What triggered Nepal’s catastrophic 2021 flood – and could it happen again

Using cutting-edge technology, USC Dornsife scientists discovered how a deadly combination of factors led to disaster. They hope their research will help identify other regions vulnerable to similar flooding events.

University of Southern California

 

image: 

Unusually heavy snowmelt under heavy rains led to overwhelming floods in Nepal. 

 

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Credit: Chan-Mao Chen

Global Relevance: Findings can inform disaster management, infrastructure planning, and public awareness globally, especially as climate change heightens extreme weather threats.

In late September and early October this year, unusually heavy monsoon rains led to deadly flooding and landslides in Nepal’s southern Kathmandu region. The disaster comes just over three years after a similar catastrophic event in the country’s Melamchi Valley, when devastating floods sent rocks, trees and mudflows sweeping through the valley, displacing thousands and wreaking havoc on local communities. 

Using sophisticated technology, researchers have now evaluated the June 2021 Melamchi flood’s impact with remarkable precision and developed insights that could help predict — and perhaps prevent — future catastrophic floods. 

Led by Josh West, professor of Earth sciences and environmental studies, and PhD student Chan-Mao Chen, both at the USC Dornsife College of Letters, Arts and Sciences, the study, published in Nature Geoscience, provides a detailed analysis of the flood’s triggers by combining cutting-edge satellite imagery, digital models of the valley’s landscape and field data. This approach allowed the researchers to investigate how rainfall, snowmelt and steep terrain worked together to unleash the powerful flood. 

Perfect storm for flooding and debris flows

The study reveals that the Melamchi flood arose from a convergence of factors that set the stage for disaster. 

“We know that climate change is intensifying the frequency and severity of extreme weather events, and this flood is a textbook example of how multiple forces can come together to create catastrophic flooding,” West said.

Researchers found that unusually heavy monsoon rainfall combined with excessive snowmelt in the higher reaches of the valley, overwhelming the region’s river systems. 

“The heavy rainfall triggered the snowmelt. This compounded the flooding and ultimately caused landslides,” Chen said. Steep topography and unstable slopes in the area worsened the flooding, he added.

Digital models of a disastrous flood 

The team mapped changes in the landscape before and after the flood with unprecedented precision by analyzing high-resolution satellite imagery collected over a decade. They then employed sophisticated software to create highly detailed 3D maps called digital surface models (DSMs) of the area. 

By analyzing the DSMs, they identified significant patterns of erosion and sediment deposits in the valley — key indicators of the flood’s destructive power. 

“Traditional methods of monitoring floods rely on gauges and field observations, but these are limited in remote or hard-to-reach areas,” said Chen. “With the satellite imagery, we gained a much more complete picture of how the landscape was transformed by the flood.”

The DSMs allowed the researchers to estimate the scale of erosion and deposition, which is critical for understanding the severity of the flood’s impact on the landscape and local infrastructure, West said.

In some areas, the landscape had been altered so drastically that entire sections of the riverbed were reshaped.

In addition, the team examined boulders in the riverbed to estimate the power of the flood. By measuring the size and movement of these massive rocks, they were able to calculate how much water was needed to move them, providing insights into the flood’s transport capacity. 

“We could tell how much energy the flood had and what it would take to move the debris,” Chen explained.

Global implications for flood policy and preparedness

The study’s findings have far-reaching implications for disaster management and policymaking in Nepal and similar regions around the world. 

“Detailed flood analysis like ours is important for designing early-warning systems,” said West. Better understanding of the factors that trigger these kinds of flood events can help authorities predict when and where the next event might occur.

The researchers also emphasized the importance of using this data to inform land use and infrastructure planning. Flood-prone areas need to be mapped and understood, not just for current risk, but for how those risks will evolve in the future as the climate continues to change, Chen said.

For the public, the study reinforces the need for greater awareness of flood risks in vulnerable regions, especially in mountainous areas and locations where wildfires have scorched the earth and rapid changes in weather can have dramatic effects. 

As the planet continues to warm and extreme weather events become more frequent, the study provides valuable insights into how scientists can better predict and mitigate the effects of floods and other natural disasters. 

“Floods like the one in Melamchi Valley could become more common as climate change intensifies,” said West. He and Chen hope their study and others like it can reduce the risks involved and save lives in the future.

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Journal

Nature Geoscience

DOI

10.1038/s41561-024-01596-x 

Method of Research

Imaging analysis

Subject of Research

Not applicable

Article Title

Erosional cascade during the 2021 Melamchi Flood

Article Publication Date

4-Dec-2024

 

Scientists embark on first study of Antarctica’s underwater avalanches

University of Plymouth

Antarctica’s turbidity currents and the role they play in helping to regulate Earth’s climate are to be studied for the first time through a groundbreaking international project.

The Antarctic Canyon Experiment (ACE) will see scientists using state of the art technology to assess the causes and effects of the currents – also known as underwater avalanches – occurring deep in the Southern Ocean.

They hope this will enable them to develop a better understanding of Antarctica’s role as one of the planet’s primary carbon sinks, given it currently stores around 40% of all the anthropogenic carbon in the ocean.

They also want to explore how its effectiveness in doing this has changed over time, particularly during warmer periods in Earth’s history, and how it could be affected by present and future changes in the global climate.

The ACE project, supported by a £2.4million grant from the European Research Council, is being conducted by an international consortium led by Dr Jenny Gales, Associate Professor in Hydrography and Ocean Exploration at the University of Plymouth.

She said: “Turbidity currents, also known as underwater avalanches, are natural hazards that can transport huge amounts of sediment that travel thousands of kilometres across the ocean. They can damage infrastructure, such as the underwater cabling that transports most of the world’s internet, but are also of critical importance in the global carbon cycle. However, the exact scale of that is something of a mystery and through this project we hope to generate the first detailed understanding of how these currents take shape around Antarctica. Given its disproportionate role in the global climate, that information will be vital in helping us predict what might happen unless we take immediate action to halt the advance of climate change.”

The ACE project is one of around 300 awarded a total of €678million in grants through the ERC’s Consolidator Grants programme. Provided through the European Union’s Horizon Europe programme, the grants aim to support outstanding scientists and scholars to establish independent research teams and develop promising scientific ideas.

For the ACE project, Dr Gales will be working alongside an interdisciplinary team of researchers from the University of Gothenburg (Sweden), Northern Illinois University (USA), the National Institute of Water and Atmospheric Research (New Zealand), National Institute of Oceanography and Applied Geophysics (Italy), The Australian National University (Australia) and the Alfred Wegener Institute (Germany).

Over the course of the five-year project, they will use scientific research cruises to deploy and collect a series of underwater monitoring equipment deployed in the canyon for a whole year, as well as using autonomous underwater vehicles, enabling them to observe Antarctic turbidity currents in unprecedented detail. 

Sediment traps will also be lowered to the ocean floor so that samples can be taken directly from the currents and later analysed in the lab to show the quantities of organic carbon and other materials they contain.

The researchers hope this new data can be used to drive forward global carbon models and climate mitigation policies by providing the first detailed measures of the processes, in turn enabling improved representation of processes influencing the global carbon cycle.

They also believe the project’s outputs will represent a paradigm shift in quantifying the role of high-latitude turbidity currents in carbon cycling.

 

We might feel love in our fingertips –– but did the Ancient Mesopotamians?

Researchers studied ancient texts to see whether humans experience emotions in their bodies in a similar manner, regardless of time, language and culture.

Peer-Reviewed Publication

Aalto University

 

image: 

Modern and Mesopotamian people experience love in a rather similar way. In Mesopotamia, love is particularly associated with the liver, heart and knees. Figure: Modern/PNAS: Lauri Nummenmaa et al. 2014, Mesopotamian: Juha Lahnakoski et al. 2024

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Credit: Figure: Modern/PNAS: Lauri Nummenmaa et al., Mesopotamian: Juha Lahnakoski.

From feeling heavy-hearted to having butterflies in your stomach, it seems inherent to the human condition that we feel emotions in our bodies, not just in our brains. But have we always felt –– or at least expressed –– these feelings in the same way?

A multidisciplinary team of researchers studied a large body of texts to find out how people in the ancient Mesopotamian region (within modern day Iraq) experienced emotions in their bodies thousands of years ago, analysing one million words of the ancient Akkadian language from 934-612 BC in the form of cuneiform scripts on clay tablets. 

‘Even in ancient Mesopotamia, there was a rough understanding of anatomy, for example the importance of the heart, liver and lungs,’ says Professor Saana Svärd of the University of Helsinki, an Assyriologist who is leading the research project. One of the most intriguing findings relates to where the ancients felt happiness, which was often expressed through words related to feeling ‘open’, ‘shining’ or being ‘full’ –– in the liver.

‘If you compare the ancient Mesopotamian bodily map of happiness with modern bodily maps [published by fellow Finnish scientist, Lauri Nummenmaa and colleagues a decade ago], it is largely similar, with the exception of a notable glow in the liver,’ says cognitive neuroscientist Juha Lahnakoski, a visiting researcher at Aalto University.

Other contrasting results between ourselves and the ancients can be seen in emotions such as anger and love. According to previous research, anger is experienced by modern humans in the upper body and hands, while Mesopotamians felt most 'heated', 'enraged' or 'angry' in their feet. Meanwhile, love is experienced quite similarly by modern and Neo-Assyrian man, although in Mesopotamia it is particularly associated with the liver, heart and knees.

‘It remains to be seen whether we can say something in the future about what kind of emotional experiences are typical for humans in general and whether, for example, fear has always been felt in the same parts of the body. Also, we have to keep in mind that texts are texts and emotions are lived and experienced,’ says Svärd. The researchers caution that while it’s fascinating to compare, we should keep this distinction in mind when comparing the modern body maps, which were based on self-reported bodily experience, with body maps of Mesopotamians based on linguistic descriptions alone.

Towards a deeper understanding of emotions

Since literacy was rare in Mesopotamia (3 000-300 BCE), cuneiform writing was mainly produced by scribes and therefore available only to the wealthy. However, cuneiform clay tablets contained a wide variety of texts, such as tax lists, sales documents, prayers, literature and early historical and mathematical texts.

Ancient Near Eastern texts have never been studied in this way, by quantitatively linking emotions to body parts. This can be applied to other language materials in the future. ‘It could be a useful way to explore intercultural differences in the way we experience emotions,’ says Svärd, who hopes the research will provide an interesting contribution to discussion around the universality of emotions.

The results of the research will be published in the iScience journal on 4 December.

The corpus linguistic method, which makes use of large text sets, has been developed over many years in the Centre of Excellence in Ancient Near Eastern Empires (ANEE), led by Svärd. Next, the research team will look at an English corpus, or textual material from the 20th century, which contains 100 million words. Similarly, they also plan to examine Finnish data. 

In addition to Svärd and Lahnakoski, the team includes Professor Mikko Sams from Aalto University, Ellie Bennett from the University of Helsinki, Professor Lauri Nummenmaa from the University of Turku and Ulrike Steinert from Johannes Gutenberg-Universität Mainz. The project is funded by the Finnish Cultural Foundation.

Anger (IMAGE)

Aalto University

Modern man experiences anger in the upper body and hands. In Mesopotamia, anger was associated specifically with the feet. Figure: Modern/PNAS: Lauri Nummenmaa et al. 2014, Mesopotamian: Juha Lahnakoski et al. 2024.

Happiness ‘lights up’ similar areas on both modern and ancient body maps, with the exception of the liver, which was more significant for the ancient Mesopotamians. Figure: Modern/PNAS: Lauri Nummenmaa et al. 2014, Mesopotamian: Juha Lahnakoski et. al 2024.

Credit

Figure: Modern/PNAS: Lauri Nummenmaa et al., Mesopotamian: Juha Lahnakoski.

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Journal

iScience

DOI

10.1016/j.isci.2024.111365 

Article Title

Embodied emotions in ancient Neo-Assyrian texts revealed by bodily mapping of emotional semantics

Article Publication Date

4-Dec-2024

 

The bisexual population in Stockholm has doubled in a decade

Karolinska Institutet

Over the past decade, the proportion of residents in Stockholm County who identify as bisexual has nearly doubled. The younger generations are driving the trend and many of them have previously identified as heterosexual. This is according to a study published in JAMA Network Open by researchers at Karolinska Institutet in collaboration with the Centre for Epidemiology and Community Medicine within Region Stockholm in Sweden.

The researchers analysed data from the Stockholm Public Health Cohort, covering more than 98,000 individuals from 2002 to 2021. The proportion of people identifying as homosexual has remained stable at around 1.7 to 2.0 per cent over the past decade. However, between 2010 and 2021, the proportion of people identifying as bisexual increased from 1.6 to 3.1 per cent, making it the largest sexual minority.

Most common in Generation Z

The findings reveal clear generational differences in sexual identity among residents in Stockholm County. Among those born in the early 1980s to mid-1990s, often referred to as Millennials or Generation Y, 7.8 per cent identified as homo- or bisexual in 2021. The corresponding figure for those born in the mid-1990s to early 2010s, Generation Z, was 12 per cent.

“This mirrors trends observed in the USA since 2016 and suggests that younger generations are much more likely to identify as bisexual,” says Willi Zhang, postdoctoral researcher at the Department of Global Public Health at Karolinska Institutet. “Given the generation effects, the bisexual population is likely to keep growing, and this group is at increased risk of ill health and discrimination. Our study therefore emphasises the need for targeted public health interventions.”

Sexual identity can be fluid

The study also highlights the fluidity of sexual identity. A sub-analysis showed that almost 16 per cent changed their sexual identity at least once between 2010 and 2021. Another sub-analysis showed that bisexual individuals were the most likely to experience such changes, with around half of those identifying as bisexual in 2021 having previously identified as heterosexual in 2010.

“Our results challenge the conventional belief that sexual orientation is fixed throughout life,” says Willi Zhang. “We want to continue investigating whether people experiencing changes in their sexual identity are more vulnerable to health risks.”

The researchers also plan to investigate health disparities between individuals of different sexual orientations over time and how this has been affected by Sweden’s legalisation of same-sex marriage in 2009.

The study was funded by the Swedish Research Council for Health, Working Life and Welfare, and Region Stockholm. There are no reported conflicts of interest.

Publication: “Population Trends and Individual Fluidity of Sexual Identity Among Stockholm County Residents”, Willi Zhang (former name Guoqiang Zhang), Per Tynelius, Maya B. Mathur, Matteo Quartagno, Gunnar Brandén, Fredrik Liljeros, Kyriaki Kosidou, JAMA Network Open, online 4 December 2024, doi: 10.1001/jamanetworkopen.2024.47627.

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Journal

JAMA Network Open

DOI

10.1001/jamanetworkopen.2024.47627 

Subject of Research

People

Article Title

Population Trends and Individual Fluidity of Sexual Identity Among Stockholm County Residents

Article Publication Date

4-Dec-2024

 

Research reveals how fructose in diet enhances tumor growth

Washington University in St. Louis

 

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Gary Patti, the Michael and Tana Powell Professor of Chemistry in Arts & Sciences and a professor of genetics and of medicine at the School of Medicine, all at WashU.

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Credit: WashU

Fructose consumption has increased considerably over the past five decades, largely due to the widespread use of high-fructose corn syrup as a sweetener in beverages and ultra-processed foods. New research from Washington University in St. Louis shows that dietary fructose promotes tumor growth in animal models of melanoma, breast cancer and cervical cancer. However, fructose does not directly fuel tumors, according to the study published Dec. 4 in the journal Nature.

Instead, WashU scientists discovered that the liver converts fructose into usable nutrients for cancer cells, a compelling finding that could open up new avenues for care and treatment of many different types of cancer.

“The idea that you can tackle cancer with diet is intriguing,” said Gary Patti, the Michael and Tana Powell Professor of Chemistry in Arts & Sciences and a professor of genetics and of medicine at the School of Medicine, all at WashU.

“When we think about tumors, we tend to focus on what dietary components they consume directly. You put something in your body, and then you imagine that the tumor takes it up,” Patti said. “But humans are complex. What you put in your body can be consumed by healthy tissue and then converted into something else that tumors use.”

“Our initial expectation was that tumor cells metabolize fructose just like glucose, directly utilizing its atoms to build new cellular components such as DNA. We were surprised that fructose was barely metabolized in the tumor types we tested,” said the study’s first author, Ronald Fowle-Grider, a postdoctoral fellow in Patti’s lab. “We quickly learned that the tumor cells alone don’t tell the whole story. Equally important is the liver, which transforms fructose into nutrients that the tumors can use.”

Using metabolomics — a method of profiling small molecules as they move through cells and across different tissues in the body — the researchers concluded that one way in which high levels of fructose consumption promote tumor growth is by increasing the availability of circulating lipids in the blood. These lipids are building blocks for the cell membrane, and cancer cells need them to grow.

“We looked at numerous different cancers in various tissues throughout the body, and they all followed the same mechanism,” Patti said.

The corn syrup era

Scientists have long recognized that cancer cells have a strong affinity for glucose, a simple sugar that is the body’s preferred carbohydrate-based energy source.

In terms of its chemical structure, fructose is similar to glucose. They are both common types of sugar, with the same chemical formula, but they differ in how the body metabolizes them. Glucose is processed throughout the whole body, while fructose is almost entirely metabolized by the small intestine and liver.

Both sugars are found naturally in fruits, vegetables, dairy products and grains. They are also added as sweeteners in many processed foods. Fructose, in particular, has penetrated the American diet over the last few decades. It is favored by the food industry because it is sweeter than glucose.

Prior to the 1960s, people consumed relatively little fructose compared with today’s numbers. A century ago, an average person consumed just 5-10 pounds of fructose per year. To put it in familiar terms, that is roughly equal to the weight of a gallon of milk. In the 21st century, that number has increased to be as high as the equivalent of 15 gallons of milk.

“If you go through your pantry and look for the items that contain high-fructose corn syrup, which is the most common form of fructose, it is pretty astonishing,” said Patti, who is also a research member of the Siteman Cancer Center, based at Barnes-Jewish Hospital and WashU Medicine, and the Center for Human Nutrition at WashU Medicine.

“Almost everything has it. It’s not just candy and cake, but also foods such as pasta sauce, salad dressing and ketchup,” he said. “Unless you actively seek to avoid it, it’s probably part of your diet.”

Cancer’s appetite for fructose

Given the rapid rise in the consumption of dietary fructose over recent decades, the WashU researchers wanted to know more about how fructose impacts the growth of tumors.

Patti and Fowle-Grider began their investigation by feeding tumor-bearing animals a diet rich in fructose, then measuring how quickly their tumors grew. The researchers found that added fructose promoted tumor growth without changing body weight, fasting glucose or fasting insulin levels.

“We were surprised to see that it had a rather dramatic impact. In some cases, the growth rate of the tumors accelerated by two-fold or even higher,” Patti said. “Eating a lot of fructose was clearly very bad for the progression of these tumors.”

But the next step in their experiments initially stumped them. When Fowle-Grider attempted to repeat a version of this test by feeding fructose to cancer cells isolated in a dish, the cells did not respond. “In most cases they grew almost as slowly as if we gave them no sugar at all,” Patti said.

So, Patti and Fowle-Grider went back to looking at changes in the small molecules in the blood of animals fed high-fructose diets. Using metabolomics, they identified elevated levels of a variety of lipid species, including lysophosphatidylcholines (LPCs). Additional dish tests showed that liver cells that were fed fructose release LPCs.

“Interestingly, the cancer cells themselves were unable to use fructose readily as a nutrient because they do not express the right biochemical machinery,” Patti said. “Liver cells do. This allows them to convert fructose into LPCs, which they can secrete to feed tumors.”

A defining characteristic of cancer is uncontrolled proliferation of malignant cells. Each time a cell divides, it must replicate its contents, including membranes. This requires a substantial amount of lipids. While lipids can be synthesized from scratch, it is much easier for cancer cells to simply take lipids up from their surrounding environment.

“Over the past few years, it’s become clear that many cancer cells prefer to take up lipids rather than make them,” Patti noted. “The complication is that most lipids are insoluble in blood and require rather complex transport mechanisms. LPCs are unique. They might provide the most effective and efficient way to support tumor growth.”

Avoiding fructose

Interestingly, over the same period of time when human fructose consumption has surged, a number of cancers have become increasingly more prevalent among people under the age of 50. This raises the question whether the trends are linked. With $25 million in support from Cancer Grand Challenges, Patti recently teamed up with Yin Cao, an associate professor of surgery at WashU Medicine, and other investigators from around the world, none of whom were involved in this study, to investigate possible connections.

“It will be exciting to better understand how dietary fructose influences cancer incidence. But one take-home message from this current study is that if you are unfortunate enough to have cancer, then you probably want to think about avoiding fructose. Sadly, that is easier said than done,” Patti said.

Aside from dietary intervention, the study authors said that this research could help us develop a way to prevent fructose from driving tumor growth therapeutically, using drugs.

“An implication of these findings is that we do not have to limit ourselves to therapeutics that only target disease cells,” Patti said. “Rather, we can think about targeting the metabolism of healthy cells to treat cancer. This has worked with mice in our study, but we would like to take advantage of our observations and try to improve the lives of patients.”

The study authors are working with clinical partners at WashU Medicine to explore a clinical trial related to fructose in the diet.

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This research was funded in part by the National Institutes of Health (NIH) (R35 ES028365)

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Journal

Nature

DOI

10.1038/s41586-024-08258-3 

Article Title

Dietary fructose enhances tumor growth indirectly via interorgan lipid transfer

Article Publication Date

4-Dec-2024

 

Largest study of CTE in male ice hockey players finds odds increased 34% with each year played

18 of 19 NHL players had CTE, but zero of 6 who played fewer than 6 years

Boston University School of Medicine

(Boston)—The largest study ever of 77 deceased male ice hockey players by the Boston University CTE Center found that the odds of having chronic traumatic encephalopathy (CTE) increased by 34% each year played, and 18 of 19 National Hockey League players had CTE. CTE is a neurodegenerative disease caused by repeated traumatic brain injuries and most frequently found in former contact sport athletes exposed to repetitive head impacts (RHI). While many perceive CTE risk as limited to enforcers, this study makes it clear that all male ice hockey players are at risk.

 

“Ice hockey players with longer careers not only were more likely to have CTE, but they also had more severe disease,” explains corresponding author Jesse Mez, MD, MS, co-director of clinical research at the CTE Center and associate professor of neurology at Boston University Chobanian & Avedisian School of Medicine. “We hope this data will help inspire changes to make the game safer as well as help former ice hockey players impacted by CTE get the care they need.”

 

To investigate the relationships between duration of ice hockey play and CTE diagnosis and severity, the researchers studied male brain donors who had been amateur and professional ice hockey players. They found 96% (27 of 28) of professional players had CTE pathology (18 of 19 NHL, 9 of 9 non-NHL professionals), 46% of college, juniors and semi-professional players (13 of 28) and 10% (2 of 21) youth and high school players. The researchers stress that the frequencies of CTE reported in this study should not be construed as the prevalence of CTE in the target population since families whose loved ones are symptomatic are more likely to donate their brains.

 

Among enforcers, they found 18 of 22 had CTE, but the difference between enforcers and non-enforcers was not statistically significant after accounting for years of play.

 

“Enforcers have dominated the CTE conversation, but our findings provide the most evidence for the cumulative amount of play as the predominant risk factor for CTE,” says Mez. “Enforcers had about twice the odds of developing CTE, but the takeaway here is that non-enforcers are getting CTE as well. Ice hockey players skate quickly, and checking leads to impacts with other players, the ice, boards and glass. We think years of play is a proxy for these impacts that are harder to measure directly, but are likely what are leading to the disease.”

 

Ice-hockey is the third major sport, after American football and rugby, to show a dose-response relationship between years of play and CTE risk, further strengthening the evidence that repetitive head impacts cause CTE. The risk for CTE among female ice hockey players remains unknown, and because the rules around checking differ, the results should not be generalized to female ice hockey players.

 

Athletes and families who are concerned their loved one is showing cognitive or behavioral symptoms that could be related to CTE pathology can reach out to BU CTE Center collaborator the Concussion Legacy Foundation (CLF) HelpLine at CLFHelpLine.org for free support. Former hockey players who would like to enroll in studies aimed at diagnosing and eventually treating CTE can sign up for the CLF Research Registry CLFResearch.org .

 

These findings appear online in JAMA Network Open.

 

Funding for the study was provided by the National Institute of Neurological Disorders and Stroke (U54NS115266, U01NS086659, U01NS093334, R01NS078337, R56NS078337, K23NS102399), National Institute on Aging (P30AG13846; supplement 0572063345, U19AG068753, R01AG061028, K23AG046377, R21HD089088, F32NS096803), National Heart, Lung and Blood Institute (75N92019D00031), Department of Veterans Affairs (I01 CX001135, CSP 501, B6796-C), Department of Defense (W81XWH-13-2-0095, W81XWH-13-2-0064, W81XWH1810580, PRARP-13267017), the Alzheimer’s Association (NIRG-15-362697, NIRG-305779), the National Operating Committee on Standards for Athletic Equipment (NOCSAE), the Nick and Lynn Buoniconti Foundation, the Concussion Legacy Foundation, the Andlinger Foundation, the WWE, and the NFL.

 

About the BU CTE Center

The BU CTE Center is an independent academic research center at the Boston University Avedisian & Chobanian School of Medicine. It conducts pathological, clinical and molecular research on CTE and other long-term consequences of repetitive brain trauma in athletes and military personnel. For people considering brain donation, click here. To support its research, click here. 

 

 

 

 

 

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Journal

JAMA Network Open

DOI

10.1001/jamanetworkopen.2024.49106 

Method of Research

Data/statistical analysis

Subject of Research

People

Article Title

Duration of Ice Hockey Play and Chronic Traumatic Encephalopathy

Article Publication Date

4-Dec-2024

Racial and ethnic disparities in regulatory air quality monitor locations in the US

JAMA Network

About The Study: 

The findings of this study suggest regulatory monitor data may not adequately capture air quality exposures for some marginalized race and ethnicity groups, and the consequences of incomplete or uncertain air quality estimates for these communities should be further investigated.

 

Corresponding Author: To contact the corresponding author, Brenna C. Kelly, MS, email brenna.kelly@utah.edu.

To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/

(doi:10.1001/jamanetworkopen.2024.49005)

Editor’s Note: Please see the article for additional information, including other authors, author contributions and affiliations, conflict of interest and financial disclosures, and funding and support.

Embed this link to provide your readers free access to the full-text article This link will be live at the embargo time http://jamanetwork.com/journals/jamanetworkopen/fullarticle/10.1001/jamanetworkopen.2024.49005?utm_source=For_The_Media&utm_medium=referral&utm_campaign=ftm_links&utm_term=120424

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Journal

JAMA Network Open

Obstetric care access at rural and urban hospitals in the US

JAMA Network

About The Study: 

Between 2010 and 2022—a time of tremendous attention to maternal health—there was a net loss of hospital-based obstetric care in both rural and urban hospitals across the U.S. In 2010, more than half of rural hospitals and two-thirds of urban hospitals offered obstetric care. Rural hospitals started with lower percentages of hospitals offering obstetrics compared with urban hospitals and experienced a larger increase in the percentage of hospitals without obstetrics. 

Corresponding Author: To contact the corresponding author, Katy B. Kozhimannil, PhD, MPA, email Brad Robideau at brobidea@umn.edu.

To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/

(doi:10.1001/jama.2024.23010)

Editor’s Note: Please see the article for additional information, including other authors, author contributions and affiliations, conflict of interest and financial disclosures, and funding and support.

Embed this link to provide your readers free access to the full-text article This link will be live at the embargo time https://jamanetwork.com/journals/jama/fullarticle/10.1001/jama.2024.23010?guestAccessKey=ac30e1b3-5c77-48e0-a293-5e9261a566d1&utm_source=For_The_Media&utm_medium=referral&utm_campaign=ftm_links&utm_content=tfl&utm_term=120424

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Journal

JAMA

 

DNA of 1,000 year-old maize sheds light on origins of globally important food crop

University of York

Researchers have tested ancient DNA from corn found at archaeological sites in Arkansas, shedding new light on the dispersal of one of the world’s most important food crops.

By reconstructing the genomes of archaeological maize cobs and kernels, the study, by researchers at the University of York and the University of Copenhagen, revealed that 1,000-year-old maize from rockshelters in the Ozark region of Arkansas, US, shares a close genetic link with modern Northern Flint varieties.

These hardy varieties are cold-adapted and are the ancestors for commercially important maize grown around the world. Researchers say that understanding its origins and journey through different geographical regions could help find new ways of sustaining and improving crops today, as pressures on global food supply increases and crop health is challenged by climate change. 

Researchers showed that maize underwent selection as it was transported from the US Southwest across the Great Plains, particularly through a gene, known as waxy1. Genetic variants in the waxy1 gene affect the stickiness and chewiness of maize, traits that are still valued in some traditional cuisines today.

This suggests that farmers 1,000 years ago were not just engaged in planting and harvesting, but in selecting traits that could help in breeding and producing the best quality yield for food, not too dissimilar to farmers today.

Dr Nathan Wales, from the University of York’s Department of Archaeology, said: “We know that maize was domesticated in Mexico, but it has long been debated what route it took to regions of the US to become what it is today - one of the most globally important food crops.

“We now have a clearer idea of the journey it took from Mexico, and we better appreciate how regional varieties can become more globally significant than varieties grown near the domestication centre. It is valuable information for crop breeders because they can chart the evolution of the crop, reintroduce any lost genetic diversity or develop new varieties, which could be vital to helping food shortages in the future.”

Ancient maize genomes from the Ozark rockshelters indicated that maize entered eastern North America at least twice, tracing ancestry to both the upland US Southwest and southern Texas.

Dr Jazmín Ramos-Madrigal, from the Globe Institute at the University of Copenhagen in Denmark, said: “We also showed that maize could only be introduced into eastern North America once humans bred local varieties with the genetic tools to cope with the challenging environment of the region, which goes someway to demonstrating the skills and knowledge of farmers 1,000 years ago.”

The study is published in the journal Cell.

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Journal

Cell

Ancient maize genomes reveal the early evolutionary history of commercially important flint and dent varieties

University of Copenhagen - The Faculty of Health and Medical Sciences

A study published today in Cell uncovers the deep evolutionary roots of flint and dent maize (also commonly known as “corn”), two foundational varieties central to modern maize breeding and cultivation. By analyzing ancient DNA from 32 maize samples spanning the last 3,000 years, researchers have reconstructed the journey of the crop into eastern North America, shedding new light on its geographic origins, dispersal routes, and history of selection.

This study was carried out by an international team of scientists and spearheaded by Jazmín Ramos Madrigal from the Center for Evolutionary Hologenomics at the University of Copenhagen, Denmark, and Nathan Wales from the Department of Archaeology at the University of York, UK.

A genetic link between Northern Flints and 1,000-year-old Ozark maize

By reconstructing the genomes of archaeological maize cobs and kernels, the study reveals that 1,000-year-old maize from rockshelters in the Ozark region of Arkansas, US, shares a close genetic link with modern Northern Flint varieties. Known for their cold tolerance and hardiness, these ancient flints form the backbone of many commercial maize hybrids cultivated today.

“Our research shows that this lineage of maize, which makes up the ancestry of most commercial maize, shares its roots with maize grown by Indigenous Peoples in the Ozark region over 1,000 years ago” explained Wales.

The long journey of maize: across the Great Plains to eastern North America

Eastern North America represents one of the last stops in maize's dispersion from its domestication center in southern Mexico. The path maize took to reach eastern North America has long been debated, with two competing hypotheses: one proposing a route through eastern Mexico and across the Gulf coast of Texas, and another suggesting maize traveled across the Great Plains from the U.S. Southwest.

The study provides clear evidence supporting the latter. Ancient maize genomes from the Ozark rockshelters indicate that maize entered eastern North America in at least two dispersion pulses, tracing ancestry to both the Upland US Southwest and southern Texas.

“One of the ancestries we find in the Ozarks comes from maize already adapted to growing in the colder and shorter days of Upland US Southwest. This suggests that maize could only be introduced into eastern North America once humans bred local varieties with the genetic tools to cope with the challenging environment of the region.”  noted Ramos-Madrigal.

Evolutionary adaptations: selection on starch gene reflects early food preferences

The study also highlights repeated selection on maize's starch metabolic pathway during its dispersion into eastern North America. A key gene in this pathway, known as waxy, which influences kernel texture, showed clear signs of selection in ancient Ozark maize 1,000 years ago. Genetic variants in the waxy gene affect the stickiness and chewiness of maize, traits that are still valued in some traditional cuisines today.

“This suggests that Indigenous farmers were not only adapting maize to local climates but might also be selecting for traits that suited their specific culinary preferences,” explained Wales. “Our research provides another piece of the puzzle that is the chronology of selection and adaptation during maize domestication, by showing this gene was selected sometime between maize departure from the US Southwest and its arrival into eastern North America at least a thousand years ago” added Ramos-Madrigal.

Conclusion

This study highlights how ancient DNA can illuminate the origins and adaptations of crops that shaped human history. By tracing maize's journey and adaptation into eastern North America, the research not only advances our understanding on the early origins and evolution of maize, one of the three pillars of modern agriculture, but also provides new insights into the evolutionary history of one of the world's most important crops.

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Journal

Cell

Article Title

The genomic origin of early maize in eastern North America

Article Publication Date

4-Dec-2024