Tuesday, May 04, 2021

Microplastics found in Europe's largest ice cap

REYKJAVIK UNIVERSITY

IMAGE: MICROPLASTICS HAVE BEEN FOUND IN VATNAJOKULL, EUROPE'S LARGEST ICE CAP. view more
CREDIT: EIRIKUR SIGURDSSON

In a recent article in Sustainability, scientists from Reykjavik University (RU), the University of Gothenburg, and the Icelandic Meteorological Office describe their finding of microplastic in a remote and pristine area of Vatnajokull glacier in Iceland, Europe's largest ice cap. Microplastics may affect the melting and rheological behaviour of glaciers, thus influencing the future meltwater contribution to the oceans and rising sea levels.

This is the first time that the finding of microplastic in the Vatnajökull glacier is described. The group visualised and identified microplastic particles of various sizes and materials by optical microscopy and μ-Raman spectroscopy.

The discussion about microplastics has mainly been focused on the contamination of the sea, but hitherto little research has been conducted on plastic in the earth's ice caps. To date, microplastic particles have been found in the Italian Alps, in the Ecuadorian Andes and icebergs at Svalbard. According to Dr Hlynur Stefansson, Associate Professor at the RU Department of Engineering and first author of the article, understanding the distribution of microplastic and its short and long-term effects on the dynamics of ice is of vital importance.

The findings confirm that microplastic particles are distributed through the atmosphere. "We do not understand well enough the pathways for microplastic particles in our environment. Is the plastic carried by snow and rain? We need to know more about the causes. The samples we took are from a very remote and pristine location in Vatnajokull glacier, with no easy access, so direct pollution from human activity is unlikely," Dr Stefansson says. "We also need to know much more about the short and long-term effects of microplastic on the dynamics of the ice and if they contribute to the melting of glaciers. If that is the case, it will play a critical role in future meltwater contribution to the oceans and rising sea levels. The plastic particles degrade very slowly in the cold glacier environment and can accumulate and persist in the glaciers for a very long time. Eventually, however, they will be released from the ice, contributing to pollution in rivers and the marine environment. It is therefore very important to map and understand the presence and dispersal of microplastics in glaciers on a global scale."

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Microplastics in Glaciers: First Results from the Vatnajökull Ice Cap https://www.mdpi.com/2071-1050/13/8/4183/htm

Mangroves and seagrasses absorb microplastics

UNIVERSITY OF SOUTHERN DENMARK

Research News

IMAGE: MANY ANIMALS LIVE IN SEAGRASS BEDS AND ARE THUS EXPOSED TO MICROPLASTIC. view more
CREDIT: TROELS LANGE/SDU.

Mangroves and seagrasses grow in many places along the coasts of the world, and these 'blue forests' constitute an important environment for a large number of animals. Here, juvenile fish can hide until they are big enough to take care of themselves; crabs and mussels live on the bottom; and birds come to feed on the plants.

However, the plant-covered coastal zones do not only attract animals but also microplastics, a new study shows.

- The denser the vegetation, the more plastic is captured, says Professor and expert in coastal ecology, Marianne Holmer, from the University of Southern Denmark.

She is concerned about how the accumulated microplastics affect animal and plant life.

- We know from other studies that animals can ingest microplastics and that this may affect their organism.

Animals ingest microplastics with the food they seek in the blue forests. They may suffocate, die of starvation, or the small plastic particles can get stuck different places in the body and do damage.

Another problem with microplastics is that they may be covered with microorganisms, environmental toxins or other health hazardous/disease-promoting substances that are transferred to the animal or plant that absorbs the microplastics.

- When microplastics are concentrated in an ecosystem, the animals are exposed to very high concentrations, Marianne Holmer explains.

She points out that microplastics concentrated in, for example, a seagrass bed are impossible to remove again.

The study is based on examinations of three coastal areas in China, where mangroves, Japanese eelgrass (Z. japonica) and the paddle weed Halophila ovalis grow. All samples taken in blue forests had more microplastics than samples from control sites without vegetation.

The concentrations were up to 17.6 times higher, and they were highest in the mangrove forest. The concentrations were up to 4.1 times higher in the seagrass beds.

Mangrove trees probably capture more microplastics, as the capture of particles is greater in mangrove forests than in seagrass beds.

Researchers also believe that microplastics bind in these ecosystems in the same way as carbon; the particles are captured between leaves and roots, and the microplastics are buried in the seabed.

- Carbon capture binds carbon dioxide in the seabed, and the blue forests are really good at that, but it's worrying if the same thing happens to microplastics, says Marianne Holmer.

Although the study was conducted along Chinese coasts, it may be relevant to similar ecosystems in the rest of the world, including Denmark, where eelgrass beds are widespread.

- It's my expectation that we will also find higher concentrations of microplastics in Danish and global seagrasses, she says.

The study was conducted in collaboration with colleagues from the Zhejiang University in China, among others, and is published in the journal Environmental Science and Technology.

The blue forests: Lots of plants grow in or below sea level; mangroves, seaweed, seagrass and marsh plants. Especially mangroves and seagrasses absorb and store carbon like plants on land and are thus extremely important for the planet's carbon footprint.

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Tiny plastic particles in the environment

Nanoplastics -- an underestimated problem?

SWISS FEDERAL LABORATORIES FOR MATERIALS SCIENCE AND TECHNOLOGY (EMPA)

Research News

IMAGE: TO FEAR OR NOT TO FEAR? NANOPLASTICS, ELECTRON MICROSCOPY IMAGE, COLORED, 150.000X. view more
CREDIT: EMPA/ETH

Wherever scientists look, they can spot them: whether in remote mountain lakes, in Arctic sea ice, in the deep-ocean floor or in air samples, even in edible fish - thousands upon thousands of microscopic plastic particles in the micro to millimeter range. This microplastic is now even considered one of the defining features of the Anthropocene, the age of the Earth shaped by modern humans.

Microplastics are formed by weathering and physicochemical or biological degradation processes from macroscopic plastic products, such as the tons of plastic waste in the oceans. It is unlikely that these degradation processes will stop at the micrometer scale. And so there is growing concern about the potential harmful effects nanoplastics could have on various ecosystems. "Numerous media reports suggest, through their sometimes highly emotional coverage, that we are facing a huge problem here," says Empa researcher Bernd Nowack, who has long studied the material flows of synthetic micro- and nanoparticles, for example from textiles or tire abrasion, into the environment. But Nowack says at present this statement can hardly be substantiated by scientific findings: "We don't even know how much nanoplastics there is in the different ecosystems."

Huge gaps in knowledge ...

This is primarily because it is enormously difficult in terms of measurement technology to identify artificial nanoparticles made of plastic in environmental samples with thousands and thousands of (natural) particles of similar size. Appropriate analytical methods would first have to be developed, says Denise Mitrano of ETH Zurich. And then it would be a matter of understanding exactly what risk the tiny plastic particles - some of which differ considerably in their chemical composition - pose to humans and the environment, in other words: how dangerous they ultimately are. Adds Nowack, "So we can't justifiably say we have a serious problem here - but we also can't say we don't."

That's because the smaller particles become, the more likely they are to reach organs and tissues that are inaccessible to larger particles. The blood-brain barrier or placenta, for instance, prevents particles and macromolecules from passing through until they reach a certain size - or rather, smallness - thereby protecting the tissues and organs "behind" them, i.e. the brain and fetus, respectively, from potentially dangerous substances such as viruses and bacteria. "Even if we ingest microplastics, for example through our food, they probably do not enter our bloodstream or our brain, but are simply excreted again," says Peter Wick, head of Empa's Particles-Biology Interactions lab, who studies the interactions of nanoparticles with biological systems. "With nanoplastics, we can't be so sure."

... and great need for research

Because of the enormous gaps in current knowledge, research into nanoplastics must thus be intensified, conclude Mitrano, Wick and Nowack. However, this should be done as systematically and broadly as possible - and with a cool head. After all, emerging pollutants do not always turn out to be as dangerous as originally assumed. "Our society initially adopts a zero-risk attitude toward many things that are new and unknown," Wick says. And that's understandable, he adds, especially in the case of nanoplastics, because, after all, "who wants plastic in their food?"

The solution to the problem, however, is as simple (at least in theory) as it is complex. On the one hand, a large proportion of nanoplastic particles are produced by the degradation of macro- and microplastics. Less plastic in the environment, therefore, reduces the amount of nanoplastics, and here every one of us can help stop polluting the environment with plastic waste. On the other hand, nanoplastics can also be created during the use of plastic products - for example, through abrasion - without the user being able to do anything about it. Indeed, our society is hardly possible without plastic. "The various polymers simply have too many positive properties for that," says Bernd Nowack.

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Literature

DM Mitrano, P Wick & B Nowack; Placing nanoplastics in the context of global plastic pollution. Nature Nanotechnology (2021). https://doi.org/10.1038/s41565-021-00888-2

Nanoplastics and other harmful pollutants found in disposable face masks -- Regulation and research urgently needed, say experts

SWANSEA UNIVERSITY

Research News

IMAGE: MICROSCOPE IMAGE OF MICROFIBRES RELEASED FROM CHILDREN'S MASK: THE COLOURFUL FIBRES ARE FROM THE CARTOON PATTERNS view more
CREDIT: SWANSEA UNIVERSITY

Swansea University scientists have uncovered potentially dangerous chemical pollutants that are released from disposable face masks when submerged in water.

The research reveals high levels of pollutants, including lead, antimony, and copper, within the silicon-based and plastic fibres of common disposable face masks.

The work is supported by the Institute for Innovative Materials, Processing and Numerical Technologies (IMPACT) and the SPECIFIC Innovation & Knowledge Centre

Project lead Dr Sarper Sarp of Swansea University College of Engineering said:

"All of us need to keep wearing masks as they are essential in ending the pandemic. But we also urgently need more research and regulation on mask production, so we can reduce any risks to the environment and human health".

Outlined in a recent paper, the tests carried out by the research team used a variety of masks - from standard plain face masks to novelty and festive masks for children with many currently being sold in UK retail outlets.

The rise in single-use masks, and the associated waste, due to the COVID-19 pandemic has been documented as a new cause of pollution. The study aimed to explore this direct link - with investigations to identify the level of toxic substances present.

The findings reveal significant levels of pollutants in all the masks tested - with micro/nano particles and heavy metals released into the water during all tests. Researchers conclude this will have a substantial environmental impact and, in addition, raise the question of the potential damage to public health - warning that repeated exposure could be hazardous as the substances found have known links to cell death, genotoxicity and cancer formation.

To combat this, the team advise further research and subsequent regulations be put in place in the manufacturing and testing process.

Project lead Dr Sarper Sarp explained:

'The production of disposable plastic face masks (DPFs) in China alone has reached approximately 200 million a day, in a global effort to tackle the spread of the new SARS-CoV-2 virus. However, improper and unregulated disposal of these DPFs is a plastic pollution problem we are already facing and will only continue to intensify.'

'There is a concerning amount of evidence that suggests that DPFs waste can potentially have a substantial environmental impact by releasing pollutants simply by exposing them to water. Many of the toxic pollutants found in our research have bio-accumulative properties when released into the environment and our findings show that DPFs could be one of the main sources of these environmental contaminants during and after the Covid-19 pandemic.

It is, therefore, imperative that stricter regulations need to be enforced during manufacturing and disposal/recycling of DPFs to minimise the environmental impact.'

'There is also a need to understand the impact of such particle leaching on public health. One of the main concerns with these particles is that they were easily detached from face masks and leached into the water with no agitation, which suggests that these particles are mechanically unstable and readily available to be detached.

Therefore, a full investigation is necessary to determine the quantities and potential impacts of these particles leaching into the environment, and the levels being inhaled by users during normal breathing. This is a significant concern, especially for health care professionals, key workers, and children who are required to wear masks for large proportions of the working or school day.'

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The research team includes Professor Trystan Watson, Dr Javier Delgado Gallardo and Dr Geraint Sullivan. The IMPACT operation is part-funded by the European Regional Development Fund through the Welsh Government and Swansea University.

Notes to editors

Read the research paper in Science Direct

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

Find us on Facebook: http://www.facebook.com/swanseauniversity

Population-based study shows air pollution exposure contributes to childhood asthma

Children born in Sarnia, Ontario at higher risk of developing asthma, compared to neighbouring cities

LAWSON HEALTH RESEARCH INSTITUTE

Research News

LONDON, ON - New findings from Ontario have shown that children born in Sarnia have a higher risk of developing asthma compared to neighbouring cities. A research team from Lawson Health Research Institute and Western University, using provincial data from ICES, found that higher air pollution exposure in the first year of life very likely contributed to this higher risk. Their results are published today in CMAJ Open.

Summary of study results:

-Air pollution exposure in the first year was found to be associated with the development of asthma in children.

-Overall rates of new childhood asthma diagnosis in Southwestern Ontario have been decreasing over time in parallel to decreases in air pollution levels.

"It's known that cities in Southwestern Ontario have varied levels of air pollution because of differences in industry and traffic. For example, Sarnia is home to the 'Chemical Valley' where numerous chemical plants and oil refineries are clustered," says Dr. Dhenuka Radhakrishnan, an Adjunct ICES Scientist, formerly working out of ICES Western in London, and Pediatric Respirologist at CHEO. "We wanted to see if children born in three cities - London, Windsor and Sarnia - had a different risk of developing asthma due to the differing air pollution levels in the three regions, even though the people living in these cities are otherwise comparable in many ways."

The researchers followed 114,427 children born in these cities between 1993 and 2009 for 10 years, and found that those in Sarnia were at the highest risk of developing asthma. The researchers found that by the age of 10, nearly 24 per cent of children in Sarnia were diagnosed with asthma, compared to 21 per cent in Windsor and 17 per cent in London. The differences were also present after accounting for many risk factors associated with asthma, such as sex, socioeconomic status and urban versus rural setting. The findings were most apparent in the first two years of life, but persistent beyond the age of six.

"Reassuringly, we found the asthma risk for children has reduced in more recent years as pollution levels have also decreased," adds Dr. Radhakrishnan.

Asthma is the most common chronic disease in Canadian children and has significant impact on quality of life. Asthma is the leading cause of emergency department visits and hospital admissions in this age group.

"It's important to find strategies to prevent asthma development and this study suggests that reducing air pollution exposure, including environmental causes, might reduce the number of children who suffer from asthma," explains Dr. Salimah Shariff, Associate Scientist at Lawson, Adjunct Professor at Western and Scientist at ICES Western.

There is also growing evidence that exposure during pregnancy can influence development of asthma in children. "We need to carefully examine how reducing air pollution exposures within a geographic area translates to reductions in asthma development. Understanding the amount of air pollution that a mother and infant are exposed to, and how this impacts their personal risk, could enable regions to target safer levels for their residents," adds Dr. Shariff.

Wednesday, May 5 is World Asthma Day (WAD). Recognizing symptoms of asthma early is the best a parent can do to improve the health of their child, so they can be diagnosed quickly and start appropriate treatments. If a parent notices their child has wheezing, persistent cough or difficulty with exercise, they are encouraged to bring this to the attention of a health care provider.

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SHORT EXPLAINER VIDEO: https://youtu.be/lfp7522tEQI

DOWNLOADABLE IMAGES: https://www.lawsonresearch.ca/children-born-sarnia-higher-risk-developing-asthma-compared-london-and-windsor

ABOUT LAWSON HEALTH RESEARCH INSTITUTE - @LawsonResearch

Lawson Health Research Institute is one of Canada's top hospital-based research institutes, tackling the most pressing challenges in health care. As the research institute of London Health Sciences Centre and St. Joseph's Health Care London, our innovation happens where care is delivered. Lawson research teams are at the leading-edge of science with the goal of improving health and the delivery of care for patients. Working in partnership with Western University, our researchers are encouraged to pursue their curiosity, collaborate often and share their discoveries widely. Research conducted through Lawson makes a difference in the lives of patients, families and communities around the world.

ABOUT WESTERN - @WesternU

Western delivers an academic experience second to none. Since 1878, The Western Experience has combined academic excellence with life-long opportunities for intellectual, social and cultural growth in order to better serve our communities. Our research excellence expands knowledge and drives discovery with real-world application. Western attracts individuals with a broad worldview, seeking to study, influence and lead in the international community.

ABOUT ICES - @ICESOntario

ICES is an independent, non-profit research institute that uses population-based health information to produce knowledge on a broad range of health care issues. Our unbiased evidence provides measures of health system performance, a clearer understanding of the shifting health care needs of Ontarians, and a stimulus for discussion of practical solutions to optimize scarce resources. ICES knowledge is highly regarded in Canada and abroad, and is widely used by government, hospitals, planners, and practitioners to make decisions about care delivery and to develop policy. In October 2018, the institute formerly known as the Institute for Clinical Evaluative Sciences formally adopted the initialism ICES as its official name.

Air pollution linked to high blood pressure in children; other studies address air quality and the heart

AMERICAN HEART ASSOCIATION

Research News

DALLAS, May 4, 2021 -- A meta-analysis of 14 air pollution studies from around the world found that exposure to high levels of air pollutants during childhood increases the likelihood of high blood pressure in children and adolescents, and their risk for high blood pressure as adults. The study is published in a special issue on air pollution in the Journal of the American Heart Association, an open access journal of the American Heart Association.

Other studies look at: the effects of diesel exhaust on the muscle sympathetic nerve; the impact of pollutants on high blood pressure; rates of hospital readmission for heart failure among those exposed to high levels of ambient air pollution; and risk of stroke and heart attack after long-term exposure to high levels of particulate matter. The studies include health outcomes of people who were exposed to pollutants in the United States, China and Europe.

High blood pressure during childhood and adolescence is a risk factor for hypertension and heart disease in adulthood. Studies on air pollution and blood pressure in adolescents and children, however, have produced inconsistent conclusions. This systematic review and meta-analysis pooled information from 14 studies focused on the association between air pollution and blood pressure in youth. The large analysis included data for more than 350,000 children and adolescents (mean ages 5.4 to 12.7 years of age).

"Our analysis is the first to closely examine previous research to assess both the quality and magnitude of the associations between air pollution and blood pressure values among children and adolescents," said lead study author Yao Lu, M.D., Ph.D., professor of the Clinical Research Center at the Third Xiangya Hospital at Central South University in Changsha, China, and professor in the department of life science and medicine at King's College London. "The findings provide evidence of a positive association between short- and long-term exposure to certain environmental air pollutants and blood pressure in children and adolescents."

The analysis included 14 studies published through September 6, 2020, exploring the impact of long-term exposure (?30 days) and/or short-term exposure (<30 days) of ambient air pollution on blood pressure levels of adolescents and/or children in China and/or countries in Europe.

The studies were divided into groups based upon length of exposure to air pollution and by composition of air pollutants, specifically nitrogen dioxide and particulate matter with diameter ?10 μm or ?2.5 μm. (The majority of research linking heart disease with particulate matter focuses on particle matter mass, which is categorized by aerodynamic diameter - μm or PM.) Fine particles are defined as PM2.5 and larger; coarse particles are defined at PM10; and the concentrations of particulate matter are typically measured in their mass per volume of air (μg/m3).

The meta-analysis concluded:

Short-term exposure to PM10 was significantly associated with elevated systolic blood pressure in youth (the top number on a blood pressure reading).
Periods of long-term exposure to PM2.5, PM10 and nitrogen dioxide were also associated with elevated systolic blood pressure levels.
Higher diastolic blood pressure levels (the bottom number on a blood pressure reading) were associated with long-term exposure to PM2.5 and PM10.

"To reduce the impact of environmental pollution on blood pressure in children and adolescents, efforts should be made to reduce their exposure to environmental pollutants," said Lu. "Additionally, it is also very important to routinely measure blood pressure in children and adolescents, which can help us identify individuals with elevated blood pressure early."

The results of the analysis are limited to the studies included, and they did not include data on possible interactions between different pollutants, therefore, the results are not generalizable to all populations. Additionally, the analysis included the most common and more widely studied pollutants vs. air pollutants confirmed to have heart health impact, of which there are fewer studies.

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The study was funded by the National Natural Science Foundation of China; Hunan Youth Talent Project; the Natural Science Foundation of Hunan Province; and the Fundamental Research Funds for Central Universities of Central South University.

Co-authors of the meta-analysis are Miao Huang, M.D.; Jingyuan Chen, M.D.; Yiping Yang, B.M.; Hong Yuan, M.D., Ph.D.; and Zhijun Huang, M.D. Author disclosures are listed in the manuscript.

Additional original articles published in JAHA's spotlight on air pollution include:

Acute exposure to diesel exhaust increases muscle sympathetic nerve activity in humans, Bosson et al.
Short-term Effects of Particle Size and Constituents on Blood Pressure in Healthy Young Adults in Guangzhou, China, Dong et al.
Lead and Cadmium as Cardiovascular Risk Factors: Has the Burden of Proof Been Met?, Lamas et al.
Particulate air pollution and risk of cardiovascular events among adults with a history of stroke or acute myocardial infarction, Liao et al.
Long-term Exposure to Particulate Air Pollution is Associated with 30-day Readmissions and Hospital Visits Among Heart Failure Patients, Ward-Caviness et al.

Additional Resources:

Multimedia is available on the right column of release link: https://newsroom.heart.org/news/air-pollution-linked-to-high-blood-pressure-in-children-other-studies-address-air-quality-and-the-heart?preview=21700d0a86c1830864668eda0f74acb4
After May 4, view this manuscript and others from the JAHA Spotlight Issue on Air Pollution online.
What is High Blood Pressure?
High Blood Pressure in Children
Understanding Blood Pressure Readings
Counties with dirtier air have more stroke deaths
Regular exercise helps prevent high blood pressure, even in areas of high air pollution
Particulate Matter Air Pollution and Cardiovascular Disease
Leading cardiovascular organizations call for urgent action to reduce air pollution

Follow AHA/ASA news on Twitter @HeartNews

Follow news from the Journal of the American Heart Association @JAHA_AHA

Statements and conclusions of studies published in the American Heart Association's scientific journals are solely those of the study authors and do not necessarily reflect the Association's policy or position. The Association makes no representation or guarantee as to their accuracy or reliability. The Association receives funding primarily from individuals; foundations and corporations (including pharmaceutical, device manufacturers and other companies) also make donations and fund specific Association programs and events. The Association has strict policies to prevent these relationships from influencing the science content. Revenues from pharmaceutical and biotech companies, device manufacturers and health insurance providers are available here, and the Association's overall financial information is available here.

Bringing up baby: A crocodile's changing niche

UNIVERSITY OF TENNESSEE AT KNOXVILLE

Research News

Relatives of the giant crocodile might have been kings of the waterways during the Cretaceous period, eating anything--including dinosaurs--that got a little too close to the water's edge, but the largest of these apex predators still started off small. Figuring out how these little crocs grew up in a world surrounded by giants is no small task. Now crocs fossils from Texas are shedding light on how these animals changed their diets as they grew, helping them find a place of their own in environments alongside their bigger, badder relatives.

According to the study, published by Cambridge University Press, the crocodiless in question are members of the Deltasuchus motherali and lived along the coastline of Texas 96 million years ago. Previously known from a single adult skull, this 20-foot-long crocodile left behind bite marks on turtles and, yes, dinosaurs. The new discoveries include at least 14 more members of Deltasuchus, ranging from sizes as large as the original specimen down to a paltry (if still snappy) four feet in length.

Having so many crocs from the same fossil population is not common, and the smaller, more delicate bones of juveniles often did not survive the fossilization process.

"So many fossil groups are only known from one or a handful of specimens," said paleontologist Stephanie Drumheller, lead author of the study and a lecturer of earth and planetary sciences at the University of Tennessee, Knoxville. "It can be easy to fall into the trap of only thinking about the adults." The researchers ran into challenges piecing together this ancient ecosystem, however. Deltasuchus wasn't alone in its coastal swamps.

Living alongside Deltasuchus were other large crocs, like Terminonaris and Woodbinesuchus.

"These two large croc species were comparable in size to an adult Deltasuchus, but because they had long, narrow snouts with slender interlocking teeth, they were targeting smaller prey in the environment," said Thomas Adams, co-author of the new study and curator of paleontology and geology at the Witte Museum in San Antonio.

A smaller crocodile, Scolomastax, lived in the area as well, but its unusual jaw and chunky dentition hint that it preferred hard food and maybe even plants.

"These results confirm previous work that shows fossil crocs were much more diverse and creative when it came to coexisting in the same environments," said Chris Noto, co-author and associate professor at the University of Wisconsin-Parkside. "The very warm conditions of the Cretaceous supported a greater number of reptiles and allowed them to explore new niches not possible in the present day."

When these crocodiles died, their skeletons fell apart as they fossilized, getting jumbled together and complicating efforts to tell which bones went with which animal. To help solve this puzzle, the team turned to 3D scanning technology to help reconstruct the skulls. UT undergraduate student Hannah Maddox meticulously scanned each piece and stitched them together into 3D models of complete skulls.

"It was like solving a great puzzle," said Maddox. "Every piece brought you closer to seeing a toothy grin that hadn't been seen in millions of years."

As the models came together, a more complete picture of how Deltasuchus lived started to take shape.

The juveniles had lighter, skinnier snouts and teeth than their older relatives--faces better suited to snap up quicker, softer prey than the heavier, powerful jaws of their parents. This might have helped make sure that little Deltasuchus were not in direct competition with the similarly sized hard-prey specialists in their environments, but as they grew they had other neighbors to consider. The large-bodied, slender-snouted role was already filled by other species. So Deltasuchus shifted in another direction as it grew, bulking up and taking on the heavy jaws and sturdy teeth of an ambush predator.

"This is an amazing fossil discovery where we not only have a population of a single species, but in an ecosystem that has multiple predators coexisting by filling separate niches," said Adams.

Similar results were found in recent analyses of young tyrannosaurs, which spent their teenaged years outcompeting other medium-sized predators in their ecosystems.

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One step closer to efficient cannabis production

Bringing a technique that has been a boon to other plants to the budding cannabis industry

UNIVERSITY OF CONNECTICUT

Research News

IMAGE: MICROPROPAGATION COULD MAKE CULTIVATING CANNABIS A MUCH EASIER TASK. view more
CREDIT: JESSICA LUBELL-BRAND

As nurseries and garden centers fill up with spring landscaping plants, home gardeners owe a lot to a technique called micropropagation, which has proven beneficial to many plants - perhaps soon to include cannabis, thanks to work by UConn researchers in the College of Agriculture, Health, and Natural Resources.

Micropropagation is a technique used for growing large quantities of new plants from fewer "parent" plants, yielding clones with the same, predictable qualities. The cannabis (Cannabis sativa) industry, however, has been largely left out of this beneficial technique, because this species of plant is extremely difficult to micropropagate.

Researchers from UConn - including Associate Professor Jessica Lubell-Brand, Ph.D. student Lauren Kurtz, and Professor Mark Brand, in the Department of Plant Science and Landscape Architecture - have worked through some of the challenges of cannabis micropropagation of hemp. Their method was recently published in HortTechnology.

Currently, the commercial cannabis industry relies on other propagation techniques, such as collecting seeds or taking carefully timed cuttings from stock "mother" plants. These methods require a lot of space and maintenance, since multiple specimens of each line of stock plants must be kept in the event of disease outbreak or plant death.

"Micropropagation produces many more clones than other methods. Since it is not relying on seed, the clones are uniform, and they will perform similarly to the parent plant. Plants that come out of tissue culture also have the benefit of being disease-free, they frequently show enhanced vigor, and you can grow a lot more in less space," says Lubell-Brand.

Plants in tissue culture depend on the grower to assume the role of nature to provide the right balance of nutrients and growth hormones in the culture media, to regulate temperature and light -- everything. For some plants, micropropagation is easy to accomplish, where explants placed in the growing medium will multiply readily. For others, like cannabis, the process requires quite a bit of refining to ensure the production of a large number of healthy plants.

"Cannabis does not really want to be in tissue culture. This research is a lot of trying to figure out, What more does the plant need?" says Lubell-Brand.

Realizing the potential to help meet the needs of the rapidly growing medical cannabis industry, the researchers set out to answer this question and decipher the needs of cannabis in tissue culture. The process requires a lot of trial and error, Lubell-Brand explains.

"We start the culture using shoot tips from greenhouse-grown plants. Then we subculture those and if we suspect something is lacking, for instance, that the plant isn't getting what it needs in the media, we experiment with nutrients like calcium, magnesium, phosphorus, and nitrogen to try to increase the length of time that they grow in culture."

Lubell-Brand says one of the issues with hemp micropropagation is hyperhydricity of the shoots: when the shoots get saturated with water, they become brittle, and they don't grow well.

Lubell-Brand explains that by adjusting the media for the first six weeks in culture while also using vented vessels to increase air flow, they were able to avoid hyperhydricity.

"In addition to creating large quantities of clones of the parent plant, micropropagated plants will very likely show enhanced growth vigor compared to conventional stem propagated plants," she says.

In the medical cannabis industry, consistency and reliability in crops is highly sought after, and micropropagation could deliver both. For growers to get started with the micropropagation technique, some equipment is needed, such as an autoclave and a laminar flow bench to ensure a sterile environment. However, for operations already using tissue culture techniques, the equipment is the same, says Lubell-Brand.

Kurtz says the research has been met with some excitement: "Tissue culture is not that well worked-out for cannabis in the literature. People are aware of the complications, problems, and downfalls, so people have been pretty receptive to the paper."

Lubell-Brand says the research is continuing, with Kurtz planning further studies to refine the process, such as determining the optimal timing of rooting and the length of time shoots can remain in culture.

The cultivars the researchers are working with are cannabidol (CBD) cultivars lacking psychoactive amounts of tetrahydrocannabinol (THC), but their micropropagation technique can be applied to THC-dominant cultivars as well. One day, maybe not so far in the future, the majority of cannabis may be micropropagated using tissue culture, though Lubell-Brand says there are still improvements to be made.

"Despite all our efforts, it's still not easy to grow cannabis in tissue culture. However, now we can multiply shoots, root shoots, and transition them from the lab to the greenhouse, which is a step forward."

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Team cracks century-old mystery over the health struggles of explorer Ernest Shackleton

The severe nutrient deficiency beriberi is found to be the primary cause of Shackleton's bouts of breathlessness and weakness

MASSACHUSETTS GENERAL HOSPITAL

Research News

BOSTON - Researchers from Massachusetts General Hospital (MGH) appear to have solved the 120-year-old mystery surrounding the failing health of famed Antarctic explorer Sir Ernest Shackleton over the course of his daring expeditions to Antarctica in the early part of the twentieth century. In a paper published online in the Journal of Medical Biography, the team moved beyond past theories of congenital heart defect and scurvy advanced by physicians and historians to conclude that the British explorer suffered from beriberi, a serious and potentially life-threatening condition caused by a deficiency of the nutrient thiamine.

"Historians have traditionally looked at Shackleton's symptoms in isolation and speculated about their cause," says lead author Paul Gerard Firth, MD, head of the Division of Community and Global Health in the Department of Anesthesia, Critical Care and Pain Medicine at MGH. "We looked at other explorers on the expedition, as well as members of other early expeditions, and found that some had symptoms--such as breathlessness, neuropathy and effort intolerance--similar to Shackleton's that could be attributed to beriberi. With the benefit of what we now know about nutritional diseases, we believe that beriberi-induced cardiomyopathy--a disease of the heart muscle that makes it difficult for the heart to pump blood--is the correct diagnosis for Ernest Shackleton's deteriorating health."

The researchers learned that Edward Wilson, one of two physicians on Shackleton's first voyage to Antarctica beginning in 1901--when the explorer fell seriously ill and had to return home after voyaging closer to the South Pole than any previous human--may have suspected beriberi after consulting his medical textbooks, but didn't settle on that diagnosis at a time when so little was known about the condition. Instead, the prolonged bouts of extreme shortness of breath and physical weakness Shackleton experienced on the British "Discovery" expedition of 1901 to 1903 were ascribed by his contemporaries and subsequent historians to scurvy or underlying heart disease.

"While Wilson concluded that Shackleton's condition was the result of scurvy--a vitamin C deficiency--that appeared to us to be an incomplete explanation for his labored breathing," says Firth. "Shackleton, after all, had very slight symptoms of scurvy when his breathing difficulties began, and mild scurvy does not cause heart problems."

This careful parsing of the historical evidence led Firth and his colleagues to an alternative nutritional cause of Shackleton's health struggles. "Many of the signs and symptoms of beriberi seen in early explorers developed after three months of thiamine deficiency," explains co-author Lauren Fiechtner, MD, director of the Center for Pediatric Nutrition at MGH. "And that would be consistent with a thiamine-deficient diet they experienced during the grueling months of winter explorations. Fortunately, replacement of thiamine with vitamin B1 supplements can resolve the deficiency within days or hours, although that was not known at the time."

Even severe health challenges were not enough to prevent Shackleton from setting out on a third attempt to reach the South Pole in 1914, a fateful voyage since recounted in books and movies of how his ship Endurance became trapped in packed ice and broke apart, with all 28 crewmen reaching safety after two years and two heroic rescue efforts engineered by Shackleton. In late 1921, the intrepid explorer embarked on his fourth expedition, but suffered a heart attack on January 5, 1922, and died on his ship at age 47.

"The exact nature of Ernest Shackleton's faltering health has puzzled historians and the public for years," says Firth, "and almost 100 years after the start of his fourth and final expedition we're satisfied that we have finally uncovered a medically and scientifically valid explanation."

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Firth is a pediatric anesthesiologist at MGH. Fiechtner is a pediatric gastroenterologist at MGH. Co-author Oscar Benavidez, MD, is division chief of Pediatric/Congenital Cardiology at MGH.

About the Massachusetts General Hospital

Massachusetts General Hospital, founded in 1811, is the original and largest teaching hospital of Harvard Medical School. The Mass General Research Institute conducts the largest hospital-based research program in the nation, with annual research operations of more than $1 billion and comprises more than 9,500 researchers working across more than 30 institutes, centers and departments. In August 2020, Mass General was named #6 in the U.S. News & World Report list of "America's Best Hospitals."