The Greenland ice sheet will lose mass at an accelerated rate throughout the 21st century, with a direct link between anthropogenic greenhouse gas emissions and the extent of Greenland’s mass loss. To combat this phenomenon, and therefore global warming, it is essential to reduce our greenhouse gas emissions. Every day new ideas emerge to slow down global warming, such as the use of solar geoengineering, a climate intervention that consists of artificially reducing solar radiation above the ice caps and thus limiting the melting of the ice. How can this be done? The idea is to inject sulphur into the stratosphere, a stable meteorological zone located between 8 and 15 km above sea level in the atmosphere,” explains Xavier Fettweis,climatologist and director of the Climatology Laboratory at ULiège. The sulphur will then act as a sort of mirror that will reflect part of the solar radiation back into space.” An intervention which therefore makes it possible to reduce the amount of sunshine on earth, similar to what happens during volcanic eruptions. In 1991, the eruption of Pinatubo (Philippines) injected millions of tonnes of sulphur dioxide into the stratosphere, causing a drop in global temperatures of around 0.5°C. This observation led to the development of solar geoengineering scenarios. Are these scenarios really reliable and risk-free? This is what the ULiège climatologists wanted to test.

We used a plausible scenario of solar geoengineering (G6solar) that would reduce global warming by a factor of 2 on a global scale compared with the most pessimistic scenario in which nothing would be done about the climate,” continues Xavier Fettweis. By forcing the MAR (Regional Atmospheric Model) developed at ULiège to use this scenario, we show that the reduction in solar radiation associated with this scenario would make it possible to locally reduce the melting at the surface of the Greenland ice sheet by 6% in addition to the global reduction in global warming. While these results seem encouraging, the researchers insist that this type of scenario would not be sufficient to maintain the ice cap in a stable state by the end of this century. Moreover, this type of intervention is not without risk since it could have a significant impact on the ozone layer and on water cycles and precipitation, accentuating the disparities between wet and dry regions. Only solar geoengineering scenarios, which are much more ambitious but becoming unrealistic and dangerous, would make it possible to save the cap,” concludes Xavier Fettweis. We are talking here about human and intentional intervention in the climate. A plan B that is not! It is therefore urgent to drastically reduce our greenhouse gas emissions by means that we know but are struggling to implement.

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However, scientists at the University of Plymouth have developed a simple algorithm-based model which accurately predicts how coastlines could be affected and — as a result — enables communities to identify the actions they might need to take in order to adapt.

The Forecasting Coastal Evolution (ForCE) model has the potential to be a game-changing advance in coastal evolution science, allowing adaptations in the shoreline to be predicted over timescales of anything from days to decades and beyond.

This broad range of timescales means that the model is capable of predicting both the short-term impact of violent storm or storm sequences (over days to years), as well as predicting the much longer-term evolution of the coast due to forecasted rising sea levels (decades).

The computer model uses past and present beach measurements, and data showing the physical properties of the coast, to forecast how they might evolve in the future and assess the resilience of our coastlines to erosion and flooding.

Unlike previous simple models of its kind that attempt forecasts on similar timescales, ForCE also considers other key factors like tidal, surge and global sea-level rise data to assess how beaches might be impacted by predicted climate change.

Beach sediments form our frontline of defence against coastal erosion and flooding, preventing damage to our valuable coastal infrastructure. So coastal managers are rightly concerned about monitoring the volume of beach sediment on our beaches.

The new ForCE model opens the door for managers to keeping track of the ‘health’ of our beaches without leaving their office and to predict how this might change in a future of rising sea level and changing waves.

Model predictions have shown to be more than 80% accurate in current tests, based on measurements of beach change at Perranporth, on the north coast of Cornwall in South West England.

It has also been show to accurately predict the formation and location of offshore sand bars in response to extreme storms, and how beaches recover in the months and years after storm events.

As such, researchers say it could provide an early warning for coastal erosion and potential overtopping, but its stability and efficiency suggests it could forecast coastal evolution over much longer timescales.

The study, published in Coastal Engineering, highlights that the increasing threats posed by sea level rise and coastal squeeze has meant that tracking the morphological evolution of sedimentary coasts is of substantial and increasing societal importance.

Dr Mark Davidson, Associate Professor in Coastal Processes, developed the ForCE model having previously pioneered a traffic light system based on the severity of approaching storms to highlight the level of action required to protect particular beaches.

He said: “Top level coastal managers around the world have recognised a real need to assess the resilience of our coastlines in a climate of changing waves and sea level. However, until now they have not had the essential tools that are required to make this assessment. We hope that our work with the ForCE model will be a significant step towards providing this new and essential capability.”

The University of Plymouth is one of the world’s leading authorities in coastal engineering and change in the face of extreme storms and sea-level rise.

Researchers from the University’s Coastal Processes Research Group have examined their effects everywhere from the coasts of South West England to remote islands in the Pacific Ocean.

They have shown the winter storms of 2013/14 were the most energetic to hit the Atlantic coast of western Europe since records began in 1948, and demonstrated that five years after those storms, many beaches had still not fully recovered.

CASE STUDY — PERRANPORTH, NORTH CORNWALL

Researchers from the University of Plymouth have been carrying out beach measurements at Perranporth in North Cornwall for more than a decade. Recently, this has been done as part of the £4million BLUE-coast project, funded by the Natural Environment Research Council, which aims to address the importance of sediment budgets and their role in coastal recovery.

Surveys have shown that following extreme storms, such as those which hit the UK in 2013/14, beaches recovered to some degree in the summer months but that recovery was largely wiped out in the following winters. That has created a situation where high water shorelines are further landward at sites such as Perranporth.

Sea level is presently forecast to rise by about 0.5m over the next 100 years. However, there is large uncertainty attached to this and it could easily be more than 1m over the same time-frame. If the latter proves to be true, prominent structures on the coastline — such as the Watering Hole bar — will be under severe threat within the next 60 years.

The findings will put scientists on the path of finding a way to better diagnose and treat VITT, possibly prevent it and potentially make vaccines safer.

The researchers’ article was fast-tracked for publication today by the journal Nature in its accelerated article preview because of the importance of the research.

“Our work also answers important questions about the connection between antibodies and clotting,” said Ishac Nazy, principal investigator and corresponding author of the study. He added it will have both diagnostic and therapeutic implications.

Nazy is the scientific director of the McMaster Platelet Immunology Laboratory and an associate professor of medicine for the Michael G. DeGroote School of Medicine at McMaster.

The COVID-19 vaccines using adenoviral vectors, such as those from AstraZeneca and Johnson and Johnson, are associated with the VITT clotting disorder caused by unusual antibodies to blood platelets that are triggered by the vaccine.

The study shows, at a molecular level, how those unusual antibodies stick to components from blood platelets causing them to trigger clot formation.

“The antibodies stick to the platelet protein called platelet factor 4 (PF4) in a very unique and specific orientation, which allows them to align with other antibodies and platelets in the precise formation that leads to a self-perpetuating vicious cycle of clotting events,” said Nazy.

“These disease-causing aggregates quickly activate platelets, creating a highly intense clotting environment in patients,” he added.

The dangerous reaction to the adenovirus vector vaccines has been found to occur in one in 60,000 of people receiving the vaccine in Canada.

“The intention of our study was to better understand how the severe clots which characterize VITT develop,” said Donald Arnold, study co-investigator and co-medical director of the McMaster Platelet Immunology Laboratory.

“A basic principle of medical care is to understand how the disorder happens and, in doing so, develop better treatments.”

John Kelton, co-investigator of the study and co-medical director of the McMaster Platelet Immunology Laboratory, added: “We believe that this study is important because it clarifies how the clotting ensues, and because we have been able to identify the molecules involved.

“The next step is to develop a rapid diagnostic and accurate test to diagnose VITT. Our major interest is now to move upstream from how the clots happen to preventing them from occurring.”

Current rapid tests yield false-negative results, and testing relies on more time-consuming tests to confirm VITT. This study now explains why the rapid tests frequently fail and allows for new strategies to improve diagnostic testing.

The investigators altered the molecular composition of the PF4 protein and, using this technology, were able to identify the binding region on the protein.

The research team included Angela Huynh, a research scientist in the McMaster Platelet Immunology Laboratory, and Mercy Daka, a graduate student of McMaster’s Department of Biochemistry and Biomedical Sciences.

The researchers thanked the agencies supporting the research, including the Public Health Agency of Canada, the Canadian Institutes of Health Research (CIHR), and the Ontario Ministry of Health.

Researchers say these results are among the first to show that mRNA vaccination benefits even those individuals who experience breakthrough infections.

“One of the unique things about this study is that it measured the secondary benefits of the vaccine,” says Sarang Yoon, D.O., a study co-author, assistant professor at the University of Utah Rocky Mountain Center for Occupational and Environmental Health (RMCOEH), and principal investigator of the RECOVER (Research on the Epidemiology of SARS-CoV-2 in Essential Response Personnel) study in Utah.

The study, published online in the New England Journal of Medicine, builds on preliminary data released by the Centers for Disease Control and Prevention (CDC) in March.

The study was designed to measure the risks and rates of infection among those on the front lines of the pandemic.

“We gave these vaccines to some of the highest risk groups in this country — doctors, nurses, and first responders,” Yoon says. “These are the people who are getting exposure to the virus day in and day out, and the vaccine protected them against getting the disease. Those who unfortunately got COVID-19 despite being vaccinated were still better off than those who didn’t.”

The study found that mRNA COVID-19 vaccines were:

• 91% effective in reducing risk for infection once participants were “fully” vaccinated, two weeks after the second dose.
• 81% effective in reducing risk for infection after “partial” vaccination, two weeks after the first dose but before the second dose was given.

The HEROES-RECOVER network recruited 3,975 participants at eight sites. In addition to Salt Lake City, sites included Miami, Florida; Temple, Texas; Portland, Oregon; Duluth, Minnesota; and Phoenix and Tucson, as well as other areas in Arizona. Participants submitted samples for COVID-19 testing on a weekly basis for 17 weeks between Dec. 13, 2020 and April 10, 2021. Participants also reported weekly whether they had COVID-19-like symptoms, including fever, shortness of breath, and loss of taste and smell.

Only 204 (5%) of the participants eventually tested positive for SARS-CoV-2, the virus that causes COVID-19. Of these, 156 were unvaccinated, 32 had an indeterminate vaccine status, and 16 were fully or partially vaccinated. The fully or partially vaccinated participants who developed breakthrough had milder symptoms than those who were unvaccinated:

• Presence of fever was reduced 58% percent among those vaccinated with a breakthrough infection.
• Days spent sick in bed were reduced by 60% among those who developed a breakthrough infection.
• Detection of the virus was reduced by 70% percent among those with breakthrough infections, from 8.9 days to 2.7 days.
• The three people who were hospitalized were not immunized, meaning that no one who developed a breakthrough infection was hospitalized.

These findings also suggest that fully or partially vaccinated individuals who get COVID-19 might be less likely to spread the virus to others. The researchers found that infected study participants who had been fully or partially vaccinated when infected had 40% less detectable virus in the nose and did so for six fewer days compared to those who were unvaccinated.

Overall, the researchers conclude the study’s findings support the CDC’s recommendation to get fully vaccinated as soon as possible.

“I hope these findings reassure the public that mRNA COVID-19 vaccines are safe and protect us from this severe disease,” Yoon says.

The RECOVER study is ongoing, and results from future phases will help determine how long COVID-19 vaccines protect against infection and the real-world effectiveness of newer vaccines. A new study will test the same questions in children 12 and older who are now eligible to receive the COVID-19 vaccination. The research will also investigate how well COVID-19 vaccines protect against new variants now circulating in the U.S., including the highly transmissible Delta variant of SARS-CoV-2.

The study, “Prevention and Attenuation of Covid-19 with the BNT162b2 and mRNA-1273 Vaccines,” appears in the New England Journal of Medicine.

In addition to Dr. Yoon, Kurt Hegmann, M.D., director of RMCOEH, Matthew Thiese, Ph.D., associate professor, and Andrew Phillips, M.D., assistant professor of RMCOEH, were co-investigators on the Utah portion of the study.

Giant water plumes erupting from Enceladus have long fascinated scientists and the public alike, inspiring research and speculation about the vast ocean that is believed to be sandwiched between the moon’s rocky core and its icy shell. Flying through the plumes and sampling their chemical makeup, the Cassini spacecraft detected a relatively high concentration of certain molecules associated with hydrothermal vents on the bottom of Earth’s oceans, specifically dihydrogen, methane and carbon dioxide. The amount of methane found in the plumes was particularly unexpected.

“We wanted to know: Could Earthlike microbes that ‘eat’ the dihydrogen and produce methane explain the surprisingly large amount of methane detected by Cassini?” said Regis Ferriere, an associate professor in the University of Arizona Department of Ecology and Evolutionary Biology and one of the study’s two lead authors. “Searching for such microbes, known as methanogens, at Enceladus’ seafloor would require extremely challenging deep-dive missions that are not in sight for several decades.”

Ferriere and his team took a different, easier route: They constructed mathematical models to calculate the probability that different processes, including biological methanogenesis, might explain the Cassini data.

The authors applied new mathematical models that combine geochemistry and microbial ecology to analyze Cassini plume data and model the possible processes that would best explain the observations. They conclude that Cassini’s data are consistent either with microbial hydrothermal vent activity, or with processes that don’t involve life forms but are different from the ones known to occur on Earth.

On Earth, hydrothermal activity occurs when cold seawater seeps into the ocean floor, circulates through the underlying rock and passes close by a heat source, such as a magma chamber, before spewing out into the water again through hydrothermal vents. On Earth, methane can be produced through hydrothermal activity, but at a slow rate. Most of the production is due to microorganisms that harness the chemical disequilibrium of hydrothermally produced dihydrogen as a source of energy, and produce methane from carbon dioxide in a process called methanogenesis.

The team looked at Enceladus’ plume composition as the end result of several chemical and physical processes taking place in the moon’s interior. First, the researchers assessed what hydrothermal production of dihydrogen would best fit Cassini’s observations, and whether this production could provide enough “food” to sustain a population of Earthlike hydrogenotrophic methanogens. To do that, they developed a model for the population dynamics of a hypothetical hydrogenotrophic methanogen, whose thermal and energetic niche was modeled after known strains from Earth.

The authors then ran the model to see whether a given set of chemical conditions, such as the dihydrogen concentration in the hydrothermal fluid, and temperature would provide a suitable environment for these microbes to grow. They also looked at what effect a hypothetical microbe population would have on its environment — for example, on the escape rates of dihydrogen and methane in the plume.

“In summary, not only could we evaluate whether Cassini’s observations are compatible with an environment habitable for life, but we could also make quantitative predictions about observations to be expected, should methanogenesis actually occur at Enceladus’ seafloor,” Ferriere explained.

The results suggest that even the highest possible estimate of abiotic methane production — or methane production without biological aid — based on known hydrothermal chemistry is far from sufficient to explain the methane concentration measured in the plumes. Adding biological methanogenesis to the mix, however, could produce enough methane to match Cassini’s observations.

“Obviously, we are not concluding that life exists in Enceladus’ ocean,” Ferriere said. “Rather, we wanted to understand how likely it would be that Enceladus’ hydrothermal vents could be habitable to Earthlike microorganisms. Very likely, the Cassini data tell us, according to our models.

“And biological methanogenesis appears to be compatible with the data. In other words, we can’t discard the ‘life hypothesis’ as highly improbable. To reject the life hypothesis, we need more data from future missions,” he added.

The authors hope their paper provides guidance for studies aimed at better understanding the observations made by Cassini and that it encourages research to elucidate the abiotic processes that could produce enough methane to explain the data.

For example, methane could come from the chemical breakdown of primordial organic matter that may be present in Enceladus’ core and that could be partially turned into dihydrogen, methane and carbon dioxide through the hydrothermal process. This hypothesis is very plausible if it turns out that Enceladus formed through the accretion of organic-rich material supplied by comets, Ferriere explained.

“It partly boils down to how probable we believe different hypotheses are to begin with,” he said. “For example, if we deem the probability of life in Enceladus to be extremely low, then such alternative abiotic mechanisms become much more likely, even if they are very alien compared to what we know here on Earth.”

According to the authors, a very promising advance of the paper lies in its methodology, as it is not limited to specific systems such as interior oceans of icy moons and paves the way to deal with chemical data from planets outside the solar system as they become available in the coming decades.

A full list of authors and funding information can be found in the paper, “Bayesian analysis of Enceladus’s plume data to assess methanogenesis,” in the July 7 issue of Nature Astronomy.

The Rice lab of chemical and biomolecular engineer Xue Sherry Gao and collaborators isolated a biocatalyst known as CtdE after identifying it as the natural mechanism that controls the chirality — the left- or right-handedness — of compounds produced by the native fungal host.

The open-access study appears in Nature Communications.

Two chiral things are, like hands, alike in structure but cannot perfectly overlap. Because the property is important in designing drugs that bind correctly to their targets, the ability to achieve 100% correct chirality is highly desired, Gao said.

“It’s important because if a pharmaceutical drug has the wrong stereochemistry (chirality in three dimensions), it could become a poison to humans, even if the planar chemical structure is the same,” she said.

Like “left” or “right” orientation in chiral objects, what’s known as a 3S or 3R orientation is determined by a molecule’s stereocenter, a one-atom connection between parts of a molecule, Gao said.

But while nature handles the process with ease, selectively synthesizing stereocenters has been a challenge for chemists. The entire mechanism behind nature’s ability to control whether a molecule has a 3S or 3R orientation has been hidden from view until now.

Understanding how it works in fungi and analyzing its structure could give scientists, particularly those who design drugs, a new chemical synthesis tool.

The focus of the study, a bioactive natural product known as 21R-citrinadin A, discovered in 2004 in a marine-derived fungal strain of Penicillium citrinum, is toxic to leukemia in mice and human lung cancer cells.

“21R-citrinadin A is a very complicated molecule, with eight stereocenters,” Gao said. “In a way, the paper emphasizes how nature uses enzymes to synthesize a complex molecule with such a precision. Eight different stereocenters are a lot to control.”

She said the molecule incorporates a “very intriguing” 3S spirooxindole ring. “Nature produces several other chemicals with a similar spirooxindole pharmacophore,” Gao said. “However, we became very curious that some of them contain a 3R spirooxindole ring, the opposite of 3S in citrinadins.

“All the genes responsible for expressing this small molecule are clustered together in these fungi, so first we found the gene cluster and looked at each gene individually to see which one could be the most important to catalyze the specific chemical transformations,” she said.

“Once we find it, we can take that gene outside of the fungus, put it back into a user-friendly host, E. coli, and then use protein purification technology to isolate and test its function in a test tube,” Gao said. “By doing everything outside of the fungus, we can be sure there’s only one enzyme that performs this one function.”

The modified E. coli express CtdE protein in bulk. When subsequently used in chemical transformations, CtdE catalyzed the desired 3S stereoselectivity across the board. “A spirooxindole is hard to synthesize already,” she said. “Our goal was to understand the mechanism of how the enzyme controls this specific 3S stereochemistry.”

Bioinformatic analysis, X-ray crystallography and experiments confirmed that CtdE is solely responsible for catalyzing 3S stereoselectivity, Gao said. (Another enzyme, PhqK, was already known to catalyze 3R orientation.) “Having a set of two enzymes that give precise control over stereochemistry will eventually improve the synthesis in pharmaceutical production,” she said.

Gao noted that because CtdE works at room temperature, it will help keep chemistry “green” as well. “Hopefully, these biocatalysts will catalyze chemical reactions in a more environmentally friendly way,” she said.

Postdoctoral researchers Zhiwen Liu and Fanglong Zhao of Rice and graduate student Boyang Zhao of Baylor College of Medicine are co-lead authors of the paper.