California Academy of Sciences researchers produce first-ever ‘family tree’ for aquarium-bred corals

Pedigree provides insights for maximizing genetic diversity and adaptability in corals bred for conservation

Peer-Reviewed Publication

CALIFORNIA ACADEMY OF SCIENCES

 

IMAGE: CORALS IN THE ACADEMY'S CORAL SPAWNING LAB © CALIFORNIA ACADEMY OF SCIENCES view more 

CREDIT: © CALIFORNIA ACADEMY OF SCIENCES

SAN FRANCISCO, CA (November 14, 2022) — Corals bred in public aquaria provide novel research opportunities and a healthy stock for outplanting into the wild, essential components of a thriving future for coral reef ecosystems, which support around 25% of all life in Earth’s oceans. But the long-term success of such efforts hinges in part on maintaining genetic diversity in aquarium-bred corals which leads to increased resilience to threats like ocean warming and acidification. In a study published today in Frontiers in Marine Science, a diverse team of Steinhart Aquarium biologists and researchers from the California Academy of Sciences' Coral Spawning Lab produce the first-ever pedigree, or ‘family tree’, for corals bred in an aquarium and provide a list of best practices to maintain genetic diversity in aquarium-bred corals. 

“Genetic diversity is what enables species to adapt to the myriad threats resulting from climate change,” says Academy Curator Rebecca Albright, PhD, who founded the Coral Spawning Lab, one of only a handful of facilities on Earth capable of successfully breeding corals. Albright’s work is an integral part of the Academy’s Hope for Reefs initiative, which is aimed at halting the decline of coral reefs in this generation. “For facilities like ours at the Coral Spawning Lab, ensuring each generation of corals is diverse allows us to conduct more robust experiments, which is a critical element of better understanding how corals can thrive on our changing planet. For organizations that do outplantings, increased genetic diversity translates to a greater chance of survival in the wild.”

For the study, the researchers conducted genetic analyses on the parents and offspring from two generations of Acropora hyacinthus corals spawned in the Coral Spawning Lab from 2019 and 2020. Based on the similarities between the DNA of the corals, the researchers were able to determine the relationships between individuals, such as parenthood or siblinghood. 

“Corals are broadcast spawners, meaning that multiple colonies release their sperm and eggs into the water simultaneously and there’s no way to immediately tell which coral parented which offspring,” says Academy coral researcher and study author Elora López-Nandam, PhD. “Surprisingly, we found that just two of the four colonies that spawned in 2019 parented 22 out of the 23 offspring that survived to their 2nd birthday. This leads to lots of new questions for us to explore how those two parents were so successful, the answers to which could help us better understand coral reproduction more broadly.” 

“While successful coral spawning events are a testament to how closely we have been able to mimic natural oceanic conditions, inevitably there are environmental pressures in aquarium settings that will differ from those in the wild and might be selecting for certain traits in each generation of coral,” López-Nandam says. Therefore, in addition to relatedness, the researchers also sifted through all 450 million DNA base pairs—if an organism’s genome is a book, then base pairs are the individual letters—from each of the sampled corals to find genetic differences between successive generations. 

In particular, the researchers found 887 points in the 450-million-letter long code that appear to be different in aquarium-bred corals when compared to those born in the wild. 

“Many of the differences we found were in gene pathways related to symbiosis with photosynthetic algae, which is how many corals get most of their energy,” López-Nandam says. “We hope to conduct future research in the Coral Spawning Lab to determine what exactly from an aquarium setting is driving these differences and how those genetic variations impact the overall fitness or health of aquarium-bred corals.”

Just as it takes a village to raise a child, the study authors note that it takes a unique cadre of experts to raise corals for such a study: from couscous-sized gamete bundles to Aspirin-sized polyps to grapefruit-sized spawning adults.

“This sort of collaboration between aquarium biologists and scientific researchers is rare,” says Steinhart Aquarium biologist and study author Lisa Larkin. “There are very few places around the world where all of those experts are housed in the same building, working together towards a shared goal. The Academy is unique in that we can propel this kind of research forward while also making a major impact on coral conservation.” 

Larkin and her colleagues in the Steinhart Aquarium spend months monitoring water quality and tracking the development of corals to ensure they are healthy enough to spawn each year. 

“Corals can be quite finicky. It takes them a lot of energy to reproduce and if they are stressed, they’ll put that energy elsewhere,” Larkin says. “It takes months of detailed attention to get them to the point where they are ready and able to spawn. 

But, Larkin adds, the end result more than justifies the effort. “You take care of a coral for an entire year and when they finally spawn you know you’ve done a great job. And since each spawn results in new opportunities for research such as this that is applicable for coral conservation, the payoff is well worth it.”

Academy Curator Rebecca Albright, PhD, diving in Palau, where the corals for this study were collected. © California Academy of Sciences

CREDIT

© California Academy of Sciences

Gametes being collected during a coral spawning event at the Academy. Gayle Laird © 2021 California Academy of Sciences

CREDIT

Gayle Laird © 2021 California Academy of Sciencescademy of Sciences
The California Academy of Sciences is a renowned scientific and educational institution with a mission to regenerate the natural world through science, learning, and collaboration. Based in San Francisco’s Golden Gate Park, it is home to a world-class aquarium, planetarium, and natural history museum, as well as innovative programs in scientific research and environmental education—all under one living roof. Museum hours are 9:30 am – 5:00 pm Monday – Saturday, and 11:00 am – 5:00 pm on Sunday. Admission includes all exhibits, programs, and shows. For daily ticket prices, please visit www.calacademy.org or call (415) 379-8000 for more information.

About Research at the California Academy of Sciences
The Institute for Biodiversity Science and Sustainability at the California Academy of Sciences is at the forefront of efforts to regenerate the natural world through science, learning, and collaboration. Based in San Francisco, the Institute is home to more than 100 world-class scientists, state-of-the-art facilities, and nearly 46 million scientific specimens from around the world. The Institute also leverages the expertise and efforts of more than 100 international Associates and 450 distinguished Fellows. Through expeditions around the globe, investigations in the lab, and analysis of vast biological datasets, the Institute’s scientists work to understand the evolution and interconnectedness of organisms and ecosystems, the threats they face around the world, and the most effective strategies for ensuring they thrive into the future. Through deeply collaborative partnerships and innovative public engagement initiatives, they also guide critical conservation decisions worldwide, inspire and mentor the next generation of scientists, and foster responsible stewardship of our planet.

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JOURNAL

Frontiers in Marine Science

DOI

10.3389/fmars.2022.961106 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Kinship and genetic variation in aquarium-spawned Acropora hyacinthus corals

ARTICLE PUBLICATION DATE

14-Nov-2022

Lack of computer access linked to poorer mental health in young people during COVID-19 pandemic

Peer-Reviewed Publication

UNIVERSITY OF CAMBRIDGE

Cambridge researchers have highlighted how lack of access to a computer was linked to poorer mental health among young people and adolescents during COVID-19 lockdowns.

The team found that the end of 2020 was the time when young people faced the most difficulties and that the mental health of those young people without access to a computer tended to deteriorate to a greater extent than that of their peers who did have access.

The COVID-19 pandemic had a significant effect on young people’s mental health, with evidence of rising levels of anxiety, depression, and psychological distress. Adolescence is a period when people are particularly vulnerable to developing mental health disorders, which can have long-lasting consequences into adulthood. In the UK, the mental health of children and adolescents was already deteriorating before the pandemic, but the proportion of people in this age group likely to be experiencing a mental health disorder increased from 11% in 2017 to 16% in July 2020.

The pandemic led to the closure of schools and an increase in online schooling, the impacts of which were not felt equally. Those adolescents without access to a computer faced the greatest disruption: in one study 30% of school students from middle-class homes reported taking part in live or recorded school lessons daily, while only 16% of students from working-class homes reported doing so.

In addition to school closures, lockdown often meant that young people could not meet their friends in person. During these periods, online and digital forms of interaction with peers, such as through video games and social media, are likely to have helped reduce the impact of these social disruptions. 

Tom Metherell, who at the time of the study was an undergraduate student at Fitzwilliam College, University of Cambridge, said: “Access to computers meant that many young people were still able to ‘attend’ school virtually, carry on with their education to an extent and keep up with friends. But anyone who didn’t have access to a computer would have been at a significant disadvantage, which would only risk increasing their sense of isolation.”

To examine in detail the impact of digital exclusion on the mental health of young people, Metherell and colleagues examined data from 1,387 10–15-year-olds collected as part of Understanding Society, a large UK-wide longitudinal survey. They focused on access to computers rather than smartphones, as schoolwork is largely possible only on a computer while at this age most social interactions occur in person at school.

The results of their study are published in Scientific Reports.

Participants completed a questionnaire that assesses common childhood psychological difficulties, which allowed the Understanding Society team to score them on five areas: hyperactivity/inattention, prosocial behaviour, emotional, conduct and peer relationship problems. From this, they derived a ‘Total Difficulties’ score for each individual.

Over the course of the pandemic, the researchers noted small changes in overall mental health of the group, with average Total Difficulties scores increasing form pre-pandemic levels of 10.7 (out of a maximum 40), peaking at 11.4 at the end of 2020 before declining to 11.1 by March 2021.

Those young people who had no access to a computer saw the largest increase in their Total Difficulties scores. While both groups of young people had similar scores at the start of the pandemic, when modelled with adjustment for sociodemographic factors, those without computer access saw their average scores increase to 17.8, compared to their peers, whose scores increased to 11.2. Almost one in four (24%) young people in the group without computer access had Total Difficulties scores classed as ‘high’ or ‘very high’ compared to one in seven (14%) in the group with computer access.

Metherell, now a PhD student at UCL, added: “Young people’s mental health tended to suffer most during the strictest periods of lockdown, when they were less likely to be able go to school or see friends. But those without access to a computer were the worst hit – their mental health suffered much more than their peers and the change was more dramatic.”

Dr Amy Orben from the Medical Research Council (MRC) Cognition and Brain Sciences at the University of Cambridge, the study’s senior author, added: “Rather than always focusing on the downsides of digital technology on young people’s mental health, we need to recognise that it can have important benefits and may act as a buffer for their mental health during times of acute social isolation, such as the lockdown.

“We don’t know if and when a future lockdown will occur, but our research shows that we need to start thinking urgently how we can tackle digital inequalities and help protect the mental health of our young people in times when their regular in-person social networks are disrupted.”

The researchers argue that policymakers and public health officials need to recognise the risks of ‘digital exclusion’ to young people’s mental health and prioritise ensuring equitable digital access.

Tom Metherell was supported by was supported by the British Psychological Society Undergraduate Research Assistantship Scheme. The research was largely funded by the Medical Research Council.

Reference
Metherell, T et al. Digital access constraints predict worse mental health among adolescents during COVID-19. Scientific Reports; 9 Nov 2022; DOI: 10.1038/s41598-022-23899-y

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JOURNAL

Scientific Reports

DOI

10.1038/s41598-022-23899-y 

METHOD OF RESEARCH

Survey

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Digital access constraints predict worse mental health among adolescents during COVID-19

Passion fruit yields high antioxidant ingredient for stable edible food coatings

Peer-Reviewed Publication

UNIVERSITY OF JOHANNESBURG

 

IMAGE: MICROENCAPSULATED POWDER OF PASSION FRUIT PEELS PRESERVE HIGH LEVELS OF ANTIOXIDANTS AND POLYPHENOLS. THE POWDERS ARE SUITABLE AS STABLE INGREDIENTS IN HIGH ANTIOXIDANT, EDIBLE FOOD COATINGS TO REDUCE POST-HARVEST LOSSES AND SPOILAGE IN FRESH FRUIT AND FRESH CUTS, RESEARCHERS FROM THE UNIVERSITY OF JOHANNESBURG FIND. IN THIS WAY, EDIBLE FOOD COATINGS CAN CONTRIBUTE TO FOOD AND NUTRITION SECURITY AND ENVIRONMENTAL SUSTAINABILITY. view more 

CREDIT: CREDIT: THERESE VAN WYK. IMAGES FROM STUDY PUBLISHED IN ANTIOXIDANTS BY KOBO ET AL. (HTTPS://DOI.ORG/10.3390/ANTIOX11081579) HTTPS://CREATIVECOMMONS.ORG/LICENSES/BY/4.0/

The high antioxidants and polyphenols content in passion fruit peels show significant potential to preserve fresh fruits and fresh cuts in an edible food coating, shows research from the University of Johannesburg. Such a coating can reduce spoilage and plastic packaging in supply chains.

The researchers extracted, micro-encapsulated, freeze-dried and powdered passion fruit (Passiflora edulis Sims) peels from an organic farm. This varietal is known for its medicinal value. Globally, passion fruit is mainly grown for concentrated juice.

Their metabolomic and other analyses in Antioxidants show the powders have the properties needed for a quality, stable, edible food coating. The powders can also be functional ingredients in natural food additives.

When fresh produce is packaged in plastic, the plastic creates a ‘micro-atmosphere’, says Prof Olaniyi Fawole, from the University of Johannesburg. And that puts the brakes on what oxygen can do to the produce.

“Oxygen is the bad guy, it causes a lot of biochemical degradation. So we want to limit the oxygen that gets to the produce. And we also want to limit dehydration. Edible food coatings can potentially solve both the oxygen and dehydration problems in the cold chain,” he adds.

The ideal coating

“If you coat the product, you reduce the interference from a high oxygen atmosphere, because there is a barrier. Dehydration is prevented because the coating keeps the moisture on the inside,” says Fawole.

However, any such coating needs to have high antioxidant content to help prevent spoilage due to oxidation and should also contain antimicrobials. An edible coating should not interfere with the colour, appearance or taste of the product.

Fresh cuts of fresh fruits, which spoil even faster than whole fruit, and which are exposed to far more microbes and dehydration, can benefit even more from such a coating.

Microencapsulation to preserve antioxidants and polyphenols

The microencapsulation process preserved high antioxidant and polyphenol content from the passion fruit peels. This is significant, because antioxidants and other bioactive compounds are easily destroyed by industrial processes, pH, high storage temperature, oxygen, light, solvents, and metal ions.

The researchers used one of three carriers for the microencapsulation: gum arabic (GA), maltodextrin (MT), or waxy starch (WS). When they measured the encapsulation efficiency (EE) of the three carriers, they found EE’s from 82.64 to 87.18%. This indicates that antioxidants and polyphenols should be well preserved within the microcapsules of the coated powder particles.

Then they analysed each encapsulated powder in turn for antioxidants and polyphenol content.

Bioactive analysis results

Phytochemicals such as polyphenols are numerous in plants, and no single analysis can describe the antioxidant content of the powders. Instead, the researchers used two analyses to indicate to what extent the encapsulation process affected the antioxidant activity of the bioactive compounds contained in the microparticles.

The first, DPPH radical scavenging activity showed that all three carriers possessed 45.85 to 51.29 mM Trolox Equivalent (TE)/ g DM (WS).

The second, ferric reducing antioxidant power (FRAP), showed that the carriers possessed 32.30 - 37.47-mM TE/ g DM.

Trolox is a synthetic water-soluble antioxidant, and it has been used as a standard antioxidant for these antioxidant assays.

There is a drive towards alternatives to synthetic antioxidants as their safety could be questioned by consumers.

“The results mean that the encapsulated powders could be viable alternatives to synthetic antioxidants and can provide valuable properties such as antibrowning and anti-senescence behaviour. They also offer the additional benefit of being edible,” says Fawole.

To identify which polyphenols are present in the microencapsulated powders, the researchers ran metabolomic analyses, using liquid chromatography mass spectrometry (LC-MS).

Commercially important polyphenols preserved in the microencapsulated powders at useful levels are vanillic acid glucoside, quercetin, citric acid, gluconic acid and caffeic acid.

Microencapsulated powder of passion fruit peels show the functional properties required from high-quality natural food additives, preservatives, and ingredients of edible food coatings, researchers from the University of Johannesburg find.

CREDIT

Credit: Therese van Wyk and Olaniyi Amos Fawole. Data from study in Antioxidants. (https://doi.org/10.3390/antiox11081579) https://creativecommons.org/licenses/by/4.0/

Long shelf life, many doses, excellent solubility

“An edible coating or natural food preservative may be potent, but if its raw material is not stable, it is useless. For example, if it is hygroscopic, meaning it absorbs moisture, it is not suitable for industrial scale applications,” says Fawole.

“These microencapsulated powders are non-hygroscopic, for all three carriers. If these are well-packaged, and stored cool and dry, they should last up to six months. Also, you can open up a container, use what you need, close the container, and the rest will be stable. It won’t be necessary to use the contents of an entire container in one go.”

Overall, the detailed laboratory results indicate that microencapsulated powders from passion fruit peels are highly suitable as an active ingredient in edible food coatings, and natural food additives, particularly for ‘naked’ fresh fruit, and fresh cuts.

ENDS

This work is based on research supported by the National Research Foundation of South Africa (Grant Number: 129295), the Gauteng Department of Agriculture and Rural Development (GDARD) and the University Research Committee at the University of Johannesburg. APC was funded by the University of Johannesburg.

The antioxidants and polyphenols in organic passion fruit peels show significant potential to preserve fresh fruits and fresh cuts, in an edible food coating. Mr Gift Kabelo Kobo (Left) and Prof Olaniyi Amos Fawole (Right) from the Postharvest and Agroprocessing Research Centre (PARC) in the Department of Botany and Plant Biotechnology at the University of Johannesburg. In their research study published in the journal Antioxidants, they show that the powders have the properties needed to functionalize a quality, stable, edible food coating. The powders can also be functional ingredients in natural food additives.

CREDIT

Photo by Therese van Wyk, University of Johannesburg.

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JOURNAL

Antioxidants

DOI

10.3390/antiox11081579 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Micro-Encapsulation of Phytochemicals in Passion Fruit Peel Waste Generated on an Organic Farm: Effect of Carriers on the Quality of Encapsulated Powders and Potential for Value-Addition

Honey bee life spans are 50% shorter today than they were 50 years ago

A drop in longevity for lab-kept honey bees could help explain colony losses and lower honey production in recent decades

Peer-Reviewed Publication

UNIVERSITY OF MARYLAND

 

IMAGE: DESPITE IMPROVED STANDARDS FOR KEEPING HONEY BEES IN THE LAB, UMD RESEARCH SHOWS CAGED BEES HAVE SHORTER LIFESPANS THAN THEY DID 50 YEARS AGO, SUGGESTING SOMETHING OTHER THAN ENVIRONMENTAL CONDITIONS COULD BE CAUSING HIGHER RATES OF HONEY BEE COLONY LOSS FOR COMMERCIAL BEE KEEPERS. view more 

CREDIT: ANTHONY NEARMAN / UMD

A new study by University of Maryland entomologists shows that the lifespan for individual honey bees kept in a controlled, laboratory environment is 50% shorter than it was in the 1970s. When scientists modeled the effect of today’s shorter lifespans, the results corresponded with the increased colony loss and reduced honey production trends seen by U.S. beekeepers in recent decades.

Colony turnover is an accepted factor in the beekeeping business, as bee colonies naturally age and die off. But over the past decade, U.S. beekeepers have reported high loss rates, which has meant having to replace more colonies to keep operations viable. In an effort to understand why, researchers have focused on environmental stressors, diseases, parasites, pesticide exposure and nutrition.

This is the first study to show an overall decline in honey bee lifespan potentially independent of environmental stressors, hinting that genetics may be influencing the broader trends seen in the beekeeping industry. The study was published November 14, 2022, in the journal Scientific Reports.

“We're isolating bees from the colony life just before they emerge as adults, so whatever is reducing their lifespan is happening before that point,” said Anthony Nearman, a Ph.D. student in the Department of Entomology and lead author of the study. “This introduces the idea of a genetic component. If this hypothesis is right, it also points to a possible solution. If we can isolate some genetic factors, then maybe we can breed for longer-lived honey bees.”

Nearman first noticed the decline in lifespan while conducting a study with entomology associate professor Dennis van Engelsdorp on standardized protocols for rearing adult bees in the laboratory. Replicating earlier studies, the researchers collected bee pupae from honey bee hives when the pupae were within 24 hours of emerging from the wax cells they are reared in. The collected bees finished growing in an incubator and were then kept as adults in special cages.

Nearman was evaluating the effect of supplementing the caged bees’ sugar water diet with plain water to better mimic natural conditions when he noticed that, regardless of diet, the median lifespan of his caged bees was half that of caged bees in similar experiments in the 1970s. (17.7 days today versus 34.3 days in the 1970s.) This prompted a deeper review of published laboratory studies over the past 50 years.

“When I plotted the lifespans over time, I realized, wow, there’s actually this huge time effect going on,” Nearman said. “Standardized protocols for rearing honey bees in the lab weren’t really formalized until the 2000s, so you would think that lifespans would be longer or unchanged, because we’re getting better at this, right? Instead, we saw a doubling of mortality rate.”

Although a laboratory environment is very different from a colony, historical records of lab-kept bees suggest a similar lifespan to colony bees, and scientists generally assume that isolated factors that reduce lifespan in one environment will also reduce it in another. Previous studies had also shown that in the real world, shorter honey bee lifespans corresponded to less foraging time and lower honey production. This is the first study to connect those factors to colony turnover rates.

When the team modeled the effect of a 50% reduction in lifespan on a beekeeping operation, where lost colonies are replaced annually, the resulting loss rates were around 33%. This is very similar to the average overwinter and annual loss rates of 30% and 40% reported by beekeepers over the past 14 years.

Nearman and vanEngelsdorp noted that their lab-kept bees could be experiencing some sort of low-level viral contamination or pesticide exposure during their larval stage, when they’re brooding in the hive and worker bees are feeding them. But the bees have not shown overt symptoms of those exposures and a genetic component to longevity has been shown in other insects such as fruit flies.

The next steps for the researchers will be to compare trends in honey bee lifespans across the U.S. and in other countries. If they find differences in longevity, they can isolate and compare potential contributing factors such as genetics, pesticide use and presence of viruses in the local bee stocks.

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JOURNAL

Scientific Reports

DOI

10.1038/s41598-022-21401-2 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Water Provisioning Increases Caged Worker bee Lifespan and Caged Worker bees Living Half as Long as Observed 50 Years Ago

Weevil may save Great Britain up to £16.8m a year in management of invasive aquatic fern

A new CABI-led study suggests that a tiny weevil (Stenopelmus rufinasus) has huge benefits in saving Great Britain up to £16.8m in annual management costs of the invasive aquatic fern Azolla filiculoides

Peer-Reviewed Publication

CABI

 

IMAGE: THE INVASIVE AQUATIC FERN AZOLLA FILICULOIDES view more 

CREDIT: CABI

A new CABI-led study suggests that a tiny weevil (Stenopelmus rufinasus) has huge benefits in saving Great Britain up to £16.8m in annual management costs of the invasive aquatic fern Azolla filiculoides.

The research, published in the CABI Agriculture and Bioscience journal, estimates that without any biocontrol the expected yearly costs of managing A. filiculoides would range from £8.4m to £16.9m.

The scientists say that the impacts of naturalised S. rufinasus populations on A. filiculoides alone could be expected to reduce management costs to £800,000 to £1.6m a year.

However, they estimate A. filiculoides management costs to be lower still due to additional augmentative releases of the weevil that take place each summer, resulting in annual management costs of £31,500 to £45,800.

Azolla filiculoides, a type of floating water fern, was introduced to Great Britain at the end of the 19th century for ornamental use in ponds and aquaria. But its introduction into the wild has meant it has spread rapidly throughout England and Wales and to a lesser degree, Scotland.

The invasive aquatic fern outcompetes native species by forming a dense covering on the surface of the water. It blocks out light and can also deoxygenate water. A. filiculoides can also block canals, drains and overflows and may lead to an increased risk of flooding. It can affect irrigation systems – both by blocking their water supply and by reducing water quality.

It has been banned from sale in England and Wales since April 2014.

Its specialist natural enemy, S. rufinasus, was first recorded in 1921. It is suspected to have been introduced from America as a stowaway on A. filiculoides. Stenopelmus rufinasus is also reported to be present in numerous additional European countries where A. filiculoides is present.

The study sought to estimate the management cost savings resulting from the presence of S. rufinasus as a biocontrol agent in Great Britain. This includes the value of additional augmentative releases of the weevil made since the mid-2000s, compared with the expected costs of control in the absence of S. rufinasus.

Corin Pratt, lead author and Invasive Species Management Researcher at CABI, said, “The unintentional introduction of the weevil S. rufinasus to Great Britain is estimated to have resulted in millions of pounds of savings annually in management costs for A. filiculoides.

“Additional augmentative releases of the weevil provide further net cost savings, tackling A. filiculoides outbreaks and bolstering naturalised populations.

“The use of herbicides in the aquatic environment is likely greatly reduced due to A. filiculoides biocontrol. Although somewhat climate-limited at present in Great Britain, climate change may result in even more effective biocontrol of A. filiculoides by S. rufinasus.

“This has been observed in warmer regions such as South Africa, where the plant is no longer considered a threat since the introduction of S. rufinasus.”

The scientists conclude by arguing that in the absence of the specialist weevil S. rufinasus, A. filiculoides could be expected to be the dominant aquatic macrophyte in Great Britain. This would require extensive, costly management and likely widespread use of herbicides in the aquatic environment.

They state that the estimated benefit to cost ratio of augmentative S. rufinasus releases to be of 43.7:1 to 88.4:1

 

Full paper reference

Corin Pratt, Suzy Wood, Kate Constantine, ‘A century of Azolla filiculoides biocontrol: The economic value of Stenopelmus rufinasus to Great Britain,’ CABI Agriculture and Bioscience, 14 November 2022, DOI: 10.1186/s43170-022-00136-0

The paper is available to view open access from 00:01HRS UK time, 14 November 2022 here: https://cabiagbio.biomedcentral.com/articles/10.1186/s43170-022-00136-0

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JOURNAL

CABI Agriculture and Bioscience

DOI

10.1186/s43170-022-00136-0 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

A century of Azolla filiculoides biocontrol: The economic value of Stenopelmus rufinasus to Great Britain

ARTICLE PUBLICATION DATE

14-Nov-2022

Study of ‘polluted’ white dwarfs finds that stars and planets grow together

Peer-Reviewed Publication

UNIVERSITY OF CAMBRIDGE

 

IMAGE: A TEAM OF ASTRONOMERS HAVE FOUND THAT PLANET FORMATION IN OUR YOUNG SOLAR SYSTEM STARTED MUCH EARLIER THAN PREVIOUSLY THOUGHT, WITH THE BUILDING BLOCKS OF PLANETS GROWING AT THE SAME TIME AS THEIR PARENT STAR. view more 

CREDIT: AMANDA SMITH

A team of astronomers have found that planet formation in our young Solar System started much earlier than previously thought, with the building blocks of planets growing at the same time as their parent star.  

A study of some of the oldest stars in the Universe suggests that the building blocks of planets like Jupiter and Saturn begin to form while a young star is growing. It had been thought that planets only form once a star has reached its final size, but new results, published in the journal Nature Astronomy, suggests that stars and planets ‘grow up’ together.

The research, led by the University of Cambridge, changes our understanding of how planetary systems, including our own Solar System, formed, potentially solving a major puzzle in astronomy.

“We have a pretty good idea of how planets form, but one outstanding question we’ve had is when they form: does planet formation start early, when the parent star is still growing, or millions of years later?” said Dr Amy Bonsor from Cambridge’s Institute of Astronomy, the study’s first author.

To attempt to answer this question, Bonsor and her colleagues studied the atmospheres of white dwarf stars – the ancient, faint remnants of stars like our Sun – to investigate the building blocks of planet formation. The study also involved researchers from the University of Oxford, the Ludwig-Maximilians-Universität in Munich, the University of Groningen and the Max Planck Institute for Solar System Research, Gottingen.

“Some white dwarfs are amazing laboratories, because their thin atmospheres are almost like celestial graveyards,” said Bonsor.

Normally, the interiors of planets are out of reach of telescopes. But a special class of white dwarfs – known as ‘polluted’ systems – have heavy elements such as magnesium, iron, and calcium in their normally clean atmospheres.

These elements must have come from small bodies like asteroids left over from planet formation, which crashed into the white dwarfs and burned up in their atmospheres. As a result, spectroscopic observations of polluted white dwarfs can probe the interiors of those torn-apart asteroids, giving astronomers direct insight into the conditions in which they formed.

Planet formation is believed to begin in a protoplanetary disc – made primarily of hydrogen, helium, and tiny particles of ices and dust – orbiting a young star. According to the current leading theory on how planets form, the dust particles stick to each other, eventually forming larger and larger solid bodies. Some of these larger bodies will continue to accrete, becoming planets, and some remain as asteroids, like those that crashed into the white dwarfs in the current study.

The researchers analysed spectroscopic observations from the atmospheres of 200 polluted white dwarfs from nearby galaxies. According to their analysis, the mixture of elements seen in the atmospheres of these white dwarfs can only be explained if many of the original asteroids had once melted, which caused heavy iron to sink to the core while the lighter elements floated on the surface. This process, known as differentiation, is what caused the Earth to have an iron-rich core.

“The cause of the melting can only be attributed to very short-lived radioactive elements, which existed in the earliest stages of the planetary system but decay away in just a million years,” said Bonsor. “In other words, if these asteroids were melted by something which only exists for a very brief time at the dawn of the planetary system, then the process of planet formation must kick off very quickly.”

The study suggests that the early-formation picture is likely to be correct, meaning that Jupiter and Saturn had plenty of time to grow to their current sizes.

“Our study complements a growing consensus in the field that planet formation got going early, with the first bodies forming concurrently with the star,” said Bonsor. “Analyses of polluted white dwarfs tell us that this radioactive melting process is a potentially ubiquitous mechanism affecting the formation of all extrasolar planets.

“This is just the beginning – every time we find a new white dwarf, we can gather more evidence and learn more about how planets form. We can trace elements like nickel and chromium and say how big an asteroid must have been when it formed its iron core. It’s amazing that we’re able to probe processes like this in exoplanetary systems.”

Amy Bonsor is a Royal Society University Research Fellow at the University of Cambridge. The research was supported in part by the Royal Society, the Simons Foundation, and the European Research Council.

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JOURNAL

Nature Astronomy

DOI

10.1038/s41550-022-01815-8 

ARTICLE TITLE

Rapid formation of exoplanetesimals revealed by white dwarfs

ARTICLE PUBLICATION DATE

14-Nov-2022

Artemisia Gentileschi’s 1616 nude to be digitally unveiled

By TRISHA THOMAS

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Restorer Elizabeth Wicks works on the "Allegory of Inclination", a 1616 work by Artemisia Gentileschi, in the Casa Buonarroti Museum, in Florence, Italy, Wednesday, Nov. 9, 2022. Restorers have begun a six-month project on the "Allegory of Inclination" using modern techniques including x-rays and UV infrared research to go beneath the veils painted over the original to cover nudities and discover the work as Gentileschi painted it. (AP Photo/Andrew Medichini)

FLORENCE, Italy (AP) — Art restorers in the Italian city of Florence have begun a six-month project to clean and virtually “unveil” a long-censored nude painting by Artemisia Gentileschi, one of the most prominent women in the history of Italian art.

Swirling veils and drapery were added to the “Allegory of Inclination” some 70 years after Gentileschi painted the life-size female nude, believed to be a self-portrait, in 1616.

The work to reveal the image as originally painted comes as Gentileschi’s contribution to Italian Baroque art is getting renewed attention in the #MeToo era, both for her artistic achievements but also for breaking into the male-dominated art world after being raped by one of her art teachers.

Her work was featured in a 2020 exhibit at the National Gallery in London.

“Through her, we can talk about how important it is to restore artwork, how important it is to restore the stories of women to the forefront,” said Linda Falcone, coordinator of the Artemisia Up Close project.

“Allegory of Inclination” originally was commissioned for the family home of Michelangelo Buonarroti the Younger, the great-nephew of the famed artist. The building later became the Casa Buonarotti museum, and the painting was displayed until recently on the ceiling in a gilded frame. When lead conservator Elizabeth Wick removed the painting in late September, a shower of 400-year-old dust was released.

Wick’s team of restorers is using ultraviolet light, diagnostic imaging and X-rays to differentiate Gentileschi’s brush strokes from those of the artist that covered the nudity. The public can watch the project underway at the museum through April 23.

Restorers won’t be able to remove the veils because the cover-up was done too soon after the original, raising the risk that Gentileschi’s painting would be damaged in the process.

Instead, the restoration team plans to create a digital image of the original version that will be displayed in an exhibition on the project opening in September 2023.

Gentileschi arrived in Florence shortly after the trial in Rome of her rapist, during which the then-17-year-old was forced to testify with ropes tied around her fingers that were progressively tightened in a test of her honesty.

She also had to endure a physical examination in the courtroom behind a curtain to confirm that she was no longer a virgin. Eventually, her rapist was convicted and sentenced to eight months in prison.

“Somebody else would have been crushed by this experience,” Wick said. “But Artemisia bounces back. She comes up to Florence. She gets this wonderful commission to paint a full-length nude figure for the ceiling of Casa Buonarroti. So, I think she’s showing people, ‘This is what I can do.’”

While in Florence, Gentileschi also won commissions from the Medici family. Her distinctive, dramatic and energetic style emerged, taking inspiration from the most renowned Baroque painter of the time, Caravaggio. Many of her paintings featured female heroines, often in violent scenes and often nude.

She was 22 when she painted “Allegory of Inclination,” which was commissioned by Michelangelo Buonarroti the Younger. Another member of the family, Leonardo Buonarroti, decided to have it embellished to protect the sensibilities of his wife and children.

“This is one of her first paintings. In the Florentine context, it was her debut painting, the same year she was then accepted into the Academy of Drawing, which was the first drawing academy in Europe at the time,” Falcone said.

With the younger Michelangelo as her patron, Gentileschi gained entry to the cultural milieu of the time.

“She was able to hobnob with Galileo and with other great thinkers. So this almost illiterate woman was suddenly at the university level, producing works of art that were then, you know, appreciated by the Grand Duke,” Falcone said. “And she became a courtly painter from then on.”

Footprints claimed as evidence of ice age humans in North America need better dating, new research shows

The preserved footprints found in New Mexico’s Lake Otero Basin would upend scientific understanding of how, and when, humans first arrived in North America, if they are accurately dated. A new study brings the age claim into question.

Peer-Reviewed Publication

DESERT RESEARCH INSTITUTE

The wide expanse of an ancient lakebed in New Mexico holds the preserved footprints of life that roamed millennia ago. Giant sloths and mammoths left their mark, and alongside them, signs of our human ancestors. Research published in September 2021 claimed that these footprints are “definitive evidence of human occupation of North America” during the last ice age, dating back to between 23 and 21 thousand years ago. Now, a new study disputes the evidence of such an early age.

Scientists from DRI, Kansas State University, the University of Nevada, Reno, and Oregon State University caution in Quaternary Research that the dating evidence is insufficient for claims that would so radically alter our understanding of when, and how, humans first arrived in North America. Using the same dating method and materials, the new study shows that the footprints could have been left thousands of years later than originally claimed.

“I read the original Science article on the human footprints at White Sands and was initially struck not only by how tremendous the footprints were on their own, but how important accurate dating would be,” says Charles Oviatt, emeritus professor of geology at Kansas State University and one of the new study’s authors. “I saw potential problems with the scientific tests of the dates reported in the Science paper.”

“It really does throw a lot of what we think we know into question,” says David Rhode, Ph.D., a paleoecologist at DRI and co-author of the new study. “That’s why it’s important to really nail down this age, and why we’re suggesting that we need better evidence.”

Archaeologists and historians use a number of methods to determine the timing of historic events. Based on these methods, scientists tend to agree that the earliest known dates of humanity’s colonization of North America lie between 14 and 16 thousand years ago, after the last ice age. If the original claims are correct, current chronological models in fields as varied as paleogenetics and regional geochronology would need to be reevaluated.

“23 to 21 thousand years ago is in a timeframe where you need to really pay attention to how people got into North America,” says Rhode. “At that time, there was a huge, mile-high mountain range of ice covering Canada to the north, and the pathway down the Pacific Coast wasn’t very accommodating either – so it may have been that people had to come here much earlier than that.”  

By studying ancient DNA from human fossils and using rates of genetic change (a sort of molecular clock using DNA), paleogeneticists surmise that the American Southwest was first occupied no earlier than 20 thousand years ago. If the footprints are older, it throws into question the use and integrity of these genetic models. It’s possible that the ages from one study at a single site in a New Mexico lake basin are valid, and that age estimates from a variety of other fields are invalid, the authors write, but more robust evidence is needed to confirm the claims.

At the center of the debate are the tiny seeds of an aquatic plant used to age the footprints. The timeframe for the seeds was identified using radiocarbon dating methods, in which researchers examine a type of carbon known as Carbon-14. Carbon-14 originates in the atmosphere and is absorbed by plants through photosynthesis. These carbon isotopes decay at a constant rate over time, and comparing the amount of Carbon-14 in the atmosphere to the amount present in fossilized plant material allows scientists to determine their approximate age. But the plant species used, Ruppia cirrhosa, grows underwater and therefore obtains much of its carbon for photosynthesis not directly from the atmosphere as terrestrial plants do, but from dissolved carbon atoms in the water.

“While the researchers recognize the problem, they underestimate the basic biology of the plant,” says Rhode. “For the most part, it’s using the carbon it finds in the lake waters. And in most cases, that means it’s taking in carbon from sources other than the contemporary atmosphere – sources which are usually pretty old.”

This method is likely to give radiocarbon-based age estimates of the plant that are much older than the plants themselves. Ancient carbon enters the groundwater of the Lake Otero basin from eroded bedrock of the Tularosa Valley and the surrounding mountains, and occurs in extensive calcium carbonate deposits throughout the basin.

The authors demonstrated this effect by examining Ruppia plant material with a known age from the same region. Botanists collected living Ruppia plants from a nearby spring-fed pond in 1947 and archived them at the University of New Mexico herbarium. Using the same radiocarbon dating method, the plants that were alive in 1947 returned a radiocarbon date suggesting they were about 7400 years old, an offset resulting from the use of ancient groundwater by the plant. The authors note that if the ages of the Ruppia seeds dated from the human footprints were also offset by roughly 7400 years, their real age would be between 15 and 13 thousand years old – a date which aligns with ages of several other known early North American archaeological sites.

The dating of the footprints can be resolved through other methods, including radiocarbon dating of terrestrial plants (which use atmospheric carbon and not carbon from groundwater) and optically stimulated luminescence dating of quartz found in the sediment, the authors write.

“These trackways really are a great resource for understanding the past, there’s no doubt about that,” says Rhode. “I’d love to see them myself. I’m just cautious about the ages that the researchers put to them.”

 

 

More information:

The full study, A critical assessment of claims that human footprints in the Lake Otero basin, New Mexico date to the Last Glacial Maximum, is available from Quaternary Research: https://doi.org/10.1017/qua.2022.38

Study authors include Charles Oviatt (K-State), David B. Madsen (UNR), David Rhode (DRI), and Loren G. Davis (OSU).

 

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About DRI

The Desert Research Institute (DRI) is a recognized world leader in basic and applied environmental research. Committed to scientific excellence and integrity, DRI faculty, students who work alongside them, and staff have developed scientific knowledge and innovative technologies in research projects around the globe. Since 1959, DRI’s research has advanced scientific knowledge on topics ranging from humans’ impact on the environment to the environment’s impact on humans. DRI’s impactful science and inspiring solutions support Nevada’s diverse economy, provide science-based educational opportunities, and inform policymakers, business leaders, and community members. With campuses in Las Vegas and Reno, DRI serves as the non-profit research arm of the Nevada System of Higher Education. For more information, please visit www.dri.edu.

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JOURNAL

Quaternary Research

DOI

10.1017/qua.2022.38 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

People

ARTICLE TITLE

A critical assessment of claims that human footprints in the Lake Otero basin, New Mexico date to the Last Glacial Maximum