Plants can be larks or night owls just like us

EARLHAM INSTITUTE

Research News

 

IMAGE: DR HANNAH REES, POSTDOCTORAL SCIENTIST AT THE EARLHAM INSTITUTE, UK view more 

CREDIT: EARLHAM INSTITUTE

Plants have the same variation in body clocks as that found in humans, according to new research that explores the genes governing circadian rhythms in plants.

The research shows a single letter change in their DNA code can potentially decide whether a plant is a lark or a night owl. The findings may help farmers and crop breeders to select plants with clocks that are best suited to their location, helping to boost yield and even the ability to withstand climate change.

The circadian clock is the molecular metronome which guides organisms through day and night - cockadoodledooing the arrival of morning and drawing the curtains closed at night. In plants, it regulates a wide range of processes, from priming photosynthesis at dawn through to regulating flowering time.

These rhythmic patterns can vary depending on geography, latitude, climate and seasons - with plant clocks having to adapt to cope best with the local conditions.

Researchers at the Earlham Institute and John Innes Centre in Norwich wanted to better understand how much circadian variation exists naturally, with the ultimate goal of breeding crops that are more resilient to local changes in the environment - a pressing threat with climate change.

To investigate the genetic basis of these local differences, the team examined varying circadian rhythms in Swedish Arabidopsis plants to identify and validate genes linked to the changing tick of the clock.

Dr Hannah Rees, a postdoctoral researcher at the Earlham Institute and author of the paper, said: "A plant's overall health is heavily influenced by how closely its circadian clock is synchronised to the length of each day and the passing of seasons. An accurate body clock can give it an edge over competitors, predators and pathogens.

"We were interested to see how plant circadian clocks would be affected in Sweden; a country that experiences extreme variations in daylight hours and climate. Understanding the genetics behind body clock variation and adaptation could help us breed more climate-resilient crops in other regions."

The team studied the genes in 191 different varieties of Arabidopsis obtained from across the whole of Sweden. They were looking for tiny differences in genes between these plants which might explain the differences in circadian function.

Their analysis revealed that a single DNA base-pair change in a specific gene - COR28 - was more likely to be found in plants that flowered late and had a longer period length. COR28 is a known coordinator of flowering time, freezing tolerance and the circadian clock; all of which may influence local adaptation in Sweden.

"It's amazing that just one base-pair change within the sequence of a single gene can influence how quickly the clock ticks," explained Dr Rees.

The scientists also used a pioneering delayed fluorescence imaging method to screen plants with differently-tuned circadian clocks. They showed there was over 10 hours difference between the clocks of the earliest risers and latest phased plants - akin to the plants working opposite shift patterns. Both geography and the genetic ancestry of the plant appeared to have an influence.

"Arabidopsis thaliana is a model plant system," said Dr Rees. "It was the first plant to have its genome sequenced and it's been extensively studied in circadian biology, but this is the first time anyone has performed this type of association study to find the genes responsible for different clock types.

"Our findings highlight some interesting genes that might present targets for crop breeders, and provide a platform for future research. Our delayed fluorescence imaging system can be used on any green photosynthetic material, making it applicable to a wide range of plants. The next step will be to apply these findings to key agricultural crops, including brassicas and wheat."

The results of the study have been published in the journal Plant, Cell and Environment.

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Notes to editors Please contact Greg Jones at the Earlham Institute with any media queries: Tel +44 (0)7792 154497 or greg.jones@earlham.ac.uk

Rees, H. et al, Naturally occurring circadian rhythm variation associated with clock gene loci in Swedish Arabidopsis accessions. Plant, Cell and Environment, 2020. DOI: 10.1111/pce.13941

About the Earlham Institute

The Earlham Institute (EI) is a world-leading research institute focusing on the development of genomics and computational biology. EI is based within the Norwich Research Park and is one of eight institutes that receive strategic funding from Biotechnology and Biological Science Research Council (BBSRC) - £5.43m in 2017/18 - as well as support from other research funders. EI operates a National Capability to promote the application of genomics and bioinformatics to advance bioscience research and innovation.

EI offers a state-of-the-art DNA sequencing facility, unique by its operation of multiple complementary technologies for data generation. The Institute is a UK hub for innovative bioinformatics through research, analysis and interpretation of multiple, complex data sets. It hosts one of the largest computing hardware facilities dedicated to life science research in Europe. It is also actively involved in developing novel platforms to provide access to computational tools and processing capacity for multiple academic and industrial users and promoting applications of computational bioscience. Additionally, the Institute offers a training programme through courses and workshops, as well as an outreach programme targeting key stakeholders and wider public audiences through dialogue and science communication activities.

earlham.ac.uk

Simple and cost-effective extraction of rare metals from industrial waste

Researchers from Kanazawa University recovered palladium and silver metal from industrial waste, which will help reduce pollution and alleviate demand from dwindling natural sources

KANAZAWA UNIVERSITY

Research News

 

Kanazawa, Japan - Many rare metals are in scarce supply, yet demand for use in electronics, medical instrumentation, and other purposes continues to increase. As waste, these metals pollute the environment and harm human health. Ideally, we would recycle the metals from waste for reuse. Unfortunately, current recycling methods are some combination of complex, expensive, toxic, wasteful, and ultimately inefficient.

In an upcoming study in Chemical Engineering Journal, researchers from Kanazawa University report a major improvement in recovering silver and palladium ions from aqueous acidic waste. Recovery of the metals in elemental, metallic form is straightforward--simply burn the extraction material and collect the remaining metal after further heating.

The researchers chemically modified ultrasmall particles of cellulose, an abundant and nontoxic biopolymer, to selectively adsorb silver and palladium ions at room temperature. Adsorption was nearly complete at acidic pH with acid concentrations of around 1 to 13 percent by volume. These are reasonable experimental conditions.

"The adsorbent selectively chelated the soft acid silver and palladium cations," explains lead author Foni Biswas. "Of the 11 competing base metals we tested, only copper and lead cations were also adsorbed, but we removed them with ease."

Maximum metal ion adsorption was fast--e.g., an hour for silver. Maximum adsorption commonly requires many hours with other approaches.

"Intraparticle diffusion did not hinder adsorption, which is an endothermic, spontaneous chemical process," explains senior author Hiroshi Hasegawa. "Maximum metal adsorption capacities--e.g., 11 mmol/g for silver--are substantially higher than that reported in prior research."

After adsorption, the researchers simply incinerated the cellulose particles to obtain elemental silver or palladium powder. Subsequent higher-temperature incineration converted the powder into pellets. Cyanide or other toxic extractants were not required. Spectroscopic analyses indicated that the final metal pellets were in metallic rather than oxide form.

"We removed nearly all of the silver and palladium from real industrial waste samples," says lead author Biswas. "Obtaining pure and elemental metals proceeded as smoothly as in our trial runs."

Palladium and silver are valuable metals yet natural supplies are increasingly limited. Future needs require that we recycle the metals that we already have in a practical manner. The research reported here is an important development that will avoid supply and distribution difficulties that will only increase in the coming years.

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Devastating skin disease covering up to 70% of a dolphin's body tied to climate change

In collaboration with Australian researchers, The Marine Mammal Center has found that the increasing frequency and severity of storm systems drastically decrease the salinity of coastal waters, causing fatal skin disease in dolphins worldwide

THE MARINE MAMMAL CENTER

Research News

 

IMAGE: A CLOSEUP VIEW OF A BOTTLENOSE DOLPHIN SHOWS SIGNS OF SKIN LESIONS ASSOCIATED WITH A DEADLY SKIN DISEASE KNOWN AS ULCERATIVE DERMATITIS. IN COLLABORATION WITH AUSTRALIAN RESEARCHERS, THE MARINE MAMMAL... view more 

CREDIT: CREDIT TIM MORGAN © MISSISSIPPI STATE UNIVERSITY

Scientists at The Marine Mammal Center in Sausalito, CA - the largest marine mammal hospital in the world - and international colleagues have identified a novel skin disease in dolphins that is linked to climate change. The study is a groundbreaking discovery, as it is the first time since the disease first appeared in 2005 that scientists have been able to link a cause to the condition that affects coastal dolphin communities worldwide. Due to the decreased water salinity brought upon by climate change, the dolphins develop patchy and raised skin lesions across their bodies - sometimes covering upwards of 70 percent of their skin.

The international study, which can be found here, was co-authored by three internationally respected scientists, from California and Australia:

• Dr. Pádraig Duignan, Chief Pathologist at The Marine Mammal Center
• Dr Nahiid Stephens, a veterinary pathologist at Murdoch University (Perth, Australia)
• Dr. Kate Robb, Founding Director, zoologist, and geneticist of the Marine Mammal Foundation (Victoria, Australia)

The study, published in Scientific Reports, a peer-reviewed natural sciences journal, provides the first-ever case definition for fresh-water skin disease in bottlenose dolphins.

This study comes on the heels of significant outbreaks in Louisiana, Mississippi, Alabama, Florida and Texas and Australia in recent years. In all of these locations, a sudden and drastic decrease in salinity in the waters was the common factor. Coastal dolphins are accustomed to seasonal changes in salinity levels in their marine habitat, but they do not live in freshwater. The increasing severity and frequency of storm events like hurricanes and cyclones, particularly if they are preceded by drought conditions, are dumping unusual volumes of rain that turn coastal waters to freshwater. Freshwater conditions can persist for months, particularly after intense storms such as hurricanes Harvey and Katrina. With the increasing climate temperatures, climate scientists have predicted extreme storms like these will occur more frequently and, consequently, will result in more frequent and severe disease outbreaks in dolphins.

"This devastating skin disease has been killing dolphins since Hurricane Katrina, and we're pleased to finally define the problem," said Duignan. "With a record hurricane season in the Gulf of Mexico this year and more intense storm systems worldwide due to climate change, we can absolutely expect to see more of these devastating outbreaks killing dolphins."

The study has major implications for the current outbreak in Australia, which is impacting the rare and threatened Burrunan dolphin in southeast Australia, and could provide professionals with the information needed to diagnose and treat affected animals. Currently, the long-term outlook for dolphins affected with the skin disease is poor. This is especially true for the animals suffering from prolonged exposure to freshwater.

The deadly skin disease was first noted by researchers on approximately 40 bottlenose dolphins near New Orleans after Hurricane Katrina in 2005.

"As warming ocean temperatures impact marine mammals globally, the findings in this paper will allow better mitigation of the factors that lead disease outbreaks for coastal dolphin communities that are already under threat from habitat loss and degradation," said Duignan. "This study helps shed light on an ever-growing concern, and we hope it is the first step in mitigating the deadly disease and marshalling the ocean community to further fight climate change."

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ABOUT THE MARINE MAMMAL CENTER:

Headquartered on the site of a former Cold War missile base, The Marine Mammal Center is a global leader in marine mammal health, science and conservation, and is the largest marine mammal hospital in the world. The Center's teaching hospital and training programs operate globally, with its headquarters in the Golden Gate National Recreation Area, part of the National Park Service. Expert teams from the Center travel around the world to work with emerging first responders and has itself rescued more than 24,000 marine mammals from 600 miles of its authorized rescue area of California coastline and the Big Island of Hawai'i. The Center's mission is to advance global ocean conservation through marine mammal rescue and rehabilitation, scientific research, and education. For more information, please visit MarineMammalCenter.org. Follow us on Facebook, Instagram and Twitter.

 

Roadmap to renewables unites climate and sustainability goals

Vision and research gaps for a low-carbon, biodiverse future

UNIVERSITY OF CALIFORNIA - DAVIS

Research News

 

IMAGE: GREAT EGRETS SIT ATOP A FLOATOVOLTAIC ARRAY IN FLORIDA IN 2020. view more 

CREDIT: REBECCA R. HERNANDEZ, UC DAVIS

While the pressures of climate change bring a sense of urgency to renewable energy development, a new study serves as a roadmap toward uniting the goals of a low-carbon future with that of ecological sustainability and conservation.

The study, published in the journal Frontiers in Sustainability from the University of California, Davis, and John Hopkins University, aims to help decision-makers avoid the unintended environmental consequences of renewable energy development.

"Renewables aren't always sustainable, but they can be if we think proactively," said co-leading author Sarah Jordaan, an assistant professor at John Hopkins University's School of Advanced International Studies. "There is a huge misalignment between United Nations Sustainable Development Goals and climate goals. This is a call to action for leaders to come together to address it."

To develop the roadmap, the authors assessed public and private investments in renewable energy and analyzed the tradeoffs and synergies of clean energy. They also identified research themes drawn from a two-day workshop held by the Electric Power Research Institute in 2019 with 58 leading experts in the fields of renewable energy and sustainability from across academia, industry, government sectors.

MISSING THE FOREST FOR THE GHGs

Among the key research priorities identified for sustainable solar and wind developments include site selection and understanding interactions with wildlife.

For example, Florida's longleaf pine forests have, for centuries, helped store carbon, protect water quality and provide wildlife habitat. Now, only a fraction of the historical range of longleaf pine forests in the state remain. Yet a sliver of that remaining sliver is slated to be replaced by a solar installation.

Meanwhile, in the same state and just a few miles away, waterbirds squawk, preen their feathers, and hunt for food atop a floating array of solar panels - a "floatovoltaic" installation. Here, both wildlife and greenhouse-gas-reduction goals appear to coexist gracefully.

"We can't pursue climate change mitigation blindly," said co-leading author Rebecca. R. Hernandez, a UC Davis assistant professor and founding director of the Wild Energy Initiative in the John Muir Institute of the Environment. "We must consider the impacts of renewables on the few ecosystems we have left."

Other key considerations and priorities the scientists identified were public acceptance of clean energy projects and the study of end-of-life management for wind and solar. For instance, the composites in wind blades are not recyclable, and solar panels contribute to a growing electronic waste problem.

CAPTION

A heron stands beside a floatovoltaic array in Florida.

CREDIT

Rebecca R. Hernandez, UC Davis

PUSHING FORWARD

The authors said the work highlights how the field of sustainable renewable energy is in its infancy, with many of the questions and solutions unclear. The roadmap, they emphasize, is a living document, designed to change as the field matures.

"We're pushing forward into maturation something that is really just being born," Hernandez said of renewable energy. "Across its sectors, everyone is trying to figure things out as quickly as possible. This roadmap points to the fact that we all need to get organized and work together to share knowledge, innovation and results."

Jordaan said while the roadmap highlights problems, they are solvable.

"We need to research the things we don't know, implement solutions we do know, and develop technology as needed and ensure accountability," she said.

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Additional

Fire-resistant tropical forest on brink of disappearance -

Research on Indonesia shows effect of human modification

SWANSEA UNIVERSITY

Research News

 

IMAGE: A NEW STUDY LED BY SWANSEA UNIVERSITY REVEALS THAT ONLY 10% OF THE FOREST THAT IS LEFT ON TWO INDONESIAN ISLANDS REMAINS FIRE-RESISTANT. THE RESEARCHERS WARN THAT PROTECTING THIS... view more 

CREDIT: T. SMITH

A new study led by researchers in the Geography Department at Swansea University reveals the extreme scale of loss and fragmentation of tropical forests, which once covered much of the Indonesian islands of Sumatra and Kalimantan.

The study also reveals that only 10% of the forest that is left remains fire-resistant. The researchers warn that protecting this is crucial for preventing catastrophic fire.

Tropical deforestation exacerbates recurrent peatland fire events in this region. These release globally significant greenhouse gas emissions and produce toxic haze events across South East Asia.

An area of tropical forest and peatland larger than the Netherlands has burned in Indonesia in the past five years, according to Greenpeace.

Yet the study shows that contiguous tracts of undisturbed forests are not susceptible to burning even under current drought conditions.

Dr Tadas Nikonovas of Swansea University, lead author of the research, explained:

"Undisturbed tropical rainforests are naturally resistant to fire due to the humid and cool micro-climate they maintain, effectively acting as a fire barrier. Contrary to the widely-held perception that worsening droughts are threatening the remaining rainforests, tropical forests in Indonesia become susceptible to fire only after human disturbance."

However, the study also reveals that currently only a small fraction (~10%) of the remaining total tropical forest cover remains fire-resistant. The rest (~90%) has been severely fragmented or degraded and therefore is no longer able to maintain a fire-resistant microclimate.

Importantly, fire-resistant forests now cover only 3% of the region's peatlands, leaving large amounts of climate-critical carbon vulnerable to burning.

The authors emphasize that the preventative role tropical forests play against fire is yet another important reason for the preservation and regeneration of the few remaining contiguous tracts of forests.

Dr Allan Spessa of Swansea University, the project leader, added:

"Protecting tropical forest is critical not only for biodiversity and carbon storage but also for preventing future catastrophic fire episodes. This is true for Indonesia, as well as for tropical forest in Africa and South America".

The research was published in a Nature group journal, Communications Earth and Environment

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This study is part of Swansea University-based Towards Fire Early Warning System for Indonesia (ToFEWSI) project.

Notes to editors

About the research: The DOI for this paper will be 10.1038/s43247-020-00069-4. Once the paper is published, it will be available to view online at
https://www.nature.com/commsenv/

For more information please get in touch with the project PI Dr Allan Spessa
(allan.spessa@swansea.ac.uk)

or the lead author Dr Tadas Nikonovas
(t.nikonovas@swansea.ac.uk).

Swansea University is a world-class, research-led, dual campus university offering a first-class student experience and has one of the best employability rates of graduates in the UK. The University has the highest possible rating for teaching - the Gold rating in the Teaching Excellence Framework (TEF) in 2018 and was commended for its high proportions of students achieving consistently outstanding outcomes.

Swansea climbed 14 places to 31st in the Guardian University Guide 2019, making us Wales' top ranked university, with one of the best success rates of graduates gaining employment in the UK and the same overall satisfaction level as the Number 1 ranked university.

The 2014 Research Excellence Framework (REF) 2014 results saw Swansea make the 'biggest leap among research-intensive institutions' in the UK (Times Higher Education, December 2014) and achieved its ambition to be a top 30 research University, soaring up the league table to 26th in the UK.

The University is in the top 300 best universities in the world, ranked in the 251-300 group in The Times Higher Education World University rankings 2018. Swansea University now has 23 main partners, awarding joint degrees and post-graduate qualifications.

The University was established in 1920 and was the first campus university in the UK. It currently offers around 350 undergraduate courses and 350 postgraduate courses to circa 20,000 undergraduate and postgraduate students. The University has ambitious expansion plans as it moves towards its centenary in 2020 and aims to continue to extend its global reach and realise its domestic and international potential.

Swansea University is a registered charity. No.1138342. Visit http://www.swansea.ac.uk

For more information:

Kevin Sullivan,
senior press officer,
Swansea University
k.g.sullivan@swansea.ac.uk

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Identifying where to reforest after wildfire

A future of fewer Christmas trees and other conifers

UNIVERSITY OF CALIFORNIA - DAVIS

Research News

 

IMAGE: A POST-FIRE AREA OF THE SIERRA NEVADA MOUNTAINS WITH VERY LITTLE CONIFER REGENERATION. view more 

CREDIT: JOSEPH STEWART, USGS/UC DAVIS

In the aftermath of megafires that devastated forests of the western United States, attention turns to whether forests will regenerate on their own or not. Forest managers can now look to a newly enhanced, predictive mapping tool to learn where forests are likely to regenerate on their own and where replanting efforts may be beneficial.

The tool is described in a study published in the journal Ecological Applications by researchers from the University of California, Davis; U.S. Geological Survey (USGS), Cal Fire and the U.S. Forest Service.

"Huge fires are converting forested areas to landscapes devoid of living trees," said lead author Joseph Stewart, a postdoctoral researcher at UC Davis and with USGS. "Managers need timely and accurate information on where reforestation efforts are needed most."

The tool, also known as the Post-fire Spatial Conifer Regeneration Prediction Tool (POSCRPT), helps forest managers identify within weeks after a fire where sufficient natural tree regeneration is likely and where artificial planting of seedlings may be necessary to restore the most vulnerable areas of the forest.

NOT SO EVERGREEN

Conifers, or plants with cones such as pine trees, dominate many forests in western North America. The study found that conifers are less likely to regenerate after fires when seedlings face drier climate conditions, especially in low-elevation forests that already experience frequent drought stress. Overall, fewer conifers are expected to grow in California's lower elevations following wildfire due to climate and drought conditions.

"We found that when forest fires are followed by drought, tree seedlings have a harder time, and the forest is less likely to come back," said Stewart.

A UC Davis team collected post-fire recovery data from more than 1,200 study plots in 19 wildfires that burned between 2004 and 2012, as well as 18 years of forest seed production data. Ecologists at USGS collected and identified over 170,000 seeds from hundreds of seed traps. The scientists combined these data with multispectral satellite imagery, forest structure maps, climate and other environmental data to create spatial models of seed availability and regeneration probability for different groups of conifers, including pines and firs.

Forest managers have used a prototype of the tool in recent years to better understand where to focus regeneration efforts. The new upgrade incorporates information on post-fire climate and seed production and includes an easy-to-use web interface expected to increase the tool's accuracy and use.

"This work is a great example of how multiple partners can come together to solve major resource management problems that are arising from California's climate and fire trends," said co-author Hugh Safford, regional ecologist for the USDA Forest Service's Pacific Southwest Region and a member of the research faculty at UC Davis.

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Additional co-authors include Phillip van Mantgem, Adrian Das, Nathan Stephenson, Jon Keeley and Micah Wright of USGS; Derek Young and James Thorne of UC Davis; Kristen Shive of Save the Redwoods League; Haiganoush Preisler of U.S. Forest Service; and Kevin Welch of California Department of Forestry and Fire Protection.

The study was funded by the USGS' Southwest Climate Adaptation Science Center, Ecosystems Mission Area and Land Change Science Program.

Climate warming linked to tree leaf unfolding and flowering growing apart

BRITISH ECOLOGICAL SOCIETY

Research News

 

An international team of researchers from the Chinese Academy of Sciences, Zhejiang A & F University and the University of Eastern Finland have found that regardless of whether flowering or leaf unfolding occurred first in a species, the first event advanced more than the second over the last seven decades.

In the four European tree species the researchers looked at: horse chestnut, scots pine, alder and ash, the time interval between leaf unfolding and flowering increased at a rate of 0.6 to 1.3 days per decade between 1950 - 2013. Similar trends were seen geographically, with the time interval between the two life-cycle (phenological) events being greater in trees in warmer areas of Europe.

Although leaf unfolding and flowering have both been shown to be happening earlier with climate warming, this is the first large scale study to examine both phenological events together and show that they are not advancing at the same rate in response to climate warming.

Leaf unfolding and flowering are key annual events for trees with each signalling the start of growth and reproduction, respectively. The timing of these events is crucial for maximising fitness.

"The unequal advances of leaf unfolding and flowering may alter trees' partitioning of resources between growth and reproduction and could leave flowers or leaves vulnerable to late spring frost damage if they appear too early" said Dr Jian-Guo Huang, the corresponding author of the study. "This could have impacts on tree species health and further affect ecosystem structure and function."

Species that produce flowers before leaves, like ash, could suffer losses in seed production if flowers were damaged by late spring frost. For species that produce leaves before flowers, like horse chestnut, late spring frost damage to leaves could reduce growth and carbon uptake.

Dr Qianqian Ma, lead author of the study said "The timing of phenological events is very sensitive to environmental factors, with temperature being particularly important in temperate plants. The changes in phenology we observed in our study may affect both growth and reproductive development in tree species and ultimately affect the ecosystem, nutrient cycles and carbon storage."

Tree species have evolved an optimal timing for growth and reproduction based on historic climate conditions. Changes to flowering times could disrupt interactions with pollinators, impacting the survival of both species with knock-on consequences for the ecosystem. Changes to when trees are able to grow in the year can have further consequences to their survival and carbon uptake.

The triggering of these phenological events is closely linked to temperature changes in the seasons. "Plants often require an exposure to chilling temperatures during winter as a cue for rest before the bursting of leaf buds or flowering can be triggered by a sufficient exposure to warmer temperatures in spring." explained Dr Qianqian Ma.

For each tree species, leaf unfolding and flowering have evolved to occur in a predetermined order. Although leaf unfolding occurs first in most species, those pollinated by wind, like alder and ash, flower first so that leaves don't inhibit pollen dispersal.

To collect the data on the four tree species, the researchers used the Pan European Phenology (PEP) network. This database contains annul observations of the date when leaves first unfold (or separate for evergreens) and the date when flowers first emerge for tree species across Europe. With this data the authors calculated the time intervals between first leaf date and first flower date between 1950 - 2013 and assessed this with corresponding temperature data.

Dr Qianqian Ma said: "Using long-term phenological records in Europe, we examined simultaneously the responses of both leaf unfolding and flowering of four common temperate tree species: ash, alder, horse chestnut and scots pine to climate warming."

These trees were chosen to give a mix of deciduous and evergreen trees with different orders of leaf unfolding and flowering.

Ideally more species would have been included in the study, but the researchers could only look at tree species with data on first leaf, first flower date and temperature. Only four tree species had sufficient data records over long enough time periods and large enough geographic areas.

Dr Jian-Guo Huang said: "Further studies that simultaneously monitor the timing of phenological events and the allocation of resources within plants are needed to better evaluate the consequences of altered phenology under climate warming."

COVID-19: what strategies are beneficial to the state

Competing benefits: economic theory and COVID constraints

NATIONAL RESEARCH UNIVERSITY HIGHER SCHOOL OF ECONOMICS

Research News

 

Those who consider themselves healthy will be more willing to comply with COVID restrictions if they believe, according to their own estimations, that the expected losses from the disease will be significant, suggest researchers of the Faculty of Economic Sciences at HSE University.

Based on the classic Prisoner's Dilemma, HSE researchers modeled human behavior strategies in the face of COVID restrictions. Their model showed that unequal access to medical care both contributes to irresponsible behavior in some citizens and the independent acceptance of restrictions by others, without any government intervention. The study was published in the journal Public Administration Issues.

During the first wave of infections of the coronavirus pandemic, government decisions were often made at random, based on common sense or epidemiological calculations. Very quickly, implemented measures came into conflict with societal ideas of efficiency and fairness--i.e., economic issues. Meanwhile, simple classical models that economists usually use in their studies can tell a lot about the motives behind citizens' behavior when restrictions are implemented, and about possible options for public policy.

One of the most famous models in game theory is the Prisoner's Dilemma. Two people caught while trying to escape are faced with a choice: to be silent or betray the other? Neither of them knows how the other will act. Both face punishment in the form of an additional term of imprisonment, but its severity depends on how the captured fugitives behave. If one of them testifies against the other, his term will be shortened, and the term of the silent fugitive will be as severe as possible. If both testify against each other, then both will be punished with serious sentences. If both are silent, then each prisoner's punishment will be mild. The benefits of cooperation outweigh the benefits of pursuing one's own interests. Despite this, people do not always agree to mutually beneficial cooperation due to imperfect information.

In the case of pandemic-related restrictions, the logic remains: for example, if everyone voluntarily self-isolates at home, then one person who violates the restriction wins, since they will not get infected and, moreover, retain their usual lifestyle. But, if everyone starts to ignore the restrictions, the increase in the rate of infection leads to a worsening of the situation for everyone (at the very least due to the decrease in the availability of medical care).

However, restrictive measures do not always find support among populations. In a lockdown, even vulnerable citizens ('at-risk groups') will be inclined to violate the bans if they consider freedom of movement important and are confident that they will receive adequate medical care. Individuals who suffer large losses under restrictive measures (quarantine, self-isolation, or bans on work or movement) and, at the same time, have high incomes and access to high-quality health services, will be willing to accept the risks of infection, even if their behavior results in an escalation of the epidemic. Only when citizens consider the likelihood of their receiving quality assistance to be low do they consider following restrictions to be more advantageous.

'Together with my colleagues Ludmila Zasimova, Marina Kolosnitsyna, and Natalia Khorkina, we consistently modeled situations in which all people support or, conversely, violate the imposed restrictions,' says Alexey Kalinin, first author of the study and Associate Professor of the Faculty of Economics at HSE University. 'If there is a significant lack of equal access to medical care in a given state, this can contribute not only to irresponsible behavior among some citizens, but also to the ready acceptance of restrictions by other citizens, without any government intervention.'

Convincing at-risk groups for whom the probability of becoming infected is close to 1 or those who are currently sick to stay home is pointless, the researchers say. The disease is already embedded in their behavior. But there is a clear rationale for conducting information campaigns aimed at healthy populations to convince people of the risk of infection: those who consider themselves healthy will be more willing to comply with restrictions if, according to their own estimations, the expected losses from the disease are significant.

In addition to analyzing individuals' behavior, the HSE researchers examined the model's results in terms of the welfare of society as a whole.

From the standpoint of utilitarianism, that is, maximizing total social welfare, it turns out that the general acceptance of restrictions (all forms of lockdowns) is not advantageous. If there is a sufficiently effective way to distinguish a carrier of the disease from a healthy person, then from the point of view of society, it is enough to isolate only one group, and it does not matter which one. This is what happens in the case of local quarantine bans: if it is known that a certain group is sick or at higher risk, it is sufficient to isolate that group without introducing bans for society as a whole.

At the same time, such an approach does not at all guarantee that partial or even more general restrictions will be better for society than abandoning them, which led to epidemic. This situation develops when the total loss of welfare from restrictions is estimated to be higher than the total damage from the massive spread of infection. This explains the rationality of the decisions of individual states that abandoned the policy of prohibitions as such, as well as the conscious acceptance of epidemics with low mortality--as in the case of seasonal ARVI diseases. This was done, for example, by Sweden (in the first wave of the pandemic), Japan, and South Korea, whose restrictions were advisory in nature.

An alternative approach to public welfare is the Rawlsian approach, where the welfare of the worst-off individuals is important. It unexpectedly leads to a situation where it is beneficial for the state to impose restrictions on the healthy, and not the sick or vulnerable population (which already 'will find a way' to get sick and suffer losses from illness in addition to losses from isolation). The fact that in practice, instead of this approach, general bans are chosen is explained by the impossibility of separating sick and healthy individuals with perfect accuracy: it is more effective to isolate everyone rather than to allow a sharp deterioration in the situation of at least one person.

'In general, the desire for maximum, complete isolation of all groups of the population from the standpoint of social welfare and the effectiveness of public administration turns out to be untenable,' says Kalinin. 'The main issue is whether the restrictions applied in order to divide society into groups that are as isolated and homogeneous as possible are sufficient to prevent direct contact between them (simultaneously being on the street or in public places). A similar approach was used, for example, at the beginning of the epidemic in the Netherlands, where isolation requirements were aimed at the high-risk group--the elderly--and no formal restrictions were introduced for other groups of the population.'

In the absence of reliable quantitative information about the scale of the pandemic, theoretical conclusions drawn from the classic Prisoner's Dilemma and focused on determining how, in principle, people can adjust their behavior, can be useful in justifying decisions made at both the individual and the state level.

Key building block for organic molecules discovered in meteorites

NASA/GODDARD SPACE FLIGHT CENTER

Research News

 

IMAGE: PHOTO OF A PIECE OF THE MURCHISON METEORITE THAT WAS USED IN THIS STUDY. view more 

CREDIT: NASA

Scientists from Japan and NASA have confirmed the presence in meteorites of a key organic molecule which may have been used to build other organic molecules, including some used by life. The discovery validates theories of the formation of organic compounds in extraterrestrial environments.

The chemistry of life runs on organic compounds, molecules containing carbon and hydrogen, which also may include oxygen, nitrogen and other elements. While commonly associated with life, organic molecules also can be created by non-biological processes and are not necessarily indicators of life. An enduring mystery regarding the origin of life is how biology could have arisen from non-biological chemical processes, called prebiotic chemistry. Organic molecules from meteorites may be one of the sources of organic compounds that led to the emergence of life on Earth.

Associate Professor Yasuhiro Oba from Hokkaido University, Japan, led an international team of researchers who discovered the presence of a prebiotic organic molecule called hexamethylenetetramine (HMT) in three different carbon-rich meteorites. Their discovery validates models and theories that propose HMT as an important molecule in the formation of organic compounds in interstellar environments.

"HMT is a key piece of a puzzle which draws the whole picture of chemical evolution in space," said Oba, lead author of a paper about the research published December 7 in the journal Nature Communications. "To explain the formation of meteoritic organic molecules such as amino acids and sugars, two easily vaporized (volatile) molecules, formaldehyde and ammonia, are necessary in asteroids, the parent bodies of many meteorites. However, since they are easily lost from asteroidal environments due to their high volatility, scientists question how enough could have been available to build the meteoritic organic molecules being found. HMT does not vaporize even at room temperature, and it can produce both molecules if it is heated with liquid water inside asteroids. Finding HMT in meteorites confirms the hypothesis that it is a stable source for ammonia and formaldehyde in asteroids."

Early in the solar system's history, many asteroids could have been heated by collisions or the decay of radioactive elements. If some asteroids were warm enough and had liquid water, HMT could have broken down to provide building blocks such as formaldehyde and ammonia that in turn reacted to make other important biological molecules which have been found in meteorites, including amino acids. Some types of amino acids are used by life to make proteins, which are used to build structures like hair and nails, or to speed up or regulate chemical reactions.

"These results shed light on the various ways amino acids can form in extraterrestrial environments," said Jason Dworkin, a co-author of the paper at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "This can be explored further when comparing the samples from Japan's Hayabusa2 and NASA's OSIRIS-REx missions. These spacecraft collected material from asteroids with what appears to be different histories of liquid water. If there is a mission to return a sample from a comet nucleus someday, perhaps we can see if there is a connection between HMT in comets and asteroids."

While the diversity of organic compounds in meteorites is well-documented, many questions remain about the processes by which these compounds were formed. The most important meteorites in this area of research are carbonaceous chondrites, stony meteorites that contain high percentages of water and organic compounds. Experimental models have shown that a combination of water, ammonia and methanol, when subjected to photochemical and thermal conditions common in extraterrestrial environments, give rise to a number of organic compounds, the most common of which is HMT. Interstellar ice is rich in methanol. Hypothetically, HMT should be common in water-containing extraterrestrial materials, but, until this study, it had not been detected.

HMT is likely to break apart when exposed to processes commonly used in the analysis of organic compounds in meteorites, and therefore, may not have been detected in other studies even though it was present. The scientists developed a method that specifically extracted HMT from meteorites with minimal breakdown. This method allowed them to isolate significant quantities of HMT and HMT derivatives from the meteorites Murchison, Murray and Tagish Lake.

Since Earth has abundant life, the researchers had to be confident that the HMT found in the meteorites was in fact extraterrestrial, and not just from contamination by terrestrial life. "The Murchison fragment used in this study was from the Chicago Field Museum that had been stored for many years inside a sealed container, and is the least contaminated and most pristine piece of Murchison we have ever studied for amino acids, giving us more confidence that the HMT detected in this meteorite is in fact extraterrestrial in origin," said Daniel Glavin of NASA Goddard, a co-author on the study.

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This work was supported by the Japan Society for the Promotion of Science (JSPS) KAKENHI (JP15H05749, JP16H04083, JP17H04862, JP20H00202), the National Aeronautics and Space Administration (NASA) Astrobiology Institute through the Goddard Center for Astrobiology (13-13NAI7-0032), NASA's Planetary Science Division Internal Scientist Funding Program through the Fundamental Laboratory Research (FLaRe) work package at NASA Goddard Space Flight Center, and the Simons Foundation (SCOL award 302497).

Yasuhiro Oba is part of the Astrophysical Chemistry/Ice & Planetary Science Group at the Institute of Low Temperature Science, where he studies chemical evolution of compounds at scales from molecular clouds to planetary systems.

Land ecosystems are becoming less efficient at absorbing CO2

NASA/GODDARD SPACE FLIGHT CENTER

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Land ecosystems currently play a key role in mitigating climate change. The more carbon dioxide (CO2) plants and trees absorb during photosynthesis, the process they use to make food, the less CO2 remains trapped in the atmosphere where it can cause temperatures to rise. But scientists have identified an unsettling trend - as levels of CO2 in the atmosphere increase, 86 percent of land ecosystems globally are becoming progressively less efficient at absorbing it.

Because CO2 is a main 'ingredient' that plants need to grow, elevated concentrations of it cause an increase in photosynthesis, and consequently, plant growth - a phenomenon aptly referred to as the CO2 fertilization effect, or CFE. CFE is considered a key factor in the response of vegetation to rising atmospheric CO2 as well as an important mechanism for removing this potent greenhouse gas from our atmosphere - but that may be changing.

For a new study published Dec. 10 in Science, researchers analyzed multiple field, satellite-derived and model-based datasets to better understand what effect increasing levels of CO2 may be having on CFE. Their findings have important implications for the role plants can be expected to play in offsetting climate change in the years to come.

"In this study, by analyzing the best available long-term data from remote sensing and state-of-the-art land-surface models, we have found that since 1982, the global average CFE has decreased steadily from 21 percent to 12 percent per 100 ppm of CO2 in the atmosphere," said Ben Poulter, study co-author and scientist at NASA's Goddard Space Flight Center. "In other words, terrestrial ecosystems are becoming less reliable as a temporary climate change mitigator."

What's Causing It?

Without this feedback between photosynthesis and elevated atmospheric CO2, Poulter said we would have seen climate change occurring at a much more rapid rate. But scientists have been concerned about how long the CO2 Fertilization Effect could be sustained before other limitations on plant growth kick in.

For instance, while an abundance of CO2 won't limit growth, a lack of water, nutrients, or sunlight - the other necessary components of photosynthesis -- will. To determine why the CFE has been decreasing, the study team took the availability of these other elements into account.

"According to our data, what appears to be happening is that there's both a moisture limitation as well as a nutrient limitation coming into play," Poulter said. "In the tropics, there's often just not enough nitrogen or phosphorus, to sustain photosynthesis, and in the high-latitude temperate and boreal regions, soil moisture is now more limiting than air temperature because of recent warming."

In effect, climate change is weakening plants' ability to mitigate further climate change over large areas of the planet.

Next Steps

The international science team found that when remote-sensing observations were taken into account - including vegetation index data from NASA's Advanced Very High Resolution Radiometer (AVHRR) and the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments - the decline in CFE is more substantial than current land-surface models have shown. Poulter says this is because modelers have struggled to account for nutrient feedbacks and soil moisture limitations - due, in part, to a lack of global observations of them.

"By combining decades of remote sensing data like we have done here, we're able to see these limitations on plant growth. As such, the study shows a clear way forward for model development, especially with new remote sensing observations of vegetation traits expected in coming years," he said. "These observations will help advance models to incorporate ecosystem processes, climate and CO2 feedbacks more realistically."

The results of the study also highlight the importance of the role of ecosystems in the global carbon cycle. According to Poulter, going forward, the decreasing carbon-uptake efficiency of land ecosystems means we may see the amount of CO2 remaining in the atmosphere after fossil fuel burning and deforestation start to increase, shrinking the remaining carbon budget.

"What this means is that to avoid 1.5 or 2°C warming and the associated climate impacts, we need to adjust the remaining carbon budget to account for the weakening of the plant CO2 Fertilization Effect," he said. "And because of this weakening, land ecosystems will not be as reliable for climate mitigation in the coming decades."

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