Black Hole Snacks on a Star

 

This illustration shows a glowing stream of material from a star, torn to shreds as it was being devoured by a supermassive black hole. The feeding black hole is surrounded by a ring of dust, not unlike the plate of a toddler is surrounded by crumbs after a meal. NASA/JPL-Caltech

While black holes and toddlers don't seem to have much in common, they are remarkably similar in one aspect: Both are messy eaters, generating ample evidence that a meal has taken place.

But whereas one might leave behind droppings of pasta or splatters of yogurt, the other creates an aftermath of mind-boggling proportions. When a black hole gobbles up a star, it produces what astronomers call a "tidal disruption event." The shredding of the hapless star is accompanied by an outburst of radiation that can outshine the combined light of every star in the black hole's host galaxy for months, even years. 

In a paper published in The Astrophysical Journal, a team of astronomers led by Sixiang Wen, a postdoctoral research associate at the University of Arizona Steward Observatory, use the X-rays emitted by a tidal disruption event known as J2150 to make the first measurements of both the black hole's mass and spin. This black hole is of a particular type – an intermediate-mass black hole – which has long eluded observation.

"The fact that we were able to catch this black hole while it was devouring a star offers a remarkable opportunity to observe what otherwise would be invisible," said Ann Zabludoff, UArizona professor of astronomy and co-author on the paper. "Not only that, by analyzing the flare we were able to better understand this elusive category of black holes, which may well account for the majority of black holes in the centers of galaxies."

Study links severe COVID-19 to increase in self-attacking antibodies

 

Hospitalized COVID-19 patients are substantially more likely to harbor autoantibodies — antibodies directed at their own tissues or at substances their immune cells secrete into the blood — than people without COVID-19, according to a new study.

Autoantibodies can be early harbingers of full-blown autoimmune disease.

“If you get sick enough from COVID-19 to end up in the hospital, you may not be out of the woods even after you recover,” said PJ Utz, MD, professor of immunology and rheumatology at Stanford Medicine.

Utz shares senior authorship of the study, which was published Sept. 14 in Nature Communications, with Chrysanthi Skevaki, MD, PhD, instructor of virology and laboratory medicine at Philipps University Marburg in Germany, and Eline Luning Prak, MD, PhD, professor of pathology and laboratory medicine at the University of Pennsylvania. The study’s lead authors are Sarah Chang, a former technician in Utz’s lab; recent Stanford undergraduate Allen Feng, now a technician in the Utz lab; and senior research investigator Wenshao Meng, PhD, and postdoctoral scholar Sokratis Apostolidis, MD, both at the University of Pennsylvania.

The scientists looked for autoantibodies in blood samples drawn during March and April of 2020 from 147 COVID-19 patients at the three university-affiliated hospitals and from a cohort of 48 patients at Kaiser Permanente in California. Blood samples drawn from other donors prior to the COVID-19 pandemic were used as controls.

The researchers identified and measured levels of antibodies targeting the virus; autoantibodies; and antibodies directed against cytokines, proteins that immune cells secrete to communicate with one another and coordinate their overall strategy.

Upward of 60% of all hospitalized COVID-19 patients, compared with about 15% of healthy controls, carried anti-cytokine antibodies, the scientists found. This could be the result of immune-system overdrive triggered by a virulent, lingering infection. In the fog of war, the abundance of cytokines may trip off the erroneous production of antibodies targeting them, Utz said.

If any of these antibodies block a cytokine’s ability to bind to its appropriate receptor, the intended recipient immune cell may not get activated. That, in turn, might buy the virus more time to replicate and lead to a much worse outcome.

Cartilage Resurfacing Implant Reduces Pain, Restores Hip Joint Function in Dogs

 

Chinni Credit: Heidi-Ann Fourkiller

A textile-based implant containing cartilage derived from stem cells reduced pain and restored hip joint function to baseline levels in a study of dogs with symptoms of moderate osteoarthritis. The study, led by researchers at North Carolina State University, Washington University in St. Louis and Cytex Therapeutics Inc., could be a significant first step toward preventative, less invasive joint resurfacing in dogs and humans.

In humans – and in dogs – a single, millimeter-thick layer of cartilage can mean the difference between an active lifestyle or painful osteoarthritis. That tiny cap of cartilage is what protects joint surfaces and allows the bones to glide over one another smoothly. Age or joint injury can cause the cartilage to degrade, leading to osteoarthritis and progressive joint pain.

“One of the holy grails of orthopedics is to replace cartilage, but there hasn’t been an effective way to do it,” says Duncan Lascelles, professor of surgery and translational pain research and management at NC State and co-corresponding author of the research. “Most of the focus is on replacing or restoring the cartilage surface with artificial materials, but regenerating cartilage isn’t possible right now. And many of the artificial products in use don’t integrate with the body.”

Farshid Guilak, the Mildred B. Simon Professor of Orthopedic Surgery at Washington University and Shriners Hospitals for Children, along with Bradley Estes and Frank Moutos, founded Cytex Therapeutics to develop an implant that could replace damaged or missing cartilage. The implant is made using a unique combination of manufacturing techniques that result in a part textile, part 3D-printed structure, which can be seeded with the patient’s own stem cells.

Cancer Cells’ Unexpected Genetic Tricks for Evading the Immune System

 

Defective versions of genes known as tumor suppressors can help cancer cells (melanoma shown) evade the immune system. Until now, scientists believed these genes’ main role was encouraging tumor growth. Credit: Julio C. Valencia, NCI Center for Cancer Research/CC BY-NC 2.0

In a surprising new finding in mice, researchers have discovered that many genes linked to human cancer block the body’s natural defense against malignancies.

Hundreds of cancer-linked genes play a different role in causing disease than scientists had expected.

So-called tumor suppressor genes have long been known to block cell growth, preventing cancerous cells from spreading. Mutations in these genes, scientists believed, thus allow tumors to flourish unchecked.

Now, Howard Hughes Medical Institute Investigator Stephen Elledge’s team has uncovered a surprising new action for many of these defective genes. More than 100 mutated tumor suppressor genes can prevent the immune system from spotting and destroying malignant cells in mice, Elledge, a geneticist at Brigham and Women’s Hospital, reports September 16, 2021, in the journal Science. “The shock was that these genes are all about getting around the immune system, as opposed to simply saying ‘grow, grow, grow!’” he says.

Conventional wisdom had suggested that, for the vast major of tumor suppressor genes, mutations allow cells to run amok, growing and dividing uncontrollably. But that explanation had some gaps. For example, mutated versions of many of these genes don’t actually cause rampant growth when put into cells in a petri dish. And scientists couldn’t explain why the immune system, which is normally highly proficient at attacking abnormal cells, doesn’t do more to nip new tumors in the bud.

“The shock was that these genes are all about getting around the immune system, as opposed to simply saying ‘grow, grow, grow!’”
Steve Elledge, HHMI Investigator at Brigham and Women’s Hospital

Elledge’s new paper offers some answers. His team probed the effects of 7,500 genes, including genes known to be involved in human cancer. A third or more of those cancer-linked genes, when mutated, trigger mechanisms that prevent the immune system from rooting out tumors, often in a tissue-specific manner.

“These results reveal a fascinating and unexpected relationship between tumor suppressor genes and the immune system,” says HHMI Investigator Bert Vogelstein, a cancer geneticist at the Johns Hopkins University who was not involved in the research.

Reforestation could help save coral reefs from catastrophe

Increasing reforestation efforts in coastal regions could substantially reduce the amount of sediment run-off reaching coral reefs and improve their resilience, a University of Queensland-led study has found.

The study analyzed more than 5,500 coastal areas from around the world and found that nearly 85 per cent of them leached sediment to coral reefs, the second most serious threat facing the world’s reefs behind climate change.

Dr Andrés Suárez-Castro from UQ’s Centre for Biodiversity and Conservation Science said it was important to address the issue of sediment runoff if efforts to reduce the human impact on reefs were to be successful.

“Increased sedimentation can cause aquatic ecosystems to be more sensitive to heat stress, which decreases the resilience of corals to pressures caused by climate change,” Dr Suárez-Castro said.

“If the link between the land and sea is not recognized and managed separately, any future efforts to conserve marine habitats and species are likely to be ineffective.”

Excess sediment runoff from land clearing and agrichemical pollution along coastlines can increase sediment transport to coastal waters.

Dr Suárez-Castro said one of the impacts of sediment runoff on coral reefs is a massive reduction in light levels that were key for coral and sea grass growth and reproduction.

Image credit: Diego Correa Gomez

One solution proposed by Dr Suárez-Castro and his team is for countries to commit to land and forest restoration in coastal regions, which will help reduce the amount of sediment runoff.

“Reforestation is hugely important as it maintains the stability of soils that are vital in limiting erosion risk – it also helps to trap more sediments and prevent them from reaching aquatic systems,” he said.

“Building coral resilience through reducing sediment and pollution is also key to improving a coral reef’s potential for recovery.

“If land management to reduce sediment runoff does not become a global priority, it will become increasingly challenging, if not impossible, to protect marine ecosystems in the face of climate change.”

The researchers said that while the benefits of land restoration activities were clear, it would be a challenge to get countries and governments to commit to restoration activities.

“It’s encouraging to see many countries with high coral diversity committing large areas to land restoration, however the cost of reforestation, as well as political and social barriers may make it difficult to achieve these ambitious goals,” Dr Suárez-Castro said.

“If an average of 1000 hectares of forest was restored per coastal basin, land-based sediments reaching coral reefs could be cut by an average of 8.5 per cent among 63,000 square kilometers of reefs.”

Dr Suárez-Castro and his team hope that local authorities can use their results to identify areas where reforestation can have the highest benefit on coral reefs.

“Our approach can be adapted with local data to identify optimal actions for preserving ‘win-wins’ for multiple ecosystems spanning the land and sea,” Dr Suárez-Castro said.

“Several global initiatives such as the Paris Climate Agreement are bringing forest restoration to the forefront of global conservation discussions and our hope is that our study can facilitate more informed and educated conversations around the importance of a more integrated land-sea approach.”

The research has been published in Global Change Biology

Source/Credit: University of Queensland

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Have we detected dark energy?

 

A new study, led by researchers at the University of Cambridge and reported in the journal Physical Review D, suggests that some unexplained results from the XENON1T experiment in Italy may have been caused by dark energy, and not the dark matter the experiment was designed to detect.

They constructed a physical model to help explain the results, which may have originated from dark energy particles produced in a region of the Sun with strong magnetic fields, although future experiments will be required to confirm this explanation. The researchers say their study could be an important step toward the direct detection of dark energy.

Everything our eyes can see in the skies and in our everyday world – from tiny moons to massive galaxies, from ants to blue whales – makes up less than five percent of the universe. The rest is dark. About 27% is dark matter – the invisible force holding galaxies and the cosmic web together – while 68% is dark energy, which causes the universe to expand at an accelerated rate.

“Despite both components being invisible, we know a lot more about dark matter, since its existence was suggested as early as the 1920s, while dark energy wasn’t discovered until 1998,” said Dr Sunny Vagnozzi from Cambridge’s Kavli Institute for Cosmology, the paper’s first author. “Large-scale experiments like XENON1T have been designed to directly detect dark matter, by searching for signs of dark matter ‘hitting’ ordinary matter, but dark energy is even more elusive.”

To detect dark energy, scientists generally look for gravitational interactions: the way gravity pulls objects around. And on the largest scales, the gravitational effect of dark energy is repulsive, pulling things away from each other and making the Universe’s expansion accelerate.

About a year ago, the XENON1T experiment reported an unexpected signal, or excess, over the expected background. “These sorts of excesses are often flukes, but once in a while they can also lead to fundamental discoveries,” said Dr Luca Visinelli, a researcher at Frascati National Laboratories in Italy, a co-author of the study. “We explored a model in which this signal could be attributable to dark energy, rather than the dark matter the experiment was originally devised to detect.”

At the time, the most popular explanation for the excess were axions – hypothetical, extremely light particles – produced in the Sun. However, this explanation does not stand up to observations, since the amount of axions that would be required to explain the XENON1T signal would drastically alter the evolution of stars much heavier than the Sun, in conflict with what we observe.

We are far from fully understanding what dark energy is, but most physical models for dark energy would lead to the existence of a so-called fifth force. There are four fundamental forces in the universe, and anything that can’t be explained by one of these forces is sometimes referred to as the result of an unknown fifth force.

However, we know that Einstein’s theory of gravity works extremely well in the local universe. Therefore, any fifth force associated to dark energy is unwanted and must be ‘hidden’ or ‘screened’ when it comes to small scales, and can only operate on the largest scales where Einstein's theory of gravity fails to explain the acceleration of the Universe. To hide the fifth force, many models for dark energy are equipped with so-called screening mechanisms, which dynamically hide the fifth force.

Vagnozzi and his co-authors constructed a physical model, which used a type of screening mechanism known as chameleon screening, to show that dark energy particles produced in the Sun’s strong magnetic fields could explain the XENON1T excess.

“Our chameleon screening shuts down the production of dark energy particles in very dense objects, avoiding the problems faced by solar axions,” said Vagnozzi. “It also allows us to decouple what happens in the local very dense Universe from what happens on the largest scales, where the density is extremely low.”

The researchers used their model to show what would happen in the detector if the dark energy was produced in a particular region of the Sun, called the tachocline, where the magnetic fields are particularly strong.

“It was really surprising that this excess could in principle have been caused by dark energy rather than dark matter,” said Vagnozzi. “When things click together like that, it’s really special.”

Their calculations suggest that experiments like XENON1T, which are designed to detect dark matter, could also be used to detect dark energy. However, the original excess still needs to be convincingly confirmed. “We first need to know that this wasn’t simply a fluke,” said Visinelli. “If XENON1T actually saw something, you’d expect to see a similar excess again in future experiments, but this time with a much stronger signal.”

If the excess was the result of dark energy, upcoming upgrades to the XENON1T experiment, as well as experiments pursuing similar goals such as LUX-Zeplin and PandaX-xT, mean that it could be possible to directly detect dark energy within the next decade.

Source/Credit: University of Cambridge / Sarah Collins

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Region of 'Super Corals' Discovered

Corals found in an area of the ocean with extremely high levels of
Carbon Dioxide in the Verde Island Passage in the Philippines.

 In 2019, a hydrology professor at The University of Texas at Austin set out on a research project to see if he could identify harmful nutrients flowing through groundwater into a delicate coral reef sanctuary in the Philippines. He achieved this goal, but following the long history of accidental scientific discoveries, he instead stumbled upon something completely unexpected: a region of possible “super corals” that are thriving despite high levels of carbon dioxide.

The findings based on the 2019 field work were published in August in the journal ACS ES&T Water.

For the first time, the UT Austin professor, Bayani Cardenas, and a team of international researchers were able to attribute the source of CO2 and other gases and nutrients in seawater at this location to groundwater, a finding that the researchers believe shows how the undersea reef environment can be vulnerable to the way communities discharge wastewater, agricultural runoff and other byproducts into the sea.

“This is an unseen vulnerability,” said Cardenas, a professor in the Department of Geological Sciences at the UT Jackson School of Geosciences. “We’ve been able to show with this site that groundwater is part of these delicate coral reef environments. There is a connection, and that’s still not as accepted in science and in many parts of the world.”

More than that, Cardenas said the research has led to new questions — and new research proposals — about the super corals they found that could be replicated elsewhere in the coming years as global CO2 levels are expected to rise.

Coral reefs have long been suffering due to climate change, most notably during a global coral bleaching event from 2014 to 2017 that caused heat stress to 75% of the world’s reefs, according to the American Meteorological Society. Yet the coral-filled area Cardenas studied in the Verde Island Passage in the Philippines, a region so vibrant and diverse that he refers to it as the “Amazon of the ocean,” is thriving despite the vast amounts of CO2 being pumped in from groundwater.

Lead author Rogger E. Correa, a researcher at Southern Cross University in Australia, estimated that groundwater is pumping about 989 grams of CO2 per square meter per year into the area they studied, which is known as “Twin Rocks” and borders a chain of volcanoes. That’s the equivalent of parking two cars on the seabed and letting them emit carbon dioxide for a full year on every hectare of reef.

To distinguish groundwater from seawater, the scientists submerged devices that measure the levels of CO2 and radon 222, a naturally occurring radioactive isotope that is found in local groundwater but not in open ocean water. The measurement technique was developed by co-author Isaac Santos, a professor at the University of Gothenburg in Sweden.

This work follows a 2020 study conducted by Cardenas where he discovered CO2 bubbling up from the seafloor off an area of the Philippine coast so dramatically that he dubbed it “Soda Springs.”

The end result from the latest investigation is an entire region of coral reefs that must be studied more closely, said Cardenas, who is a geoscientist and not a coral researcher.

Adina Paytan, a research scientist at the Institute of Marine Sciences at the University of California, Santa Cruz, who was not associated with the study, warned that other human-made stressors, including sedimentation, overfishing and pollution, can still doom coral reefs. But she was heartened that Cardenas’ team showed corals can grow in high-carbon environments, a finding that “provides some hope for the future of corals.”

Study co-authors included researchers from the Leibniz Centre for Tropical Marine Research (ZMT) in Germany; the State Office for Mining, Energy and Geology in Germany; and the following institutions in the Philippines: Ateneo de Manila University, Agricultural Sustainability Initiatives for Nature Inc., and Planet Dive Resort.

Source/Credit: University of Texas at Austin

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New ALMA study reveals the many molecular faces of protoplanetary disks

 

Pictured is a collage showing about 50% of the complete data from the MAPS collaboration. Image credit: Charles Law, Molecules with ALMA at Planet-forming Scales

An international group of scientists, including University of Michigan astronomers, has mapped the chemical composition of protoplanetary disks surrounding five nearby young stars—an effort that will allow the astronomers to search the disks for planet formation in real time.

The survey provides the most detailed pictures of planet-forming gases to date, which will help scientists understand how planets form, ranging from gas giants called hot Jupiters to our own life-sustaining planet.

“The goal of this program was to survey the chemistry of planet formation with the highest resolution possible in a limited amount of time—just 130 hours. We wanted to know how planets are born and what sets their composition at birth,” said Edwin Bergin, U-M professor of astronomy, co-principal investigator of the survey and co-author on the papers.

“This can then be compared to the composition of exoplanetary atmospheres and in solar system planets to understand how common Jupiters are and, eventually, life-bearing worlds like the Earth.”

The collaboration used the Atacama Large Millimeter/submillimeter Array, or ALMA, to complete the most extensive chemical composition mapping of the protoplanetary disks at high resolution that allows scientists to probe the makeup of their planet- and comet-forming regions.

The new study unlocks clues about the role of molecules in planetary system formation, and whether these young planetary systems in-the-making have what it takes to host life. The results of the program, called MAPS, or Molecules with ALMA at Planet-forming Scales, will appear in an upcoming 20-paper special edition of The Astrophysical Journal Supplement Series.

Planets form in the disks of dust and gas, called protoplanetary disks, surrounding young stars. The chemical makeup of these disks may have an impact on the planets themselves, including how and where planetary formation occurs, the chemical composition of the planets, and whether those planets have the organic composition necessary to support life.

“A planet’s composition is a record of the location in the disk in which it was formed,” said U-M astronomer Arthur Bosman, lead author of many of the studies. “Connecting planet and disk composition enables us to peer into the history of a planet and helps us to understand the forces that formed it.”

This composite image of ALMA data from the young star HD 163296 shows hydrogen cyanide emission laid over a starfield. The MAPS project zoomed in on hydrogen cyanide and other organic and inorganic compounds in planet-forming disks to gain a better understanding of the compositions of young planets and how the compositions link to where planets form in a protoplanetary disk. Image credit: ALMA (ESO/NAOJ/NRAO)/D. Berry (NRAO), K. Öberg et al (MAPS)

MAPS specifically looked at the protoplanetary disks surrounding the young stars IM Lup, GM Aur, AS 209, HD 163296 and MW480, where evidence of ongoing planet formation has already been detected. The project led to multiple discoveries, including a link between dust and chemical substructures and the presence of large reservoirs of organic molecules in the inner disk regions of the stars.

“With ALMA, we were able to see how molecules are distributed where exoplanets are currently assembling, and what we saw is that most planets likely form in a chemical environment that looks rather similar to the solar nebula, the birthplace of our solar system,” said MAPS principal investigator Karin Öberg, an astronomer at the Harvard Smithsonian Center for Astrophysics.

“Most importantly, we saw that the planet-forming disks around these five young stars are factories of a special class of organic molecules, so-called nitriles, which are implicated in the origins of life here on Earth.”

Bosman led Maps VII, which examined the elemental composition of the gas at locations in three of the five disks targeted by MAPS where Jupiter-like planets may be forming. In his study, Bosman and co-authors found the gas surrounding these potentially nascent planets to be poor in carbon, oxygen and heavier elements, while rich in hydrocarbons, such as methane.

“The chemistry that is seen in protoplanetary disks should be inherited by forming planets,” Bosman said. “A carbon- and oxygen-poor environment suggests the existence of a subset of giant planets that have low water abundances in general. This is the opposite of current planet composition studies, and we are finding that the building blocks of many giant planets out there are very different from what we think formed our own solar system giants, Jupiter and Saturn.”

Bosman and Bergin pushed ALMA’s techniques to its limits in order to observe the velocities of gas very close to a disk’s star, within three astronomical units—an astronomical unit is the distance between the Earth and the sun. Gas swirls at higher velocity the closer it is to the star, and based on these velocities, Bosman and Bergin were able to observe one object that appears to be on the verge of planet formation. These results are published in the study MAPS XV.

“This allows us to look for signatures of these hidden forming planets in the gas structure—sort of a planet calling card: ‘I’m here,'” Bergin said.

U-M postdoctoral fellows and graduate students also led papers published in the supplement series. In MAPS XIX, postdoctoral fellow Jane Huang and co-authors showed that one disk (GM Aur) is still accreting material from its parent cloud while actively forming planets, providing a fresh supply of material to these young worlds.

In MAPS XVII, graduate student Jenny Calahan and co-authors measured the gas temperature and its structure using sophisticated models around HD 163296. In MAPS VIII, graduate student Felipe Alarcón and co-authors explored how the observed chemical composition comes to be with a detailed chemical model of the AS209 planet-forming disk.

Altogether, MAPS is providing exactly that: a map for scientists to follow, connecting the dots between the gas and dust in a protoplanetary disk and the planets that eventually form from them to create a planetary system.

Studies:
MAPS VII (PDF)
MAPS XV (PDF)
MAPS XVII (PDF)
MAPS XIX (PDF)

Source/Credit: University of Michigan

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Troubled waters

Dr Katrina Davis
Associate Professor of Conservation Biology

New research led by the University of Oxford, published in Conservation Letters, has examined the conflict between small-scale fisheries and marine mammals, using the experience of fisheries on the west coast of South America to highlight a worldwide issue.

Globally, conflict between recovering seal and sea lion populations and fishing communities has been escalating. This new research presents a unique overview of this conflict, particularly from the fishers’ perspective, and proposes solutions that will be relevant to many fishing communities around the world. 

In this part of South America, specifically Peru and Chile, marine mammals have been protected since the mid-20th century. Conservation policies have mostly been successful and over the last thirty years marine mammal populations - specifically those of sea lions and seals - have recovered. The study found:

• Nearly 9 out of 10 fishers have a negative impression of sea lions.

• Fishers report that on average sea lions reduce their catch and income by over 50%. 

• Whilst it’s illegal for sea lions and seals to be killed, this is happening regularly with over 70% of fishers admitting that sea lions are being killed to defend catches.

• Fishers’ overwhelming concern is that sea lion populations are now too large. 

To manage this conflict, there’s a need to balance the competing objectives of wildlife conservation with protection for local communities. There’s still concern about sea lion and seal populations because of how recently they’ve recovered, but small-scale fisheries are struggling, and fishers are often earning less than the minimum wage.

The international community needs to incorporate the needs and opinions of fishers in the global dialogue, including considering if protecting human welfare could involve reducing protection for marine mammals. 

‘If the global community is committed to a post-2020 deal for nature and people where improvements to people's wellbeing and nature conservation are both fulfilled - the elusive ‘win-win’ - then governments and scientists must engage with these “messy” local conflicts that repeat across the globe but resist high-level simplification.’ Professor Katrina Davis

'The recovery of marine mammals means that there’s a much higher likelihood that these animals will come into conflict with local fishers.'  Professor Katrina Davis

Sea lions and seals eat the same fish targeted by fisheries, so they’re in competition for resources, and it’s not uncommon for fishers to catch fish that have already been ‘nibbled’ by the marine mammals. They can also be accidentally caught in fishing nets and break them, meaning that the fisheries must pay to replace equipment.  

By understanding fishers’ motivations and perceptions we can develop more effective managerial solutions to the fisheries. Including managing sea lion populations, providing financial compensation for catch losses and gear damage, training programs, and shifting focusing from fishing to eco-tourism. 

Lead author Professor Katrina Davis says, 'A tricky balance must be met between ensuring the future viability of marine mammal populations and ensuring that the livelihoods of small-scale fishers are protected. Fishers perceive that they are suffering large catch and income losses because of sea lions—and it’s these perceptions that we have to manage when we’re developing policy solutions.'

Moving forward, researchers plan to investigate the impact of culls on these interactions, whether this would be viable without harming population levels, and whether it would curb aggression towards marine mammals. 

Source/Credit: University of Oxford

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A rare Tibetan worm may hold key to long-acting COVID vaccines

 

Caterpillars with emerging Ophiocordyceps sinensis
Credit: William Rafti Institute

A molecule isolated from the world’s most valuable parasite, the caterpillar fungus (Ophiocordyceps sinensis), may provide clues to better and more stable mRNA vaccines, according to research being done in Australia.

The molecule was first isolated from cordyceps fungi in the 1950s. These fungi infect ghost moth larvae, to make 'summer grass' prized in Tibetan and Chinese medicines for its benefits as a tonic and as a treatment for sexual dysfunction.

Associate Professor Traude Beilharz, from the Biomedicine Discovery Institute at Monash University in Melbourne, and her team have been studying the cordycepin molecule because of its ability to trick cells into increasing nucleotides and making mRNA with longer 3'UTRs. According to Associate Professor Beilharz, understanding how 3' UTRs work is really important to improving the stability and function of vaccines. Their research was recently published in the eLife journal.

The lab is now using what they have learned about 3'UTRs from that study to create a screening

Associate Professor Traude Beilharz

platform to identify optimal 3'UTRs for new mRNA vaccines. These 3’UTRs are crucial in stimulating immunity and may reduce the need for booster shots to maintain this immunity. Rachael Turner, first author of the study, has nearly completed her PhD thesis. Next she will apply her expertise in 3’ UTR function toward improving future mRNA vaccines.

The caterpillar fungus, Ophiocordyceps sinensis, is the world’s most valuable parasite. It’s a relative of the tropical fungus that turns ants into zombies, but unlike its infamous cousin, it is found only on the Tibetan plateau, where it infects the larvae of ghost moths. It has long been part of traditional Chinese medicine, and demand for it has risen so sharply in recent decades that in Beijing it is now worth three times its weight in gold. In Bhutan, one of the countries where the fungus is harvested, it accounts for a significant slice of the gross domestic product.

The development of mRNA vaccines, largely due to COVID-19, has been rapid. In addition, the development of mRNA vaccines against cancer has also developed at pace. According to Associate Professor Beilharz, “mRNA vaccines are a promising technology as the production process is simple, safety profiles are better than those of DNA vaccines, and mRNA-encoded antigens are readily expressed in cells, which stimulate immunity against the virus.”

However, mRNA vaccines also possess some inherent limitations. While side effects such as allergy, renal failure, heart failure, and infarction remain a risk, the vaccine mRNA may also be degraded quickly after administration, leading to the need for boosters.

The best types of mRNA vaccines are those that only encode the target antigen (in the case of COVID vaccines, the spike protein) and contain 5' and 3' untranslated regions (UTRs), which provide comprehensive stimulation of the adaptive and innate immunity. “Studying the cordyceps fungi molecule and how it can be used to understand the function of 3’UTRs is a key step in making better vaccines against infectious diseases like COVID-19 and also cancers,” Associate Professor Beilharz said.

Monash is home to Australia's largest network of RNA and mRNA researchers. Keep up to date with our work on life-saving vaccines and therapeutic treatments on the Monash RNA webpage.

Source/Credit: Monash University

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