Malformed seashells, ancient sediment provide clues about Earth’s past

New studies confirm mid-Cretaceous volcanism caused ocean acidification

Peer-Reviewed Publication

NORTHWESTERN UNIVERSITY

 

IMAGE: SCANNING ELECTRON MICROSCOPE IMAGES OF TINY, ANCIENT PLANKTONIC FORAMINIFERA, RECOVERED FROM GUBBIO, ITALY. view more 

CREDIT: GABRIELLA KITCH

• New analyses of fossil plankton and sedimentary rock confirm that massive volcanic CO2 emissions triggered ocean acidification and anoxia during the mid-Cretaceous
• Associated with the onset of volcanism, fossil plankton diminished in size, consistent with stress from increasingly acidic conditions 
• A biocalcification slowdown ultimately raised the alkalinity of seawater, which the researchers hypothesize triggered the Plenus Cold Event
• Understanding how Earth responded to massive carbon dioxide influxes from volcanic activity can help us predict how the oceans and climate will respond to increases in carbon dioxide from human activities 

EVANSTON, Ill. — Nearly 100 million years ago, the Earth experienced an extreme environmental disruption that choked oxygen from the oceans and led to elevated marine extinction levels that affected the entire globe. 

Now, in a pair of complementary new studies, two Northwestern University-led teams of geoscientists report new findings on the chronology and character of events that led to this occurrence, known as Ocean Anoxic Event 2 (OAE2), which was co-discovered more than 40 years ago by late Northwestern professor Seymour Schlanger.

By studying preserved planktonic microfossils and bulk sediment extracted from three sites around the world, the team collected direct evidence indicating that ocean acidification occurred during the earliest stages of the event, due to carbon dioxide (CO2) emissions from the eruption of massive volcanic complexes on the sea floor. 

In one of the new studies, the researchers also propose a new hypothesis to explain why ocean acidification led to a strange blip of cooler temperatures (dubbed the “Plenus Cold Event”), which briefly interrupted the otherwise intensely hot greenhouse period.

By analyzing how an influx of CO2 from volcanoes affected ocean chemistry, biomineralization and climate, the researchers hope to better understand how today’s Earth is responding to an increase of CO2 due to human activities, which potentially could lead to solutions for adapting to and mitigating anticipated consequences.

A paper, with findings from deep-sea cores, including a newly drilled site near southwest Australia, will be published on Thursday (Jan. 19) in the journal Nature Geoscience. A complementary paper detailing findings from ancient malformed microfossils was published on Dec. 13, in the Nature journal Communications Earth & Environment. 

“Ocean acidification and anoxia resulted from massive CO2 release from volcanoes,” said Northwestern’s Brad Sageman, a senior co-author of both studies. “These major CO2 emission events in Earth’s history provide the best examples we have of how the Earth system responds to very large inputs of CO2. This work has fundamental applicability to our understanding of the climate system, and our ability to predict what will happen in the future.”

“Based on isotopic analyses of the element calcium, we propose a possible explanation for the Plenus Cold Event, which is that a slowdown in biocalcification rates due to ocean acidification allowed alkalinity to accumulate in seawater,” said Northwestern’s Andrew Jacobson, a senior co-author of both studies. “Increased alkalinity led to a drawdown of CO2 from the atmosphere. It could very well be the case that such cooling is a predictable — but transitory — consequence of warming. Our results for OAE2 provide a geological analog for ocean alkalinity enhancement, which is a leading strategy for mitigating the anthropogenic climate crisis.”

Experts on climate during the Cretaceous Period and isotope geochemistry, Sageman and Jacobson are both professors of Earth and planetary sciences in Northwestern’s Weinberg College of Arts and Sciences. The two studies were led by their former Ph.D. students, Gabriella Kitch and Matthew M. Jones, who initiated this research while at Northwestern. 

Reconstructing Cretaceous conditions

Based on over 40 years of study, OAE2 is one of the most significant perturbations of the global carbon cycle to have occurred on planet Earth. Researchers have hypothesized that oxygen levels in the oceans dropped so low during OAE2 that marine extinction rates increased significantly. To better understand this event and the conditions leading up to it, the researchers studied ancient organic carbon-rich and fossil-bearing layers of sedimentary rock in widely distributed outcrop sites, as well as deep-sea cores obtained by the International Ocean Discovery Program (IODP) (funded by the National Science Foundation and its international partners).

The sites included Gubbio, Italy (a famous area in mainland Italy that used to be a deep ocean basin), the Western Interior Seaway (an ancient seabed stretching from the Gulf of Mexico to the Arctic Ocean in North America) and a several deep-sea sites, including a new one from the eastern Indian Ocean, offshore of southwest Australia.

Deep-sea cores provide an invaluable record of conditions in parts of the paleo-oceans that were completely unknown prior to the development of ocean drilling programs. In all three cores, the researchers focused on sections from the mid-Cretaceous Period, just before the boundary of the Turonian and Cenomanian Ages, in order to reconstruct conditions leading up to OAE2.

“The challenging part of studying ocean acidification in the geologic past is that we don’t have ancient seawater,” said Jones, who is now a Peter Buck Postdoctoral Fellow at the Smithsonian Institution. “It’s extremely rare that you would find anything that resembles ancient seawater trapped in a rock or mineral. So, we have to look for indirect evidence, particularly changes in the chemistry of fossil shells and lithified sediments.”

Malformed fossils

For the study published in Communications Earth & Environment, Kitch and her co-authors focused on fossilized foraminifera, ocean-dwelling unicellular organisms with an external shell made of calcium carbonate, which were collected at the Gubbio site by an Italian collaborator, Professor Rodolfo Coccioni at the University of Urbino.

Kitch and her collaborators were drawn to the Gubbio specimens because Coccioni’s optical observations and measurements of their shells showed abnormalities, including a consistent pattern of “dwarfing,” or a decrease in overall size, coincident with the onset of OAE2.

“These are optical signs of stress,” said Kitch, who is now a Knauss Fellow at the National Oceanic and Atmospheric Administration. “We hypothesized that the stress could have been caused by ocean acidification, which then affected the way the organisms built their shells.”

To test this hypothesis, Kitch analyzed the calcium isotope composition of the fossils. After dissolving the fossilized shells and analyzing their composition with a thermal ionization mass spectrometer, the Northwestern team observed that calcium isotope ratios shifted in the malformed specimens in a way consistent with stress from acidification.

“This is the first paper to marry calcium isotopic evidence for acidification with observations of biological indicators of stress,” Sageman said. “It’s these independent biological and geochemical observations that confirm there was an impact on biomineralization during the onset of OAE2.”

‘Cause-and-effect relationship’

For the second study, published in Nature Geoscience, Jones and his co-authors focused on deep sea cores of lithified sediments from offshore southwest Australia, which he and colleagues collected during an IODP expedition in 2017. For this piece of the puzzle, the researchers were less interested in what was in the sediment and more interested in what the sediment was noticeably lacking.

The core contains stacks of limestone, rich with calcium carbonate minerals, but is punctuated by a sudden absence of carbonate right before OAE2.

“For this time interval, we found that calcite is absent,” Jones said. “There are no carbonate minerals. This section of the core is visibly darker; it jumped right out at us. The carbonate either dissolved at the seafloor or fewer organisms were making calcium carbonate shells in the surface water. It’s a direct observation of an ocean acidification event.”

In his geochemical analyses conducted in collaboration with Professor Dave Selby at Durham University, Jones noticed that carbonate was not the only component showing significant change. Coincident with the onset of OAE2, there is also a marked shift in osmium isotope ratios that signal a massive input of mantle-derived osmium, the fingerprint of a major submarine volcanism event. This observation is consistent with the work of many other researchers, who have found evidence for the eruption of a large igneous province (LIP) preceding OAE2.

These events of massive volcanic activity occur throughout Earth history and are increasingly recognized as major agents of global change. Many LIPs were submarine, injecting tons of CO2 directly into the oceans. When CO2 dissolves into seawater, it forms a weak acid that can inhibit calcium carbonate formation and may even dissolve preexisting carbonate shells and sediments.

“Right at the onset of OAE2, osmium isotope ratios shift to really, really low values,” Jones said. “The only way that can happen is through a large igneous province eruption. That helps us establish a cause-and-effect relationship. We can see the evidence that volcanoes were really active because the osmium values crash. Then, suddenly, there’s no carbonate.”

Biological feedback

While ocean acidification following a LIP is not necessarily surprising, the Northwestern team did uncover something unusual. Acidic conditions during OAE2 lasted much longer than other widely recognized acidification events in the ancient world. Jones posits that the lack of oxygen in ocean waters may have extended the acidification state.

“Organisms that consumed sinking plankton and organic matter in the water column during OAE2 were also respiring CO2, which contributed to the ocean acidification that was initially triggered by CO2 emission from LIP volcanic activity,” Jones said. “So, marine anoxia can be a ‘positive feedback’ on ocean acidification. That's important because the global ocean today, in addition to having its pH levels decrease, is losing oxygen content as well. That suggests that decreases in oxygen may prolong acidification and highlights that the two phenomena are closely related.”

In Kitch’s study, she found that biology played yet another role during the event. Global warming and ocean acidification did not just passively affect foraminifera. The organisms also actively responded by reducing calcification rates when building their shells. As calcification slowed, the foraminifera consumed less alkalinity from seawater, which helped buffer the ocean’s increasing acidity. This also heightened the ocean’s ability to absorb CO2, potentially triggering the Plenus Cold Event.

“We call this phase a ‘hothouse period’ because temperatures were really, really warm,” Kitch said. “However, there is evidence for relative cooling during the OAE2 interval. No one has been able to explain why this cooling happened. Our study shows that by decreasing carbonate production in the ocean, you actually bump up alkalinity, which gives the ocean a buffering capacity to absorb CO2. The ocean suddenly has the capacity to draw down CO2 and balance carbon fluxes.”

Stabilization ‘comes with a cost’

But just because brief cooling interrupted this otherwise hothouse period, the researchers caution that the oceans’ natural ability to buffer CO2 is not the answer to current human-caused climate change. Sageman explains the scenario by comparing climate change to cancer.

“It’s like if a patient had cancer, and the cancer went away for a month,” Sageman said. “But then it came back and killed the patient. Don’t get fooled into thinking the ocean will cool us off and everything will be OK. It was cool for a tiny sliver of time.”

“Although the Earth rebounded and healed itself, extinctions in the marine realm helped achieve that,” Jacobson added. “The Earth has some stabilizing feedbacks, but they come with a cost.”

Kitch’s study, “Calcium isotope ratios of malformed foraminifera reveal biocalcification stress preceded Ocean Anoxic Event 2,” was supported by the National Science Foundation (award numbers DGE-1842165 and EAR 0723151) and the David and Lucile Packard Foundation (award number 2007-31757).

Jones’ study, “Mid-Cretaceous acidification linked to massive volcanism,” was supported by the National Science Foundation (award number EAR 1338312) and the U.S. Science Support Program/IODP.

Sediment core from the eastern Indian Ocean, offshore of southwest Australia. Lighter colored sedimentary rocks (below right) are rich in carbonate microfossils deposited before the ocean acidification event, and darker mudstones (left) represent the time interval when ocean acidification occurred. These stones are darker due to the absence of carbonate microfossils caused by more corrosive seawater during the acidification event.

CREDIT

Matt Jones

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JOURNAL

Nature Geoscience

DOI

10.1038/s41561-022-01115-w 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Abrupt episode of mid-Cretaceous ocean acidification triggered by massive volcanism

Plague trackers: Researchers cover thousands of years in a quest to understand the elusive origins of the Black Death

Researchers studied more than 600 genome sequences of Yersinia pestis, the bacterium that causes plague

Peer-Reviewed Publication

MCMASTER UNIVERSITY

 

IMAGE: THE EAST SMITHFIELD PLAGUE PITS, WHICH WERE USED FOR MASS BURIALS IN 1348 AND 1349. view more 

CREDIT: MUSEUM OF LONDON ARCHAEOLOGY (MOLA)

Seeking to better understand more about the origins and movement of bubonic plague, in ancient and contemporary times, researchers at McMaster University, University of Sydney and the University of Melbourne, have completed a painstaking granular examination of hundreds of modern and ancient genome sequences, creating the largest analysis of its kind.

Despite massive advances in DNA technology and analysis, the origin, evolution and dissemination of the plague remain notoriously difficult to pinpoint. 

The plague is responsible for the two largest and most deadly pandemics in human history. However, the ebb and flow of these, why some die out and others persist for years has confounded scientists. 

In a paper published today in the journal Communications Biology, McMaster researchers use comprehensive data and analysis to chart what they can about the highly complex history of Y. pestis, the bacterium that causes plague.

The research features an analysis of more than 600 genome sequences from around the globe, spanning the plague’s first emergence in humans 5,000 years ago, the plague of Justinian, the medieval Black Death and the current (or third) Pandemic, which began in the early 20th century.

“The plague was the largest pandemic and biggest mortality event in human history. When it emerged and from what host may shed light on where it came from, why it continually erupted over hundreds of years and died out in some locales but persisted in others.   And ultimately, why it killed so many people,” explains evolutionary geneticist Hendrik Poinar, director of McMaster’s Ancient DNA Centre.

Poinar is a principal investigator with the Michael G. DeGroote Institute for Infectious Disease Research and McMaster’s Global Nexus for Pandemics & Biological Threats.

The team studied genomes from strains with a worldwide distribution and of different ages and determined that Y. pestis has an unstable molecular clock. This makes it particularly difficult to measure the rate at which mutations accumulate in its genome over time, which are then used to calculate dates of emergence.

Because Y. pestis evolves at a very slow pace, it is almost impossible to determine exactly where it originated.

Humans and rodents have carried the pathogen around the globe through travel and trade, allowing it to spread faster than its genome evolved. Genomic sequences found in Russia, Spain, England, Italy and Turkey, despite being separated by years are all identical, for example, creating enormous challenges to determining the route of transmission.    

To address the problem, researchers developed a new method for distinguishing specific populations of Y. pestis, enabling them to identify and date five populations throughout history, including the most famous ancient pandemic lineages which they now estimate had emerged decades or even centuries before the pandemic was historically documented in Europe.

“You can’t think of the plague as just a single bacterium,” explains Poinar. “Context is hugely important, which is shown by our data and analysis.”

To properly reconstruct pandemics of our past, present, and future, historical, ecological, environmental, social and cultural contexts are equally significant.

He explains that genetic evidence alone is not enough to reconstruct the timing and spread of short-term plague pandemics, which has implications for future research related to past pandemics and the progression of ongoing outbreaks such as COVID-19. 

The East Smithfield plague pits, which were used for mass burials in 1348 and 1349.

CREDIT

Museum of London Archaeology (MOLA)

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JOURNAL

Communications Biology

DOI

10.1038/s42003-022-04394-6 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Plagued by a cryptic clock: insight and issues from the global phylogeny of Yersinia pestis

ARTICLE PUBLICATION DATE

19-Jan-2023

COI STATEMENT

The authors declare no competing interests.

 Nature Medicine publishes breakthrough Owkin research on the first ever use of federated learning to train deep learning models on multiple hospitals’ histopathology data

Peer-Reviewed Publication

OWKIN, INC.

 

IMAGE: JEAN DU TERRAIL, SENIOR MACHINE LEARNING SCIENTIST AT OWKIN, AND LEAD AUTHOR OF NEW RESEARCH PUBLISHED TODAY IN NATURE MEDICINE view more 

CREDIT: OWKIN

In research published in Nature Medicine today, AI biotech company Owkin has demonstrated for the first time that federated learning (FL) can be used to train deep learning models on data from multiple hospitals on histopathology data without the data leaving hospital firewalls.

The discovery paves the way for AI-powered medical research using larger multi-centric datasets, allowing models to escape the biases of single-centric studies. This has the potential to unlock breakthroughs in precision medicine through the use of secure and privacy-preserving AI.

Using data kept within four leading French hospitals, Owkin built AI models that can accurately predict the future response of triple-negative breast cancer (TNBC) patients to neoadjuvant chemotherapy. By using interpretable AI to extract information from digital pathology slides, Owkin was able to find potential novel biomarkers. This could in the future help funnel patients towards either less toxic treatments or new experimental treatments, improving the personalization of medical care.

The project used federated learning – a collaborative AI framework that preserves data privacy and security through Substra, Owkin’s recently-open sourced software that make every operation traceable using hyperledger technology. The research is the first time that machine learning models have been trained using histopathology data from multiple hospitals without the data leaving the hospitals. Previously, most studies were restricted to simulating FL by artificially splitting data. It is a landmark proofpoint of FL in medical research and represents a breakthrough in the realization of AI’s practical benefit to research.

The study used digital pathology data and clinical information from 650 patients from Institut Curie in Paris, Centre Léon Bérard in Lyon, Gustave Roussy in Villejuif and IUCT Oncopole in Toulouse, making it one of the largest TNBC cohorts of its kind ever assembled for such kind of analysis.

The research builds on Owkin’s pioneering use of FL to enable pharmaceutical companies to collaborate on drug discovery research while safeguarding privacy, security and competitive considerations. The MELLODDY project’s results, published this year, showed that collaborating in AI for drug discovery is possible at industrial scale thanks to FL, a first for the industry. In addition to addressing privacy and security concerns, FL can also simplify data governance issues, removing the need to transfer data and fostering more collaborative research.

Jean du Terrail, lead author and Senior Machine Learning Scientist at Owkin, said:

Thanks to our partners, we are proud to have performed an original federated analysis on medical data in real-life conditions, and the first of its kind on histopathology data. By connecting institutions in a federated manner we were able to reach the critical mass of triple negative breast cancer data necessary for the AI to discover, on its own, histological patterns predictive of the response to treatment. We hope that this proof of concept will inspire medical institutions to collaborate in federated learning networks in order to move research forward while keeping patient data private.

Julien Guérin, Chief Data Officer at Institut Curie in Paris, France, said:

We reached an important milestone with the deployment of this federated learning infrastructure, showing a new cutting-edge approach of building AI in cancer research. We are really happy to have been part of this adventure and hope this will open promising perspectives for the future of patient care.

Dr Guillaume Bataillon, pathologist at IUCT Oncopole in Toulouse, France, and former pathologist at Institut Curie in Paris, France, said:

Through this multidisciplinary partnership, we verify the feasibility of an inter hospital collaborative federated learning approach on a relevant biological question. This allowed us to create pooled heterogeneous dataset in a secure and faster way in order to develop reproductible, transferable and even interpretable models.  This proof of concept has the potential to become a tool for therapeutic decision.

Dr Pierre Etienne Heudel, Medical oncologist at Centre Léon Bérard in Lyon, France, said:

The rise of digital pathology coupled with the explosion of different machine learning techniques should enable increasingly precise and personalized medicine. Moreover, the federated learning, achieved in this project by avoiding external data streams, facilitates and secures the process for future daily clinical practice.

Dr Magali Lacroix-Triki, pathologist at Gustave Roussy in Villejuif, France, said:

Digital pathology and AI represent the third revolution in the world of pathology, and pathologists are excited to lead this new change in their practice. Federated learning, pioneering AI research in digital pathology, brings us one step closer to identifying new biomarkers in oncology while ensuring data privacy and security.

Dr Camille Franchet, pathologist at IUCT Oncopole in Toulouse, France, said:

By enabling AI models to be trained on multicentric data without centralization, federated learning unlocks one of the major obstacles in machine learning on medical data with no compromise regarding the respect of personal data.

About Owkin

Owkin is an AI biotechnology company that uses artificial intelligence to find the right treatment for every patient. We bridge shared innovation challenges between biopharma and academic researchers and close the translational gap between complex biology and new drugs. 

We use AI to identify new treatments, de-risk and accelerate clinical trials and build diagnostic tools that improve patient outcomes. Using federated learning, a pioneering collaborative AI framework, Owkin enables medical and biopharma partners to unlock valuable insights from siloed datasets while protecting patient privacy and securing proprietary data.

Owkin was co-founded by Thomas Clozel MD, a former assistant professor in clinical onco-haematology, and Gilles Wainrib, a pioneer in the field of machine learning in biology, in 2016. Owkin has raised over $300 million and became a unicorn through investments from leading biopharma (Sanofi and BMS) and venture funds (Fidelity, GV and BPI, among others).

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JOURNAL

Nature Medicine

DOI

10.1038/s41591-022-02155-w 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Federated learning for predicting histological response to neoadjuvant chemotherapy in triple-negative breast cancer

ARTICLE PUBLICATION DATE

19-Jan-2023

UK

500,000 missed out on blood pressure lowering drugs during pandemic

Researchers warn of additional heart attacks and strokes adding to a healthcare system already under extreme pressure

HEALTH DATA RESEARCH UK

Nearly half a million people missed out on starting medication to lower their blood pressure during the Covid-19 pandemic, according to research supported by the British Heart Foundation (BHF) Data Science Centre at Health Data Research UK published today in Nature Medicine [1].

The researchers say that thousands of people could suffer an avoidable heart attack or stroke due to delays in starting these vital medications known to stave-off deadly heart and circulatory diseases.

Using data on routinely dispensed prescriptions in England, Scotland and Wales [2], scientists found that 491,306 fewer people than expected started taking blood pressure lowering medication between March 2020 and the end of July 2021.

If these individuals’ high blood pressure remains untreated over their lifetime, the team estimate that this could lead to more than 13,500 additional cardiovascular events [3], including over 2,000 heart attacks and 3,000 strokes [4].

These findings highlight an important opportunity for the NHS to identify and treat people who should have started taking medicines to reduce their risk of conditions including heart attack and stroke.

Lead author Professor Reecha Sofat, Associate Director at the BHF Data Science Centre, Breckenridge Chair of Clinical Pharmacology at the University of Liverpool, warned:

“Measures to prevent infection spread were necessary and undoubtedly saved lives. The NHS has already taken important and positive steps towards identifying people with high blood pressure as early as possible. However, we need this focus to be sustained in the long-term to prevent any increase in heart attacks and strokes which will add to a healthcare system already under extreme pressure.”

To understand more about the impact of the Covid-19 pandemic on the management of risk factors for heart and circulatory diseases, the researchers analysed 1.32 billion records of medications dispensed to 15.8 million people in England, Scotland and Wales between 1st April 2018 and 31st July 2021.

This showed that, by the first half of 2021, on average, 27,070 fewer people started taking blood pressure lowering medication each month between compared with 2019. In the same period, they found that 16,744 fewer people started taking medication to reduce levels of fat or cholesterol in their blood each month.

Identifying the individuals who missed starting medication as soon as possible will be critical to reduce their cardiovascular risk. The team believe that identifying those who missed out on blood pressure treatment within five years would reduce the total number of cardiovascular events to just over 2,700 [5].

This is the first time that medicines data has been used to follow changes in day-to-day management of chronic conditions. The researchers say that being able to routinely track this in future, particularly during healthcare crises, would allow the NHS and policymakers to step in earlier to avoid a repeat of the impact of the Covid-19 pandemic.

Professor Sofat added:

“Despite the incredible work done by NHS staff, our data show that we’re still not identifying people with cardiovascular risk factors at the same rate as we were before the pandemic.

“Detecting these risk factors early and beginning medication where appropriate is crucial to manage them, helping more people to avoid a preventable heart attack or stroke so they can live in good health for longer.”

Dr Sonya Babu-Narayan, Associate Medical Director at the British Heart Foundation and consultant cardiologist, said:

“Yet again we’re seeing clear evidence of the major disruption to healthcare people in the UK experienced during the Covid-19 pandemic.

“But it’s not too late to limit the damage. These findings demonstrate how getting heart healthcare back on track can curb the additional strain that untreated risk factors such as high blood pressure would otherwise place on the NHS.

“We need to make it easier and more accessible for everyone to know their numbers - particularly their blood pressure and cholesterol. This means empowering people to access the help they need when they need it so they can be supported to manage their own health.”

The British Heart Foundation Data Science Centre is part of Health Data Research UK and is funded by the British Heart Foundation.

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JOURNAL

Nature Medicine

DOI

10.1038/s41591-022-02158-7 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

People

Study sheds light on how human activities shape global forest structure

Peer-Reviewed Publication

CHINESE ACADEMY OF SCIENCES HEADQUARTERS

Climate change and human activities strongly influence forests, but researchers have not fully understood the pervasiveness of these stressors and how they will shape future forest structure.

Forests are expected to be mostly intact in protected areas (PAs) and so-called intact forest landscapes (IFLs). However, human impacts are expanding and intensifying to affect even these areas, and the global importance of such effects remains poorly understood.

Now, researchers led by Dr. LI Wang from the Aerospace Information Research Institute (AIR) of the Chinese Academy of Sciences (CAS) have provided, for the first time, a panoramic view of global patterns in the multidimensional structure of forests. As part of their work, the researchers have discerned the relative importance of climate and human impacts as well as other environmental factors in shaping global forest structure, particularly that of PAs and IFLs.

The study was published in Nature Sustainability on Jan. 19.

The research team provided a near-global assessment of human impacts on forest structural density using massive, high-quality, quantitative, global-scale data integrated from Global Ecosystem Dynamics Investigation (GEDI) and Moderate Resolution Imaging Spectroradiometer (MODIS) satellites.

"While acknowledging the importance of climate and other factors, we focused on the role played by human activities in shaping forest structural density at a near-global scale across all, protected, and intact forests," said Dr. LI.

The researchers found that human impacts are the second-most important driver after climate in shaping forest structure both globally and regionally. They further showed that anthropogenic degradation is pervasive even in forest areas that are formally protected or perceived to be intact.

"Given the ways in which forests support overall function of the biosphere and serve as major repositories of biodiversity," said LI, "the more fragile condition we find them in, the more it represents a considerable and unperceived ecological and climatic—and therefore human—risk."

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JOURNAL

Nature Sustainability

DOI

10.1038/s41893-022-01020-5 

ARTICLE TITLE

Human fingerprint on structural density of forests globally

ARTICLE PUBLICATION DATE

19-Jan-2023

Anti-Asian discrimination cost Chinese restaurants $7.4 billion during the pandemic's first year, new study finds

Researchers find strong link between nearly 20-percent drop in business at Chinese restaurants and political rhetoric that focused blame for Covid-19 on China

Peer-Reviewed Publication

BOSTON COLLEGE

Chestnut Hill, Mass (1/19/2023) – At the onset of the COVID-19 pandemic, anti-China fervor stoked consumer discrimination that cost Chinese restaurants $7.4 billion in lost revenue in 2020 – losses 18.4 percent greater than at other types of restaurants – according to a new study by researchers from Boston College, the University of Michigan, and Microsoft Research, published today in the journal Nature Human Behaviour.

The findings begin to put a finer point on the broad economic costs of anti-Asian discrimination during the pandemic and the role of politicians who focused blame on China, where the coronavirus emerged in late 2019, said study co-author and Boston College Assistant Professor of Political Science Masha Krupenkin.

Attitudes towards Chinese and non-Chinese Asian food declined precipitously during the pandemic and this change in attitudes was driven by a mix of assigning blame for COVID-19 spread to Asians and experiencing fear of Chinese food, Krupenkin and colleagues from the University of Michigan and Microsoft Research found.

“The Covid-19 pandemic originated in China,” said Krupenkin. “Many actors in US politics and media, especially those that were ideologically conservative, emphasized the connection between covid and China as a way of placing blame for the pandemic. At the same time, there was a sharp increase in incidents of discrimination and violence against Asian-Americans.”

The pandemic effectively delivered a “shock” to consumer discrimination against Chinese and other Asian restaurants, survey data, online search trends, and consumer cellular device mobility data studied by the team revealed.

“Our analysis estimates that COVID-related stigma and anti-Asian hate cost Asian American businesses $7.42 billion in lost revenue in 2020, highlighting how negative sentiment towards foreign entities can spillover into consumer discrimination targeting domestic minority groups,” said co-author Justin T. Huang, an assistant professor of marketing at the University of Michigan. “These patterns echo how Muslim Americans faced widespread discrimination, hate, and stigma post-9/11 and exemplify how some American minority groups are perceived through the lens of the perpetual foreigner stereotype."

There were political aspects to the downturn in business, according to the team. A range of data found anti-Asian discrimination was stronger in areas that had a higher percentage of residents who voted for Donald Trump in 2016.

According to the organization Stop AAPI Hate, there were almost 11,000 hate incidents against Asian Americans and Pacific Islanders reported to the organization between March 2020 and December 2021.

“While there's been research on violence against Asian-Americans, most acts of discrimination are more subtle,” said Krupenkin. “We set out to measure one of these more subtle forms of discrimination - consumer discrimination. This allowed us to examine a much more common – and economically meaningful – form of discrimination against Asian-Americans.”

The team – which also included Julia Lee of the University of Michigan and David Rothschild of Microsoft Research – was surprised to find that anti-China bias among consumers also affected restaurants serving cuisine from other Asian cultures.

Consumers would sometimes misidentify other Asian restaurants as Chinese, leading to decreased visits to those restaurants as well.

“Trump and conservative media had very thoroughly connected Covid to China specifically, so it was surprising to see a decrease in visits to other Asian restaurants as well,” Krupenkin said. “We tested this more thoroughly and found that many Americans misidentify other Asian restaurants as Chinese, which likely explains the spillover effects we saw.”

Parsing unique economic challenges faced by Asian Americans during the COVID-19 pandemic, the team believes the research has substantial implications for the study of consumer discrimination and stigmatization in public health communications.

Krupenkin said the researchers hope to further examine and connect patterns of discrimination to negative media narratives about specific groups.

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JOURNAL

Nature Human Behaviour

DOI

10.1038/s41562-022-01493-6 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

People

ARTICLE TITLE

The cost of anti-Asian racism during the COVID-19 pandemic

ARTICLE PUBLICATION DATE

19-Jan-2023

Tracing the flow of water with DNA

Peer-Reviewed Publication

UNIVERSITY OF BASEL

 

IMAGE: OLIVER SCHILLING ANALYZES SPRING WATER AT MOUNT FUJI. view more 

CREDIT: T. SCHILLING

Environmental DNA analysis of microbial communities can help us understand how a particular region’s water cycle works. Basel hydrogeologist Oliver Schilling recently used this method to examine the water cycle on Mount Fuji. His results have implications for other regions worldwide.

Where does the water come from that provides drinking water to people in a particular region? What feeds these sources and how long does it take for groundwater to make its way back up to the surface? This hydrological cycle is a complex interplay of various factors. A better grasp of the system allows us to understand, for example, why pollution is worse in some spots than others, and it can help us implement sustainable water management policies and practices.

Environmental DNA (eDNA) provides some important data to improve our understanding. In combination with the evaluation of other natural tracers – noble gases, for example – this microbial data provides important glimpses into the flow, circulation and functioning of complex groundwater systems. “It’s a vast toolbox that’s new to our field of research,” says Oliver Schilling, Professor of Hydrogeology at the University of Basel and at Eawag, the Swiss Federal Institute of Aquatic Science and Technology. Quantitative hydrogeology maps out where and how quickly new groundwater will accumulate.

Starting in 2018, Schilling conducted various measurements on Mount Fuji in Japan in order to determine where spring water comes from – that is, where the groundwater flows through before it arrives back at the surface and forms the hundreds of pristine natural springs which are scattered around Mt Fuji. His results are published in the first edition of the journal Nature Water, which just came out.

Determining water origins from eDNA

The choice of this particular mountain was no coincidence: “The geological setting of Mount Fuji is unique on Earth since it is the only place where three tectonic plates meet up like this. This makes the groundwater system highly complex and therefore poorly suited to investigation using the standard methods,” Oliver Schilling explains.

It was thanks to a Japanese colleague that he arrived at the idea of examining microbial eDNA in the region. “He told me about water sources on Mount Fuji that exhibit noteworthy signatures, namely that the eDNA contained in the water shows the presence of organisms that can only grow at a depth of 500 to 1,000 meters,” he recalls. This is an indicator that some of the source water comes from deep groundwater. “This was the first indication that microbial eDNA might provide some clues as to the groundwater’s flow trajectory when combined with other, independent tracers such as noble gases,” Schilling continues.

His curiosity was piqued. During his time as a postdoc at the Université Laval in Québec, he traveled to Japan during his vacations and conducted various measurements together with his Japanese colleague. He also delved deep into the existing scientific literature, which is primarily in Japanese. Along with eDNA, the hydrogeologist also analyzed two groundwater tracers with higher incidences due to Mount Fuji’s unique geological setting: the noble gas helium and the trace element vanadium. “All three natural tracers tell the same story: there is systematic deep circulation of the water within Mount Fuji. Such analyses are the key to understanding the system,” Schilling concludes.

Potential findings for Switzerland, too

This new application of tracers can be used to examine groundwater systems all over the world. In Switzerland, for example, it can be applied to determine where the water comes from that is pumped out of the ground for drinking water. “A large proportion of eDNA from cold-loving microbes in the groundwater, for example, would indicate that meltwater from snow and glaciers forms a substantial proportion of the sourced groundwater,” Schilling explains.

With an eye to the future, this means: “If we know the importance of these natural water reserves, we can look for alternatives ahead of time in order to shield affected regions from seasonal water shortages as much as possible,” the hydrogeologist continues. As a result of climate change, in Switzerland glaciers are melting and snow is reducing, which means that these important sources of water for streams and groundwater are slowly disappearing. This will negatively affect the water availability particularly in the more and more frequent hot and dry summer months.

One possibility to prevent severe water shortages in summer would be to collect more rainwater in reservoirs during the winter half year, for example by artificially enhancing groundwater reservoirs or adapting how above-ground reservoirs are managed. “The analysis of microbiological eDNA offers us a new tool for better calibrating the hydrological models used in groundwater management,” Schilling explains. This in turn is an important part of making realistic prognoses for water quality and availability and allows a sustainable, long-term planning for the management of groundwater – our most valuable and abundant source of drinking water.

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DOI

10.1038/s44221-022-00001-4 

ARTICLE TITLE

Revisiting Mt. Fuji’s groundwater origins with helium, vanadium and eDNA tracers.

ARTICLE PUBLICATION DATE

19-Jan-2023

Massive fuel hungry black holes feed off intergalactic gas

Peer-Reviewed Publication

UNIVERSITY OF SOUTHAMPTON

 

IMAGE: TWO INTERACTING GALAXIES VIEWED FROM THE HUBBLE SPACE TELESCOPE. view more 

CREDIT: NASA/ESA/HUBBLE HERITAGE TEAM

Research led by the University of Southampton has revealed how supermassive black holes (SMBHs) are feeding off gas clouds which reach them by travelling hundreds of thousands of light years from one galaxy to another.

An international team of scientists has shown there is a crucial link between the interaction of neighbouring galaxies and the enormous amount of gas needed to ‘fuel’ these giant, super-dense, space phenomena. Their findings are due to be published in the journal Nature Astronomy.

A black hole can be created when a star collapses, squeezing matter into a relatively tiny space. This increases the force of gravity to a point where nothing can escape, not even light – hence the name.

Some black holes are gigantic, with masses millions of times greater than our sun, emitting enormous amounts of energy. These are known as ‘supermassive black holes’ and exactly how they are formed or gain enough fuel to power themselves is still a mystery.

Astrophysicist and lead researcher from the University of Southampton, Dr Sandra Raimundo, comments: “Supermassive black holes fuel their activity by, in part, the gradual accumulation of gas from the environment around them. Supermassive black holes can make the centres of galaxies shine very brightly when they capture gas and it’s thought this process can be a major influence on the way that galaxies look today. How SMBHs get enough fuel to sustain their activity and growth still puzzles astronomers, but the work we have carried out provides a step towards understanding this.”

The Southampton scientist, working with researchers at the universities of Copenhagen and California, used data from the 4-metre Anglo-Australian telescope in New South Wales, Australia* to study the orbits of gas and stars in a large sample of more than 3000 galaxies. They identified those with the presence of what is known as ‘misaligned’ gas – in other words, gas which rotates in a different direction from the stars in the galaxy, signalling a past galaxy interaction. They then found that galaxies with misaligned gas had a higher fraction of active supermassive black holes.

The results showed a clear link between misaligned gas and supermassive black hole activity – suggesting the gas is transferred where two galaxies meet, meanders vast distances through space and then succumbs to the huge gravitational forces of the supermassive black hole – pulled in and swallowed up as a vital source of fuel. Astronomers have long suspected that a merger with another galaxy could provide this source of gas, but direct evidence for this has been elusive.

Dr Raimundo explains: “The work that we carried out shows the presence of gas that is misaligned from stars is associated with an increase in the fraction of active supermassive black holes. Since misaligned gas is a clear sign of a past interaction between two galaxies, our work shows that galaxy interactions provide fuel to power active supermassive black holes.

“This is the first time that a direct connection has been observed between the formation and presence of misaligned gas and the fuelling of active supermassive black holes.”

Dr Marianne Vestergaard, a co-author in the study, highlights: “What is exciting about these observations is that we can now, for the very first time, identify the captured gas and trace it all the way to the centre where the black hole is devouring it.”

The scientists now hope to extend their research and use their findings to calculate how much of the total mass of supermassive black holes grew from this mechanism and how important this was in the early Universe.

Ends

* Data from the Sydney-Australian-Astronomical-Observatory Multi-object Integral-Field Spectrograph (SAMI) survey, with the 4-metre Anglo-Australian telescope.

 

Notes to Editors

1. The paper ‘An increase in black hole activity in galaxies with misaligned gas’ is due for release in the journal Nature Astronomy, and can be viewed at https://doi.org/10.1038/s41550-022-01880-z once published. For sight of an advance copy, please contact Media Relations at press@soton.ac.uk.
    
2. For interviews with Dr Sandra Raimundo, please contact Peter Franklin, Media Relations, University of Southampton – press@soton.ac.uk 07748 321087
    
3. The University of Southampton drives original thinking, turns knowledge into action and impact, and creates solutions to the world’s challenges. We are among the top 100 institutions globally (QS World University Rankings 2023). Our academics are leaders in their fields, forging links with high-profile international businesses and organisations, and inspiring a 22,000-strong community of exceptional students, from over 135 countries worldwide. Through our high-quality education, the University helps students on a journey of discovery to realise their potential and join our global network of over 200,000 alumni. www.southampton.ac.uk
    
4. For more about Physics and Astronomy at the University of Southampton visit: https://www.southampton.ac.uk/about/faculties-schools-departments/school-of-physics-and-astronomy
    
5. For more on the University of Copenhagen visit: https://www.ku.dk/english/
    
6. For more about the University of California Los Angeles visit: https://www.ucla.edu/
    
7. The research project has received funding from the European Union′s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 891744

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JOURNAL

Nature Astronomy

DOI

10.1038/s41550-022-01880-z 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

An increase in black hole activity in galaxies with kinematically misaligned gas

ARTICLE PUBLICATION DATE

19-Jan-2023