Risk of death from COVID-19 lessens, but infection still can cause issues 3 years later

Study also shows that patients hospitalized within 30 days after infection face 29% higher death risk in 3rd year compared with those not infected

WASHINGTON UNIVERSITY IN ST. LOUIS

New findings on long COVID — long-term effects on health experienced by many who have had COVID-19 — present a good-news, bad-news situation, according to a study at Washington University School of Medicine in St. Louis and the Veterans Affairs St. Louis Health Care system.

The bad news: COVID-19 patients who were hospitalized within the first 30 days after infection face a 29% higher risk of death in the third year compared with people who have not had the virus. However, the three-year death risk still marks a significant decline compared with such risk at the one- and two-year marks post-infection. The findings also show that even people with mild COVID-19 were still experiencing new health problems related to the infection three years later.

The good news: The increased risk of death diminishes significantly one year after a SARS-CoV-2 infection among people who were not hospitalized for the virus. This demographic accounts for most people who have had COVID-19.

The new research, published May 30 in Nature Medicine, tracked the virus’s health effects in people three years after being infected with the original strain of COVID-19 in 2020. That year, about 20 million people tested positive for the virus in the U.S. The new study assessed the risk of death and 80 adverse health conditions in people three years after being diagnosed with COVID-19.

“We aren’t sure why the virus’s effects linger for so long,” said senior author Ziyad Al-Aly, MD, a Washington University clinical epidemiologist and a global leader in long COVID research. “Possibly it has to do with viral persistence, chronic inflammation, immune dysfunction or all the above. We tend to think of infections as mostly short-term illnesses with health effects that manifest around the time of infection. Our data challenges this notion. I feel COVID-19 continues to teach us — and this is an important new lesson — that a brief, seemingly innocuous or benign encounter with the virus can still lead to health problems years later.”

Up to 10% of people infected with the virus experience long COVID, according to federal data.

Al-Aly’s prior research has documented COVID-19’s damage to nearly every human organ, contributing to diseases and conditions affecting the lungs, heart, brain, and the body’s blood, musculoskeletal and gastrointestinal (GI) systems.

Such studies with longer follow-up are limited, said Al-Aly, a nephrologist who treats patients at the Washington University-affiliated John J. Cochran Veterans Hospital in midtown St. Louis. “Addressing this knowledge gap is critical to enhance our understanding of long COVID and will help inform care for people suffering from long COVID.”

Al-Aly and his team analyzed millions of de-identified medical records in a database maintained by the U.S. Department of Veterans Affairs, the nation’s largest integrated health-care system. The study included more than 114,000 veterans with mild COVID-19 who did not require hospitalization; more than 20,000 hospitalized COVID-19 patients; and 5.2 million veterans with no COVID-19 diagnosis. Patients were enrolled in the study from March 1, 2020, to Dec. 31, 2020, and followed for at least three years, until Dec. 31, 2023. Patients included people of diverse ages, races and sexes; statistical modeling ensured parity in representation.

In the third year after infection, COVID-19 patients who had been hospitalized experienced a 34% elevated health risk across all organ systems compared with people who did not have COVID. That number is down from a 182% increased risk one year after a COVID infection and a 57% risk two years after.

Among nonhospitalized patients, researchers found a 5% increased risk in suffering from long COVID in the third year after infection. This translates into 41 more health problems per 1,000 persons – a small but not trivial burden. The long-term health effects in the third year primarily affected the GI, pulmonary and neurological systems. By comparison, the risk was increased by 23% one year after infection and increased by 16% two years after.

In the analysis, researchers also measured and compared the number of healthy life-years lost due to COVID-19. They found that among the nonhospitalized, at three years after infection, COVID-19 had contributed to 10 lost years of healthy life per 1,000 persons. By comparison, three years post-infection, those hospitalized for COVID-19 had experienced 90 lost years of healthy life per 1,000 persons.

For context, in the U.S., heart disease and cancer each cause about 50 lost years of healthy life per 1,000 persons, while stroke contributes to 10 lost years of healthy life per 1,000 persons.

“That a mild SARS-CoV-2 infection can lead to new health problems three years down the road is a sobering finding,” said Al-Aly, who is also director of the Clinical Epidemiology Center at the VA St. Louis Health Care System, and head of the research and development service. “The problem is even worse for people with severe SARS-CoV-2 infection. It is very concerning that the burden of disease among hospitalized individuals is astronomically higher.”

“COVID-19 is a serious threat to the long-term health and well-being of people and it should not be trivialized,” he said.

The extended trajectory for long COVID may change as researchers incorporate data from years beyond 2020. At that time, vaccines and antivirals had not been developed. Similarly, Al-Aly’s analysis does not consider subsequent variants such as omicron or delta.

“Even three years out, you might have forgotten about COVID-19, but COVID hasn’t forgotten about you,” Al-Aly said. “People might think they’re out of the woods, because they had the virus and did not experience health problems. But three years after infection, the virus could still be wreaking havoc and causing disease or illness in the gut, lungs or brain.”

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JOURNAL

Nature Medicine

DOI

10.1038/s41591-024-02987-8 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Risk of death from COVID-19 lessens, but infection still can cause issues 3 years later

ARTICLE PUBLICATION DATE

30-May-2024

 

A multimodal approach to better predict recovery in patients with disorders of consciousness

INSTITUT DU CERVEAU (PARIS BRAIN INSTITUTE)

 

IMAGE: 

SEARCHING FOR SIGNS OF CONSCIOUSNESS

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CREDIT: NICOLAS DECAT.

After a severe cranial trauma or cardiac arrest, some patients admitted to intensive care show little or no reaction to their environment—and are sometimes unable to communicate. This condition is called a disorder of consciousness (DoC), which includes comas, vegetative states and states of “minimal consciousness.”

This disorder sometimes persists for several days or weeks. In such cases, healthcare teams and relatives must obtain the most accurate information on the patient's cognitive recovery capacities. Usually, a neurological prognosis is established using several indicators—including standard measurements of brain anatomy (CT and MRI scans) and function (electroencephalogram).

“Despite having these data at our disposal, there remains a degree of uncertainty about the prognosis, which can significantly impact medical decision-making. These patients are often in a fragile state and prone to numerous complications, which raises questions about the appropriateness of the care they receive,” explains Benjamin Rohaut, neurologist, researcher and lead author of the study. “Moreover, doctors sometimes observe a discrepancy between the patient's behaviour and their brain activity: some patients in a vegetative state seem to understand what is being said to them but are unable to let their caregivers know.”

To improve the description of the state of consciousness of these patients, the “PICNIC team”, co-led by Lionel Naccache at the Paris Brain Institute, has been working for around fifteen years to define new brain measurements and clinical examination signs. Their approach has gradually evolved towards “multi-modality”, combining PET scans, multivariate EEG analysis, functional MRI, cognitive evoked potentials (electrical responses to sensory stimulation) and other tools.

Consciousness markers under scrutiny

To assess the clinical value of this approach, the team worked with the “Neurologically Oriented Intensive Care Unit” at the Pitié-Salpêtrière Hospital in Paris. Led by Benjamin Rohaut and Charlotte Calligaris, the clinicians and researchers followed and assessed 349 intensive-care patients between 2009 and 2021. At the end of each multimodal evaluation, they formulated a “good”, “uncertain”, or “unfavourable” prognostic opinion.

Their results indicate that patients with a “good prognosis” (22% of cases) showed a much more favourable evolution of their cognitive abilities than patients with a prognosis judged “uncertain” (45.5% of cases) or “unfavourable” (32.5% of cases); none of the patients assessed as “unfavourable” regained consciousness after one year. Above all, this prognostic performance was correlated with the number of modalities: the greater the number of indicators used, the greater the accuracy of the prognosis, and the greater the team's confidence in its assessments.

“This long-term study shows for the first time the benefit of the multimodal approach, which is essential information for intensive care units worldwide. It also provides empirical validation of the recent recommendations of the European and American Neurology Academies, " explains Jacobo Sitt, who co-supervised this study. 

Towards a standardised neuroprognostic approach

However, the multimodal approach is not a magic wand. It provides the best possible information to caregivers and families in situations of uncertainty—an ethical advance in patient care—but does not guarantee bias-free decision-making.

Finally, there is the question of access to assessment tools, which are expensive and require specific expertise. “We are aware that multimodal assessment is not accessible to all the intensive care units that receive these patients”, continues Lionel Naccache. “We propose to build a network of collaborations at the national and European levels. Thanks to telemedicine tools and automated EEG or brain imaging analysis, all intensive care units could have a first level of access to multimodal assessment. Should this prove insufficient, recourse to a regional expert centre would provide a more in-depth assessment. Finally, in the most complex situations, it would be possible to call on all available experts, wherever they may be. We aim to ensure that all patients with a disorder of consciousness can benefit from the highest standards of neurological prognosis.”

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JOURNAL

Nature Medicine

DOI

10.1038/s41591-024-03019-1 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Multimodal assessment improves neuroprognosis performance in clinically unresponsive critical care patients with brain injury

ARTICLE PUBLICATION DATE

30-May-2024

COI STATEMENT

Jacobo Sitt and Lionel Naccache are co-founders and shareholders of Neurometers, a company dedicated to the medical use of electroencephalogram (EEG) to quantify the brain signatures of consciousness and cognition.

 

HudsonAlpha researchers create valuable genomic tools for the cotton industry

HUDSONALPHA INSTITUTE FOR BIOTECHNOLOGY

We live in an ever-changing and growing world. Changing climates, emerging pests, and other environmental stressors put pressure on the cash crops that feed and fuel the world. As we race to meet the growing demand for sustainable and high-quality food and fiber crops, genomics is emerging as a powerful tool in the fight. By understanding plants’ genetic codes, researchers and breeders can develop crops with increased yields, improved resistance to pests and diseases, and greater adaptability to environmental challenges. 

Genome-informed breeding primarily benefits crops with existing high-quality genomic resources, like rice and wheat. However, crops with less mature genomic resources must continue to rely on traditional breeding methods, which sometimes suffer due to a lack of genomic diversity within the breeding populations. 

Cotton, a vital cash crop worldwide, lacks robust genomic resources. The cotton industry is big business, with a global economic impact of $600 billion and providing jobs for more than 250 million people. Successful cotton production relies on cotton varieties with desirable characteristics like high yield, good fiber quality, pest and disease resistance, and drought tolerance. 

“Cotton breeders have improved fiber yield and quality over the years using traditional breeding methods,” says Jeremy Schmutz, co-director of the HudsonAlpha Genome Sequencing Center, who has been working on cotton genomics for over a decade. “Achieving additional improvements may be difficult for them due to the lack of genetic variation across modern domesticated cotton. Creating new genomic tools for the industry will help take cotton improvements to the next level.” 

Scientists at the HudsonAlpha Institute for Biotechnology Genome Sequencing Center (GSC) and other collaborators set out to create high-quality genome sequences for three important cotton varieties, providing necessary genome resources for cotton breeders. The results were recently published in Nature Plants. 

“Cotton research has relied heavily on one reference genome, ‘TM1’, a variety of cotton that is no longer widely used in breeding programs,” says Avinash Sreedasyam, PhD, first author of the manuscript. “In order for molecular breeding to benefit the cotton industry, many, varied genomes must exist to represent the diversity of cotton varieties. This study generated high-quality reference genomes for three modern upland cotton cultivars and updated the ‘TM-1’ cotton genetic standard reference.” 

Initial analysis of the new reference genomes produced important information about fiber quality. The highly accurate and complete genome assemblies were used to identify genetic material from Pima cotton (known for superior fiber quality) within modern cotton varieties. Small segments of each genome were compared to both Pima and the reference cotton genome. 

Segments that matched Pima more closely than the reference cotton were classified as potential introgressions, suggesting Pima DNA had been incorporated into the modern cotton's genetic makeup. Knowledge of these Pima introgressions will help breeders to efficiently select progeny with these fiber-quality linked genetic markers in their breeding programs.  

“Leveraging relatively inexpensive low-pass sequencing alongside these genomes empowers breeders to select progeny rapidly,” says Sreedasyam. “This will not only save time but also reduce costs associated with traditional fiber phenotyping, a laborious process usually requiring hundreds to thousands of samples per breeding cycle.” 

These findings highlight the significance of using detailed genome assemblies to uncover genetic variations that can improve cotton breeding programs. The more these new, high-quality genomes are used for comparative studies, the more information about economically important cotton traits will emerge. The genomic resources described in this study represent a valuable addition to the cotton breeding toolkit and will reap benefits for years to come. 

Collaborators on this project include Don C. Jones, Cotton Incorporated, NC; Peng W. Chee, University of Georgia, Tifton, GA; Warwick N. Stiller, CSIRO, Cotton Research Unit, Australia; and Fred Bourland, University of Arkansas, Keiser, AR.

This work is supported by Cotton Incorporated (Award 18-753) and the intramural research program of the US Department of  Agriculture,  National Institute of  Food and Agriculture  Foundational and Applied Science Program Award 2022-67013-36899. The findings, conclusions, or recommendations expressed here have not been formally disseminated by the US Department of Agriculture and should not be construed to represent any agency determination or policy.

Byline: Sarah Sharman, PhD

JOURNAL

Nature Plants

DOI

10.1038/s41477-024-01713-z 

ARTICLE TITLE

Genome resources for three modern cotton lines guide future breeding efforts

ARTICLE PUBLICATION DATE

30-May-2024

 

Statisticians call for rigour and transparency in the evaluation of diagnostic tests

UNIVERSITY OF BIRMINGHAM

Recommendations designed to reframe the evaluation of in vitro diagnostic tests have been published today by the Royal Statistical Society in its Series A journal.

The report, which will be submitted to the UK Covid-19 Inquiry, is intended to help prevent future scenarios in which IVDs are marketed widely, but later attract serious concerns about the standards applied to their evaluation.

The research was prompted by concerns about the standards applied to the evaluation of diagnostic tests during the Covid-19 pandemic – particularly lateral flow tests – however the recommendations cover all new tests, especially those designed to detect infectious diseases.

It is published today in the RSS’s Series A journal and also presented at the Evidence Based Early Diagnosis conference at St Andrews.

A working group of statisticians, co-chaired by Professor Jon Deeks, at the University of Birmingham, and former RSS President, Professor Deborah Ashby, at Imperial College London, collaborated on the report with co-authors from the Universities of Oxford, Cambridge, Edinburgh, Birmingham and the London School of Hygiene and Tropical Medicine.

The RSS Working Group on Diagnostic Tests set out 22 recommendations, designed to ensure that in vitro diagnostic (IVD) tests – which typically test samples of fluids such as blood, urine or saliva – are statistically robust and fit for purpose. The RSS Working Group identified Study-Design matters (10 recommendations); Regulation matters (6 recommendations); Transparency matters (6 recommendations).

Jon Deeks, Professor of Biostatistics at the University of Birmingham, said:

“The Covid-19 pandemic provided a microcosmic insight into inadequacies in current processes to evaluate and regulate diagnostic tests. It’s important that we learn from these failures and establish robust processes that can be applied broadly across diagnostic tests.”

The report covers three areas of diagnostic testing: study-design of evaluations; regulation of tests; and transparency of test evaluations.

Key recommendations included:

• Evaluation needs to take into account each specific intended use of the test, including the person being tested, the target condition and even the facilities where the testing will be done. Field or clinical evaluation studies should be carried out for each intended use.
• Direct comparison of alternative IVDs and testing strategies should be available to inform clinical and public health decision-making.
• The Medicines and Healthcare products Regulatory Agency (MHRA) should collaborate with independent experts to revise the national licensing process for IVDs. This will ensure public safety is protected. Protocols and reports for test evaluations should be publicly available to ensure transparency in all planning and decision-making.

The publication of the report is relevant for the opening of the ‘Test, Trace and Isolate’ module of the UK Covid-19 Inquiry. It also coincides with the MHRA’s recently-launched consultation on improved safety for high-risk diagnostic devices.

Professor Sheila Bird at the MRC Biostatistics Unit at the University of Cambridge, said:

“Past Royal Statistical Society Working Party reports on matters which affect the public health have had enduring impact. Official Statistics – Counting with Confidence led to the UK Statistic Act of 2007; Statistics and Statisticians in Drug Regulation led to the appointment of professional statisticians by the UK, and later, European drug regulator; Statistical Issues in First-in-Man Studies led to safety-enhanced study-designs with open protocols. I hope that this month’s consultation by MHRA is indicative that Diagnostic Tests is making its mark already.”

Dr Andrew Garrett, President of the Royal Statistical Society, said:

“The report provides a thorough evaluation of both diagnostic tests and diagnostic testing.  It addresses how to develop, regulate, and use diagnostic tests in the future – a subject that is of increasing importance to individual and public health.”

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JOURNAL

Journal of the Royal Statistical Society Series A (Statistics in Society)

DOI

10.1093/jrsssa/qnae053 

METHOD OF RESEARCH

Data/statistical analysis

ARTICLE TITLE

Lessons to be learned from test evaluations during the COVID-19 pandemic: RSS Working Group’s Report on Diagnostic Tests

ARTICLE PUBLICATION DATE

30-May-2024

 

EU citizens feel increasingly European

Research reveals that the sense of European identity among inhabitants of most EU countries has increased in the past 15 years

UNIVERSITEIT VAN AMSTERDAM

The sense of a European identity has increased among inhabitants of the European Union in the past 15 years – in spite of crises like Brexit and the Eurozone crisis. That is the conclusion of professor of European Studies Theresa Kuhn in a recent publication. ‘The euro and open borders have made the EU tangible.’

With the European elections just around the corner, one question is more relevant than ever: to what extent do the inhabitants of Europe feel a sense of connection with the European Union? And where does that come from? ‘We wanted to map out how European identity has evolved over the years,’ says Theresa Kuhn, ‘but our research into this was severely limited by the types of opinion polls that we usually consult for our research. Most polls don’t date back very far and usually only one type of question was asked on the subject.'

In order to rectify this problem, Kuhn and her team combined various opinion polls from dozens of countries over a period of 41 years. ‘We subsequently applied a calculation to this, as a result of which we now have information about the development of European identity since the 1980s.’

Crisis has a reinforcing effect

The research reveals that the sense of European identity among inhabitants of most EU countries has increased in the past 15 years. ‘That surprised us to be honest’, says Kuhn. ‘The past two decades were marked by crises, not only externally, but also internally, such as Brexit and the Eurozone crisis. You might expect that this would make people want to distance themselves from the European Union, but that does not appear to be the case. One explanation for this could be that people are more inclined to adhere to a group as a result of a crisis. People feel threatened and are more likely to surround themselves with people whose views align closely with their own.’

The fact that an entire generation has only ever known the European Union to be part of Europe may be another explanation for this according to Kuhn. ‘This group of people have grown up in an era in which there are open borders and many countries have the euro as currency unit. These things have also made Europe something tangible, as a result of which people have been able to experience the EU, rather than it being an abstract institution.'

It is the case, however, that there are major differences in the development of European identity from country to country. ‘In Northern and Western European countries, the sense of a European identity is usually more prevalent, while South and Central Europe exhibit a more diverse development. For example, you see that Italians have become increasingly less pro-European over the years, whereas Spain has actually experienced growth in that regard.’

Euroscepticism

A lot of Eurosceptic parties are poised to make gains according to polls for the upcoming European elections. In Kuhn’s opinion, however, that does not mean that people also feel less European. ‘A clear differentiation needs to be made between the perception of a European identity and support for the European Union. Someone may feel European, but not agree with the current policy. The opposite may also be true.’

She also argues that the popularity of the Eurosceptic parties does not automatically mean that people are less pro-Europe at present. ‘Eurosceptic voters have most likely existed since the 1950s. However, they didn’t have any way yet to express that electorally, because almost all parties were pro-European at national level. Parties have only decided to make this an issue since the 1990s.

In her research, Kuhn argues that the European Union should do even more to strengthen a sense of European identity. ‘Many important decisions are taken at European level. That’s why it is important for the democratic legitimacy of the EU that a significant proportion of Europeans also feel connected to Europe. In addition, research shows that people who identify as European are less likely to vote for populist parties and more likely to show solidarity for other Europeans.

Report

'A community of fate: growing european identity in times of polycrisis. Exploring Long-Term Trends of European Identity Across the European Member States.',  By Theresa Kuhn, Armin Seimel, and John M. Michaelis, University of Amsterdam

 

Researchers discover that a type of childhood leukaemia originates during foetal development

JOSEP CARRERAS LEUKAEMIA RESEARCH INSTITUTE

 

IMAGE: 

PABLO MENÉNDEZ, TALÍA VELASCO AND OSCAR MOLINA, AUTHORS OF THE STUDY AND RESEARCHERS OF THE JOSEP CARRERAS LEUKAEMIA RESEARCH INSTITUTE 

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CREDIT: JOSEP CARRERAS LEUKAEMIA RESEARCH INSTITUTE

Acute myeloid leukaemia is the second most common type of acute leukaemia in childhood and can be diagnosed within a few months of life. The early onset of the disease had led to the suspicion that the tumour could have a prenatal origin. However, proving this theory has been challenging due to the lack of prenatal or birth samples.

‘The opportunity to study the origin of this leukaemia arose from the case of a five-month-old baby diagnosed with acute myeloid leukaemia at the Hospital Niño Jesús in Madrid,’ explains Pablo Menéndez, ICREA professor at the University of Barcelona and the Josep Carreras Institute. ‘The parents, who had preserved the umbilical cord blood, opened a line of research that until now had not been possible to address,’ adds the researcher.

Using precision medicine techniques, researchers analysed the complete genome of the tumour. Unlike tumours in adults, where thousands of mutations are detected, only two chromosomal alterations were identified in this leukaemia. ‘Genome analysis allowed us to design a personalised diagnostic method to monitor the disease,’ says Xose S. Puente, Professor of Biochemistry at the University of Barcelona. Puente, Professor of Biochemistry and Molecular Biology at the University of Oviedo. ‘But these data raise new questions, such as when the tumour arose and in what order these mutations have appeared,’ he highlights. These questions are difficult to answer, since such research requires blood samples from the baby before the diagnosis, something that is impossible in the vast majority of cases. However, in this particular case, the existence of a frozen umbilical cord sample allowed researchers to separate different populations of blood cells at birth and to study whether any of the chromosomal alterations detected in the tumour were already present during foetal development.

The study revealed that a translocation between chromosome 7 and 12 was already present in some haematopoietic stem cells in the umbilical cord. In contrast, the other chromosomal alteration, a trisomy of chromosome 19, was not present in the foetus, but was found in all tumour cells, suggesting that it contributes to increasing the malignancy of the leukemic cells. ‘These data are highly relevant for understanding the development of a devastating disease, and the existence of this umbilical cord sample was crucial to be able for conducting a study that had been impossible until now in acute myeloid leukaemia’, adds Talía Velasco, researcher at the Josep Carreras Institute and the University of Barcelona and co-leader of the study.

In addition to reconstructing the genomic alterations that the cells undergo to generate this leukaemia, the study has also identified a molecular mechanism that had not been observed before in this type of leukaemia and which causes the activation of a gene, called MNX1, which is frequently altered in this type of tumour. Knowledge of these alterations is essential for developing cell and animal models that allow us to understand the disease’s evolution and develop new therapies for treating these pathologies.

The study has been led by Xose S. Puente, Professor of Biochemistry and Molecular Biology at the University of Oviedo-IUOPA, Talía Velasco and Pablo Menéndez, from the Josep Carreras Institute and the University of Barcelona, with participation from researchers from four other institutions, including the Hospital Infantil Universitario Niño Jesús, the Hospital Universitario Central de Asturias, the Instituto de Biomedicina y Biotecnología de Cantabria and the Instituto de Investigación Sanitaria La Princesa de Madrid.

This research has been made possible thanks to the collaboration of the parents and funding from the Ministry of Science, Innovation and Universities, the European Research Council, the AECC Scientific Foundation, the Foundation Unoentrecienmil, the “La Caixa” Foundation, the Government of Catalonia, CIBERONC and the III Health Institute.

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JOURNAL

Leukemia

DOI

10.1038/s41375-024-02293-9 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Human tissue samples

ARTICLE PUBLICATION DATE

28-May-2024

 

Tracing the evolution of ferns’ surprisingly sweet defense strategy

BOYCE THOMPSON INSTITUTE

 

IMAGE: 

ANT FEEDING ON FERN NECTARIES.

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CREDIT: JACOB S. SUISSA

Plants and the animals that eat them have evolved together in fascinating ways, creating a dynamic interplay of survival strategies. Many plants have developed physical and chemical defenses to fend off herbivores. A well-known strategy in flowering plants is to produce nectar to attract “ant bodyguards.” Recent research explores the evolution of this same defense strategy in ferns.

Jacob Suissa, an assistant professor at the University of Tennessee Knoxville, led the study in collaboration with Boyce Thompson Institute's fern expert, Fay-Wei Li, and Cornell University’s ant expert, Corrie Moreau.

The study, recently published in Nature Communications, revealed that ferns and flowering plants independently evolved nectaries, specialized structures that secrete sugary rewards to attract ant bodyguards, around the same time in the Cretaceous period. This finding is significant as it suggests similar evolutionary dynamics shaped the development of ant-plant mutualisms across these two divergent lineages, separated by more than 400 million years.

"Our research highlights a fascinating example of convergent evolution, where ferns and flowering plants independently developed similar strategies to defend themselves against predation by recruiting ant defenders with nectaries," said Suissa.

By integrating phylogenetic data and comparative analyses, the research team discovered that nectaries originated concurrently in ferns and angiosperms, but ferns experienced a significant lag in diversification compared to their flowering plant counterparts. The study also revealed that ferns likely recruited ant defenders secondarily, tapping into pre-existing ant-angiosperm relationships as they transitioned from the forest floor to the canopy.

"The evolutionary history of fern nectaries not only demonstrates the complex relationships between plants and insects—relationships that have been previously underestimated—but also underscores the ability of ferns to adapt to ecological challenges,” explained Suissa.

The research offers new insights into the evolutionary dynamics that shape plant-animal interactions. By understanding how ferns and flowering plants independently developed similar defense mechanisms, scientists can better appreciate the underlying principles governing biodiversity and ecosystem function. This study opens new avenues for exploring the evolutionary history of other plant traits and their ecological impact, reinforcing the importance of mutualistic relationships in the natural world.

Learn more about this fascinating research in this related news story.

About the Boyce Thompson Institute (BTI)
Founded in 1924 and located in Ithaca, New York, BTI is at the forefront of plant science research. Our mission is to advance, communicate, and leverage pioneering discoveries in plant sciences to develop sustainable and resilient agriculture, improve food security, protect the environment, and enhance human health. As an independent nonprofit research institute affiliated with Cornell University, we are committed to inspiring and training the next generation of scientific leaders. Learn more at BTIscience.org.

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JOURNAL

Nature Communications

DOI

10.1038/s41467-024-48646-x 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Cells

ARTICLE TITLE

Convergent evolution of fern nectaries facilitated independent recruitment of ant-bodyguards from flowering plants

ARTICLE PUBLICATION DATE

24-May-2024

 

Cheap, dirty leftovers can produce pure oxygen

Oxygen is a critical component in many manufacturing processes. Researchers have discovered a way to produce this element in an energy efficient way

NORWEGIAN UNIVERSITY OF SCIENCE AND TECHNOLOGY

 

IMAGE: 

FRIDA HEMSTAD DANMO WITH A MATERIAL THAT SEEMS PROMISING FOR PRODUCING OXYGEN CHEAPLY. 

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CREDIT: PHOTO: PER HENNING, NTNU

New materials for producing oxygen may challenge traditional production methods. This is exciting news, because pure oxygen is in demand from many areas in industry and medicine.

“We have identified materials that can store and release pure oxygen much faster and at much lower temperatures than known materials currently used for this purpose,” says Professor Sverre Magnus Selbach at the Norwegian University of Science and Technology (NTNU’s) Department of Materials Science and Engineering.

Oxygen is an element, so it cannot be made, only released. The most common method is to distil oxygen directly from the air, but it can also be extracted from materials that have oxygen bound in them.

Retrieving oxygen from materials

Many materials absorb oxygen from the air. When these materials are heated up, they release this oxygen, and small changes in the materials can change their properties.

As the chemical process speeds up, scientists refer to ‘the kinetics being faster’ in the material. The fact that this process can take place at low temperatures is a big advantage. Not only does it mean that less energy is required for heating, but also that reactors can be made from cheaper materials that will need less maintenance than if they had to be exposed to higher temperatures.

“Both of these improvements in material properties make the materials more competitive,” says Frida Hemstad Danmo. The research was part of her doctoral work.

The research results have now been published in the Chemistry of Materials journal.

The wonder material

So, what kind of wonder material are we talking about? It might be a little surprising. Have you heard of hexagonal manganites?

Probably not. Almost no one has heard of hexagonal manganites. Fortunately, the researchers at NTNU have. The material is not only very suitable for extracting oxygen, it can also be made quite cheaply and efficiently.

“Because oxygen is absorbed so quickly into the material, we can use bulk materials that can be made in large quantities using cheaper methods than those required to make nanoparticles,” explains Danmo.

If the oxygen transport was not already so rapid in these hexagonal manganites, the process would have required nanoparticles to increase surface area and provide the oxygen with a ‘shorter way’ in and out of the material.

Nanoparticles are more complicated to produce and cannot be made in large quantities as easily as bulk material.

Impurities in the material are unproblematic

The hexagonal manganites they have developed are so-called ‘high-entropy materials’. This means that they are neither pure nor have a particularly well-ordered crystal structure, and this is where the secret lies.

Not only are the materials quite cheap, they are also not that particular when it comes to chemical composition. Impurities and small defects in the material are therefore not a problem. Things don’t have to be so precise, the process works anyway, and it makes it possible to achieve cheaper production on an industrial scale.

The researchers used five to six different rare earth metals in the mix they experimented with, and the result was much better than when well-ordered materials with just one or two rare earth metals were used.

“The high-entropy materials are actually more stable than those with simpler chemical composition. The reason is the entropy, i.e. the disorder that comes from having many different elements in the crystal structure instead of fewer,” says Selbach.

Disorder is the natural state

“All spontaneous processes will increase the disorder of the universe. Interestingly, it is the disorder itself that also provides such rapid oxygen absorption, since our materials are not sensitive to precise chemical composition. Focusing on high entropy is a paradigm shift for this particular class of materials, and something that has given us exceptional properties,” says Danmo.

Using cheaper and available materials

These types of materials are not currently used in the industry, but a great deal of research is being done on them precisely because the potential for cheaper oxygen production is so great.

“Industry can use cheaper raw materials, such as oxides of recycled rare earth metals or low-quality ore. These raw materials remain after more expensive elements such as neodymium and dysprosium are extracted for use in electric motors in windmills and electric cars,” says Selbach.

Did you catch that? Industry may even be able to use waste materials from the production of electric motors.

In collaboration with Danmo, Aamund Westermoen conducted much of the experimental work. Senior Engineer Elvia Anabela Chavez Panduro contributed measurements at NTNU, and Kenneth Marshall and Dragos Stoian at the European Synchrotron Radiation Facility (ESRF) in France helped with the synchrotron measurements made at the Swiss–Norwegian Beamlines facility in Grenoble. Frida Hemstad Danmo now works at Norsk Hydro.

Reference: Frida Hemstad Danmo, Aamund Westermoen, Kenneth Marshall, Dragos Stoian, Tor Grande, Julia Glaum, and Sverre M. Selbach. High-Entropy Hexagonal Manganites for Fast Oxygen Absorption and Release. Chem. Mater. 36, 2711, 2024. https://doi.org/10.1021/acs.chemmater.3c02702

Hexagonal manganites. It's just as well to learn the name right away. 

CREDIT

Photo: Frida Hemstad Danmo

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JOURNAL

Chemistry of Materials

DOI

10.1021/acs.chemmater.3c02702 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

High-Entropy Hexagonal Manganites for Fast Oxygen Absorption and Release