Tuesday, May 24, 2022

Researchers succeed in monitoring the "journey" of microplastics through the intestine of a living organism

UNIVERSITAT AUTONOMA DE BARCELONA

A UAB research team has managed to track the behaviour of microplastics during their "journey" through the intestinal tract of a living organism and illustrate what happens along the way. The study, carried out on Drosophila melanogaster using electron microscopy equipment developed by the researchers themselves, represents a significant step towards a more precise analysis of the health risks of being exposed to these pollutants.

The behaviour of micro and nanoplastics (MNPLs) inside the organism is a question impossible to answer at present in humans, and in vitro models are not useful. Hence, there is a need to look for models that allow us to answer this question. Furthermore, there are limitations in the current methodologies for detecting and quantifying their presence in different human biological samples, which prevents an accurate assessment of the health risk of exposure.

In this context, researchers from the Mutagenesis Research Group of the Universitat Autònoma de Barcelona (UAB) have managed to monitor the tracking of MNPLs in their "journey" from the environment to the interior of a living organism. They have done it by developing tools based on electron microscopy and in larvae of the Drosophila melanogaster fly, a model organism widely used to study biological phenomena and processes.

The research team has studied the behaviour of MNPLs along their pathway with commercial polystyrene of nanometric sizes. The "photographic report" obtained has allowed them to see the interaction of MNPLs with the microbiota and cells of the membrane that recovers the inside of the intestines, their ability to cross the intestinal barrier and their presence in haemolymph, which is equivalent to blood in humans, and in blood cells, which correspond to our lymphocytes.

"In addition to establishing a new methodological approach, our study confirms the great advantages of Drosophila melanogaster as a model to determine the potential harmful effects associated with the ingestion of these pollutants", explains Ricard Marcos, researcher at the Department of Genetics and Microbiology of the UAB and coordinator of the study.

Effects at the nanometric level

The evaluation of the biological effects at different stages of the larvae's life showed that, although no significant toxicity was observed, the exposure produced a broad molecular response, altering the expression of genes involved in the general response to stress, oxidative damage and genotoxicity, as well as in genes related to the response to physical damage on the intestinal barrier.

"Our work adds information on what happens, in terms of effects, when the exposure is to nanoplastics, which, due to their small size, are of particular relevance to us, because of their greater capacity to break down biological barriers and produce toxicological effects that can affect the health of organisms, including humans," says Alba Hernández Bonilla, a researcher at the UAB and co-author of the study.

So far, most of the effects of MNPLs have been carried out in micro- and even millimetric ranges, and in aquatic models, mainly marine. In vivo studies using nanoplastics are almost non-existent. It is in this context that the relevance of the study, which has used methodologies that have never before been used for these purposes, is clear, researchers point out.

The study has been published recently in the journal Environmental Sciences: Nano and is part of the European project PLASTICHEAL, coordinated by the UAB, which aims to provide regulators with new methodologies and solid scientific evidence to establish the knowledge base for an adequate risk assessment of MNPLs.

CAPTION

Monitoring nanoplastic particles from their ingestion until their translocation to the haemolymph compartment. They were detected inside the midgut lumen (A), surrounding the peritrophic membrane (B), surrounding midgut bacteria (C), inside the cytoplasm of enterocytes (D), surrounded by midgut vacuoles (E) and, finally, reaching the haemolymph (F).

CREDIT

Universitat Autònoma de Barcelona (UAB).

JOURNAL

Environmental Science Nano

DOI

10.1039/D1EN01199E

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Hazard assessment of ingested polystyrene nanoplastics in Drosophila larvae

New measurements from Northern Sweden show less methane emissions than feared

GREENHOUSE GASES

Peer-Reviewed Publication

UNIVERSITY OF COPENHAGEN - FACULTY OF SCIENCE

It is widely understood that thawing permafrost can lead to significant amounts of methane being released. However, new research shows that in some areas, this release of methane could be a tenth of the amount predicted from a thaw. The research was conducted in Sweden by an international group that includes researchers from the University of Copenhagen. A crucial, yet an open question is how much precipitation the future will bring.

A typical landscape in northern Sweden. On the left is a pond vegetation controlled by high water levels and on the right a drier tundra vegetation, which is becoming more prevalent in areas where the water level is low and the soil dries out in summer. In areas where permafrost disappears, new studies show that the release of methane can be reduced by a factor of 10 due to changes in hydrology, plant community and the composition of microorganisms in the soil (photo: Bo Elberling)

Permafrost runs like a frozen belt of soil and sediment around Earth’s northern arctic and sub-arctic tundra. As permafrost thaws, microorganisms are able to break down thousands of years-old accumulations of organic matter. This process releases a number of greenhouse gases. One of the most critical gasses is methane; the same gas emitted by cattle whenever they burp and fart.

Because of this, scientists and public agencies have long feared methane emissions from permafrost to rise in step with global temperatures. But, in some places, it turns out that methane emissions are lower than once presumed.

In a comprehensive new study by a collaborative from the University of Gothenburg, Ecole Polytechnique in France and the Center for Permafrost (CENPERM) at the University of Copenhagen, researchers measured the release of methane from two localities in Northern Sweden. Permafrost disappeared from one of the locations in the 1980’s, and 10-15 years later in the other.

The difference between the two areas shows what can happen as a landscape gradually adapts to the absence of permafrost. The results show that the first area to lose its permafrost now has methane emissions ten times less than in the other locality. This is due to gradual changes in drainage and the spread of new plant species. The study’s findings were recently published in the journal Global Change Biology.

"The study has shown that there isn’t necessarily a large burst of methane as might have been expected in the wake of a thaw. Indeed, in areas with sporadic permafrost, far less methane might be released than expected," says Professor Bo Elberling of CENPERM (Center for Permafrost), at the University of Copenhagen’s Department of Geosciences and Natural Resource Management.

Water, plants and microbes all play a role

According to Professor Elberling, water drainage accounts for why far less methane was released than anticipated. As layers of permafrost a few meters deep begin to disappear, water in the soil above begins to drain.

"Permafrost acts somewhat like the bottom of a bathtub. When it melts, it's as if the plug has been pulled, which allows water to seep through the now-thawed soil. Drainage allows for new plant species to establish themselves, plants that are better adapted for drier soil conditions. This is exactly what we’re seeing at these locations in Sweden," he explains.

Grasses typical of very wet areas with sporadic permafrost have developed a straw-like system that transports oxygen from their stems down into to their roots. These straws also act as a conduit through which methane in the soil quickly find its way to the surface and thereafter into the atmosphere.

As the water disappears, so do these grasses. Gradually, they are replaced by new plant species, which, due to the dry soil conditions, do not need transport oxygen from the surface via their roots. The combination of more oxygen in the soil and reduced methane transport means that less methane is produced and that the methane that is produced can be better converted to CO2 within the soil.

"As grasses are outcompeted by new plants like dwarf shrubs, willows and birch, the transport mechanism disappears, allowing methane to escape quickly up through soil and into the atmosphere," explains Bo Elberling.

The combination of dry soil and new plant growth also creates more favorable conditions for soil bacteria that help break methane down.

"When methane can no longer escape through the straws, soil bacteria have more time to break it down and convert it into CO2," Bo Elberling elaborates.

As a result, one can imagine that as microorganisms reduce methane emissions, the process will lead to more CO2 being released. Yet, no significant increase in CO2 emissions was observed by the researchers in their study. This is interpreted as being the result of the CO2 balance, which is more heavily determined by plant roots than the CO2 released from the microorganisms that break down methane. Crucially, even though methane ends up as CO2, it is considered less critical in climate change context as methane is at least 25 more potent greenhouse gas as compared to CO2.

Infobox

Areas of sporadic permafrost cover the southern part of the Arctic around the globe, where the temperature is typically between minus five and zero degrees. This means that a rise in temperature can cause the permafrost to completely disappear.

Future precipitation will be decisive

According to Professor Elberling, the future’s greatest unknown is the amount of future precipitation. Because, while thawing permafrost makes it easier for soil to drain in areas with sporadic permafrost, increased rainfall or poor drainage can prevent an area from drying. Where the latter is the case, we shouldn’t expect a corresponding drying out and reduction in methane being released.

"The balance between precipitation and evaporation will be crucial for the release and absorption of greenhouse gases. However, predicting Arctic precipitation is fraught with uncertainty. In some areas we’re seeing increased precipitation, while in others, things are drying out - especially in the summer," says Elberling.

The study focuses on data from two localities in northern Sweden. As such, Professor Elberling is cautious about concluding that analogous conditions extend to other areas with similar permafrost, such as in Canada or Russia.

The study contributes to a new understanding of a process that must be taken into account whenever future methane emissions are assessed in permafrost-affected areas.

"In their most recent report on the Arctic’s future methane budget, the IPCC (Intergovernmental Panel on Climate Change) has not considered the conditions highlighted by us in the study. Our study reverses the general perception that thawed permafrost is to be consistently associated with increased levels of methane being released," Professor Elberling concludes.

Lead author Mats Björkman from University of Göteborg adds:

“Our research shows that methane emissions from areas where permafrost thaws are not the same everywhere. The new observations represent an important component of a more comprehensive picture of the climate impact in the Arctic. Our results also underscore the importance of including hydrological, vegetation, and microbial changes when studying the long-term effects of permafrost thawing and disappearing.”

In the future Mats Björkman wants to determine which areas will either get wetter or drier and see how they are affected when the permafrost thaws.

JOURNAL

Global Change Biology

DOI

10.1111/gcb.16137

ARTICLE TITLE

Reduced methane emissions in former permafrost soils driven by vegetation and microbial changes following drainage

What happens when plants have stress reactions to touch

Peer-Reviewed Publication

LUND UNIVERSITY

Olivier Van Aken and Essam Darwish — IMAGE: THE RESEARCHERS IN THE LAB view more
CREDIT: JOHAN JOELSSON

A 30-year-old genetic mystery has been solved. It has previously been established that touch can trigger stress reactions in plants. However, the molecular models for explaining this process have been quite spartan so far. Now researchers at Lund University in Sweden have found genetic keys that explain how plants respond so strongly to mechanical stimuli. Cracking this code could help lead to higher yields and improved stress resistance in crops in the future.

When you water your garden plants, they react directly at a biochemical level. When a knife edge cuts a rhubarb stalk, thousands of genes are activated, and stress hormones are released.

Unlike humans, plants can not feel pain, but they still react strongly to mechanical stimuli from human touch, hungry animals, wind and rain, for example. These external factors lead to the plant's molecular defense system being activated quickly, which in turn can contribute to plants becoming more resistant and flowering later.

Although the phenomenon has been known since Darwin, there are still many question marks. A new study published in Science Advances has examined the complex regulating networks that affect how the plant's defenses are strengthened by external influences.

“We exposed the plant thale cress to soft brushing, after which thousands of genes were activated and stress hormones were released. We then used genetic screening to find the genes that were responsible for this process”, explains Olivier Van Aken, biology researcher at Lund University.

Previous studies have shown that the plant hormone jasmonic acid is an important mediator in touch signaling. It has also been known that jasmonic acid is only part of the plant's complex network of touch-sensitive responses, and that there are several unidentified pathways that have not yet been unveiled. After extensive laboratory work, the researchers were able to identify three new proteins that play a key role in the plants' response to touch.

“Our results solve a scientific mystery that has eluded the world's molecular biologists for 30 years. We have identified a completely new signaling pathway that controls a plant's response to physical contact and touch. Now the search for more paths continues”, says Essam Darwish, biology researcher at Lund University.

What possible applications will the new results have? Olivier Van Aken is also studying a centuries-old Japanese agricultural technology that involves trampling grain during the growth phase, to obtain more abundant harvests. The researchers believe that there is a lot of hidden knowledge about how mechanical stimuli can lead to higher yields and improved stress resistance in crops. Knowledge that in the long run can change modern agriculture at its core.

“Given the extreme weather conditions and pathogen infections that climate change leads to, it is of utmost importance to find new ecologically responsible ways to improve crop productivity and resistance”, concludes Olivier Van Aken.

JOURNAL

Science Advances

DOI

10.1126/sciadv.abm2091

ARTICLE TITLE

Touch signaling and thigmomorphogenesis are regulated by complementary CAMTA3- and JA-dependent pathways

Disclaimer: AAAS and Eurek

Crystal Palace dinosaurs: how we rediscovered five missing sculptures from the famous park

Published: May 20, 2022

THE CONVERSATION

The iconic Iguanodon sculptures of the Crystal Palace Dinosaurs.

Witton and Michel (2022), CC BY-SA

This summer sees our love for dinosaurs manifest in two major releases: the David Attenborough documentary Prehistoric Planet, and Jurassic World: Dominion. Such multi-million dollar projects are a far cry from the first attempts to bring dinosaurs to life in people’s imagination.

Perhaps the most famous of these took place almost 170 years ago at Crystal Palace Park, in south-east London, where over 30 life-sized sculptures of prehistoric animals, including dinosaurs, revealed extinct life to the public for the first time.

Much like the unveiling of Jurassic Park’s computer generated dinosaurs in 1993, the Crystal Palace dinosaurs stunned visitors. This historic site still enjoys hundreds of thousands of visitors each year.

Our new book, The Art and Science of the Crystal Palace Dinosaurs, reveals that neglect of the site allowed seven – almost a fifth – of the original sculptures to disappear. It was thought the original park had 32 sculptures, of which only 29 originals (with one replica, making 30) stand today. We showed 37 once existed.

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The lost statues include the tapir-like Palaeotherium magnum, three delicate llama-like Anoplotherium gracile, two Jurassic pterodactyls, and a female giant deer. It’s unknown when and how each vanished, but dereliction, site redevelopment and perhaps vandalism may be responsible.

Built as part of the Crystal Palace Park project, the dinosaurs were unveiled in 1854 and completed in 1855. Although books and magazines brought dinosaurs to the attention of the rich and educated in the early 1800s, fossils were an interest reserved for the upper tiers of society. The sculptures, crafted by a team led by Benjamin Waterhouse Hawkins, aimed to introduce prehistoric life to the wider public.

Map of the Geographical Court as originally planned.

Image by Mark P. Witton and Ellinor Michel.

Working with geologists David Thomas Ansted and Joseph Campbell, Hawkins created a learning experience one part spectacle and one part enlightenment: the “Geological Court”. This showcase of geological and palaeontological science allowed visitors to walk through geological time.

The largest of Hawkins’ sculptures were the dinosaurs, reaching over 10m long. Mock geological features contained hundreds of tonnes of rocks sourced from all over the UK. This was expensive blockbuster edutainment.

For all the mockery cast on the sculptures for their scientific inaccuracy today, at the time they were cutting edge representations of extinct species – and a major hit with the public. But budget issues saw the site fall into disrepair from 1870 onward. Degraded and patchy records mean the full extent of the original display is uncertain.

An 1853 image of the Crystal Palace palaeontological sculpture workshed. Several now missing models are indicated by red arrows: the Palaeotherium magnum (left) and three Anoplotherium gracile (right). The surviving A. gracile is marked with a blue arrow. Image in public domain, modified by Mark P. Witton and Ellinor Michel.

Virtually no physical remains of the missing sculptures exist. Only archive photographs, illustrations and texts prove their existence. For example, the image above shows several models that no longer exist.

From these sources, we also re-identified one sculpture at the park – an alleged giant deer fawn – as Anoplotherium gracile, which resembles a gazelle and is the sole surviving representative of what was once a group of four statues.

If we know almost 20% of this unique Victorian site was allowed to vanish so quietly, what else might be missing?

A history at risk of extinction

While the Victorian artistry and creative engineering that went into creating the Geological Court is celebrated today, the site has long suffered from a lack of conservation.

The unchanging nature of the concrete displays, now numerous generations behind the latest palaeontological findings, gives a sense the they will always be here. But visit the site today and it’s obvious many of the displays are still crumbling.

Weathering, vandalism and redevelopment mean the Geological Court is a blend of originals and replicas of structures destroyed in the mid-20th century.

The state of the southern corner of the Geological Court as of 2021. This portion of the site has received some minor maintenance since this photo was taken.

Photo by Mark P. Witton

There is hope. The Friends of Crystal Palace Dinosaurs charity was established in 2013, and the entire site is now Grade 1 listed and on the official Heritage At Risk Register by Historic England.

But the Geological Court’s status is a precarious one. Without urgent conservation the sculptures face major deterioration.

As you enjoy the digital descendants of Hawkins’ dinosaurs when they hit our screens this summer, spare a thought for their Victorian ancestors. To lose what remains of these displays, that changed the way many people thought about life on Earth, would be tragic.

Authors

Mark P. Witton
Research Fellow in Palaeontology, University of Portsmouth

Ellinor Michel
Scientific Associate, Natural History Museum

Disclosure statement

Mark P. Witton is the co-author of The Art and Science of the Crystal Palace Dinosaurs, out now on Crowood Press.

Ellinor Michel is the co-author of The Art and Science of the Crystal Palace Dinosaurs, out now on Crowood Press.

New discovery of missing Victorian

dinosaurs at world’s first Jurassic Park

Book Announcement

UNIVERSITY OF PORTSMOUTH

CP Megalosaurus — IMAGE: THE LONGEST SCULPTURE IN THE PARK IS MEGALOSAURUS, THE ORIGINAL CARNIVOROUS DINOSAUR. THIS RESTORATION SHOWS THE ARTISTIC SKILL AND SCIENTIFIC CONSIDERATION THAT WENT INTO EACH MODEL THROUGH ITS MUSCULAR, POWERFUL LIMBS, ENLARGED, HEAD-SUPPORTING SHOULDERS AND FINELY DETAILED JAWS. view more
CREDIT: MARK P. WITTON

New insights about the world’s first life-sized models of dinosaurs have been revealed.
A new book provides missing evidence that seven - almost a fifth - of the world-famous Crystal Palace Dinosaurs have disappeared.
The lost sculptures include the tapir-like Palaeotherium magnum, three delicate llama-like Anoplotherium gracile, two Jurassic pterodactyls, and a female giant deer.

Evidence for numerous missing models at the world-famous Crystal Palace Dinosaurs and re-identification of a sculpture as one of the park’s “lost species” are revealed in a new book, The Art and Science of the Crystal Palace Dinosaurs (The Crowood Press).

The Crystal Palace Dinosaurs were a series of over 37 Grade 1 listed sculptures of prehistoric animals and geological displays arranged in a simulated “walk through time”, which were unveiled to the public as part of the famous Crystal Palace Park in 1854.

It was thought the original park had 32 life-sized sculptures, of which 30 (29 originals and one replica) and a handful of geological displays survive today. The new research adds five lost mammal sculptures to that list, showing that 37 sculptures once existed.

This globally significant historic site, which includes iconic depictions of monumental dinosaurs, regal extinct mammals, serpentine marine reptiles and giant amphibians, captured a snapshot of palaeontology from a golden era of scientific discovery in the mid-19th century. Today, they are internationally recognised as a milestone in the portrayal of extinct life and the history of science.

The book’s co-author, Dr Mark Witton, a leading palaeontological artist and researcher at the University of Portsmouth, said: “We’ve uncovered a lot of new insights into the Dinosaurs and their park home in this project, but the evidence for so many lost models blew us away. They weren’t small, obscure sculptures either, but included pony-sized, tapir-like Palaeotherium magnum and a horse-sized female Megaloceros. More amazingly, we found lots of evidence for a hitherto overlooked species, ”Anoplotherium gracile”, which we call Xiphodon gracilis today.

“There were originally four Xiphodon but only one model survives, mislabeled as a Megaloceros fawn. Happily, we have photos and illustrations of these lost models that show us what they looked like, but their existence also exposes large gaps in the documented history of the site. It means that, in total, eight original models have been lost, with only one successfully replaced - a standing Anoplotherium commune.”

Using new archive sources, the authors have revealed how grand the site was in its heyday before almost 20 per cent of the original constructed animal sculptures went missing in following decades, mostly under unknown circumstances. In addition, 14 planned extinct animal sculptures were never made due to funding restrictions.

Several mysteries about how the non-dinosaur animal models were manufactured have also been answered. Using new analysis of historic images, the authors discovered that the smaller sculptures were probably built indoors and moved around with carts, sometimes in pieces, to be assembled on site. The largest models, including the dinosaurs, were assembled in place, under tents to protect them from poor weather.

Co-author Dr Ellinor Michel, an evolutionary biologist at the Natural History Museum London, said: “This book celebrates these classic scientific artworks and explores their history, their conception as a wider part of the Crystal Palace project, their execution using unorthodox building materials, their reception by 19th century and modern critics, and their enduring mysteries.

“These sculptures and landscapes have been a gateway to the wondrous ideas of Deep Time and to teaching us how scientific ideas come to life since 1854. These Victorian creations can still teach us a lot today about science, art and history. I hope this book will continue to bring those important messages to many generations of curious minds.”

The book, which is published by The Crowood Press, includes hundreds of historic and modern photos and original paintings that offer a detailed study of the art and science behind each sculpture, and covers:

How prehistoric life and the geological record was reconstructed at life-size for the first time in the 1850s, detailing how the models and their associated geological landscape were rationalised from scientific data before being rendered in iron and concrete.
How palaeoartists and palaeontologists view them today, with a discussion of their historical reconstructions and the debates about the animals over time.
An evaluation of the roles performed by the site’s consultant, the historically controversial scientist Richard Owen, and its visionary artist, Benjamin Waterhouse Hawkins.

Dr Witton said: “The Crystal Palace Dinosaurs are the world’s first major palaeoart project and they played a significant role in making geological sciences accessible to the public. This is the most detailed and complete history of these world-famous sculptures yet, reinforcing their status as masterworks of education and palaeoartistry.”

Unfortunately, conservation risks have faced generations of custodians keeping the display intact, and the challenges still face the site today.

Dr Michel, who is co-founder and chair of the Friends of Crystal Palace Dinosaurs, said: “The need for greater care, maintenance and research in the Geological Court is even more urgent than anyone knew as the site has suffered more damage than we thought. Through this book, we want to show the importance of conserving these endangered sculptures for the next generation.”

All authors’ royalties from the book will support the charity Friends of Crystal Palace Dinosaurs to help in the conservation and interpretation of the models.

ART AND SCIENCE OF THE CRYSTAL PALACE DINOSAURS

MARK WITTON ELLINOR MICHEL

£30.00

The Crystal Palace Dinosaurs, a series of thirty-seven incredible sculptures of prehistoric animals and geological displays, were unveiled to the public as part of the famous Crystal Palace Park in 1854. The display, which includes iconic depictions of rhinoceros-like dinosaurs, regal extinct mammals, serpentine marine reptiles and giant, frog-like amphibians, captured a snapshot of palaeontology from a golden era of scientific discovery in the mid-nineteenth century. Today, they are internationally recognized as a milestone in our portrayals of extinct life. This book celebrates these classic scientific artworks and explores: their history, their conception as a wider part of the Crystal Palace project, their execution using unorthodox building materials, their reception by nineteenth century and modern critics, and their enduring mysteries. Hundreds of historic and modern photos and original paintings show modern scientific visions of the extinct animals restored. Written in collaboration with and in support of the Friends of Crystal Palace Dinosaurs charity, this superb book gives the most detailed and complete history of these world-famous sculptures yet, reinforcing their status as masterworks of education and palaeoartistry.