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Database shows the diversity of the world’s languages


Grammatical similarity in the Grambank sample of languages. The color coding represents the distribution of languages according to the first three principal components of a Principal Component Analysis mapped onto RGB color space (PC1 = Red, PC2 = Green and PC3 = Blue). Similarity in color indicates similarity in grammatical structure on the first three dimensions. Credit: © MPI f. Evolutionary Anthropology

What shapes the structure of languages? In a new study, an international team of researchers reports that grammatical structure is highly flexible across languages, shaped by common ancestry, constraints on cognition and usage, and language contact.

The study used the Grambank database, which contains data on grammatical structures in more than 2,400 languages. The project was initiated by the Department of Linguistic and Cultural Evolution at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, in collaboration with a team of more than one hundred linguists from around the world. The work is published in the journal Science Advances.

Linguists have long been interested in variation. What are common or universal patterns across languages? What limits the possible variation between them? Grambank, the world’s largest and most comprehensive database of language structure, enables researchers to answer some of these questions.

Grambank was constructed in an international collaboration between the Max Planck institutes in Leipzig and Nijmegen, the Australian National University, the University of Auckland, Harvard University, Yale University, the University of Turku, Kiel University, Uppsala University, SOAS, the Endangered Languages Documentation Program, and more than one hundred scholars from around the world. Grambank’s coverage spans 215 different language families and 101 isolates from all inhabited continents.

“The design of the feature questionnaire initially required numerous revisions in order to encompass many of the diverse solutions that languages have evolved to code grammatical properties,” says Hedvig Skirgård, who coordinated much of the coding and is the lead author of the study.

Limits on variation

The team settled on 195 grammatical properties, ranging from word order to whether or not a language has gendered pronouns. For instance, many languages have separate pronouns for “he” and “she,” but some also have male and female versions of “I” or “you.” The possible “design space” would be enormous if grammatical properties were to vary freely. Limits on variation could be related to cognitive principles rooted in memory or learning, rendering some grammatical structures more likely than others. Limits could also be related to historical “accidents,” such as descent from a common language or contact with other languages.

The researchers discovered much greater flexibility in the combination of grammatical features than many theorists have assumed. “Languages are free to vary considerably in quantifiable ways, but not without limits,” explains Stephen Levinson, Director emeritus of the Max Planck Institute for Psycholinguistics in Nijmegen and one of the founders of the Grambank project. “A sign of the extraordinary diversity of the 2,400 languages in our sample is that only five of them occupy the same location in design space (share the same grammatical properties).”

Languages show much greater similarity to those with a common ancestor than those they are in contact with. “Genealogy generally trumps geography,” says Russell Gray, Director of the Department of Linguistic and Cultural Evolution and senior author of the study. “Nevertheless, if processes of linguistic evolution and diversification were run again from the beginning, there would still be some resemblance to what we now have. The constraints of human cognition mean that, while there is a great deal of historical contingency in the organization of grammatical structures, there are regular patterns as well.”

Diversity under threat

“The extraordinary diversity of languages is one of humanity’s greatest cultural endowments,” concludes Levinson. “This endowment is under threat, especially in some areas such as Northern Australia, and parts of South and Northern America. Without sustained efforts to document and revitalize endangered languages, our linguistic window into , cognition and culture will be seriously fragmented.”

The Grambank database is an open-access comprehensive resource maintained by the Max Planck Society. “It puts linguistics on an even footing with genetics, archaeology and anthropology in terms of quantitative, large scale, accessible data,” says Gray. “I hope it will facilitate the exploration of links between linguistic diversity and a broad array of other cultural and biological traits, ranging from religious beliefs to economic behavior, musical traditions and genetic lineages. These links with other facets of human behavior will make Grambank a key resource not only in linguistics, but in the multidisciplinary endeavor of understanding human diversity.”

More information:
Hedvig Skirgård et al, Grambank reveals the importance of genealogical constraints on linguistic diversity and highlights the impact of language loss, Science Advances (2023). DOI: 10.1126/sciadv.adg6175. www.science.org/doi/10.1126/sciadv.adg6175

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As pandemic prison populations fell, proportion of Black prisoners rose, finds new analysis


Dynamics of the US prison population. a, Total number of incarcerated people in the USA from January 2013 to January 2022. b, Total percentage of incarcerated Black people, as reported by states’ Departments of Correction. According to data from the US census, Black people account for 13.4% of the total population. This plot includes data from 49 states and the District of Columbia—data from Michigan are excluded as the state reports only “white” and “nonwhite” as race categories. Credit: Nature (2023). DOI: 10.1038/s41586-023-05980-2

The U.S. prison population plummeted during the early months of the COVID-19 pandemic but the percentage of incarcerated Black people rose, according to a new analysis of prison data published April 19 in the journal Nature.

The higher percentage of incarcerated Black people by mid-2020 was found in almost all states, and temporarily reversed a decades-long decrease in the percentage of Black people in the national population, researchers from Yale and Northeastern Universities and the Santa Fe Institute found.

While several factors contributed to the increase in percentage of incarcerated Black people during the height of the pandemic, researchers argue that sentencing disparities between Black and white incarcerated people may have played a major role. As court closures at the height of the pandemic slowed the admission of individuals into the , the makeup of prison populations was strongly influenced by differences in sentence lengths by race.

“And disparities in sentencing is something society can do something about,” said co-corresponding author Brandon Ogbunu, an assistant professor of ecology and in Yale’s Faculty of Arts and Sciences (FAS) and computational biologist.

By the end of spring in 2020, the U.S. prison population had fallen by 200,000 people from pre-pandemic levels. This 17 percent reduction in prisoner population between March 2020 and July 2021 was “the largest decarceration in American history,” Ogbunu said. Courts closed and new admissions to prisons decreased. Many states instituted early release guidelines to reduce prison populations.

Prior to the pandemic, the percentage of incarcerated Black people in U.S. prisons had fallen to 38.9 percent, the lowest level in decades, as more whites without a were imprisoned. However, at the height of the pandemic, from March and November of 2020, the percentage of incarcerated Black people increased by almost a full percentage point.

This spike in proportion of Blacks in prison was temporary in most states and approached pre-pandemic rates in early 2021.

Nonetheless, the pandemic prison experience carries lessons for society as a whole, said co-corresponding author Elizabeth Hinton, a professor of history and African American Studies in the FAS and also a professor of law at Yale Law School.

“We think that the served as a for the criminal legal system. When you put a system like it under stress, the underlying disparities can be amplified,” Hinton said.

“In response to these findings, we believe that society has an ethical obligation to act in order to reduce such , including the reform of sentencing practices.”

Brennan Klein of Northeastern University and Samuel Scarpino of the Santa Fe Institute are co-corresponding authors.

More information:
Brennan Klein, COVID-19 amplified racial disparities in the US criminal legal system, Nature (2023). DOI: 10.1038/s41586-023-05980-2. www.nature.com/articles/s41586-023-05980-2

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Alignment of galaxies millions of light years away supports general relativity


3D position and shape information for each galaxy helped to measure the magnitude of alignment relative to distant galaxies. Credit: KyotoU/Jake Tobiyama

Scientists from research institutions including Kyoto University have confirmed that the intrinsic alignments of galaxies have characteristics that allow it to be a powerful probe of dark matter and dark energy on a cosmological scale.

By gathering evidence that the distribution of galaxies more than tens of millions of away is subject to the gravitational effects of dark matter, the team succeeded in testing general theory of gravity at vast spatial scales. The international team analyzed the positions and orientations of galaxies, acquired from archived data of 1.2 million galaxy observations.

With the help of available 3D positional information of each galaxy, the resulting statistical analysis quantitatively characterized the extent to which the orientation of distant galaxies is aligned. The work is published in The Astrophysical Journal Letters.

“These alignments, which are primarily produced by interactions with nearby objects, have been regarded as systematic noise in measuring weak lensing effect,” states lead author Atsushi Taruya of KyotoU’s Yukawa Institute for Theoretical Physics.

“We have also successfully measured the rate at which the galaxy distribution gradually becomes denser due to gravity, which is consistent with the general theory of relativity,” says Teppei Okumura of the Academia Sinica Institute of Astronomy and Astrophysics.

“Our research verified at the distant universe, but the nature of or the origin of cosmic acceleration still remains unresolved,” adds Okumura.

The archived data—obtained from the Sloan Digital Sky Survey and the Baryon Oscillation Spectroscopic Survey—consists of three galaxy samples selected for their brightness and distance. In addition, 3D positions and shape information for each galaxy helped to measure the magnitude of alignment relative to distant galaxies.

The results of the team’s model corroborated with theoretical calculations and gave Taruya and Okumura strong evidence that the orientations of these are related to each other, demonstrating a stronger case for general relativity on a cosmological scale.

“Current endeavors, such as the Subaru Telescope project, will provide extremely high-quality, high-precision observational data. These will spearhead innovative cosmological research using the intrinsic alignments to shed light on the nature of dark energy,” notes Taruya.

More information:
Teppei Okumura et al, First Constraints on Growth Rate from Redshift-space Ellipticity Correlations of SDSS Galaxies at 0.16 < z < 0.70, The Astrophysical Journal Letters (2023). DOI: 10.3847/2041-8213/acbf48

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Ancient DNA reveals commercial viticulture in Byzantine and Early Islamic settlements


Top and Right. Geographic locations of the ancient and modern samples that were processed for this study, including annual rainfall data of the region. Bottom Left. An aerial view of the archaeological site Avdat. The arrow points to the recovery location of the five archaeological samples that were used in the analyses. Credit: Proceedings of the National Academy of Sciences (2023). DOI: 10.1073/pnas.2213563120

Researchers in Israel led by Tel Aviv University have uncovered commercial-scale viticulture in ancient Byzantine and Early Islamic settlements dated to the 4th to the 9th centuries. In a paper, “Ancient DNA from a lost Negev Highlands desert grape reveals a Late Antiquity wine lineage,” published in the Proceedings of the National Academy of Sciences, the researchers link the ancient varieties to grapes grown in modern-day Greece and the southern Levant.

Excavations in the Negev Highlands of southern Israel found that the ancient cultivators could continuously produce a wide variety of grapes in an arid environment over centuries.

Target-enriched, genome-wide sequencing and were used to examine grapevine pips excavated at three sites. The genetically diverse pips provided clues to ancient cultivation strategies to improve and ensure food security in a challenging environment.

The samples were processed in dedicated aDNA (ancient DNA) facilities at Tel Aviv University, the University of Copenhagen, and the University of York. Applying genomic prediction analysis to the aDNA results, researchers were able to date the oldest pip to the 8th century CE.

Another pip was found to be related to a modern Greek variety and was linked with several historic wines that were once traded across the Byzantine Empire. These findings shed light on historical Byzantine trading networks and the genetic contribution of Levantine varieties to the classic Aegean landscape.

The authors point out that of the thousands of winemaking grape varieties, only 11 cultivars of European origin (Cabernet Sauvignon, Chasselas, Chardonnay, Grenache, Merlot, Monastrell, Pinot Noir, Riesling, Sauvignon Blanc, Syrah, and Ugni Blanc) cover more than a third of the winemaking vineyards worldwide. These select grapes are grown over relatively narrow geographic zones under specific climatic conditions, which the authors suggest exposes the winemaking industry to stressors like global warming.

The paper cites a 2020 study, “Diversity buffers winegrowing regions from climate change losses” also published in PNAS, which found that a rise of 2°C in worldwide median temperatures would devastate grapevine cultivation in more than half of the current winegrowing areas. Though that study does illustrate how diversifying varieties or growing in entirely different regions (or countries) could mitigate much of that loss, it is an increasingly looming threat to viticulture that the climate cultivators have relied on for centuries is quickly changing.

In looking at the ancient pips grown in arid climates, the study authors suggest endemic grapevine lineages bred in hot and , often preserved over centuries, may present an alternative to the classic winemaking grape cultivars.

More information:
Pnina Cohen et al, Ancient DNA from a lost Negev Highlands desert grape reveals a Late Antiquity wine lineage, Proceedings of the National Academy of Sciences (2023). DOI: 10.1073/pnas.2213563120

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Scientists identify 2022 sea urchin killer: The mass die-off of the long-spined sea urchin — a loss that threatens the health of coral reefs from the Caribbean to Florida’s east coast — was caused by a one-celled organism called a ciliate.


The search for the 2022 killer that decimated the long-spined sea urchin population in the Caribbean and along Florida’s east coast is over. A team of researchers organized by Mya Breitbart, Distinguished University Professor at the University of South Florida’s College of Marine Science, identified a single-celled organism called a ciliate as the cause of a massive die-off event to a marine animal vital to coral reef health.

Their findings were reported in Science Advances.

“We’re beyond thrilled to get to the bottom of the 2022 mystery and a bit stunned we did it so quickly,” said Breitbart, senior author on the Science Advances study and an expert in marine genomics. “We had a great team in place and the tools needed to do the ocean science equivalent of a forensic investigation.”

Ciliates are microscopic organisms covered in hair-like structures called cilia that help them move and eat. They are found almost anywhere there is water and most are not disease-causing agents. However, this specific species of ciliate — called a scuticociliate — has been implicated in die-offs of other marine species, such as sharks, in the past.

Examining urchins collected from 23 sites in the Caribbean, the research team used a series of techniques to confirm the source of the die-off event.

After identifying the ciliate in every affected urchin specimen using genomic techniques, the team grew ciliates in the lab and performed infection experiments at the USF College of Marine Science. When the pathogen was introduced to otherwise healthy urchins in an aquarium tank, the urchins died within a few days — replicating what was taking place in the ocean and confirming the ciliate as the disease source.

“We’re excited to share this information with everyone, from reef managers to additional scientists so we can explore it further and try to stop its spread,” Breitbart said.

The long-spined sea urchins inhabit shallow tropical waters and feed on algae that would otherwise destroy a reef. They began to lose their spines within days of contracting an unknown disease and died in droves starting in January 2022.

A similar die-off event took place in the early 1980s, which wiped out 98 percent of the long-spined sea urchin population. The culprit of that die-off remains a mystery.

Breitbart first got the call about the unfolding die-off at the end of March 2022. She immediately assembled a team consisting of Ian Hewson, lead author on the publication and a marine ecologist at Cornell University; Christina Kellogg, a microbiologist from the U.S. Geological Survey in St. Petersburg, Fla. who has worked extensively on coral reef diseases; and USF graduate student Isabella Ritchie.

“At the time, we didn’t know if this die-off was caused by pollution, stress, something else — we just didn’t know,” said Hewson, an expert in diseases that cause mass die-offs of sea stars, who flew from New York to the Caribbean Islands to observe the situation.

Even with the source of the mysterious die-off uncovered, questions still remain. For example:

  • Is this ciliate new to the area, or was it there prior to the die-off?
  • If it has been there, what environmental conditions favored its growth and why did it infect the urchins?
  • Can it affect other species of urchins?

“One theory we have is that the ciliate grew well under high-productivity conditions that were observed in the Caribbean when the die-off first started,” Kellogg said. “We’re also curious about the fact that there is some overlap in some geographic areas where this die-off occurred and where corals are declining from stony coral tissue loss disease.”

The research was funded by the National Science Foundation, Atkinson Center for Sustainable Futures Rapid Response Award, AGGRA, the National Oceanic and Atmospheric Administration, National Fish and Wildlife Foundation, Florida Keys Marine Sanctuary and the Florida Fish and Wildlife Conservation Commission.

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Indian astronomers investigate open cluster NGC 1027


R/B-band color composite image of NGC 1027 from the Second Digitized Sky Survey (DSS2). Credit: DSS2

By analyzing the data from the 104-cm Sampurnanand Telescope (ST) and ESA’s Gaia satellite, astronomers from India have inspected a Galactic open cluster known as NGC 1027. Results of the study, published April 12 on the arXiv pre-print server, shed more light on the properties of this cluster.

Open clusters (OCs), formed from the same giant molecular cloud, are groups of stars loosely gravitationally bound to each other. So far, more than 1,000 of them have been discovered in the Milky Way, and scientists are still looking for more, hoping to find a variety of these stellar groupings. Expanding the list of known galactic and studying them in detail could be crucial for improving our understanding of the formation and evolution of our galaxy.

Located some 3,300 light years away in the eastern part of the Cassiopeia constellation, NGC 1027 (also known as Melotte 16 or Collinder 30) is an intermediate-age OC discovered by William Herschel in 1787. The cluster is estimated to be 355 million years old and its reddening was found to be at a level of 0.36 mag.

A team of astronomers led by Apara Tripathi of the Deen Dayal Upadhyaya Gorakhpur University in Gorakhpur, India, decided to perform a photometric and kinematic study of NGC 1027 in order to get more insights into its structural and fundamental parameters. For this purpose they analyzed the available data collected by ST and Gaia.

“We present the photometric and kinematic study of the intermediate-age open cluster NGC 1027 using UBV RIc data taken with the 1.04m Sampunanand telescope and Gaia EDR3 [Early Data Release 3] data,” the researchers wrote in the paper.

The study found that NGC 1027 has a radius of about 8.64 light years and that its center is approximately 2 arcminutes away from the center reported by previous observations. The mean proper motion for the cluster was measured to be -0.84 and 2.04 mas/year, in right ascension and declination, respectively.

The conducted a membership analysis of NGC 1027 and identified 217 member stars (with membership probability higher than 70%) in the cluster region. They noted that the distribution of proper motion of the stars in the cluster region shows a clear separation between the cluster members and field stars.

The researchers found that NGC 1027 has an age of some 130 million years, therefore, the cluster is younger than previously thought. The distance to NGC 1027 was measured to be about 3,700 and the cluster’s reddening was found to be 0.36—in good agreement with previous estimates.

The study conducted by Tripathi’s team also found that relatively massive stars are dominantly distributed in the inner regions of NGC 1027. The authors of the paper concluded that this suggests mass segregation, and they assume that the cluster is under the influence of external tidal interactions.

More information:
Apara Tripathi et al, Photometric and Kinematic study of the open cluster NGC 1027, arXiv (2023). DOI: 10.48550/arxiv.2304.05762

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A once-stable glacier in Greenland is now rapidly disappearing: Study finds warming Atlantic waters threaten previously stable glaciers


As climate change causes ocean temperatures to rise, one of Greenland’s previously most stable glaciers is now retreating at an unprecedented rate, according to a new study.

Led by researchers at The Ohio State University, a team found that between 2018 and 2021, Steenstrup Glacier in Greenland has retreated about 5 miles, thinned about 20%, doubled in the amount of ice it discharges into the ocean, and quadrupled in velocity. According to the study, such a rapid change is so extraordinary among Greenland ice formations that it now places Steenstrup in the top 10% of glaciers that contribute to the entire region’s total ice discharge.

The study was published today in Nature Communications.

The Steenstrup Glacier is part of The Greenland Ice Sheet, a body of ice that covers nearly 80% of the world’s largest island, which is also the single largest contributor to global sea rise from the cryosphere, the portion of Earth’s ecosystem that includes all of its frozen water. While the region plays a crucial part in balancing the global climate system, the area is steadily shrinking as it sheds hundreds of billions of tons of ice each year because of global warming.

Over the past few decades, much of this loss has been attributed to accelerated ice discharge from tidewater glaciers, glaciers that make contact with the ocean. Many glaciologists believe that this recent uptick in ice discharge can be explained by the intrusion of warming waters that are being swept from the Atlantic into Greenlandic fjords — critical oceanic gateways that can impact the stability of local glaciers and the health of polar ecosystems.

The research team aimed to test that theory by examining a glacier in the southeastern region of Greenland called K.I.V Steenstrups Nordre Bræ, an entity more colloquially known as the Steenstrup Glacier.

“Up until 2016, there was nothing to suggest Steenstrup was in any way interesting,” said Thomas Chudley, lead author of the study, who completed this work as a research associate at the Byrd Polar and Climate Research Center. Chudley is now a Leverhulme research fellow at Durham University in the UK.

“There were plenty of other glaciers in Greenland that had retreated dramatically since the 1990s and increased their contribution to sea level rise, but this really wasn’t one of them.”

As far as scientists knew, Steenstrup had not only been stable for decades but was generally insensitive to the rising temperatures that had destabilized so many other regional glaciers, likely because of its isolated position in shallow waters.

It wasn’t until Chudley and his colleagues compiled observational and modeling data from previous remote sensing analyses on the glacier that the team realized Steenstrup was likely experiencing melt due to anomalies in deeper Atlantic water.

“Our current working hypothesis is that ocean temperatures have forced this retreat,” Chudley said. “The fact that the glacier’s velocity has quadrupled in just a few years opens up new questions about how fast large ice masses can really respond to climate change.”

In recent years, glaciologists have been able to use satellite data to estimate the potential volume of glacial ice stored at the poles and how it might affect current sea levels. For instance, if the Greenland Ice Sheet were to melt, Earth’s sea levels could rise by nearly 25 feet. In contrast, if the ice sheet in Antarctica were to fall apart, it’s possible that oceans would rise by nearly 200 feet, Chudley said.

While Greenland and Antarctica would take centuries to collapse completely, the global cryosphere has the potential to cause sea levels to rise about six feet this century if the West Antarctic Ice Sheet undergoes collapse.

As around 10% of the planet’s population lives in low-lying coastal zones, Chudley said that any significant rise in sea level can cause increased risk to low-lying islands and coastal communities from storm surges and tropical cyclones.

In the United States, sea level rise poses a particular risk to coastal cities in places like Florida or Louisiana, Chudley said. But that doesn’t necessarily mean it’s too late to stop such a future from happening. If climate policies evolve rapidly, humans might have a chance at halting the worst of sea level rise, Chudley said.

Overall, Steenstrup’s unique behavior reveals that even long-term stable glaciers are susceptible to sudden and rapid retreat as warmer waters begin to intrude and influence new environments.

While the research says continued scientific observation of the Steenstrup Glacier should be a priority, it concludes other similar glaciers also deserve attention because of their potential to retreat due to warming waters.

Understanding more about these interactions could provide key insight into how glaciers thrive in other locations around the world and even become an indicator of how these environments might change in the future.

“What’s happening in Greenland right now is kind of the canary in the coal mine of what might happen in West Antarctica over the next few centuries,” Chudley said. “So it would be great to be able to get into the fjord with real on-the-ground observations and see how and why Steenstrup has changed.”

This work was supported by NASA. Other Ohio State co-authors were Ian M. Howat and Adelaide Negrete of the Byrd Polar and Climate Research Center. Michalea D. King of the University of Washington was also a co-author.

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Study links ‘stuck’ stem cells to hair turning gray


Certain stem cells have a unique ability to move between growth compartments in hair follicles, but get stuck as people age and so lose their ability to mature and maintain hair color, a new study shows.

Led by researchers from NYU Grossman School of Medicine, the new work focused on cells in the skin of mice and also found in humans called melanocyte stem cells, or McSCs. Hair color is controlled by whether nonfunctional but continually multiplying pools of McSCs within hair follicles get the signal to become mature cells that make the protein pigments responsible for color.

Publishing in the journal Nature online April 19, the new study showed that McSCs are remarkably plastic. This means that during normal hair growth, such cells continually move back and forth on the maturity axis as they transit between compartments of the developing hair follicle. It is inside these compartments where McSCs are exposed to different levels of maturity-influencing protein signals.

Specifically, the research team found that McSCs transform between their most primitive stem cell state and the next stage of their maturation, the transit-amplifying state, and depending on their location.

The researchers found that as hair ages, sheds, and then repeatedly grows back, increasing numbers of McSCs get stuck in the stem cell compartment called the hair follicle bulge. There, they remain, do not mature into the transit-amplifying state, and do not travel back to their original location in the germ compartment, where WNT proteins would have prodded them to regenerate into pigment cells.

“Our study adds to our basic understanding of how melanocyte stem cells work to color hair,” said study lead investigator Qi Sun, PhD, a postdoctoral fellow at NYU Langone Health. “The newfound mechanisms raise the possibility that the same fixed-positioning of melanocyte stem cells may exist in humans. If so, it presents a potential pathway for reversing or preventing the graying of human hair by helping jammed cells to move again between developing hair follicle compartments.”

Researchers say McSC plasticity is not present in other self-regenerating stem cells, such as those making up the hair follicle itself, which are known to move in only one direction along an established timeline as they mature. For example, transit-amplifying hair follicle cells never revert to their original stem cell state. This helps explain in part why hair can keep growing even while its pigmentation fails, says Sun.

Earlier work by the same research team at NYU showed that WNT signaling was needed to stimulate the McSCs to mature and produce pigment. That study had also shown that McSCs were many trillions of times less exposed to WNT signaling in the hair follicle bulge than in the hair germ compartment, which is situated directly below the bulge.

In the latest experiments in mice whose hair was physically aged by plucking and forced regrowth, the number of hair follicles with McSCs lodged in the follicle bulge increased from 15% before plucking to nearly half after forced aging. These cells remained incapable of regenerating or maturing into pigment-producing melanocytes.

The stuck McSCs, the researchers found, ceased their regenerative behavior as they were no longer exposed to much WNT signaling and hence their ability to produce pigment in new hair follicles, which continued to grow.

By contrast, other McSCs that continued to move back and forth between the follicle bulge and hair germ retained their ability to regenerate as McSCs, mature into melanocytes, and produce pigment over the entire study period of two years.

“It is the loss of chameleon-like function in melanocyte stem cells that may be responsible for graying and loss of hair color,” said study senior investigator Mayumi Ito, PhD, a professor in the Ronald O. Perelman Department of Dermatology and the Department of Cell Biology at NYU Langone Health.

“These findings suggest that melanocyte stem cell motility and reversible differentiation are key to keeping hair healthy and colored,” said Ito, who is also a professor in the Department of Cell Biology at NYU Langone.

Ito says the team has plans to investigate means of restoring motility of McSCs or of physically moving them back to their germ compartment, where they can produce pigment.

For the study, researchers used recent 3D-intravital-imaging and scRNA-seq techniques to track cells in almost real time as they aged and moved within each hair follicle.

Funding for the study was provided by National Institutes of Health grants P30CA016087, S10OD021747, R01AR059768, R01AR074995, and U54CA263001; and Department of Defense grants W81XWH2110435 and W81XWH2110510.

Besides Sun and Ito, other NYU Langone researchers involved in this study are co-investigators Wendy Lee, Hai Hu, Tatsuya Ogawa, Sophie De Leon, Ioanna Katehis, Chae Ho Lim, Makoto Takeo, Michael Cammer, and Denise Gay. Other study co-investigators are M. Mark Taketo, at Kyoto University in Japan, and Sarah Millar, at Icahn School of Medicine at Mount Sinai in New York City.

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Why this bird flu is different: Scientists say new avian influenza requires urgent coordinated response


A highly pathogenic avian influenza has been spreading in the U.S., making headlines as the price of eggs soared at the start of the year and fears of the next zoonotic pandemic creep into popular media. A University of Maryland (UMD)-led team of researchers tracked the arrival and progression of the deadly bird flu (H5N1) in North America to determine how this outbreak is different from previous ones.

The team found that the deadly impact on wild birds and a shift from seasonal to year-round infections signal dangerous changes in avian influenza in the U.S. They concluded that there is an urgent need for unprecedented coordination at a national and regional-scale to manage the spread of a disease reaching across jurisdictions and disciplines. The team also suggests that H5N1 will likely become endemic, potentially posing risks to food security and the economy.

The paper was published April 19, 2023, in the journal Conservation Biology.

“We’ve been dealing with low pathogenic avian influenza for decades in the poultry industry, but this is different.” said Jennifer Mullinax, assistant professor in the UMD Department of Environmental Science & Technology and a co-author of the study. Low pathogenic disease is less contagious and easier to contain than the highly pathogenic variety.

“This high pathogenic virus is wiping out everything in numbers that we’ve never seen before,” Mullinax said. “This paper illustrates how unprecedented it is, and describes what we think is coming. It’s really a call to arms saying, we can’t afford to address this from our individual silos. Federal agencies, state agencies, the agriculture sector and wildlife management, we are all going to have to deal with this together, because we can’t afford not to.”

The team’s conclusions are based on an analysis of five different data sources that provide information on the incidence of highly pathogenic avian influenza in wild birds and poultry focusing on the USA and Canada as well as a global database from 2014 through early 2023.

The data show the progression of highly pathogenic H5N1 as it spread from Eurasia to the U.S. where it was first documented in late 2021. By October 2022, the disease had resulted in 31 reported wild bird mass mortalities, accounting for an estimated 33,504 wild bird detections in the U.S. and Canada. In addition, more than 58 million domestic poultry were infected or had to be culled to limit the spread of infection in the U.S. and 7 million in Canada.

In 2015, an outbreak of highly pathogenic H5N8 in the U.S. led to the culling of 50 million poultry birds. But the disease was eradicated in North America that same year, largely because it did not seriously impact wild birds, which made containment through culling poultry relatively easy. But H5N1 poses new challenges.

“Unlike H5N8, this disease is heavily impacting wild birds,” said Johanna Harvey, a postdoctoral researcher at UMD and lead author of the study. “It’s difficult to estimate how many birds are truly affected across wild populations, but we’re seeing dramatic disease impacts in raptors, sea birds and colonial nesting birds. And we now have the highest amount of poultry loss to avian influenza, so this is a worst-case scenario.”

The data also reveals a shift from a seasonal to a year-round disease. Previous outbreaks of avian influenza — whether low pathogenic virus that is endemic in the U.S. or highly pathogenic H5N8 in 2015 — typically occurred in the fall, which meant farmers could prepare for seasonal outbreaks, cull flocks to halt the spread of disease, and have nearly a full year to recover losses. But this new virus appears sustained throughout the year, with summertime disease detections in wild birds and poultry outbreaks occurring in both the spring and fall.

Although declaring a disease endemic is a complicated process, the authors of the study suggest that the U.S. will likely follow patterns seen in Europe where highly pathogenic avian influenza is already being treated as an endemic disease rather than something that can be eradicated.

The research team recommends a management approach based on a method called Structured Decision-Making, which follows a specific process of identifying and bringing together relevant individuals with an interest, expertise or stake in an issue, distinguishing the unknown from the known factors and establishing measurable goals and actions with quantifiable results. The process is much like dealing with a human pandemic.

“Good decision science is what you do when you don’t know what is going to happen next,” said Mullinax, who teaches decision-making science. “This is a novel virus for North American birds, so no one knows if their immune systems will adapt, or how long that will take, or what that will look like. Where do we direct our funds for maximum benefit? Is it a vaccine? How do we track it in wild birds? Do we test the water or the soil? What are the triggers for different actions, and how do we measure if we’re succeeding? These decisions have to be made on multiple scales.”

The paper outlines examples of potential triggers for action, identifying the relevant decision-makers required to coordinate a response and some of the challenges that may come up. The researchers hope their work will bring key players to the table to consider the next steps.

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X-ray analysis sheds new light on prehistoric predator’s last meal


We now know more about the diet of a prehistoric creature that grew up to two and a half metres long and lived in Australian waters during the time of the dinosaurs, thanks to the power of x-rays and a team of scientists at The Australian National University (ANU) and the Australian Museum Research Institute (AMRI).

The researchers used micro-CT scans to peer inside the fossilised stomach remains of a small marine reptile — a plesiosaur nicknamed ‘Eric’ after a song from the comedy group Monty Python — to determine what the creature ate in the lead up to its death.

The researchers were able to find 17 previously undescribed fish vertebrae inside Eric’s gut, confirming the plesiosaur’s diet consisted mostly of fish — reinforcing findings from previous studies conducted in 2006.

The findings could help scientists learn more about the evolutionary history of extinct organisms such as Eric, as well as help predict what the future might look like for our marine life. According to the researchers, the study demonstrates the potential to use x-rays to reconstruct the diets of other extinct organisms that inhabited Earth hundreds of millions of years ago.

“Previous studies examined the exterior surface of Eric’s opalised skeleton to find clues,” PhD researcher Joshua White, from the ANU Research School of Physics and the AMRI, said.

“But this approach can be difficult and limiting as fossilised stomach contents are rare to find and there can more hidden beneath the surface that would be near impossible for palaeontologists to see without destroying the fossil.

“We believe our study is the first in Australia to use x-rays to study the gut contents of a prehistoric marine reptile.

“Our research employed very powerful x-rays to help us see the animal’s stomach contents in never-before-seen detail, including finding fish bones in its gut.

“The benefit of using x-rays to study these prehistoric animals is that it does not damage the fossil, which is incredibly important when dealing with valuable and delicate specimens such as Eric.”

Mr White sifted through mountains of data and CT imagery to differentiate between what he believed to be evidence of fish bones, gastroliths, also known as stomach stones, and other materials that the reptile had consumed. The data was used to create a 3D model of Eric’s gut contents.

“Eric was a mid-tier predator, sort of like a sea lion equivalent, that ate small fish and was likely preyed upon by larger, apex predators,” Mr White said.

“We are also lucky in the sense that Eric is one of the most complete opalised vertebrae skeletons in Australia. The fossil is approximately 93 per cent complete which is pretty much unheard of in any fossil record.

“There is practically nowhere else other than Australia that can actually get opalised vertebrae fossils.”

The ANU scientists say learning more about the diet of extinct organisms is an important step in understanding their evolutionary past, but it can also help us understand how animals alive today might be impacted by things such as climate change.

“As environments change, so too does a marine reptile’s diet and understanding these changes can be used to help predict how animals of today will respond to current and emerging climate challenges,” Mr White said.

“If there’s any change to an animals’ diet, we want to look at why this change occurred and by some measure we can compare this to modern animals such as dolphins or whales and try to predict how their diets might change due to climate change and why.”

Eric was first discovered in the opal mines in Coober Pedy in South Australia in 1987. The prehistoric predator is on display at the Australian Museum in Sydney.

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