Tuesday, November 30, 2021

Origins of Earth’s water could be solved in space dust analysis

Meteorites on their way to earth and breaking through atmosphere.
Elements of this image furnished by NASA- earthmap for 3Drender

A key mystery about the origins of Earth’s water may have been solved after an international team of scientists uncovered persuasive new evidence pointing to an unlikely culprit—the Sun.

In a paper published in Nature Astronomy, a team of researchers, including two from the University of Hawaiʻi at Mānoa School of Ocean and Earth Science and Technology (SOEST), describe how analysis of dust grains from the surface of an ancient asteroid suggests that extraterrestrial dust grains from asteroids and comets carried water to the surface of the early Earth. The water in the grains is produced by space weathering, a process by which charged particles from the Sun, known as solar wind, altered the chemical composition of the grains to produce water molecules.

The finding could answer the longstanding question about the sources of the water that covers 70% of Earth’s surface—far more than any other rocky planet in our Solar System. Planetary scientists have been puzzled for decades over the source of Earth’s oceans. One theory suggests that comets and asteroids brought the water to the planet in the final stages of its formation 4.6 billion years ago.

Researchers discover a potential new therapeutic pathway to clear chronic viral infections

A recent study in mice has uncovered the role of a
protein, called BMI-1, in chronic viral infections.
Chronic infectious diseases have a devastating effect on global health. When someone is suffering from a chronic viral infection such as HIV or hepatitis C, their B cells get altered resulting in low-quality antibodies that are not strong enough to help the body clear the infection.

A recent study in mice, conducted by the Monash Biomedicine Discovery Institute (BDI), has uncovered that during chronic viral infection, a protein called BMI-1 gets turned on too early in B cells and messes up the delicate balance of gene expression, resulting in antibodies that are unsuccessful in their endeavor to clear the virus from the body.

However, when this protein is targeted, the nature of the B cell can be changed to produce a higher quality antibody that accelerates clearance of a virus and may provide a new therapeutic pathway to help improve and regulate the body’s antibody response to achieve better outcomes.

The findings have now been published in Nature Immunology.

B cells, a type of white blood cell, respond to infection and can eventually turn into plasma cells. It is the plasma cells that make and secrete antibodies. During an infection, some of the B cells that become activated can quickly become plasma cells and start to produce antibodies in the first few days of the body’s immune response. While these antibodies are helpful, they are typically lower in quality and do not clear the infection. However, they do give the immune system some time to allow other B cells to undergo a "training period" to become high-quality memory B cells and plasma cells for immunity.

Miniature grinding mill closes in on the details of ‘green’ chemical reactions

Credit: Photo by Chokniti Khongchum from Pexels
The study, published in Nature Communications and led by Cambridge Earth Sciences’ Dr Giulio Lampronti, observed reactions as materials were pulverized inside a miniaturized grinding mill — providing new detail on the structure and formation of crystals.

Knowledge of the structure of these newly-formed materials, which have been subjected to considerable pressures, helps scientists unravel the kinetics involved in mechanochemistry. But they are rarely able to observe it at the level of detail seen in this new work.

The study also involved Dr Ana Belenguer and Professor Jeremy Sanders from Cambridge’s Yusuf Hamied Department of Chemistry.

Mechanochemistry is touted as a ‘green’ tool because it can make new materials without using bulk solvents that are harmful to the environment. Despite decades of research, the process behind these reactions remains poorly understood.

To learn more about mechanochemical reactions, scientists usually observe chemical transformations in real time, as ingredients are churned and ground in a mill — like mixing a cake — to create complex chemical components and materials.

Study aims to understand why COVID-19 vaccines can lead to very rare blood clotting with low platelets

A group of 11 institutions, led by the University of Liverpool and including the University of Bristol, is seeking to understand the very rare, but very serious, condition of blood clotting with low platelets in the general population, in COVID-19 infection, and potentially following vaccination.

The vast majority of people who experience a side effect from COVID-19 vaccination have only mild reactions lasting for two or three days. However, in March 2021 reports of small numbers of people being admitted to hospital predominantly after the Oxford/AstraZeneca vaccine with what could potentially be a very rare side effect of vaccination began to emerge. These people had blood clots in the major veins in the brain, abdomen, or elsewhere in the body, but at the same time a low level of platelets – which are responsible for clotting – in the blood.

The group of researchers, supported by a wide range of collaborators within the NHS and national agencies, will work together to study the mechanisms underlying the occurrence of blood clots with low platelets – known as thrombotic thrombocytopenia syndrome (TTS). This project is supported by the National Institute for Health Research and backed by £1.6 million of government funding from the Vaccine Taskforce.

Bristol's involvement in the study, led by Professor Jonathan Sterne, will be to look at the association of COVID-19 vaccination with cardiovascular events after vaccination by analyzing very large (population-level) datasets.

Which glioblastoma patients will respond to immunotherapy?

Northwestern Medicine scientists have discovered a new biomarker to identify which patients with brain tumors called glioblastomas — the most common and malignant of primary brain tumors — might benefit from immunotherapy.

The treatment could extend survival for an estimated 20% to 30% of patients. Currently, patients with glioblastoma do not receive this life-prolonging treatment because it has not been fully understood which of them could benefit.

“This is an important breakthrough for patients who have not had an effective treatment in the cancer drug arsenal available to them,” said Dr. Adam Sonabend, the senior/corresponding author of this study, and associate professor of neurosurgery at Northwestern University Feinberg School of Medicine and a Northwestern Medicine brain-tumor neurosurgeon. “It might ultimately influence the decision on how to treat glioblastoma patients and which patients should get these drugs to prolong their survival.”

“Our study emphasizes important immune cells that might be relevant for response to immunotherapy. We hope that ultimately this benefits glioblastoma patients,” said Victor Arrieta, a post-doctoral scientist at the Sonabend lab and the first author of this study.

The immunotherapy response marker now needs to be validated in a clinical trial to make sure the study findings are reproducible and applicable to any glioblastoma patient, Sonabend said. He also is a member of the Robert H. Lurie Comprehensive Cancer Center of Northwestern University.

The study was published in Nature Cancer Nov. 29.

Glioblastomas are the most common form of malignant brain tumors in adults and have the worst prognosis. Patients are treated with radiation and chemotherapy, but the cancer inevitably recurs. Upon recurrence, there are no treatments that prolong survival.

How T Cells recognize infection or disease

Research illuminating an elusive component of the adaptive immune system,
how gamma delta T cells sense the metabolite-antigen presenting molecule MR1.
Artwork image created by Dr Erica Tandori. 
Monash University researchers have expanded their knowledge of how T cells might recognize infections or disease, providing key insight into how an often-overlooked T cell lineage becomes activated when encountering pathogens such as viruses, bacteria, and cancers.

T cells communicate with other cells in the body in search of infections or diseases. This crosstalk relies on specialized receptors known as T cell receptors that recognize foreign molecular fragments from an infection or cancer that are presented for detection by particular molecules called major histocompatibility complex (MHC) or MHC-like.

In this study, Monash Biomedicine Discovery Institute scientists have expanded the understanding of how a poorly defined class of gamma delta T cells recognizes an MHC-like molecule known as MR1. MR1 is a protein sensor that takes cellular products generated during infections or disease and presents them for T cells to detect, thereby alerting the immune system.

These gamma delta T cells play an understudied role within specific tissues around the body including the intestinal tract and may be an important factor in diseases that impact these tissues.

The findings are published today in the Proceedings of the National Academy of Sciences.

The study was co-led by Dr Benjamin S. Gully and Dr Martin Davey with first author Mr Michael Rice from the Monash Biomedicine Discovery Institute.

Closest pair of supermassive black holes yet

Hi-Res Zoomable Left Image | Hi-Res Zoomable Right Image
This image shows close-up (left) and wide (right) views of the two bright galactic nuclei, each housing a supermassive black hole, in NGC 7727, a galaxy located 89 million light-years away from Earth in the constellation Aquarius. Each nucleus consists of a dense group of stars with a supermassive black hole at its center. The two black holes are on a collision course and form the closest pair of supermassive black holes found to date. It is also the pair with the smallest separation between two supermassive black holes found to date — observed to be just 1600 light-years apart in the sky.    The image on the left was taken with the MUSE instrument on ESO’s Very Large Telescope (VLT) at the Paranal Observatory in Chile while the one on the right was taken with ESO's VLT Survey Telescope.  Credit: ESO/Voggel et al.; ESO/VST ATLAS team.
Acknowledgement: Durham University/CASU/WFAU

Using the European Southern Observatory’s Very Large Telescope (ESO’s VLT), astronomers have revealed the closest pair of supermassive black holes to Earth ever observed. The two objects also have a much smaller separation than any other previously spotted pair of supermassive black holes and will eventually merge into one giant black hole.

Located in the galaxy NGC 7727 in the constellation Aquarius, the supermassive black hole pair is about 89 million light-years away from Earth. Although this may seem distant, it beats the previous record of 470 million light-years by quite some margin, making the newfound supermassive black hole pair the closest to us yet.

Monday, November 29, 2021

Team Builds First Living Robots That Can Reproduce

To persist, life must reproduce. Over billions of years, organisms have evolved many ways of replicating, from budding plants to sexual animals to invading viruses.

Now scientists have discovered an entirely new form of biological reproduction — and applied their discovery to create the first-ever, self-replicating living robots.

The same team that built the first living robots ("Xenobots,” assembled from frog cells — reported in 2020) has discovered that these computer-designed and hand-assembled organisms can swim out into their tiny dish, find single cells, gather hundreds of them together, and assemble “baby” Xenobots inside their Pac-Man-shaped “mouth” — that, a few days later, become new Xenobots that look and move just like themselves.

And then these new Xenobots can go out, find cells, and build copies of themselves. Again and again.

“With the right design — they will spontaneously self-replicate,” says Joshua Bongard, a computer scientist and robotics expert at the University of Vermont who co-led the new research.

The results of the new research were published November 29, 2021, in the Proceedings of the National Academy of Sciences.

Bots talk like humans but their cloned personalities give them away

The image indicates the amount of genuine human accounts (blue) and fake bot accounts (red) by different ages and personality scores within the data of the study. The bot accounts have reasonable ages and personalities but only within an extremely thin range of values (ie, they all express the same human attributes), while the genuine human accounts have a large spread of values.
Credit: Stony Brook University

Social Bots, or accounts from non-genuine people, are posted all over social media. They infiltrate popular topics and serious ones like the Covid-19 pandemic. These bots are not like obvious robocalls or spam emails. They are designed to be human-like and interact with real social media users without their awareness. In fact, recent studies show that social media users find them mostly indistinguishable from real humans.

Now a study by Stony Brook University and University of Pennsylvania researchers published in Findings of the Association for Computational Linguistics (ACL) attempts to look at how human these social spambots really are by estimating 17 human attributes of the bot and implementing state-of-the-art machine learning and natural language processing. The study findings shed light on how bots behave on social media platforms and interact with genuine accounts, as well as the capabilities of current bot-generation technologies.

“This research gives us insight into how bots are able to engage with these platforms undetected,” explains lead author Salvatore Giorgi, a Visiting Scholar at Stony Brook University and a PhD student in the Department of Computer and Information Science (CIS) at the University of Pennsylvania’s School of Engineering and Applied Sciences. “If a Twitter user thinks an account is human, then they may be more likely to engage with that account. Depending on the bot’s intent, the end result of this interaction could be innocuous, but it could also lead to engaging with potentially dangerous misinformation.”

The superfoods that fueled ancient Andeans through 2,500 years of turmoil

Quinoa growing on Bolivia’s Taraco Peninsula
Photo by Maria Bruno

What if Indigenous diets could save our politically and ecologically strained planet? The answer may lie in the success of an ancient civilization high in the Andes Mountains, where not much grows.

UC Berkeley archaeologists reconstructed the diets of ancient Andeans living around Lake Titicaca, which straddles Bolivia and Peru 12,500 feet above sea level. They found that quinoa, potatoes and llama meat helped fuel the Tiwanaku civilization through 2,500 years of political and climate upheaval.

The findings, appearing this week in the Proceedings of the National Academy of Sciences journal, help explain the endurance of Andean cultural practices in the millennia preceding the Inca Empire. Moreover, they underscore the contribution of traditional Indigenous foods to human resilience.

“Thousands of years ago, these people already knew that quinoa was a superfood. They came up with this lucky triangle to meet their dietary needs in a pretty stark environment, and we can learn something from them,” said study senior author Christine Hastorf, a UC Berkeley professor of anthropology.

“Today, we’re living under the cloud of climate change. Rising sea levels are drowning tiny Pacific islands, and droughts and wildfires are destroying California’s crops,” she added. “Our findings point to how ancient people successfully adjusted to environmental and political changes, bolstered by a healthy Indigenous diet.”

FDA approves pioneering drug for ovarian cancer surgery

Ovarian cancer patient Carol Giandonato admits to being apprehensive when her oncologist told her he wanted to make her cancer cells turn fluorescent green.

"Am I going to glow in the dark? Will I be green?" she asked him.

Her surgeon explained that when viewing the cancer site, the cancerous lesions would be illuminated with near-infrared light during surgery.

Using this approach, her surgeon was able to find a hidden tumor that would have otherwise gone undetected. Giandonato was one of the first patients for a new drug designed to help surgeons find ovarian cancer tumors and cells — that imaging agent was just approved Monday (November 29) by the U.S. Food and Drug Administration.

The drug will be released with the brand name Cytalux. It was invented at Purdue University and will be released by On Target Laboratories.

The imaging agent is delivered via an IV injection between one and nine hours before the surgery for ovarian cancer. The fluorescent imaging agent binds to the cancer cells, allowing surgeons to find additional tumors in 27% of the patients, which would have otherwise been left behind, according to results of the Phase 3 clinical trial.

Pesticides Can Affect Multiple Generations of Bees

The blue orchard bee, shown here on the lacy phacelia wildflower,
was exposed to a neonicotinoid for the study.
Credit: Clara Stuligross/UC Davis
A new study from researchers at the University of California, Davis, finds that pesticides not only directly affect bee health, but effects from past exposure can carry over to future generations. The study, published in the journal Proceedings of the National Academy of Sciences, suggests that bees may require multiple generations to recover from even a single application.

Bees play a critical role in agricultural ecosystems, providing pollination for many important crops. In most agricultural areas, bees may be exposed to pesticides multiple times, over multiple years. Studies to date have only looked at exposure to pesticides in one life stage or over one year.

“It was important for us to understand how exposure persists from one generation to the next,” said lead author Clara Stuligross, a Ph.D. candidate in ecology at UC Davis. “Our findings suggest we need to be doing more to help mitigate risks or we limit critical pollination services.”

Rhythms of the krill

Diffuse sunlight, moonlight, aurora, and artificial light can all be seen during the Arctic Polar night, including near Kongsfjorden, Svalbard. Svalbard is an archipelago northeast of Greenland. When it is lightest in the Arctic polar night, usually around the middle of the day known as midday twilight, Arctic krill (inset) know to swim down to the bottom in order to hide from predators. When it is darkest in the Arctic polar night, they swim to the surface in search of bioluminescent food.
Photo by Geir Johnsen Photo illustration inset by Tammy Beeson

Around 11:30 a.m. or so, you might find yourself hankering for lunch. The reason for this is that our biological rhythms are trained to tell ourselves when we are hungry, and when we do get that craving, our bodies know that it’s time to eat. The same is true for visual rhythms.

During the day, it is typically lighter than at night. Because of this, our visual system changes so that it can be ready to work under brighter light conditions. During the night time, our eyes become more sensitive to adjust to the lack of light available.

It turns out that the same thing happens for Arctic krill. When it is lightest in the Arctic polar night — a time of year at high latitudes when the sun remains below the horizon for the entire 24-hour period — usually around the middle of the day known as midday twilight, the Arctic krill know to swim down to the bottom in order to hide from predators. When it is darkest in the Arctic polar night, that’s when they swim to the surface in search of bioluminescent food.

A new study published in the PLOS Biology Research Journal looked at this visual sensitivity rhythm in Arctic krill during the Arctic polar night.

New cancer therapy from Yibin Kang’s lab

Yibin Kang
Photo by Denise Applewhite, Office of Communications
Imagine you could cure cancer by targeting one tiny gene. Imagine that same gene occurred in every major cancer, including breast, prostate, lung, liver and colon. Imagine that the gene is not essential for healthy activity, so you could attack it with few or no negative side effects.

Cancer biologist Yibin Kang has spent more than 15 years investigating a little-known but deadly gene called MTDH, or metadherin, which enables cancer in two important ways — and which he can now disable, in mice and in human tissue, with a targeted experimental treatment that will be ready for human trials in a few years. His work appears in two papers in today’s issue of Nature Cancer (Paper One, Paper Two).

“You can’t find a drug target better than this: MTDH is important for most major human cancers, not important for normal cells, and it can be eliminated with no obvious side effects,” said Kang, Princeton’s Warner-Lambert/Parke-Davis Professor of Molecular Biology and one of the principal investigators of the Princeton Branch of the Ludwig Institute for Cancer Research.

“In the two papers we are publishing back-to-back today, we identify a compound, show it is effective against cancer, and show that it is very, very effective when combined with chemotherapy and immunotherapy,” said Kang. “Even though metastatic cancers are scary, by figuring out how they work — figuring out their dependency on certain key pathways like MTDH — we can attack them and make them susceptible to treatment.”

For years, Kang has focused on metastasis — the term for cancer’s ability to spread from one place to another in the body — because he knows that metastasis makes cancer deadly. While 99% of breast cancer patients survive five years after diagnosis, only 29% do if the cancer has metastasized, according to current numbers from the National Cancer Institute.

Sizing Up the Challenges in Extracting Lithium from Geothermal Brine

The hot brine that comes up from the subsurface as part of geothermal power production at the Salton Sea in California is a rich stew of minerals, including iron, magnesium, calcium, sodium, and lithium. Using various extraction techniques, lithium chloride can be extracted from the brine, then processed into other forms for battery production.
Credit: Jenny Nuss/Berkeley Lab

If you had a jar of marbles of many different colors but wanted only the green ones, how could you efficiently pick them out? What if it wasn’t marbles but a jar of glitter, and there was sand, glue, and mud mixed in? That begins to describe the complexity of the brine pumped out from beneath California’s Salton Sea as part of geothermal energy production.

For geothermal fields around the world, produced geothermal brine has been simply injected back underground, but now it’s become clear that the brines produced at the Salton Sea geothermal field contain an immense amount of lithium, a critical resource need for low-carbon transportation and energy storage. Demand for lithium is skyrocketing, as it is an essential ingredient in lithium-ion batteries. Currently there is very little lithium production in the U.S. and most lithium is imported; however, that may change in the near future.

Nibbling prehistoric herbivore sheds new light on Triassic diversity

Credit: Mark Witton
A Triassic herbivore, known for its supposed similarities to a modern-day ostrich, has been revealed to have entirely different approach to feeding from previously thought, according to research at the University of Birmingham.

The new discovery reveals a much broader diversity of herbivore behavior during the Triassic period than has been recognized to date.

Called Effigia, the animal was about the size of a gazelle and lived in North America around 205 million years ago. Its fossil remains were found in the Ghost Ranch Quarry in New Mexico in the 1940s, although the material was not formally described by paleontologists until 2006.

The remains had been relatively poorly preserved in the quarry and the skull, in particular, was quite badly deformed, making accurate reconstruction problematic. Early analysis of the specimen concluded that it belonged to the group of reptiles that includes crocodilians and birds and which started to flourish in the Triassic period.

Although more closely related to crocodilians, Effigia’s lightweight body, elongated neck, large eyes and beak shared many similarities with a modern-day ostrich, leading researchers to believe the animal fed by pecking plant material from the ground.

People want a better world after the COVID-19 pandemic but don’t believe it will really happen

Photo by Ron Lach from Pexels
People strongly favor a fairer and more sustainable way of life in the wake of the COVID-19 pandemic, despite not thinking it will actually materialize or that others share the same progressive wishes, according to new research which sheds intriguing light on what people have missed most and want for the future.

The international study, led by the University of Bristol, reflects people’s preferences in the United Kingdom and United States in the early as well as later stages of the pandemic, and shows striking commonality in their perspectives.

A “fairer future with grassroots leadership” was around four times more popular, favored by some 40% of participants, than a “return to normal”, which only garnered support from little more than 10%, in both the UK and US, when presented with various scenario options for the future.

However, the majority of respondents expected normality to resume regardless of their preferences, mistakenly believing their views were in the minority and that most wanted a return to the status quo.

Lead author Professor Stephan Lewandowsky, Chair in Cognitive Psychology at the University of Bristol, said: “The findings revealed people’s appetite for positive change, but also a strong sense of skepticism about whether this would actually materialize or that their views were in fact widely shared.

“This is important for everyone, including leaders and policy makers, to know so we can recognize and raise awareness of the common consensus contrary to popular belief. When people start to feel in the majority with their hopes, this instils greater belief and action towards achieving and making them real.”

The paper, entitled ‘Losses, hopes, and expectations for sustainable futures after COVID,’ and published in the journal Humanities & Social Sciences Communications, comprised two online questionnaires undertaken between May and July, 2020, and July 2021, involving nearly 1,000 (981) adults in total aged from 18 to 85 years old.

Monkeys go fishing to survive harsh Japanese winters

Snow monkey (Japanese macaque Macaca fuscata) 
Photo by Prof. Alexander Milner
Snow monkeys living in one of the world’s coldest regions survive by ‘going fishing’ – scooping live animals, including brown trout, out of Japanese rivers and eating them to stay alive, a new study reveals.

The snow monkey (Japanese macaque Macaca fuscata) is native to the main islands of Japan, except Hokkaido. The most northerly living non-human primate find that snow cover limits the availability of their preferred foods in the Kamikochi area of Chubu Sangaku National Park of the Japanese Alps.

With favorite foods difficult to find, the snow monkeys run low on energy and face death by starvation, but groundwater-fed streams flow during the winter with a constant water temperature of about 5 0C and are easily accessible for Japanese macaques to search for alternative live food.

Led by University of Birmingham experts, the international research team published its findings today in Scientific Reports - the first published scientific paper of Japanese macaques definitively eating freshwater animals in streams, including brown trout.

Previously, Japanese macaques have been shown to opportunistically capture marine fish, either when being dried or washed up on beaches, whilst closely-related species have been shown to feed on freshwater fish.

Researchers found brown trout in Japanese macaques’ fecal samples and believe that macaques capture brown trout in shallow pools along the stream margin.

Researchers developed mini-breast cancer as a new weapon against the most common type of breast cancer

Breast cancer tissue in a culture model in which hormone receptors disappear (left) and within the culture model developed in this study which maintains the hormone receptors (right). The hormone receptors are indicated in green.
Image: Pauliina Munne

Breast cancer is currently the most common form of cancer among the working age in Finland. Most breast cancers belong to a so-called hormone receptor-positive subtype. This means that there are hormone receptors on the cancer cells that receive hormones from the body and trigger a chain reaction that increases cancer growth.

These breast cancers can be effectively treated with hormone therapies. However, in 40 percent of the cases the effectiveness of the treatments decreases over time until it becomes difficult to control the cancer with medication. Additionally, it is problematic to study the effects of hormone therapies, the lack of treatment response, and new therapies that may be effective in unresponsive cancers as hormone receptors disappear completely from breast cancer cells under laboratory cell culture conditions.

Researchers at the University of Helsinki and Aalto University have found a way to keep the hormone receptors under laboratory conditions in their gel-grown mini-breast cancers. This discovery opens new avenues for the development of hormonal therapies, the study of individual drug responses, and the elucidation of the mechanisms of drug resistance.

Sunday, November 28, 2021

Morally divided societies more likely to elect extreme political leaders

Unorthodox leaders who shake up the political system are more likely to be elected if people believe their society is morally divided and breaking down, University of Queensland research has found.

Dr Charlie Crimston from UQ’s School of Psychology said people may vote outside their own political orientation if they felt the need to restore moral order.

“Our research is the first that provides evidence of the causal links between moral division and the desire to elect extreme leaders as a potential solution,” Dr Crimston said.

“The study found that if people believed there was a breakdown in societal fabric, they were more likely to elect an authoritarian figure to restore order, such as Donald Trump or Pauline Hanson.

“On the other hand, if there is a feeling of lack of leadership in society, voters may be drawn to a progressive leader to unify and lead the country in a new direction, such as Bernie Sanders or Alexandria Ocasio-Cortex.”

The paper examined core values of groups such as right and left wing voters in Australia, the US, and the UK and the perception that opposing groups have incompatible moral values.

Saturday, November 27, 2021

Destroying Black Holes

Watch as eight stars skirt a black hole 1 million times the mass of the Sun in these supercomputer simulations. As they approach, all are stretched and deformed by the black hole’s gravity. Some are completely pulled apart into a long stream of gas, a cataclysmic phenomenon called a tidal disruption event. Others are only partially disrupted, retaining some of their mass and returning to their normal shapes after their horrific encounters.

These simulations are the first to combine the physical effects of Einstein’s general theory of relativity with realistic stellar density models. The virtual stars range from about one-tenth to 10 times the Sun’s mass.

The division between stars that fully disrupt and those that endure isn’t simply related to mass. Instead, survival depends more on the star’s density.

Scientists investigated how other characteristics, such as different black hole masses and stellar close approaches, affect tidal disruption events. The results will help astronomers estimate how often full tidal disruptions occur in the universe and will aid them in building more accurate pictures of these calamitous cosmic occurrences.

Source/Credit: NASA's Goddard Space Flight Center/Taeho Ryu (MPA) 
Video Music: "Lava Flow Instrumental" from Universal Production Music
Final Editing and Conversion: Scientific Frontline
Full Credits included in video

Friday, November 26, 2021

In the quantum realm, not even time flows as you might expect

Artistic illustration of a gondolier trapped in a
quantum superposition of time flows.
Credit: Aloop Visual and Science, University of Vienna
A team of physicists at the Universities of Bristol, Vienna, the Balearic Islands and the Institute for Quantum Optics and Quantum Information (IQOQI-Vienna) has shown how quantum systems can simultaneously evolve along two opposite time arrows - both forward and backward in time.

The study, published in the latest issue of Communications Physics, necessitates a rethink of how the flow of time is understood and represented in contexts where quantum laws play a crucial role.

For centuries, philosophers and physicists have been pondering the existence of time. Yet, in the classical world, our experience seems to extinguish any doubt that time exists and goes on. Indeed, in nature, processes tend to evolve spontaneously from states with less disorder to states with more disorder and this propensity can be used to identify an arrow of time. In physics, this is described in terms of ‘entropy’, which is the physical quantity defining the amount of disorder in a system.

Dr Giulia Rubino from the University of Bristol’s Quantum Engineering Technology Labs (QET labs) and lead-author of the publication, said: “If a phenomenon produces a large amount of entropy, observing its time-reversal is so improbable as to become essentially impossible. However, when the entropy produced is small enough, there is a non-negligible probability of seeing the time-reversal of a phenomenon occur naturally.

“We can take the sequence of things we do in our morning routine as an example. If we were shown our toothpaste moving from the toothbrush back into its tube, we would be in no doubt it was a rewinded recording of our day. However, if we squeezed the tube gently so only a small part of the toothpaste came out, it would not be so unlikely to observe it re-entering the tube, sucked in by the tube’s decompression.”

The authors of the study, under the lead of Professor Caslav Brukner of the University of Vienna and the IQOQI-Vienna, applied this idea to the quantum realm, one of whose peculiarities is the principle of quantum superposition, according to which if two states of a quantum system are both possible, then that system can also be in both states at the same time.

Dr Rubino said: “Extending this principle to time’s arrows, it results that quantum systems evolving in one or the other temporal direction (the toothpaste coming out of or going back into the tube), can also find themselves evolving simultaneously along both temporal directions.

“Although this idea seems rather nonsensical when applied to our day-to-day experience, at its most fundamental level, the laws of the universe are based on quantum-mechanical principles. This begs the question of why we never encounter these superpositions of time flows in nature."

Dr Gonzalo Manzano, co-author from the University of the Balearic Islands, said: “In our work, we quantified the entropy produced by a system evolving in quantum superposition of processes with opposite time arrows. We found this most often results in projecting the system onto a well-defined time’s direction, corresponding to the most likely process of the two. And yet, when small amounts of entropy are involved (for instance, when there is so little toothpaste spilled that one could see it being reabsorbed into the tube), then one can physically observe the consequences of the system having evolved along the forward and backward temporal directions at the same time.”

Aside from the fundamental feature that time itself might not be well-defined, the work also has practical implications in quantum thermodynamics. Placing a quantum system in a superposition of alternative time’s arrows could offer advantages in the performance of thermal machines and refrigerators.

Dr Rubino said: “Although time is often treated as a continuously increasing parameter, our study shows the laws governing its flow in quantum mechanical contexts are much more complex. This may suggest that we need to rethink the way we represent this quantity in all those contexts where quantum laws play a crucial role.”

Source/Credit: University of Bristol


Thursday, November 25, 2021

Extraordinary Roman mosaic and villa discovered beneath farmer's field in Rutland

Archaeologists have unearthed the first Roman mosaic of its kind in the UK. Today (Thursday), a rare Roman mosaic and surrounding villa complex have been protected as a Scheduled Monument by DCMS on the advice of Historic England. The decision follows archaeological work undertaken by a team from University of Leicester Archaeological Services (ULAS), working in partnership with Historic England and in liaison with Rutland County Council.

The initial discovery of the mosaic was made during the 2020 lockdown by Jim Irvine, son of landowner Brian Naylor, who contacted the archaeological team at Leicestershire County Council, heritage advisors to the local authority. Given the exceptional nature of this discovery, Historic England was able to secure funding for urgent archaeological investigations of the site by ULAS in August 2020. Further excavation involving staff and students from the University of Leicester’s School of Archaeology and Ancient History examined more of the site in September 2021. The remains of the mosaic measure 11m by almost 7m and depict part of the story of the Greek hero Achilles.

The artwork forms the floor of what’s thought to be a large dining or entertaining area. Mosaics were used in a variety of private and public buildings across the Roman Empire, and often featured famous figures from history and mythology. However, the Rutland mosaic is unique in the UK in that it features Achilles and his battle with Hector at the conclusion of the Trojan War and is one of only a handful of examples from across Europe.

Super jelly’ can survive being run over by a car

The soft-yet-strong material, developed by a team at the University of Cambridge, looks and feels like a squishy jelly, but acts like an ultra-hard, shatterproof glass when compressed, despite its high water content.

The non-water portion of the material is a network of polymers held together by reversible on/off interactions that control the material’s mechanical properties. This is the first time that such significant resistance to compression has been incorporated into a soft material.

The ‘super jelly’ could be used for a wide range of potential applications, including soft robotics, bioelectronics or even as a cartilage replacement for biomedical use. The results are reported in the journal Nature Materials.

The way materials behave – whether they’re soft or firm, brittle or strong – is dependent upon their molecular structure. Stretchy, rubber-like hydrogels have lots of interesting properties that make them a popular subject of research – such as their toughness and self-healing capabilities – but making hydrogels that can withstand being compressed without getting crushed is a challenge.

“In order to make materials with the mechanical properties we want, we use crosslinkers, where two molecules are joined through a chemical bond,” said Dr Zehuan Huang from the Yusuf Hamied Department of Chemistry, the study’s first author. “We use reversible crosslinkers to make soft and stretchy hydrogels, but making a hard and compressible hydrogel is difficult and designing a material with these properties is completely counterintuitive.”

Working in the lab of Professor Oren A. Scherman, who led the research, the team used barrel-shaped molecules called cucurbiturils to make a hydrogel that can withstand compression. The cucurbituril is the crosslinking molecule that holds two guest molecules in its cavity – like a molecular handcuff. The researchers designed guest molecules that prefer to stay inside the cavity for longer than normal, which keeps the polymer network tightly linked, allowing for it to withstand compression.

Super jelly  Credit: Zehuan Huang

“At 80% water content, you’d think it would burst apart like a water balloon, but it doesn’t: it stays intact and withstands huge compressive forces,” said Scherman, Director of the University’s Melville Laboratory for Polymer Synthesis. “The properties of the hydrogel are seemingly at o
dds with each other.”

“The way the hydrogel can withstand compression was surprising, it wasn’t like anything we’ve seen in hydrogels,” said co-author Dr Jade McCune, also from the Department of Chemistry. “We also found that the compressive strength could be easily controlled through simply changing the chemical structure of the guest molecule inside the handcuff.”

To make their glass-like hydrogels, the team chose specific guest molecules for the handcuff. Altering the molecular structure of guest molecules within the handcuff allowed the dynamics of the material to ‘slow down’ considerably, with the mechanical performance of the final hydrogel ranging from rubber-like to glass-like states.

“People have spent years making rubber-like hydrogels, but that’s just half of the picture,” said Scherman. “We’ve revisited traditional polymer physics and created a new class of materials that span the whole range of material properties from rubber-like to glass-like, completing the full picture.”

The researchers used the material to make a hydrogel pressure sensor for real-time monitoring of human motions, including standing, walking and jumping.

“To the best of our knowledge, this is the first time that glass-like hydrogels have been made. We’re not just writing something new into the textbooks, which is really exciting, but we’re opening a new chapter in the area of high-performance soft materials,” said Huang.

Researchers from the Scherman lab are currently working to further develop these glass-like materials towards biomedical and bioelectronic applications in collaboration with experts from engineering and materials science. The research was funded in part by the Leverhulme Trust and a Marie Skłodowska-Curie Fellowship. Oren Scherman is a Fellow of Jesus College.

Source/Credit: University of Cambridge


Electrons Set the Stage for Neutrino Experiments

Neutrinos may be the key to finally solving a mystery of the origins of our matter-dominated universe, and preparations for two major, billion-dollar experiments are underway to reveal the particles’ secrets. Now, a team of nuclear physicists have turned to the humble electron to provide insight for how these experiments can better prepare to capture critical information. Their research, which was carried out at the U.S. Department of Energy’s Thomas Jefferson National Accelerator Facility and recently published in Nature, reveals that major updates to neutrino models are needed for the experiments to achieve high-precision results.

Neutrinos are ubiquitous, generated in copious numbers by stars throughout our universe. Though prevalent, these shy particles rarely interact with matter, making them very difficult to study.

“There is this phenomenon of neutrinos changing from one type to another, and this phenomenon is called neutrino oscillation. It’s interesting to study this phenomenon, because it is not well understood,” said Mariana Khachatryan, a co-lead author on the study who was a graduate student at Old Dominion University in Professor and Eminent Scholar Larry Weinstein’s research group when she contributed to the research. She is now a postdoctoral research associate at Florida International University.

One way to study neutrino oscillation is to build gigantic, ultra-sensitive detectors to measure neutrinos deep underground. The detectors typically contain dense materials with large nuclei, so neutrinos are more likely to interact with them. Such interactions trigger a cascade of other particles that are recorded by the detectors. Physicists can use that data to tease out information about the neutrinos.

Misinformation about COVID-19 spreads faster on social media

New research has found that the amount of misinformation related to COVID-19 is disproportionately higher than content produced by fact-checkers on Twitter. COVID misinformation also maintains attention and engagement for longer online than fact-based content.

The research, led by Open University academics, aimed to examine misinformation about COVID-19 online as a means of improving the effectiveness of the response to the pandemic.

Over 350,000 tweets that shared misinforming or fact-checking content related to COVID-19 between December 2019 to January 2021 were studied.

It was found that fact-checking may not be as successful as expected in reducing misinformation spread on Twitter. The amount of misinformation on COVID-19 was shared on Twitter around 3.5 times more than content trying to correct misinformation.

This highlighted the importance of fact-checkers making their content attractive and eye-catching to social media users – thereby more shareable and likely to gain traction on platforms.

Misinformation is also more often re-published or re-shared after some time than fact-checking. This is particularly observable in relation to conspiracy theories and COVID origins or causes as these are often much harder to debunk based on known facts (i.e. conspiracy theories are ‘beyond’ factual content and COVID causes still remain unclear).

Himalayan bats are functionally less diverse at high than at lower elevations, but show the same evolutionary diversity

Rohit Charkararty during fieldwork in the Himalayas
Credit: Emily Stanford
Million years of evolution have produced a dazzling variety of species, each uniquely adapted to its environment. A straightforward way to measuring biodiversity is by the number of species (taxonomic diversity). Recently, there is growing emphasis to quantify diversity also in other ways: a) functional diversity, which is the diversity of phenotypic traits that allow organisms to perform their ecological functions and b) phylogenetic diversity, meaning the variation in the branches in the tree of life. In a paper published recently in the journal “Scientific Reports” a team of scientists led by the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW) compares these approaches: They found that species richness and functional diversity of Himalayan bat communities decline at high elevation without the loss of phylogenetic diversity. Their findings provide insights on the diversity of bats in the Himalayas and serve as an important baseline in assessing this diversity in the context of environmental changes.

Lead author Rohit Chakravarty from the Leibniz-IZW and his colleagues evaluated three different diversity approaches to identifying biodiversity patterns in bats in the Himalayas. Mountain regions provide ideal settings for these kinds of analyses as they encompass a high number of different climate and vegetation zones along elevational gradients over short spatial scales. “It is quite well known how species richness responds to these elevational gradients, but in order to understand the evolutionary processes that lead to this distribution of species, we need to analyze the diversity of traits and diversity in evolutionary history”, explains Chakravarty. The team caught bats at elevations between 1500 and 3500 meters in the western Himalayas and measured phenotypic traits related to their wing shape and echolocation calls – both important traits that determine foraging style. They compared this information with phylogenetic data of Himalayan bat species from the literature. “Phylogenetic diversity indicates the number of steps or evolutionary adaptations that differentiate species from each other”, says Chakravarty. “It is interesting from an evolutionary standpoint. Three species that sit on the same branch of the evolutionary tree have a shared history of evolution, that is, they evolved from a common ancestor and may hence show similar adaptations to environmental conditions.”

Collapse of ancient Liangzhu culture caused by climate change

Stalagmites in caves located southwest of the excavation site show
a climatic cause for the collapse of the ancient chinese Liangzhu culture.
Credit: Haiwei Zhang
"China's Venice of the Stone Age": The Liangzhu excavation site in eastern China is one of the most significant testimonies of Chinese civilization. More than 5000 years ago, the city had an elaborate water management system. Massive flooding triggered by anomalously intense monsoon rains caused a sudden collapse, as a team with geologist Christoph Spötl shows in Science Advances.

In the Yangtze Delta, about 160 kilometers southwest of Shanghai, the archeological ruins of Liangzhu City are located. There, a highly advanced culture blossomed about 5300 years ago, which is considered to be one of the earliest proofs of monumental water culture. The oldest evidence of large hydraulic engineering structures in China originates from this late Neolithic cultural site. 

The walled city had a complex system of navigable canals, dams and water reservoirs. This system made it possible to cultivate very large agricultural areas throughout the year. In the history of human civilization, this is one of the first examples of highly developed communities based on a water infrastructure. Metals, however, were still unknown in this culture. 

Thousands of elaborately crafted jade burial objects were found during excavations. Long undiscovered and underestimated in its historical significance, the archaeological site is now considered a well-preserved record of Chinese civilization dating back more than 5000 years. Liangzhu was declared a UNESCO World Heritage Site in 2019. However, the advanced civilization of this city, which was inhabited for almost 1000 years, came to an abrupt end. 

Secrets of planet formation take researchers on quest near and far

Students visit Bin Chen’s high pressure mineral
physics laboratory, learn from Robert Rapp.
From laboratory experiments to observations of young star systems, University of Hawaiʻi at Mānoa researchers are on a quest to understand how rocky planets like Earth form.

Planets form from disks of gas and dust that surround young stars. Previous research has shown that nearly all stars are born with such disks, and revealed hints of planet formation within them. Surveys for planets around other stars, termed “exoplanets,” have discovered that Earth-size and presumably rocky planets are common, and many stars have planets orbiting much closer to their host star than the Earth-Sun distance. But most of the steps between dust and planets are poorly understood, in part because they are obscured within the inner region of these proto-planetary disks.

The National Science Foundation (NSF) and NASA recently awarded a total of $1.3 million in three separate grants to teams of UH Mānoa scientists from the Department of Earth Sciences and Hawaiʻi Institute of Geophysics and Planetology in the School of Ocean and Earth Science and Technology (SOEST), the Institute for Astronomy (IfA), and the Information and Computer Science Department (ICS) to explore this inner realm around other stars—and our Sun—in search of the secrets to planet formation.

SOEST Earth Sciences professor Eric Gaidos, lead investigator on two of the grants, explained, “the story of planet formation is like an epic movie, where we could watch only the dramatic opening scene and the happy ending, but missed everything between, leaving us guessing about the main characters, their roles and most of the plot.”

Wednesday, November 24, 2021

Water disinfection byproduct disrupts reproductive hormones, damages pituitary in female mice

A byproduct formed during water disinfection disrupts hormones
that regulate reproduction in female mice, found Illinois
professor Lori Raetzman (left) and graduate student Rachel Gonzalez. 
Photo by L. Brian Stauffer
Chemical disinfection makes water from both natural sources and wastewater streams drinkable; however, the process also creates byproducts, not all of which are understood or regulated. A new study from University of Illinois Urbana-Champaign researchers has found that one byproduct disrupts hormones in the brain that regulate the female reproductive cycle in mice and also damages cells in the pituitary gland.

Iodoacetic acid, or IAA, is created when an oxidizing disinfectant such as chlorine reacts with the iodide naturally present in water, said study leader Lori Raetzman, a professor of molecular and integrative physiology. The new study’s findings of IAA’s effects on reproductive regulation in the brain complement previous work by study co-author Jodi Flaws, a professor of comparative biosciences, which found that IAA also disrupts function in and causes damage to ovary cells, indicating that the chemical could impact the entire reproductive system.

“We know we need to disinfect water, but the water that’s coming out of our taps isn’t pure – regulators only screen for the things they know about. Water regulatory bodies have not been looking for IAA,” Raetzman said. “This study is contributing to the growing body of evidence that suggests that IAA may impact reproduction, so it might be reasonable to have screening for this too, and to establish a safe level for it.”

Robust approach needed to reduce risk of disease transmission between humans and wild animals

Credit: Pixabay
The threat of disease transmission from conservationists moving wild animals between habitats or back into the wild needs to be urgently assessed to minimize risk. Experts at the University of Birmingham are calling on local and national health authorities and wildlife managers to adopt a robust approach.

In a new paper, published in Frontiers in Veterinary Science, researchers in the University’s College of Life and Environmental Sciences, collaborating with Wildlife Impact and other sector partners, have highlighted the issues using the example of translocated orangutans in Indonesia.

All three species of orangutans in Indonesia are listed as Critically Endangered, and moving animals between habitats is a fairly common practice as demands for agriculture, mining, and other natural resource use puts pressure on the forests they inhabit. Interactions and conflict between humans and orangutans sharing the same habitats also contributes to the complex problems facing these rare species across their range.

During the covid 19 pandemic, the team identified instances of orangutans being released who had been in direct contact or proximity to humans without any protective equipment. In some cases, formerly captive orangutans were released after long periods of contact and potential exposure to human diseases.

The team’s results suggest that there is a potential problem of pathogen transmission between humans and animals which needs to be properly understood and managed.

SARS-CoV-2 infects sustentacular cells in the olfactory epithelium of COVID-19 patients

A lone infected sustentacular cell is surrounded by non-infected cells in the olfactory mucosa of a COVID-19 patient who died four days after diagnosis of the infection. The infected cell has the characteristic shape of a wine glass. The blue color comes from staining with an antibody against the nucleocapsid protein of the virus. The red dots represent staining with an RNAscope probe for a gene that is expressed in sustentacular cells (GPX3). Within the lone infected cell, there are few or no red dots, because infection of a cell with SARS-CoV-2 causes decay of host RNA molecules. The green dots represent staining with an an RNAscope probe for a type of viral RNA molecules that are only present during ongoing viral replication. This lone sustentacular cell was thus serving as a “factory” for replicating viral RNA at the time the postmortem tissue sample was taken.
© MP Research Unit f. Neurogenetics/ Mona Khan

It is now widely known that COVID-19 is associated with the transient or long-term loss of olfaction (the sense of smell) but the mechanisms remain obscure. An unresolved question is whether the olfactory nerve can provide SARS-CoV-2 with a route of entry to the brain. Scientists at the Max Planck Research Unit for Neurogenetics in Frankfurt in collaboration with physicians and scientists at the University Hospitals Leuven (Leuven, Belgium) and a major hospital in Bruges, Belgium, together with scientists at NanoString Technologies Inc. in Seattle, USA, report that SARS-CoV-2 does not appear to infect the sensory neurons of the olfactory epithelium in COVID-19 patients. Moreover, the team failed to find evidence for infection of olfactory bulb neurons. Instead, the sustentacular cells, also known as supporting cells, are the main target cell type for the virus in the olfactory epithelium. Since SARS-CoV2 spares olfactory sensory neurons and olfactory bulb neurons, it does not appear to be a neurotropic virus.

For the brain, context is key to new theory of movement and memory

Photo by lebih dari ini from Pexels
How is it that a chef can control their knife to fillet a fish or peel a grape and can wield a cleaver just as efficiently as a paring knife? Even those of us less proficient in the kitchen learn to skillfully handle an astonishing number of different objects throughout our lives, from shoelaces to tennis rackets.

This ability to continuously acquire new skills, without forgetting or degrading old ones, comes naturally to humans but is a major challenge even for today’s most advanced artificial intelligence systems.

Now, scientists from the University of Cambridge and Columbia University have developed and experimentally verified a new mathematical theory that explains how the human brain achieves this feat. Called the COntextual INference (COIN) model, it suggests that identifying the current context is key to learning how to move our bodies.

The model describes a mechanism in the brain that is constantly trying to figure out the current context. The theory suggests that these continuously changing beliefs about context determine how to use existing memories — and whether to form new ones. The results are reported in the journal Nature.

“Imagine playing tennis with a different racket than usual or switching from tennis to squash,” said co-senior author Dr Daniel Wolpert from Columbia University. “Our theory explores how your brain adjusts to these situations and whether to treat them as distinct contexts.”

According to the COIN model, the brain maintains a repertoire of motor memories, each associated with the context in which it was created, such as playing squash versus tennis. Even for a single swing of the racket, the brain can draw upon many memories, each in proportion to how much the brain believes it is currently in the context in which that memory was created.

Antibody treatment for Covid-19

Dr. Christoph Spinner is an infectiologist and pandemic officer
at the Klinikum rechts der Isar university hospital
of the Technical University of Munich.
Image: argum, MRI
A new treatment could prevent serious illness in case of Covid-19 infections during the pandemic. This would prevent hospitalization of patients and thus ease the burden on the healthcare system. For several months, inpatients at the Klinikum rechts der Isar university hospital of the Technical University of Munich (TUM) have been successfully treated with neutralizing antibodies. This treatment option at the Antibody Center has now been extended to outpatients.

The new form of treatment has proven highly effective against severe Covid-19 illness above all in persons with chronic conditions who do not respond sufficiently to an active vaccination.

“With approval by the European Medicines Agency (EMA) on November 12, the neutralizing antibodies can now be widely used at an early stage of the illness,” said adjunct teaching professor Dr. Christoph Spinner, infectious disease specialist and pandemic officer at Klinikum rechts der Isar, and his colleague, adjunct teaching professor Dr. Jochen Schneider, who heads the new Covid-19 outpatient clinic for monoclonal antibody treatment at the same hospital.

With the current surge in patient numbers, especially in Bavaria, the experts believe that this treatment can benefit many people and should therefore be made widely available as quickly as possible.

“To make that happen, we will be happy to share our skills and experience from a university clinic with colleagues at other hospitals in the fight against the pandemic,” says Dr. Spinner.

Tuesday, November 23, 2021

Compounds from soybeans may improve animal health

The sprouting soybeans, in front, have been inoculated with a pathogen to trigger production of glyceollins, which have antimicrobial properties. Scaling up these lab experiments at the POET Bioproducts Institute may lead to soybeans that are rich in glyceollins being integrated into animal feed to help prevent disease and reduce the need for antibiotics.

Antimicrobial compounds that soybean plants produce when threatened by insects, diseases and even drought may help animals stay healthy, thereby reducing the need for antibiotics.

“When a soybean is attacked by a pathogen, the plant produces phytochemicals called glyceollins as a defense mechanism,” explained assistant professor Bishnu Karki of South Dakota State University’s Department of Biology and Microbiology. Her research group has identified pathogens and lab-scale processes to trigger production of glyceollins and begun assessing soybean varieties to see which produce higher levels of the antimicrobial compounds.

“Animals, such as pigs and poultry, already consume diets high in soybeans and could benefit from the phytochemical’s antimicrobial properties,” Karki said, pointing out scientists are studying the impact of glyceollins on human health, specifically in relation to cancer, inflammation and cardiovascular diseases.

Karki’s research is supported by U.S. Department of Agriculture Hatch Act funding through the South Dakota Agricultural Experiment Station. Two master’s students and several undergraduates have also worked on the project.

Scientists Find SARS CoV-2-Related Coronaviruses in Cambodian Bats from 2010

Rhinolophus shameli Credit: Ben Hayes 

A team of scientists have identified coronaviruses closely related to SARS-CoV-2 from two bats sampled in Cambodia more than a decade ago. The discovery described in the journal Nature Communications, along with the recent detection of the closest ancestors of SARS-CoV-2 known to date in cave-dwelling bats in Laos, indicates that SARS-CoV-2-related viruses that cause COVID-19 have a much wider geographic distribution than previously reported and further supports the hypothesis that the pandemic originated via spillover of a bat-borne virus.

Scientists used metagenomic sequencing to identify the nearly identical viruses in two Shamel’s horseshoe bats (Rhinolophus shameli) originally sampled in 2010. The finding suggests that SARS-CoV-2 related viruses likely circulate via multiple Rhinolophus species.

The authors state that the current understanding of the geographic distribution of the SARS-CoV and SARS-CoV-2 lineages possibly reflects a lack of sampling in Southeast Asia, or at least across the Greater Mekong Subregion, which encompasses Myanmar, Laos, Thailand, Cambodia and Vietnam, as well as the Yunnan and Guanxi provinces of China.

Two-meter COVID-19 rule is ‘arbitrary measurement’ of safety

Credit: University of Cambridge
A team of engineers from the University of Cambridge used computer modeling to quantify how droplets spread when people cough. They found that in the absence of masks, a person with COVID-19 can infect another person at a two-meter distance, even when outdoors.

The team also found that individual coughs vary widely, and that the ‘safe’ distance could have been set at anywhere between one to three or more meters, depending on the risk tolerance of a given public health authority.

The results, published in the journal Physics of Fluids, suggest that social distancing is not an effective mitigation measure on its own, and underline the continued importance of vaccination, ventilation and masks as we head into the winter months in the northern hemisphere.

Despite the focus on hand-washing and surface cleaning in the early days of the pandemic, it’s been clear for nearly two years that COVID-19 spreads through airborne transmission. Infected people can spread the virus through coughing, speaking or even breathing, when they expel larger droplets that eventually settle or smaller aerosols that may float in the air.

“I remember hearing lots about how COVID-19 was spreading via door handles in early 2020, and I thought to myself if that were the case, then the virus must leave an infected person and land on the surface or disperse in the air through fluid mechanical processes,” said Professor Epaminondas Mastorakos from Cambridge’s Department of Engineering, who led the research.

Global warming, not just drought, drives bark beetles to kill more ponderosa pines

Outbreaks of western pine beetles are decimating ponderosa pines
 in California’s Sierra Nevada and across the West.
Credit: Los Alamos National Laboratory 
In California’s Sierra Nevada, western pine beetle infestations amped up by global warming were found to kill 30% more ponderosa pine trees than the beetles do under drought alone. A new supercomputer modeling study hints at the grim prospect of future catastrophic tree die-offs and offers insights for mitigating the combined risk of wildfires and insect outbreaks.

“Forests represent a crucial buffer against warming climate and are often touted as an inexpensive mitigation strategy against climate change,” said Zachary Robbins, a researcher at Los Alamos National Laboratory, graduate student at North Carolina State University, and lead author of the paper on beetles and ponderosa pine tree die-offs. “Our research shows that warming shortens the time between beetle generations, supercharging beetle population growth. That can then spur catastrophic mortality in forest systems during drought in the Sierra Nevada and throughout the Western United States.”

In the recently published study in Global Change Biology, Robbins and his collaborators developed a new modeling framework to assess the risk western pine beetles, or bark beetles, pose in many forest ecosystems under climate change. If the effects of compromised tree defenses (15% to 20%) and increased bark beetle populations (20%) are additive, the team determined that 35% to 40% more ponderosa pines would die from beetle attacks for each degree Celsius of warming.

“Our study is the first to attribute a level of tree mortality to the direct effect of warming on bark beetles, using a model that captures both beetle reproduction and development rates and host stress,” Robbins said. “We found that even slight increases in the number of annual generations of bark beetles due to warming can significantly increase tree mortality during drought.”

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