Study links household chaos with sleep quality among teens with ADHD symptoms

New study explored the important role of household structure and stability for healthy sleep in teens

AMERICAN ACADEMY OF SLEEP MEDICINE

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DARIEN, IL – A new study to be presented at the SLEEP 2024 annual meeting found that household chaos and sleep hygiene are important factors in the relationship between sleep quality and ADHD symptoms in teens.

Results of structural equation modeling show that household chaos and sleep hygiene were significant mediators of the relationship between ADHD symptoms and poor sleep quality. The results suggest that improving the daily routine and stability of the household is an important strategy to consider when seeking to improve sleep quality in adolescents with symptoms of attention-deficit/hyperactivity disorder.

“These results begin to explicate some contextual factors that may help explain the increase in sleep difficulties observed in youth with higher symptoms of ADHD,” said lead author and co-principal investigator Jamie Flannery, who is a doctoral candidate in developmental psychology at the University of Notre Dame in South Bend, Indiana. “It suggests that when ADHD symptoms are high, aspects of the individual — poor sleep hygiene — and the familial environment — household chaos — are associated with poor sleep quality in adolescents.”

The American Academy of Sleep Medicine recommends that teenagers 13 to 18 years of age should sleep 8 to 10 hours. Healthy sleep is associated with better health outcomes including: improved attention, behavior, learning, memory, emotional regulation, quality of life, and mental and physical health.

The researchers collected data from 259 pairs of mothers and adolescents from across the U.S. Mothers used a scale to rate the severity of their adolescent’s ADHD symptoms, while adolescents completed three separate surveys about sleep quality, home environment and sleep hygiene.

Flannery noted that it’s important for adolescents and their families to know that it is more than just individual characteristics that can impact their sleep.

“While improving sleep hygiene in youths with ADHD may be beneficial, a household characterized by a lack of structure, routine and stability may undermine the adolescent’s sleep quality,” Flannery said.

The research abstract was published recently in an online supplement of the journal Sleep and will be presented Monday, June 3, during SLEEP 2024 in Houston. SLEEP is the annual meeting of the Associated Professional Sleep Societies, a joint venture of the American Academy of Sleep Medicine and the Sleep Research Society.

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Abstract Title: Examining the Relation Between ADHD Symptoms and Poor Sleep Quality: The Role of Household Chaos and Sleep Hygiene

Abstract ID: 0989

Poster Presentation Date: Monday, June 3, from 11-11:45 a.m. CDT, Board 212

Presenter: Jamie Flannery, M.A.

About the Associated Professional Sleep Societies, LLC

The APSS is a joint venture of the American Academy of Sleep Medicine and the Sleep Research Society. The APSS organizes the SLEEP annual meeting each June (sleepmeeting.org).

About the American Academy of Sleep Medicine

Established in 1975, the AASM advances sleep care and enhances sleep health to improve lives. The AASM has a combined membership of 12,000 accredited sleep centers and individuals, including physicians, scientists and other health care professionals who care for patients with sleep disorders. As the leader in the sleep field, the AASM sets standards and promotes excellence in sleep medicine health care, education and research (aasm.org).

About the Sleep Research Society 

The SRS is a professional membership society that advances sleep and circadian science. The SRS provides forums for the exchange of information, establishes and maintains standards of reporting and classifies data in the field of sleep research, and collaborates with other organizations to foster scientific investigation on sleep and its disorders. The SRS also publishes the peer-reviewed, scientific journals Sleep and Sleep Advances (sleepresearchsociety.org).

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JOURNAL

SLEEP

DOI

10.1093/sleep/zsae067.0989 

METHOD OF RESEARCH

Survey

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Examining the Relation Between ADHD Symptoms and Poor Sleep Quality: The Role of Household Chaos and Sleep Hygiene

Sleep moderates the link between bullying and suicide in teens

Sleep duration is an important preventative factor among adolescents who experience online and in-school bullying

AMERICAN ACADEMY OF SLEEP MEDICINE

DARIEN, IL – A new study to be presented at the SLEEP 2024 annual meeting found that sleep duration significantly moderates the association between bullying and suicide attempts among adolescents in the U.S.

The study revealed that 15% of adolescents reported they were bullied at school, and 16% were bullied electronically; 10.2% reported they had attempted suicide during the past year; and 77.3% did not adhere to sleep duration recommendations. Adolescents who reported 4 hours of sleep or less per night were two times as likely to attempt suicide, and sleep duration significantly moderated the association between bullying in school and suicide attempts.

“Adolescent suicide and suicide attempts constitute a serious public health crisis in the United States,” said lead author Marie-Rachelle Narcisse, who has a doctorate in public health and is an assistant professor in the Warren Alpert School of Medicine of Brown University and a research scientist at the E.P. Bradley Hospital COBRE Center for Sleep and Circadian Rhythms in Child and Adolescent Mental Health in Providence, Rhode Island. “The fact that sleep duration significantly modifies the association between bullying and suicide attempts is a remarkable finding.”

According to the Centers for Disease Control and Prevention, suicide is the second-leading cause of death among teens between 14 and 18 years of age. The American Academy of Sleep Medicine recommends that teens should sleep 8 to 10 hours on a regular basis to promote optimal health. Insufficient sleep in teenagers is associated with increased risk of self-harm, suicidal thoughts, and suicide attempts.

The study involved an analysis of data from the 2021 Youth Risk Behavior Surveillance System, comprising a nationally representative sample of 17,134 participants. The researchers analyzed the relationships among electronic or school bullying, sleep duration, and past-year suicide attempts among adolescents between 12 and 18 years of age. Results were adjusted for potential confounders including sex, age, race/ethnicity, screen time, and poor mental health.

Adolescents who were bullied in school or electronically were three times as likely to attempt suicide compared with those who were not bullied. Those reporting no bullying showed reduced likelihood of suicide attempts as sleep duration increased to 7 hours, and the likelihood remained constant with more hours of sleep.

According to Narcisse, the results emphasize that sleep duration is an important target for interventions to reduce suicide in teens.

“If improved sleep duration can inhibit the adverse effect of bullying on suicide attempts, then interventions aimed at improving sleep duration could potentially have a positive influence on lowering suicide risk among adolescents,” said Narcisse.

This study was supported by a Centers of Biomedical Research Excellence grant from the National Institute of General Medical Sciences. The research abstract was published recently in an online supplement of the journal Sleep and will be presented Monday, June 3, and Wednesday, June 5, during SLEEP 2024 in Houston. SLEEP is the annual meeting of the Associated Professional Sleep Societies, a joint venture of the American Academy of Sleep Medicine and the Sleep Research Society.

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Abstract Title: Sleep Duration Moderates the Association Between Bullying and Suicide Attempts Among U.S. Adolescents

Abstract ID: 0813

Oral Presentation Date: Monday, June 3, 4:30 to 4:45 p.m. CDT, Room 362

Poster Presentation Date: Wednesday, June 5, 11-11:45 a.m. CDT, Board 168

Presenter: Marie-Rachelle Narcisse, Ph.D.

About the Associated Professional Sleep Societies, LLC

The APSS is a joint venture of the American Academy of Sleep Medicine and the Sleep Research Society. The APSS organizes the SLEEP annual meeting each June (sleepmeeting.org).

About the American Academy of Sleep Medicine

Established in 1975, the AASM advances sleep care and enhances sleep health to improve lives. The AASM has a combined membership of 12,000 accredited sleep centers and individuals, including physicians, scientists and other health care professionals who care for patients with sleep disorders. As the leader in the sleep field, the AASM sets standards and promotes excellence in sleep medicine health care, education and research (aasm.org).

About the Sleep Research Society 

The SRS is a professional membership society that advances sleep and circadian science. The SRS provides forums for the exchange of information, establishes and maintains standards of reporting and classifies data in the field of sleep research, and collaborates with other organizations to foster scientific investigation on sleep and its disorders. The SRS also publishes the peer-reviewed, scientific journals Sleep and Sleep Advances (sleepresearchsociety.org).

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JOURNAL

SLEEP

DOI

10.1093/sleep/zsae067.0813 

METHOD OF RESEARCH

Survey

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Sleep Duration Moderates the Association Between Bullying and Suicide Attempts Among U.S. Adolescents

Focus on cities will boost benefits of air pollution action for most vulnerable

IMPERIAL COLLEGE LONDON

Meeting UK air pollution targets by focussing on urban areas will maximise health benefits for the most deprived communities.

A study led by Imperial College London researchers shows that reducing typically urban sources of fine-particle air pollution like roads, wood burners, and machinery would also reduce inequalities in how different communities suffer the health impacts.

Air pollution can reach the lungs, causing short-term irritation and more harmful long-term impacts on heart and lung function. For people with existing conditions like heart failure and asthma, this can worsen already serious health problems.

Residents or workers in more deprived areas are more likely to suffer these conditions, and as such are  disproportionately impacted by air pollution.

The new study shows that while there are many ways to reduce the UK population’s exposure to air pollution overall, focusing on these typically urban sources benefits deprived areas more, reducing the health inequalities across the country. The research is published in Environmental Advances.

Lead researcher Dr Huw Woodward, from the Centre for Environmental Policy at Imperial College London, said: “People facing higher air pollution in deprived areas suffer health inequalities, which have a profound impact on their quality of life. Reducing air pollution will benefit everyone, but thinking more deeply about how we get there can also help us alleviate the impact on the most vulnerable in society.”

Reducing bias

There are several types of air pollution, including nitrous dioxide and fine particles. This study focused on a type of fine-particle pollution called PM2.5 (pollution particles that are less than 2.5 microns across).

The UK Environment Act of 2021 set a target for cutting the population’s exposure to PM2.5 by 35% by 2040, compared to 2018 levels. In practice, this means reducing the sources of the pollution, which include industry, road transport, energy production and agriculture.

Experts and policymakers use models to explore different ways of reaching the target by reducing pollution from these sources by different proportions. While all reductions in pollutant emissions will reduce the population’s exposure, previous studies have not considered how different ways of reaching the target would influence the health inequality.

To track how different scenarios impact the inequality, the team created a new metric, called the Indicator of Exposure Bias (IoEB). They paired this with the UK Integrated Assessment Model, used to investigate the impact of future emissions scenarios on air quality in England.

The team modelled several of these scenarios, including two that meet the 2040 target, and used the IoEB to assess their impact on the exposure bias. The ‘successful’ scenarios both achieved the target by reducing PM2.5 sources from all sectors, but one focused more on urban sources, including road transport and wood burners.

While both these scenarios reduced the exposure bias, the one focusing more on urban sources had a larger impact, reduced the bias by 59% (compared to 43% for the other scenario).

North-South divide

There is also a bias between Southern and Northern areas of England, with the former experiencing higher levels of PM2.5 air pollution. This bias is due to the south receiving a greater proportion of pollution from shipping channels and continental neighbours. The south of England has fewer deprived areas than the north, and as such this north-south divide in PM2.5 from non-UK sources reduces the overall bias towards deprived areas.

Despite this, deprived areas still experience higher levels of PM2.5­ pollution. Of the sources under English control, the bias towards deprived areas is greater than that assessed by considering all sources including those from outside of the UK.

The study looked at pollution on the level of populations, as individual exposure is very difficult to estimate accurately.

The team believe their new measure can be applied to different countries or regions using models that estimates population exposure and socio-economic status. This could allow policymakers to identify the sectors which contribute disproportionately to the bias in exposure and to identify effective strategies for reducing this bias.

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JOURNAL

Environmental Advances

DOI

10.1016/j.envadv.2024.100529 

ARTICLE TITLE

Assessing PM2.5 exposure bias towards deprived areas in England using a new indicator

Novel mobile air monitoring technology yields greater insight into post-disaster pollution levels

Study was the first to apply the method to a real-world disaster—a major industrial fire in Indiana

TEXAS A&M UNIVERSITY

A team including researchers from the Texas A&M University School of Public Health and School of Medicine has found that high resolution mass spectrometry could be a valuable tool for identifying and assessing air-borne contaminants produced by natural and man-made disasters. Their findings were published in the Journal of Exposure Science & Environmental Epidemiology.

The scientists used high resolution mass spectrometry—a highly accurate means of identifying molecular compounds in a sample—in fall 2023 to identify volatile organic compounds (VOCs) present following a major fire that occurred on April 11, 2023, in Richmond, Indiana. The fire and subsequent explosions at the My Way plastic recycling plant led to the evacuation of residents in a half-mile radius from the facility. The fire was sufficiently large to be captured in satellite images, and debris was found as far away as Oxford, Ohio, nearly 30 miles from the site.

“The Environmental Protection Agency does extensive, long-term recovery work after disasters like this,” said researcher Natalie Johnson, PhD, from the Department of Environmental & Occupational Health. “We believe that our study proves this method produces accurate data very quickly, which could help officials determine the best evacuation zones following a disaster.”

The research was funded by the National Institute of Environmental Health Sciences. Others on the team were Eva C.M. Vitucci, PhD, a postdoctoral student in the Department of Environmental and Occupational Health, Carolyn L. Cannon, MD, PhD, from the Texas A&M School of Medicine and two colleagues from Carnegie Mellon University.

The team monitored the air within and bordering the half-mile evacuation zone using high resolution mass spectrometry and non-targeted analysis, a relatively new computational tool for detecting and identifying chemicals in environmental exposures.

Johnson said this approach is an improvement over the ones currently used in the field, which frequently have issues with instrument sensitivity, time limitations in sampling and ability to characterize a broad range of pollutants. Non-targeted analysis, on the other hand, quickly and effectively identifies all the compounds—even those not known to be present initially. While this approach has shown promise in previous tests, this was the first time it was applied to a real-world disaster.

After receiving training and guidance on the Hzard Comparison Module by Antony Williams of US-EPA’s Center for Computational Toxicology and Exposure, the team used the module to create a risk assessment from the VOCs present. Their analysis identified 46 VOCs, and the average levels in the area studied were higher than those they found in Middleton, Ohio, about 520 miles away.

The levels of hydrogen cyanide—which disrupts the body’s use of oxygen and can cause death—and four other VOCs were at least 1.8-fold higher near the incidence site. Of the 46 VOCs, approximately 45 percent were classified as high hazards, and 39 percent were classified as very high hazards.

“Each of the VOC levels we detected were individually below the hazard thresholds for single exposures, but we currently do not fully understand what the hazard thresholds would be for exposure to VOC mixtures such as these,” Johnson said.

She noted that facilities such as My Way contain large amounts of harmful toxins, and a large number of different toxins, which makes prediction of the VOCs produced in fires and similar disasters difficult.

“Fires at recycling plants and other typically smaller-scale disasters are usually overlooked as contributors to pollution levels, but they also are happening more frequently across the United States,” Johnson said. “This makes research and the application of research findings a pressing public health issue.”

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JOURNAL

Journal of Exposure Science & Environmental Epidemiology

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

The application of PTR-MS and non-targeted analysis to characterize VOCs emitted from a plastic recycling facility fire

 

Bezos Earth Fund Grant creates sustainable protein research hub at NC State

NORTH CAROLINA STATE UNIVERSITY

The Bezos Center for Sustainable Protein launched today at North Carolina State University. The Bezos Earth Fund awarded NC State $30 million over five years to lead a center of excellence to create a biomanufacturing hub for dietary proteins that are environmentally friendly, healthy, tasty, and affordable. The Earth Fund has committed $100 million to establish a network of open-access research and development centers focused on sustainable protein alternatives, expanding consumer choices. 

The center will engage partners from academia and industry to research, create, and commercialize new technologies, provide training for the emerging industry workforce, and gauge consumers’ protein preferences.

“As a land-grant university in a state with significant animal agriculture, NC State is uniquely positioned to help shape the future of sustainable food production,” said Chancellor Randy Woodson. “We’re thankful for the support from the Bezos Earth Fund that will help drive economic and workforce development in this critical area of sustainable protein production in order to feed a growing world population in an economically and environmentally sustainable way. The state legislature's funding of the Food Innovation Lab in Kannapolis and new facilities in the College of Engineering have made NC State incredibly competitive for this grant.”

Protein is essential to human health, whether it comes from animal or plant sources. Without the amino acids in protein, our cells, tissues and organs can’t function. And as the global population expands, the health of both humans and the planet will increasingly depend on widespread availability of proteins that taste good and are produced in ways that reduce greenhouse gas emissions and protect nature.

“Food production is the second largest source of greenhouse gas emissions, so it’s critical we find ways to feed a growing population without degrading the planet,” said Andrew Steer, President and CEO of the Earth Fund. “Sustainable protein has tremendous potential but more research is needed to reduce the price and boost the flavor and texture to ensure nutritious, affordable products are available. It's about choice.”

The grant funding will support research on three types of sustainable proteins: plant-based products; precision fermentation to produce proteins and nutrients that can be used in food formulations; and cultivated meat grown from animal cells.

“Feeding a growing world requires producing tasty proteins that won’t further degrade nature,”  said Andy Jarvis, the Earth Fund’s Director of Future of Food. “These centers will advance open-source, sustainable protein R&D to benefit consumer choice while protecting our planet.”

“This effort is all about expanding the sustainable protein knowledge base and ecosystem,” said Rohan Shirwaiker, James T. Ryan Professor of Industrial and Systems Engineering at NC State, principal investigator on the grant, and co-director of the center. “The center’s capabilities and partnerships will add a new dimension to expand NC State’s biotechnology and advanced manufacturing expertise.”  

The center will also provide more reasons for biomanufacturing firms to locate in North Carolina, generating jobs and economic growth. The grant funding will help prepare the workforce for jobs in advanced food technology through various university and community college partnerships, while industry partnerships will support food production and processing, including small companies and start-ups.

“This is a significant opportunity for North Carolina to not only be a state with a thriving animal-sourced foods sector, but also one where it is a powerhouse in complementary proteins, building new industry and driving economic growth for the state,” said Bill Aimutis, co-principal investigator on the grant and co-director of the new center who has extensive experience working with sustainable protein producers and start-up companies. “With the center we are looking to develop solutions that will provide greater diversity of choices for consumers that are both tasty and sustainable.”

NC State will work with academic partners N.C. A&T State University, the University of North Carolina at Pembroke, Duke University, and Forsyth Tech Community College on the research, workforce development, and community engagement efforts. More than 20 industry partners will also be part of the center, which will facilitate technology transfer and student internships and mentorships.

This announcement builds on the Bezos Earth Fund’s $1 billion grant commitment to help transform food and agricultural systems to support healthy lives without degrading the planet, which also includes efforts to reduce emissions from livestock.

More information on the center and its work is available.

 

U of T researchers discover ‘trojan horse’ virus hiding in human parasite

UNIVERSITY OF TORONTO

 

IMAGE: 

UNDERGRADUATE STUDENT PURAV GUPTA AND ASSISTANT PROFESSOR ARTEM BABAIAN.

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CREDIT: UNIVERSITY OF TORONTO

An international team led by researchers at the University of Toronto has found a new RNA virus that they believe is hitching a ride with a common human parasite.

The virus, called Apocryptovirus odysseus, along with 18 others that are closely related to it, was discovered through a computational screen of human neuron data – an effort aimed at elucidating the connection between RNA viruses and neuroinflammatory disease. The virus is associated with severe inflammation in humans infected with the parasite Toxoplasma gondii, leading the team to hypothesize that it exacerbates toxoplasmosis disease.

“We discovered A. odysseus in human neurons using the open-science Serratus platform to search through more than 150,000 RNA viruses” said Purav Gupta, first author on the study, recent high school graduate and current undergraduate student at U of T’s Donnelly Centre for Cellular and Biomolecular Research. “Serratus identifies RNA viruses from public data by flagging an enzyme called RNA-dependent RNA polymerase, which facilitates replication of viral RNA. This enzyme allows the virus to reproduce itself and for the infection to spread.”

The study was published recently in the journal Virus Evolution.

The parasite T. gondii is far-reaching, infecting an estimated one-third of the global population. It can live in any non-blood cell type, including neurons, forming cysts inside cells. The parasite is transmitted to nearby cells when the infected cell ruptures.

T. gondii infections often go unnoticed because they only lead to symptoms in rare cases. Regardless, toxoplasmosis merits investigation considering how widespread it is and the potential effects it may have on pregnant women and those who are immunocompromised, Gupta said.

“We believe the virus and parasite work hand-in-hand to cause disease in the human host, where the virus hides inside the parasite, like a soldier in a trojan horse, to gain entry to the human brain,” said Gupta. “Our research marks the first time that scientists have connected toxoplasmosis to a virus.”

The newly discovered A. odysseus is found in two hypervirulent strains of the T. gondii parasite, referred to as RUB and COUGAR.

RUB has been documented in French Guinea to cause severe fever and organ failure, while COUGAR has been shown in British Columbia to be connected to ocular toxoplasmosis – the leading cause of infectious blindness. Researchers found the strains in different geographical locations at different times, demonstrating their potentially wide-ranging impacts.

Symptoms of toxoplasmosis can be aggravated by a hyperactivated human immune response. The virus-carrying parasite triggers this type of response when the immune system senses the foreign RNA of the virus.

“The group of 19 RNA viruses we found are strong biomarkers for parasitic infection,” said Artem Babaian, principal investigator on the study and assistant professor of molecular genetics at the Donnelly Centre and the Temerty Faculty of Medicine. “It’s obvious now that the A. odysseus virus could be a valuable marker of disease-causing infections, like severe toxoplasmosis, in humans or other animals. The next step is to test if this raises the possibility that treating a parasite's viruses could be an effective means of treating symptoms that arise from parasitic infections.”

Zoonotic viruses that infect other living things in our environment in order to reach us are expected to cause the majority of emerging infectious diseases in humans, Babaian noted. “This study underscores the importance of looking beyond the viruses that infect humans directly into the extended virome,” he said.

This research was supported by the Canadian Institutes of Health Research.

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JOURNAL

Virus Evolution

DOI

10.1093/ve/veae040 

ARTICLE TITLE

A parasite odyssey: An RNA virus concealed in Toxoplasma gondii

 

Clues to mysterious disappearance of North America’s large mammals 50,000 years ago found within ancient bone collagen

Dr Mariya Antonosyan, Dr Torben Rick, and Prof Nicole Boivin are co-authors of a new Frontiers in Mammal Science article in which they used new methods to identify fossil bone fragments housed at the Smithsonian’s National Museum of Natural History.

FRONTIERS

 

IMAGE: 

USNM 23792, MAMMUTHUS PRIMIGENIUS, OR WOOLLY MAMMOTH (COMPOSITE), DEPARTMENT OF PALEOBIOLOGY, SMITHSONIAN INSTITUTION. 

view more 

CREDIT: PHOTO BY GARY MULCAHEY.

50,000 years ago, North America was ruled by megafauna. Lumbering mammoths roamed the tundra, while forests were home to towering mastodons, fierce saber-toothed tigers and enormous wolves. Bison and extraordinarily tall camels moved in herds across the continent, while giant beavers plied its lakes and ponds. Immense ground sloths weighing over 1,000 kg were found across many regions east of the Rocky Mountains.

And then, sometime at the end of the Last Ice Age, most of North America’s megafauna disappeared. How and why remains hotly contested. Some researchers believe the arrival of humans was pivotal. Maybe the animals were hunted and eaten, or maybe humans just altered their habitats or competed for vital food sources. But other researchers contend that climate change was to blame, as the Earth thawed after several thousand years of glacial temperatures, changing environments faster than megafauna could adapt. Disagreement between these two schools has been fierce and debates contentious.

Despite decades of study, this Ice Age mystery remains unsolved. We simply don’t have sufficient evidence at this point to rule out one scenario or the other – or indeed other explanations that have been proposed (eg disease, an impact event from a comet, a combination of factors). One of the reasons is that many of the bones through which we track the presence of megafauna are fragmented and difficult to identify. While some sites preserve megafaunal remains really well, conditions at others have been tough on the animal bones, wearing them down into smaller fragments that are too altered to identify. These decay processes include exposure, abrasion, breakage, and biomolecular decay.

Such problems leave us lacking critical information about where particular megafaunal species were distributed, exactly when they disappeared, and how they responded to the arrival of humans or the climatic alteration of environments in the Late Pleistocene.

Applying modern technology to old bones

Our work has set out to address this information deficit. To do so, we have turned our attention to the exceptional collections of the Smithsonian National Museum of Natural History in Washington, DC. Housing the findings of numerous archaeological excavations conducted over the past hundred years, the Museum is an extraordinary reservoir of animal bones that are deeply relevant to the question of how North America’s megafauna went extinct. Yet many of these remains are heavily fragmented and unidentifiable, meaning their ability to shed light on this question has, at least up until now, been limited.

Fortunately, recent years have seen the development of new biomolecular methods of archaeological exploration. Rather than heading out to excavate new sites, archaeologists are increasingly turning their attention to the scientific laboratory, using new techniques to probe existing material. One such novel technique is called ZooMS – short for Zooarchaeology by Mass Spectrometry. The method relies on the fact that while most of its proteins degrade quickly after an animal dies, some, like bone collagen, can preserve over long time periods. Since collagen proteins frequently differ in small, subtle ways between different taxonomic groups of animals, and even individual species, collagen sequences can provide a kind of molecular barcode to help identify bone fragments that are otherwise unidentifiable. So, collagen protein segments extracted from minute quantities of bone can be separated and analyzed on a mass spectrometer to perform the identifications of remnant bones that traditional zooarchaeologists cannot.

Selecting archaeological material for study

We decided to use this method to revisit the Smithsonian Museum’s archived material. Our study was a pilot one that asked the key question: would bones housed in the Smithsonian Museum preserve sufficient collagen for us to learn more about fragmented bone material in its storerooms? The answer was not obvious, because many of the excavations had taken place decades ago. While the material had been stored for the last decade or so in a state-of-the-art, climate-controlled facility, the early date of the excavations meant that modern standards were not necessarily applied to their handling, processing, and storage at all stages.

We examined bone material from five archaeological sites. The sites all dated to the Late Pleistocene/earliest Holocene (c. 13,000 to 10,000 calendar years before present) or earlier and were located in Colorado, in the western United States. The earliest had been excavated in 1934, the latest in 1981. Although some of the material from the sites was identifiable, much of it was highly fragmented and did not retain diagnostic features that could enable zooarchaeological identification to species, genus or even family. Some of the bone fragments looked highly unpromising – they were bleached and weathered, or edge-rounded, suggesting they had been transported by water or sediment prior to burial at the site.

Discovering excellent biomolecular preservation

What we found surprised us. Despite the old age of many of the collections, the unpromising appearance of much of the material, and the ancient origins of the bones themselves, they yielded excellent ZooMS results. In fact, a remarkable 80% of the bones sampled yielded sufficient collagen for ZooMS identifications. 73% could be identified to genus level.

The taxa we identified using ZooMS included Bison, Mammuthus (the genus to which mammoths belong), Camelidae (the camel family), and possibly Mammut (the genus to which mastodons belong). In some cases, we could only assign the specimens to broad taxonomic groups because many North American animals still lack ZooMS reference libraries. These databases, which are comparatively well developed for Eurasia but not for other regions, are essential for identifying the spectra a sample produces when we run it on a mass spectrometer.

Our findings have major implications for museum collections. The material we looked at is in every way the poor cousin of the glamorous material that goes on display in natural history museums. To look at, these highly fragmentary, small and undiagnostic animal bones are uninspiring and superficially uninformative. But like other biomolecular tools, ZooMS is revealing the rich information retained in neglected specimens that have drawn neither researcher nor visitor attention for decades.

Our results also highlight the potential of such collections for addressing ongoing debates about exactly when, where and how megafauna went extinct. By opening up for analysis the fragmented bone material that makes up much of the megafaunal record, ZooMS has the potential to help provide much new research data to address long-standing questions about megafaunal extinctions. ZooMS offers a relatively easy, rapid, and cheap way to extract new information from long-ago excavated sites.

Our research also highlights the importance of preserving archaeological collections. When researchers and institutions are strapped for funding, archaeological artefacts and bones that are not glamorous or of obvious immediate benefit may be neglected or even discarded. It is critical that museums are provided with adequate funding to care for and house archaeological remains over the long term. As our analysis shows, such old material can find new life in unexpected ways – in this case, allowing us to use tiny bone fragments to help get a little closer to solving the mystery of why some of Earth’s largest ever animals disappeared from the landscapes of ancient North America.

Preparation of a sample plate for ZooMS analysis

The preparation of a sample plate for ZooMS analysis. The tiny droplets being deposited using the pipette contain small amounts of ground up collagen that will be analyzed on a mass spectrometer. 

CREDIT

Photo by Samantha Brown

1961 excavation at Lamb Spring, showing Ed Lewis (standing on left) and Waldo Wedel, along with two fieldmen. Glenn Scott can be seen in the excavation pit alongside some mammoth bones wrapped in plaster jackets for preservation.

CREDIT

Image: USGS public domain image.

JOURNAL

Frontiers in Mammal Science

DOI

10.3389/fmamm.2024.1399358 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

A new legacy: potential of zooarchaeology by mass spectrometry in the analysis of North American megafaunal remains

ARTICLE PUBLICATION DATE

31-May-2024