quickly after removing the headset. But in severe cases, they sometimes last for hours.

Women reported experiencing more motion sickness and screen-based sickness than men, and this increased susceptibility is part of the reason that women experience more cybersickness.

The  researchers will continue to investigate the causes of cybersickness and methods to help individuals have a positive experience with VR.

Jonathan W. Kelly et al, Gender differences in cybersickness: Clarifying confusion and identifying paths forward, 2023 IEEE Conference on Virtual Reality and 3D User Interfaces Abstracts and Workshops (VRW) (2023). DOI: 10.1109/VRW58643.2023.00067

Taylor A. Doty et al, Does interpupillary distance (IPD) relate to immediate cybersickness?, 2023 IEEE Conference on Virtual Reality and 3D User Interfaces Abstracts and Workshops (VRW) (2023). DOI: 10.1109/VRW58643.2023.00173

Comment by Dr. Krishna Kumari Challa on May 3, 2023 at 9:11am

When your house spreads gossip about you

More and more of the devices that we surround ourselves with on a daily basis are connected to the internet. This makes them not only smart, but also vulnerable to cyberattacks and criminal acts.

Before long, we might have smart fridges that help us keep track of what foods are about to expire and when to shop. How could this be harmful? Who would be interested in the expiry date of your milk or monitoring your food inventory?

When you think about it, everyday objects in a modern smart home process a lot of data that you probably don't wish to share with all and sundry.

Your thermostat, for example, could give clues about when you are away from home. Your fitness equipment often stores health information about you and your family.

And as an American software developer recently demonstrated—your smart speaker may have security holes that allow eavesdropping on your private conversations.

In the wrong hands, this is information can be misused for everything from burglary to identity theft and extortion. Smart devices are increasingly finding their way into large companies and government institutions, a trend that does not exactly make the situation any less serious.

 Fartein Færøy et al, Automatic Verification and Execution of Cyber Attack on IoT Devices, Sensors (2023). DOI: 10.3390/s23020733

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Comment by Dr. Krishna Kumari Challa on May 3, 2023 at 9:04am

'Explainable AI' can efficiently detect AR/VR cybersickness

Exposure to an augmented reality (AR) or virtual reality (VR) environment can cause people to experience cybersickness—a special type of motion sickness with symptoms ranging from dizziness to nausea—and existing research to mitigate the severity of the symptoms often relies upon a one-size-fits-all approach.

However, a team of researchers are working to develop a personalized approach to identifying cybersickness by focusing on the root causes, which can be different for every person.

Cybersickness is not generic. For instance, one simulation could trigger cybersickness in me while the same simulation may not cause cybersickness for someone else. 

One of the problems people typically face when wearing virtual reality or augmented reality headsets is the user experience can get bad after some time, including symptoms of nausea and vomiting, especially if the user is immersed in a virtual environment where a lot of motion is involved. It can depend on many factors, including a person's gender, age and experience.

Explainable AI is a great tool to help with this because typically machine learning or deep learning algorithms  can tell you what the prediction and the decision may be, whereas explainable AI can also tell the user how and why the AI made the decision. So, instead of imposing a static mitigation technique for all users, it will be more effective if we know why a particular person is developing cybersickness and give that person the right mitigation that they need. Explainable AI can help us do that without hindering the user experience.

This research was recently presented at three conferences for AR/VR research:

• "LiteVR: Interpretable and Lightweight Cybersickness Detection using Explainable AI" was presented at the IEEE Virtual Reality Conference on March 25-29, 2023.
• "VR-LENS: Super Learning-based Cybersickness Detection and Explainable AI-Guided Deployment in Virtual Reality" was presented at the ACM Conference on Intelligent User Interfaces on March 27-31, 2023.
• "TruVR: Trustworthy Cybersickness Detection using Explainable Machine Learning" was presented at the International Symposium on Mixed and Augmented Reality (ISMAR) Conference on October 17-21, 2022.

 TruVR: Trustworthy Cybersickness Detection using Explainable Machin...

Comment by Dr. Krishna Kumari Challa on May 3, 2023 at 8:43am

'Zero plant extinction' is possible

Like animals, many plant species are struggling to adapt to a human-dominated planet. However, plants are often overlooked in conservation efforts, even though they are cheaper and easier to protect than animals and play a pivotal role in bolstering our food, fuel and medical systems. In a review published in the journal Trends in Plant Science on May 2,  ecologists suggest an approach for preventing all future land plant extinctions across the globe which includes training more plant experts, building an online "metaherbarium," and creating "microreserves."

An estimated 21%–48% of vascular plant species—which includes flowering plants and trees—could go extinct, primarily due to changes in land use and unsustainable harvesting practices. While it's potentially possible to prevent the extinction of all 382,000 currently known plant species, no single solution works for all species.

Conservation plans can take many forms and can be carried out either in a plant's natural habitat, often in the form of a nature reserve, or in a curated environment like a botanical garden. Sometimes a combination works best. For example, a microreserve—a tiny piece of protected land designed to get around space constraints—could be coupled with a supply of frozen seeds to fall back on if necessary.

Conservation of self-sustaining wild populations in protected areas is the ideal. This allows continued evolution in response to ongoing environmental change (such as climate change, and new pests and diseases) and the continued support of mutualists, herbivores, and pathogens, some of which may face extinction without their only plant hosts.

 Richard T. Corlett, Achieving zero extinction for land plants, Trends in Plant Science (2023). DOI: 10.1016/j.tplants.2023.03.019

Comment by Dr. Krishna Kumari Challa on May 2, 2023 at 1:39pm

However, they found that sometimes the machinery translating the CDC20 RNA into protein skips the normal starting point, and begins following the instructions from one of two unofficial starting points farther down the RNA sequence, which causes it to create alternative short versions of the molecule. These short versions vary from the full-length protein in one crucial way: they are not inhibited by the SAC. This means that the cell cannot stop them from activating the APC/C, even in the presence of errors that should arrest cell division.

This difference between versions of CDC20 enables cells to set a timer for arrest. Early in cell division, the APC/C is most likely to be bound by full-length CDC20, because cells produce more of the full-length protein than the alternatives. This keeps the cells responsive to the signal to enter arrest.

As cells spend more time in arrest, they continue to produce all versions of CDC20, but they break down full-length CDC20 faster than the shorter versions. The ratio of full-length to short CDC20 shifts in favor of the short versions. Eventually, the ratio shifts enough that the APC/C is most likely to be bound by short CDC20, which means that the SAC can no longer inhibit it. At this point, the timer runs out: the cells activate the APC/C and escape arrest.

A cell's arrest timer is therefore determined by factors that affect its starting levels of full-length and short CDC20 and the speed at which it makes and breaks them down, such as what machinery the cell has active for translating RNA. These factors vary from cell type to cell type, so different cell types have different length timers.

Understanding how cells set their timers helps to explain why some cancer cells are better at resisting certain cancer drugs.

Tsang, MJ., Cheeseman, I.M. Alternative CDC20 translational isoforms tune mitotic arrest duration. Nature (2023). https://doi.org/10.1038/s41586-023-05943-7

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