Climate change may have driven the emergence of SARS-CoV-2

UNIVERSITY OF CAMBRIDGE

Research News

 

IMAGE: ESTIMATED INCREASE IN THE LOCAL NUMBER OF BAT SPECIES DUE TO SHIFTS IN THEIR GEOGRAPHICAL RANGES DRIVEN BY CLIMATE CHANGE SINCE 1901. THE ZOOMED-IN AREA REPRESENTS THE LIKELY SPATIAL... view more 

CREDIT: DR ROBERT BEYER

Global greenhouse gas emissions over the last century have made southern China a hotspot for bat-borne coronaviruses, by driving growth of forest habitat favoured by bats.

A new study published today in the journal Science of the Total Environment provides the first evidence of a mechanism by which climate change could have played a direct role in the emergence of SARS-CoV-2, the virus that caused the COVID-19 pandemic.

The study has revealed large-scale changes in the type of vegetation in the southern Chinese Yunnan province, and adjacent regions in Myanmar and Laos, over the last century. Climatic changes including increases in temperature, sunlight, and atmospheric carbon dioxide - which affect the growth of plants and trees - have changed natural habitats from tropical shrubland to tropical savannah and deciduous woodland. This created a suitable environment for many bat species that predominantly live in forests.

The number of coronaviruses in an area is closely linked to the number of different bat species present. The study found that an additional 40 bat species have moved into the southern Chinese Yunnan province in the past century, harbouring around 100 more types of bat-borne coronavirus. This 'global hotspot' is the region where genetic data suggests SARS-CoV-2 may have arisen.

"Climate change over the last century has made the habitat in the southern Chinese Yunnan province suitable for more bat species," said Dr Robert Beyer, a researcher in the University of Cambridge's Department of Zoology and first author of the study, who has recently taken up a European research fellowship at the Potsdam Institute for Climate Impact Research, Germany.

He added: "Understanding how the global distribution of bat species has shifted as a result of climate change may be an important step in reconstructing the origin of the COVID-19 outbreak."

To get their results, the researchers created a map of the world's vegetation as it was a century ago, using records of temperature, precipitation, and cloud cover. Then they used information on the vegetation requirements of the world's bat species to work out the global distribution of each species in the early 1900s. Comparing this to current distributions allowed them to see how bat 'species richness', the number of different species, has changed across the globe over the last century due to climate change.

"As climate change altered habitats, species left some areas and moved into others - taking their viruses with them. This not only altered the regions where viruses are present, but most likely allowed for new interactions between animals and viruses, causing more harmful viruses to be transmitted or evolve," said Beyer.

The world's bat population carries around 3,000 different types of coronavirus, with each bat species harbouring an average of 2.7 coronaviruses - most without showing symptoms. An increase in the number of bat species in a particular region, driven by climate change, may increase the likelihood that a coronavirus harmful to humans is present, transmitted, or evolves there.

Most coronaviruses carried by bats cannot jump into humans. But several coronaviruses known to infect humans are very likely to have originated in bats, including three that can cause human fatalities: Middle East Respiratory Syndrome (MERS) CoV, and Severe Acute Respiratory Syndrome (SARS) CoV-1 and CoV-2.

The region identified by the study as a hotspot for a climate-driven increase in bat species richness is also home to pangolins, which are suggested to have acted as intermediate hosts to SARS-CoV-2. The virus is likely to have jumped from bats to these animals, which were then sold at a wildlife market in Wuhan - where the initial human outbreak occurred.

The researchers echo calls from previous studies that urge policy-makers to acknowledge the role of climate change in outbreaks of viral diseases, and to address climate change as part of COVID-19 economic recovery programmes.

"The COVID-19 pandemic has caused tremendous social and economic damage. Governments must seize the opportunity to reduce health risks from infectious diseases by taking decisive action to mitigate climate change," said Professor Andrea Manica in the University of Cambridge's Department of Zoology, who was involved in the study.

"The fact that climate change can accelerate the transmission of wildlife pathogens to humans should be an urgent wake-up call to reduce global emissions," added Professor Camilo Mora at the University of Hawai'i at Manoa, who initiated the project.

The researchers emphasised the need to limit the expansion of urban areas, farmland, and hunting grounds into natural habitat to reduce contact between humans and disease-carrying animals.

The study showed that over the last century, climate change has also driven increases in the number of bat species in regions around Central Africa, and scattered patches in Central and South America.

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Not all banking crises involve panics

Study shows many kinds of finance-sector failures -- not just history's most famous bank runs -- lead to economic downturns

MASSACHUSETTS INSTITUTE OF TECHNOLOGY

Research News

 

A banking crisis is often seen as a self-fulfilling prophecy: The expectation of bank failure makes it happen. Picture people lining up to withdraw their money during the Great Depression or customers making a run on Britain's Northern Rock bank in 2007.

But a new paper co-authored by an MIT professor suggests we have been missing the bigger picture about banking crises. Yes, there are sometimes panics about banks that create self-reinforcing problems. But many banking crises are quieter: Even without customers panicking, banks can suffer losses serious enough to create subsequent economy-wide downturns.

"Panics are not needed for banking crises to have severe economic consequences," says Emil Verner, the MIT professor who helped lead the study. "But when panics do occur, those tend to be the most severe episodes. Panics are an important amplification mechanism for banking crises, but not a necessary condition."

Indeed, in an ambitious piece of research, spanning 46 countries and going back to 1870, the study surveys banking crises that occurred with and without panics. When there is a panic and bank run, the research finds, a 30 percent decline in banking-sector equity predicts a 3.4 percent drop in real GDP (gross domestic product adjusted for inflation) after three years. But even without any creditor panic, a 30 percent decline in bank equity predicts a 2.7 percent drop in real GDP after three years.

Thus, virtually all banking crises, not just history's greatest hits, create long-term macroeconomic damage, since banks are less able to furnish the credit used for business expansion.

"Banking crises do often come with very severe recessions," says Verner, who is the Class of 1957 Career Development Professor and an assistant professor of finance at the MIT Sloan School of Management.

The paper, "Banking Crises Without Panics," appears in the February issue of the Quarterly Journal of Economics. The authors are Matthew Baron, an assistant professor of finance at Cornell University; Verner; and Wei Xiong, a professor of finance and economics at Princeton University.

A rigorous, quantitative approach

To conduct the study, the researchers constructed a new dataset of bank stock prices and dividends in 46 countries from 1870 through 2016, using existing databases and adding information from historical newspaper archives. They also gathered nonbank stock prices, monthly credit spread information, and macroeconomic information such as GDP and inflation.

"People had looked historically at defining and identifying different episodes of banking crises, but there wasn't that much of a rigorous, quantitative approach to defining these episodes," Verner says. "There was a bit more of a 'know it when you see it' approach."

Scholars examining past banking crises divide roughly into two camps. One group has focused on panics, with the implication that if bank runs could be prevented, then banking crises would not be as bad. Another group has looked more at bank assets and focused on circumstances in which banks' decisions lead to big losses -- through bad loans, for instance.

"We come down in the middle, in some sense," Verner says. Panics make bank troubles worse, but nonetheless, "There are a number of examples of banking crises where banks suffered losses and cut back lending, and businesses and households had a harder time getting access to credit, but there weren't runs or panics by creditors. Those episodes still led to bad economic outcomes."

More specifically, the study's close look at the monthly dynamics of banking crises shows how often these circumstances are in fact presaged by an erosion of the bank's portfolio, and recognition of this fact by its investors.

"The panics don't just come out of the blue. They tend to be preceded by bank stocks declining," Verner says. "The bank equity investors recognize the bank is going to suffer loses on the loans it has. And so what that suggests is that panics are really often the consequences, rather than the fundamental cause, of troubles that have already built up in the banking system due to bad loans."

The study also quantifies how impaired bank activity becomes in these situations. After banking crises with visible panics involved, the average bank credit-to-GDP ratio was 5.7 lower after three years; that is, there was less bank lending as a basis for economic activity. When a "quiet" banking crisis hit, with no visible panic, the average bank credit-to-GDP ratio was 3.5 percent lower after three years.

Historical detective work

Verner says the researchers are pleased they were "able to do some historical detective work and find some episodes that had been forgotten." The study's expanded set of crises, he notes, comprises "new information that other researchers are already using."

Formerly overlooked banking crises in this study include a welter of episodes from the 1970s, Canada's struggles during the Great Depression, and various 19th century banking failures. The researchers have presented versions of this study to an array of policymakers, including some regional U.S. Federal Reserve boards and the Bank of International Settlements, and Verner also says he hopes such officials will keep the work in mind.

"I think it's valuable going forward, and not just for historical perspective," he says. "Having a broad sample across many countries is important for recognizing what the lessons are when new crises happen."

The researchers are continuing their research in this area with further studies about patterns in the loans banks make before losing value -- for instance, identifying the kinds of businesses who are less likely to repay bank loans. When banks start lending more heavily to certain kinds of companies -- possibly including restaurant, construction, and real estate companies -- it may be a sign of incipient trouble.

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Support for the research was provided, in part, by the Cornell Center for Social Sciences and the Institute for New Economic Thinking.

Written by Peter Dizikes, MIT News Office

Additional background

Paper: "Banking Crises Without Panics" https://academic.oup.com/qje/article-abstract/136/1/51/5919461?redirectedFrom=fulltext

Women's voices in the media still outnumbered by those of men - study

New gender gap research finds men outnumber women quoted in the media about three to one

SIMON FRASER UNIVERSITY

Research News

 

New research from Simon Fraser University shows that women's voices continue to be underrepresented in the media, despite having prominent female leaders across Canada and internationally. Researchers in SFU's Discourse Processing Lab found that men outnumber women quoted in Canadian news media about three to one. The findings from the team's Gender Gap Tracker study were published this week in the journal PLOS ONE.

The research team collected data from seven major Canadian media outlets from October 2018 to September 2020. Over the two-year period, 29 per cent of people quoted in media stories were women versus 71 per cent men. B.C. Provincial Health Officer Dr. Bonnie Henry, quoted more than 2,200 times, notably topped the list for women most quoted in the news--many others were also public health officials during the COVID-19 pandemic--but still had fewer quotes than the top three male voices, all politicians.

"What this study shows is that we are very far from parity in mainstream news," says SFU linguistics professor and lab director Maite Taboada. "This has profound implications, as we tend to look for role models in the media."

Politicians, both male and female, were most often quoted in the media, followed by sports figures for men, and healthcare professionals for women.

"We found that, although men and women politicians appear regularly, men are quoted far more often. This is the case even despite Canada's gender-balanced cabinet," says Taboada.

Former U.S. President Donald Trump was found to be quoted the most often - 15,746 times to be exact, followed by Canada's Prime Minister Justin Trudeau and Ontario's Premier Doug Ford. Other top women quoted were Ontario Health Minister Christine Elliott and Canada's Minister of Finance Chrystia Freeland.

The team used its Gender Gap Tracker software to analyze daily coverage from CBC, CTV, Global, HuffPost Canada, National Post, The Star and the Globe and Mail. Researchers used the power of large-scale text processing and big data storage to collect news stories daily and perform Natural Language Processing (NLP) to identify who is mentioned and who is quoted by gender.

"We are very proud of this team effort, as it highlights the potential of Natural Language Processing to contribute positively to society, in this case to show the gender gap in media," Taboada adds. "Natural Language Processing is a field at the intersection of computer science and linguistics that aims to analyze and extract information from large amounts of language data."

The researchers found that articles written by women quote more women (34 per cent for articles authored by women compared to 25 per cent for articles authored by men) and suggest part of the solution to addressing the gender gap in media includes hiring more women as reporters.

The study was conducted in partnership with Informed Opinions, which encourages media to diversify their sources and better reflect both genders. While the Gender Gap Tracker can only capture one kind of diversity, since it relies on names to assign gender to sources, the authors suggest considering other forms of diversity, given many other groups are underrepresented in the news.

The Gender Gap Tracker is available online (gendergaptracker.informedopinions.org) and updates 

Tom Hanks' COVID-19 diagnosis likely shaped behaviors, thoughts toward virus

PENN STATE

Research News

 

UNIVERSITY PARK, Pa.-- When actor Tom Hanks announced his COVID-19 diagnosis on March 11, 2020, many Americans were still learning about the virus and its severity. According to new research, Hanks' announcement may have affected how some people understood the virus and their behavior toward its prevention.

The day after Hanks posted the news on social media, Jessica Gall Myrick, an associate professor in the Donald P. Bellisario College of Communications at Penn State, and Jessica Fitts Willoughby, associate professor at Washington State University, surveyed 682 people about their attitudes and behaviors toward COVID-19.

Just under 90% of the people surveyed had heard about Hanks' social media posts saying he contracted the virus, and approximately half of that group reported it changed their attitudes and behaviors. The results were published in the journal Health Communication.

"There is a growing body of research about how celebrity behavior and social media posts can affect public health," Myrick said. "This research was different in that we were able to launch our study really fast and collect survey data within a day of Hanks posting about his diagnosis."

According to the study, the people who had heard the news reported Hanks' diagnosis "highlighted the reality of COVID-19" and broadened their understanding of not only the severity of the situation, but also their susceptibility to the illness.

Nearly half of the participants who had heard the news when surveyed reported a range of emotional responses, according to the study. Responses included "surprise, fear, anger, sadness and hope." The respondents who reported making changes said Hanks' disclosure inspired them to seek more information and/or take stricter precautions.

"Celebrities can have a huge reach, often more so than typical scientists or doctors or the health department," Myrick said. "If they are encouraging positive health behavior change, then it can serve as a de facto public health intervention."

The half of respondents who heard the news and said Hanks' diagnosis did not change their thoughts or behaviors reported thinking the actor would recover from the illness. They also noted they were already aware of COVID-19 and its effects and did not think Hanks' announcement changed their outlook or intentions regarding the virus.

The researchers conducted a statistical analysis to see if and what characteristics could predict whether people's attitudes and behaviors changed after learning Hanks' diagnosis. The results indicated that people who identified with Hanks or said they knew him were more likely to change their thoughts or COVID-related behaviors due to the announcement.

"People who said they typically trust celebrities, friends, family, or Donald Trump for health information were more likely to say that Hanks' announcement led to positive behavior change," Myrick said. "This suggests that public health officials and advocates may want to use these types of celebrity announcements to help reach people who may be harder to reach. They don't rely as much on news or on scientists for health information."

Because the study was launched so quickly -- the day after the announcement -- the researchers were able to talk to some people who had not yet heard the news. Nearly 4% of respondents reported not hearing the news about Hanks' diagnosis. The researchers showed half of these participants the Facebook post where Hanks announced his COVID-19 diagnosis and the other half a non-COVID Hanks post.

The researchers found one notable difference among these groups. Those who read the COVID-19 post said they felt less capable of avoiding the virus compared to the group who read the non-COVID-related Facebook post. It could be that learning of Hanks' diagnosis, despite his wealth and resources, resulted in people thinking that if Hanks could not avoid COVID-19 then they may not be able to, either, said the researchers.

Myrick is affiliated with the Science Communication Program, a program in the Bellisario College that supports research in the science of science communication. Willoughby is an associate professor at the Edward R. Murrow College of Communication at Washington State, where she is a member of the strategic communications department.

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Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.

The Lancet Public Health: Survey taken after France's first COVID-19 wave indicates almost one-third of working-age people could reject a vaccine

Around one in three working-age adults (29%) surveyed in France in July 2020

would refuse any COVID-19 vaccine

THE LANCET

Research News

 

• Around one in three working-age adults (29%) surveyed in France in July 2020 would refuse any COVID-19 vaccine.
• Willingness to receive a COVID-19 vaccination depended upon its country of origin, effectiveness, rate of serious side effects, and site of vaccination.
• Although attitudes may have changed since July 2020 with the approval of several vaccines and a second wave of COVID-19, the findings suggest that communicating the collective benefits of herd immunity reduced people's hesitancy about being vaccinated.

Nearly one in three working-age adults in France (29%) surveyed in July 2020 - when lockdown restrictions had been eased - were outright opposed to being vaccinated against the virus, according to new research published in The Lancet Public Health journal.

Researchers found that more than two-thirds of people (71%) could accept a vaccine depending on its characteristics, with their decision based largely on its effectiveness and country of origin.

Based on their findings, the authors recommend that mass vaccination strategies in France would be most successful if they use vaccines with robust evidence of high levels of effectiveness, especially vaccines produced in the USA or the European Union, and emphasise the collective benefits of herd immunity.

While the study was conducted in France - where vaccine skepticism, in general, is high -highlights potential hurdles that widespread distrust of new vaccines could pose to a vaccine rollout strategy to achieve herd immunity. The authors also note that the study was undertaken before the development of highly effective vaccines, which may have altered people's attitudes.

To date, three COVID-19 vaccines have been approved for use in the European Union. Reaching herd immunity - when upwards of 60% of a country's population is immune due to infection or vaccination - will likely involve the need for mass vaccination, as physical distancing measures aim to prevent people from becoming infected. However, recent evidence from opinion polls suggests that COVID-19 vaccine hesitancy is increasing worldwide. [1]

The authors of the new study surveyed a representative sample of 1,942 adults in France aged 18-64 years using a two-part online questionnaire. The first section sought background information such as participants' past vaccination behaviour and their risk of having a severe case of COVID-19.

In the second part, participants selected from a range of options relating to scenarios involving several hypothetical vaccines. These differed on four characteristics: efficacy (50%, 80%, 90%, or 100%); risk of serious side effects (1/10,000 or 1/100,000 vaccinated people); country of manufacturer (European Union, USA, or China); and site of vaccination (GP practice, local pharmacy, or mass vaccination centre).

Analysing survey responses using a behavioural model enabled researchers to distinguish between people who would accept a vaccination with certain characteristics (known as vaccine hesitancy) and those who would always refuse one - a distinction that is usually not explored using opinion poll data.

Dr Verity Watson, of the University of Aberdeen, UK, said: "We used a study design that allowed us to separate people into two groups: those who will accept vaccination depending on its characteristics, and those who would always refuse one. This information is important for designing mass vaccination campaigns because it shows how sensitive uptake is to the design of the campaign. Opinion polls are rarely able to separate people in this way."

The authors found that nearly one third (29%, 650/1,942) of the French working-age population would refuse any COVID-19 vaccine. Among participants who would not outright refuse a vaccine (71%, 1,382/1,942), hesitancy mainly depended upon the effectiveness of vaccines and the country where they were made.

Vaccine hesitancy was minimised - resulting in a 61% acceptance rate overall - in a scenario using a vaccine manufactured in the European Union that was 90% effective and had a low risk of serious side effects (1/100,000 people vaccinated). Vaccine hesitancy was at its highest - an acceptance rate of only 27% overall - in a scenario involving a Chinese-made vaccine with 50% effectiveness and a risk of serious side effects of 1/10,000.

Survey responses also indicated that a reduction in hesitancy for a vaccine with 90% efficacy (compared with a vaccine with 50% efficacy) was entirely offset if it was made in China rather than the European Union. The authors suggest that hesitancy based on country of origin may be due to perceived rushed development and safety concerns about vaccines made in countries outside the European Union.

The collective benefits of herd immunity should be emphasised as part of mass vaccination strategies, the authors suggest, as communicating these was associated with significantly less COVID-19 vaccine hesitancy.

Both hesitancy and outright refusal to be vaccinated were more likely among women, people with lower educational achievements, and those who had previously chosen not to receive other recommended vaccinations. People aged 18-24 years and 55-64 years were less likely to outright refuse or be hesitant about accepting a vaccine than people aged 25-54 years.

Dr Michaël Schwarzinger, of Bordeaux University Hospital, France, said: "Understanding the factors that determine whether or not working-age people will accept a COVID-19 vaccine is vital. Like France, the majority of the population in most high-income countries is made up of working-age people, which means that reaching herd immunity through a mass vaccination campaign can only be achieved if they are willing to take part."

"Our findings suggest that vaccine hesitancy, alongside other factors including limited vaccine supplies and the emergence of new COVID-19 strains, continues to pose major challenges to getting the pandemic under control. With evidence indicating that hesitancy to receive a COVID-19 vaccine is growing worldwide, studies such as ours are important for helping to inform the development and rollout of national vaccination strategies that people are likely to support." [2]

The authors acknowledge that the main limitation of the study is the timing of the survey. In July 2020, stringent physical-distancing measures had been lifted following the first wave of infections, and information on COVID-19 vaccination was limited. People's attitudes towards COVID-19 vaccination may have changed since then in response to a resurgence of the virus, reintroduced physical distancing measures, and the development of highly effective vaccines.

Writing in a linked Comment, Pierre Verger and Patrick Peretti-Watel from Observatoire Regional de la Santé Provence-Alpes-Côte d'Azur and Aix-Marseille University, France, respectively, suggest the results may be important for informing mass vaccination strategies, saying: " ...this study shows that most people are probably not absolutely for or against COVID-19 vaccines. Depending on their own profile and preferences, and on the characteristics of the vaccines available, vaccine-hesitant individuals might consider taking the vaccine or delay it to get another vaccine. Health authorities must anticipate these behaviours, especially since the characteristics that influence them could change over time."

Publication of this research coincides with two other new studies in The Lancet Public Health journal assessing different aspects of the pandemic in France. One sought to better understand common factors associated with in-hospital COVID-19 cases and deaths across the country, while the other investigated prevalence of the virus among homeless people in Paris.

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Peer-reviewed / Survey / People

** Paper published as part of a collection of three papers assessing different aspects of the COVID-19 pandemic in France**

NOTES TO EDITORS

This study was funded by the French Public Health Agency. It was conducted by researchers from Bordeaux University Hospital, Centre National de la Recherche Scientifique (Aix-Marseille University), Santé Publique France, and University of Aberdeen, UK.

The labels have been added to this press release as part of a project run by the Academy of Medical Sciences seeking to improve the communication of evidence. For more information, please see: http://www.sciencemediacentre.org/wp-content/uploads/2018/01/AMS-press-release-labelling-system-GUIDANCE.pdf if you have any questions or feedback, please contact The Lancet press office pressoffice@lancet.com

[1] Lin C, Tu P, Beitsch LM. Confidence and Receptivity for COVID-19 Vaccines: A Rapid Systematic Review. Vaccines 2020; 9(1).

[2] Quote direct from author and cannot be found in the text of the Article.

#ZOONOSIS

Pangolin coronavirus could jump to humans

THE FRANCIS CRICK INSTITUTE

Research News

 

Scientists at the Francis Crick Institute have found important structural similarities between SARS-CoV-2 and a pangolin coronavirus, suggesting that a pangolin coronavirus could infect humans.

While SARS-CoV-2 is thought to have evolved from a bat coronavirus, its exact evolutionary path is still a mystery. Uncovering its history is challenging as there are likely many undiscovered bat coronaviruses and, due to differences between bat coronaviruses and SARS-CoV-2, it is thought that the virus may have passed to humans via at least one other species.

In their study, published in Nature Communications, the scientists compared the structures of the spike proteins found on SARS-CoV-2, the most similar currently identified bat coronavirus RaTG13, and a coronavirus isolated from Malayan pangolins which were seized by authorities after being smuggled to China. They found that the pangolin virus was able to bind to receptors from both pangolins and humans. This differs to the bat coronavirus, which could not effectively bind with human or pangolin receptors.

Antoni Wrobel, co-lead author and postdoctoral training fellow in the Structural Biology of Disease Processes Laboratory at the Crick, says: "By testing if the spike protein of a given virus can bind with cell receptors from different species, we're able to see if, in theory, the virus could infect this species."

"Importantly here, we've shown two key things. Firstly, that this bat virus would unlikely be able to infect pangolins. And secondly that a pangolin virus could potentially infect humans."

The team used cryo-electron microscopy to uncover in minute detail the structure of the pangolin coronavirus' spike protein, which is responsible for binding to and infecting cells. While some parts of the pangolin virus' spike were found to be incredibly similar to SARS-CoV-2, other areas differed.

In terms of understanding the evolutionary path of SARS-CoV-2, this work does not confirm whether or not this pangolin virus is definitely part of the chain of evolution for SARS-CoV-2. But the findings do support various possible scenarios for how the coronavirus jumped from bats to humans. One potential route is that SARS-CoV-2 originated from a different, currently unknown bat coronavirus which could infect pangolins, and from this species it then moved to humans. Or alternatively, RaTG13 or a similar bat coronavirus might have merged with another coronavirus in a different intermediate species, other than a pangolin.

Donald Benton, co-lead author and postdoctoral training fellow in the Structural Biology of Disease Processes Laboratory at the Crick, says: "We still don't have evidence to confirm the evolutionary path of SARS-CoV-2 or to prove definitively that this virus did pass through pangolins to humans."

"However, we have shown that a pangolin virus could potentially jump to humans, so we urge caution in any contact with this species and the end of illegal smuggling and trade in pangolins to protect against this risk."

Steve Gamblin, group leader of the Structural Biology of Disease Processes Laboratory at the Crick says: "A lot is still to be uncovered about the evolution of SARS-CoV-2, but the more we know about its history and which species it passed through, the more we understand about how it works, and how it may continue to evolve."

This work builds upon previous studies from the Crick team, including research published in July 2020, which found that the bat coronavirus RaTG13 could not effectively bind to human receptors.

The team are continuing to examine the spikes of SARS-CoV-2 and related coronaviruses, including other bat viruses, to better understand the mechanisms of infection and evolution.

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Chinese scientists use knowledge from climate system modeling to develop a global prediction system for the COVID-19 pandemic

INSTITUTE OF ATMOSPHERIC PHYSICS, CHINESE ACADEMY OF SCIENCES

Research News

 

IMAGE: THE CAMPUS OF LANZHOU UNIVERSITY. view more 

CREDIT: CHUWEI LIU

At the time of writing, coronavirus disease 2019 (COVID-19) is seriously threatening human lives and health throughout the world. Before effective vaccines and specific drugs are developed, non-pharmacological interventions and numerical model predictions are essential. To this end, a group led by Professor Jianping Huang from Lanzhou University, China, developed the Global Prediction System of the COVID-19 Pandemic (GPCP).

Jianping Huang is a Professor in the College of Atmospheric Sciences and a Director of the Collaborative Innovation Center for Western Ecological Safety, Lanzhou University, China. He has for a long time been dedicated to studying long-term climate prediction, dust-cloud interaction, and semi-arid climate change by combining field observations and theoretical research. Lockdown in early 2020 seriously affected his research. Therefore, stuck at home, he held online discussions with his team members on how their experience of developing climate system models might be able to contribute to fighting the pandemic. He didn't expect much response, but was surprised and touched when many of his colleagues responded enthusiastically.

Therefore, he and his team combined the results of 30 years of work in statistical dynamic numerical weather prediction methods, and developed the GPCP based on the traditional Susceptible-Infected-Recovered (SIR) infectious disease model. The improved methods and results were published in Atmospheric and Ocean Science Letters.

In order to combine epidemiological data and models, the Levenberg-Marquardt (LM) parameter optimization algorithm was proposed to identify epidemiological models, thereby constructing a Statistical-SIR model. The LM algorithm introduces a damping coefficient when calculating the Hessian matrix by the traditional least-squares method, thereby combining the advantage of the Gauss-Newton method and gradient descent method and improving the stability of parameters.

"From the simulation results of four selected countries with relatively high numbers of confirmed cases, the Statistical-Susceptible-Infected-Recovered model using the LM algorithm was found to be more consistent with the actual curve of the epidemic, being better able to reflect its trend of development," explains Prof. Huang.

In addition, the ensemble empirical mode decomposition (EEMD) model and the autoregressive moving average (ARMA) model were also used in combination to improve the prediction results of the GPCP. The EEMD method has been widely used in the fields of engineering, meteorology, ecology, etc. It can decompose the signal according to its own scale, and is suitable for non-stationary and nonlinear signal processing. The ARMA method can better predict time series.

"We found that the EEMD-ARMA method can be directly used to predict the number of daily new cases in countries with a smaller number of confirmed cases whose development trend cannot be predicted by the infectious disease model. Based on the results, this method is more effective for improving prediction results and making direct predictions," concludes Prof. Huang.

The GPCP model developed by Jianping Huang's team can carry out targeted predictions for different countries and regions, and has achieved good prediction results. The team will continue to improve the model in the future to provide more accurate forecasts for different countries and regions.

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Fingerprint for the formation of nitrous oxide emissions

Scientists succeeded in studying emissions of the greenhouse gas N2O under the influence of environmental impacts in an unprecedented level of detail

UNIVERSITY OF INNSBRUCK

Research News

 

IMAGE: THE 16 GRASSLAND MONOLITHS COME FROM THE KASERSTATTALM IN THE TYROLEAN STUBAITAL - A SITE FOR LONG-TERM ECOSYSTEM RESEARCH. view more 

CREDIT: ELIZA HARRIS

Scientists led by Eliza Harris and Michael Bahn from the Institute of Ecology at the University of Innsbruck have succeeded in studying emissions of the greenhouse gas N2O under the influence of environmental impacts in an unprecedented level of detail. The study, which has now been published in Science Advances, is thus also a starting point for the creation of models that could predict future trends in the greenhouse gas emission dynamics of ecosystems under global climate change.

Nitrous oxide (N2O) is a potent greenhouse gas whose atmospheric growth rate has accelerated over the past decade. The largest share of anthropogenic N2O emissions results from the fertilization of soils with nitrogen, which is converted into N2O via various abiotic and biological processes. A team of scientists led by Eliza Harris and Michael Bahn from the Functional Ecology research group at the University of Innsbruck has now been able to trace in detail the N2O production and consumption pathways that occur within the nitrogen cycle, and ultimately lead to the emission of this greenhouse gas, as part of the FWF-funded project NitroTrace. In an experimental setup at the University of Innsbruck, 16 intact grassland monoliths of the subalpine Long-Term Ecosystem Research (LTER) site Kaserstattalm in the Stubaital region of Tyrol were studied. The soil blocks were exposed to extreme drought and subsequent rewetting. These weather conditions reflect the climatic changes to which many regions across the globe, including the Alps, are increasingly exposed. "Our goal was to quantify the net effect of drought and rewetting on N2O formation processes and emissions, which is currently largely unexplored", says Eliza Harris. Contrary to expectations of the researchers, the process of denitrification, the breakdown of nitrate to N2O and molecular nitrogen (N2) by specialized microorganisms, was found to dominate N2O production in very dry soils. According to previous assumptions, this process takes place primarily in moist, oxygen-poor soils, and as a result more N2O can be released into the atmosphere during drought than expected. The researchers had expected the process of nitrification to predominate in dry soils, producing nitrate, which is an important chemical compound for plants. "We assumed that if the soil was dry, there would be enough oxygen available for nitrification. After closer examination, we were able to detect drought-induced accumulations of nitrogen-containing organic matter on the surface of our soil samples and identify them as triggers for denitrification in dry soil. This suggests a strong role for the previously poorly understood chemodenitrification and codenitrification pathways, where additional abiotic and biotic processes lead to the formation of N2O", explains Eliza Harris the surprising result. Overall, N2O emission was greatest during rewetting after extreme drought.

The results provide researchers with unprecedented insights into the nitrogen cycle and the processes involved in the formation of the greenhouse gas N2O in response to environmental parameters. A better understanding of production and consumption reactions can help to find solutions to reduce greenhouse gas emissions, which have been increasing for decades.

Innovative analysis method

Crucial to the research success was the use of laser isotope spectroscopy, made possible through the FFG-funded project LTER-CWN. "Through this novel analytical technique, we can determine the isotopic composition of N2O. Thus, we get a kind of fingerprint for the formation process of the emitted N2O, which in turn helps us to understand its microbial formation process", emphasizes Eliza Harris the importance of this procedure. Molecular ecology analyses also helped them determine which genes and microbes were involved in the nitrogen transformation. In addition, spatial analysis techniques helped determine elemental composition and distribution in the soil. "We hope that by continuing to apply the combination of these methods in future similar research projects, we will gain further insights into feedback effects between climate change and the nitrogen cycle across different ecosystems and environments", says Eliza Harris. The researchers' long-term goal is to use models to predict ecosystem emission dynamics in the context of climate change.

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Sensor and detoxifier in one

Crystalline polymers for the rapid detection and efficient degradation of ozone

WILEY

Research News

 

Ozone is a problematic air pollutant that causes serious health problems. A newly developed material not only quickly and selectively indicates the presence of ozone, but also simultaneously renders the gas harmless. As reported by Chinese researchers in Angewandte Chemie, the porous "2-in-one systems" also function reliably in very humid air.

Ozone (O(3)) can cause health problems, such as difficulty breathing, lung damage, and asthma attacks. Relevant occupational safety regulations therefore limit the concentrations of ozone allowable in the workplace. Previous methods for the detection of ozone, such as those based on semiconductors, have a variety of disadvantages, including high power consumption, low selectivity, and malfunction due to humid air. Techniques aimed at reducing the concentration of ozone have thus far been based mainly on activated charcoal, chemical absorption, or catalytic degradation.

A team led by Zhenjie Zhang at Nankai University (Tianjin, China) set themselves the goal of developing a material that can both rapidly detect and efficiently remove ozone. Their approach uses materials known as covalent organic frameworks (COFs). COFs are two- or three-dimensional organic solids with extended porous crystalline structures; their components are bound together by strong covalent bonds. COFs can be tailored to many applications through the selection of different components.

The researchers selected easily producible, highly crystalline COFs made of aromatic ring systems. The individual building blocks are bound through connective groups called imines (a nitrogen atom bound to a carbon atom by a double bond). These are at the center of the action.

The imine COFs indicate the presence of ozone through a rapid color change from yellow to orange-red, which can be seen with the naked eye and registered by a spectrometer. Unlike many other detectors, the imine COF also works very reliably, sensitively, and efficiently at high humidity and over a wide temperature range. In the presence of water, the water molecules will preferentially bind to the imine groups. Consequently, the researchers assert, a hydroxide ion (OH(?)) is released, which reacts with an ozone molecule. The positively charged hydrogen atom remains bound to the imine group, causing the color change. If more ozone than water is present (or the ozone-laden air is fully dry), the excess ozone binds to the imine groups and splits them. Each imine group degrades two molecules of ozone. This also causes a color change and the crystalline structure slowly begins to collapse. The imine COF thus doesn't just detect the ozone, but also reliably and efficiently breaks the harmful gas down. This makes it more effective than many of the traditional materials employed for this purpose.

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About the Author

Dr. Zhenjie Zhang is a full Professor of inorganic chemistry at Nankai University. He is currently focusing on developing new crystalline porous materials (e.g., MOFs, COFs, and cages) for value-added product separation and purification, as well as creating smart materials for sensors, actuators, or robots. He is a recipient of the ACS-DIC Young Investigator Award and the CCS JINGQING Chemistry Investigator Award.

Arctic stew: Understanding how high-latitude lakes respond to and affect climate change

S.J. & JESSIE E. QUINNEY COLLEGE OF NATURAL RESOURCES, UTAH STATE UNIVERSITY

Research News

 

IMAGE: NUNAVUT, A VAST REGION IN NORTHERN CANADA, PLAYS A CRUCIAL ROLE IN UNDERSTANDING GLOBAL CLIMATE CHANGE. NEW RESEARCH FROM SOREN BROTHERS DETAILS HOW LAKES IN THE REGION COULD HAVE A... view more 

CREDIT: PAUL SIBLEY

To arrive at Nunavut, turn left at the Dakotas and head north. You can't miss it--the vast tundra territory covers almost a million square miles of northern Canada. Relatively few people call this lake-scattered landscape home, but the region plays a crucial role in understanding global climate change. New research from Soren Brothers, assistant professor in the Department of Watershed Sciences and Ecology Center, details how lakes in Nunavut could have a big impact on carbon dioxide levels in the atmosphere, and it's not all bad news--at least for now. Brothers examined 23 years of data from lakes near Rankin Inlet. He noted a peculiarity--as the lakes warmed, their carbon dioxide concentrations fell. Most lakes are natural sources of carbon dioxide, but these lakes were now mostly near equilibrium with the atmosphere.

This was odd. The expected pattern is that warmer temperatures should trigger larger releases of greenhouse gases from lakes. In places like Alaska, centuries of accumulated plant material in the permafrost release a hoard of carbon as they thaw, and are consumed by microbes. Experiments have also shown that as waters warm, carbon dioxide production by microbes increases more quickly than carbon dioxide uptake by plants, throwing the system out of balance. Together, these processes should increase atmospheric greenhouse gas emissions from waterways, in theory anyway. So why not in Nunavut? There is no question that the first step in this Rube Goldberg machine is engaged ... the climate is warming. Why then, are the lakes near Rankin Inlet not belching out carbon?

Pulling on good, thick parkas, Brothers and his team visited the lakes and came up with a few ideas as to why this is happening. First, they note that much of Nunavut is on the Canadian shield--an ancient granitic bedrock where thin soils are unlikely to contain--and thus release--the massive stores of organic matter entering waterways elsewhere in the Arctic. Second, longer ice-free seasons might be changing the water chemistry and biology in ways that actually lower carbon dioxide concentrations, including longer growing seasons for plants (which take up carbon dioxide), and potentially better growing conditions for algae on the bottom of these shallow, clear lakes.

Does this mean that nature has come to the climate rescue? Likely not--other lakes around the world may still increase carbon dioxide emissions with warming, and the lakes in Nunavut might eventually catch up with them too. More likely, Brothers suggests that the link between ice cover duration and carbon dioxide concentrations might be buying us some time, before stronger positive feedbacks are unleashed between the planet's warming and its ecosystems. It may be a complicated process, but understanding this complexity helps scientists predict variations in how lakes are responding to--and influencing--climate change. It's a view under the hood, making planetary feedbacks and tipping points a little more predictable. While the long-term trajectory of greenhouse gas emissions from lakes is not settled, these results are an important piece of the puzzle in climate change science.

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