These massive ripples through the upper atmosphere, known as atmospheric gravity waves, appear in AWE’s images as concentric bands (artificially colored here in red, yellow, and blue) extending away from northern Florida.

“Like rings of water spreading from a drop in a pond, circular waves from Helene are seen billowing westward from Florida’s northwest coast,” said Ludger Scherliess, who is the AWE principal investigator at Utah State University in Logan.

Launched in November 2023 and mounted on the outside of the International Space Station, the AWE instrument looks down at Earth, scanning for atmospheric gravity waves, ripple-like patterns in the air generated by atmospheric disturbances such as violent thunderstorms, tornadoes, tsunamis, wind bursts over mountain ranges, and hurricanes. It does this by looking for brightness fluctuations in colorful bands of light called airglow in Earth’s mesosphere. AWE’s study of these gravity waves created by terrestrial weather helps NASA pinpoint how they affect space weather.

These views of gravity waves from Hurricane Helene are among the first publicly released images from AWE, confirming that the instrument has the sensitivity to reveal the impacts hurricanes have on Earth’s upper atmosphere.

In 79 AD, Mount Vesuvius experienced one of its most significant eruptions, burying the Roman city of Pompeii and its inhabitants under a thick layer of small stones and ash known as lapilli. Many of Pompeii’s inhabitants lost their lives as their homes collapsed under the weight of the lapilli raining down from many kilometres above. Those who survived the initial phase of the eruption eventually succumbed to the dangerous pyroclastic flows. This fast-moving stream of hot gas and volcanic matter instantly enveloped their bodies in a solid layer of ash, effectively preserving their bodies, including their features.

Since the 1800s, casts had been made by pouring plaster into the voids left by these bodies after their decay. The research team extracted DNA from the heavily fragmented skeletal remains embedded in 14 of the 86 famous casts undergoing restoration. This extraction process allowed them to accurately establish genetic relationships, determine sex and trace ancestry. Interestingly, their findings largely contradicted previous assumptions based solely on physical appearance and the positioning of the casts.

Genetic relationships of victims revisited

“This research shows how genetic analysis can significantly add to the stories constructed from archaeological data,” says Professor David Caramelli, from the Department of Anthropology at the University of Florence. “The findings challenge enduring notions such as the association of jewellery with femininity or the interpretation of physical proximity as evidence of familial relationships.” “Moreover,” Caramelli adds, “the genetic evidence adds a layer of complexity to simple kinship narratives. For example, in the House of the Golden Bracelet, the only site where we have genetic information from multiple individuals, the four people traditionally thought to be the two parents and their children actually have no genetic ties to each other.”

“The scientific data we provide do not always align with common assumptions,” says David Reich of Harvard University. “For instance, one notable example is the discovery that an adult wearing a golden bracelet and holding a child, traditionally interpreted as a mother and child, were an unrelated adult male and child. Similarly, a pair of individuals thought to be sisters, or mother and daughter, were found to include at least one genetic male. These findings challenge traditional gender and familial assumptions.”

Cosmopolitan nature of the Roman Empire

The genetic data also provided information about the ancestry of the Pompeians, who had different genomic backgrounds. The finding that they were mainly descended from recent immigrants from the eastern Mediterranean highlights the cosmopolitan nature of the Roman Empire.

“Our findings have significant implications for the interpretation of archaeological data and the understanding of ancient societies,” says Alissa Mittnik of the Max Planck Institute for Evolutionary Anthropology. “They highlight the importance of integrating genetic data with archaeological and historical information to avoid misinterpretations based on modern assumptions. This study also underscores the diverse and cosmopolitan nature of Pompeii’s population, reflecting broader patterns of mobility and cultural exchange in the Roman Empire.”

“It is also likely that the use of these casts for narration purposes could have led to past restorers modifying their postures and placements,” adds David Caramelli. “The combined use of genetic data and other bioarchaeological methods provides us with the chance to better comprehend the lives and habits of the victims of the Vesuvius eruption.”

Gabriel Zuchtriegel, Director of the Pompeii Park, says, “The Pompeii Park has been including ancient DNA analysis in its study protocols for years, not only for human victims, but also for animal victims.” He explains that the Park manages a variety of research projects through its own laboratory. These include isotopic analysis, diagnostics, geology, volcanology and, in particular, reverse engineering. He stresses that “all these elements together contribute to a comprehensive, updated interpretation of the archaeological findings. These efforts are turning Pompeii into a veritable incubator for the development of new methods, resources and scientific comparisons.” Zuchtriegel concludes: “From this point of view, this study marks a true change in perspective, in which the site itself plays a central role in advancing archaeology and research.”

The research, published today in The Astrophysical Journal Letters, introduces a method that could provide direct evidence of photons circling black holes due to an effect known as “gravitational lensing.”

Gravitational lensing occurs when light passes near a black hole and its path is bent by the black hole’s strong gravitational field. The effect allows the light to take multiple paths from a source to an observer on Earth: some light rays might follow a direct route while others could loop around the black hole once — or multiple times — before reaching us. This means that light from the same source can arrive at different times, resulting in an “echo.”

“That light circles around black holes, causing echoes, has been theorized for years, but such echoes have not yet been measured,” says the study’s lead author, George N. Wong, Frank and Peggy Taplin Member in the Institute’s School of Natural Sciences and Associate Research Scholar at the Princeton Gravity Initiative at Princeton University. “Our method offers a blueprint for making these measurements, which could potentially revolutionize our understanding of black hole physics.”

The technique allows the faint echo signatures to be isolated from the stronger direct light captured by well-known interferometric telescopes, such as the Event Horizon Telescope. Both Wong and one of his co-authors, Lia Medeiros, Visitor in the Institute’s School of Natural Sciences and NASA Einstein Fellow at Princeton University, have worked extensively as part of the Event Horizon Telescope Collaboration.

To test their technique, Wong and Medeiros, working alongside James Stone, Professor in the School of Natural Sciences, and Alejandro Cárdenas-Avendaño, Feynman Fellow at Los Alamos National Laboratory and former Associate Research Scholar at Princeton University, ran high-resolution simulations which took tens of thousands of “snapshots” of light traveling around a supermassive black hole akin to that at the center of the M87 galaxy (M87*), which is located around 55 million light-years away from Earth. Using these simulations, the team demonstrated that their method could directly infer the echo delay period in the simulated data. They believe that their technique will be applicable to other black holes, in addition to M87*.

“This method will not only be able to confirm when light orbiting a black hole has been measured, but will also provide a new tool for measuring the black hole’s fundamental properties,” explains Medeiros.

Understanding these properties is important. “Black holes play a significant role in shaping the evolution of the universe,” says Wong. “Even though we often focus on how black holes pull things in, they also eject large amounts of energy into their surroundings. They play a major role in the development of galaxies, affecting how, when, and where stars form, and helping to determine how the structure of the galaxy itself evolves. Knowing the distribution of black hole masses and spins, and how the distribution changes over time, greatly enhances our understanding of the universe.”

Measuring the mass or spin of a black hole is tricky. The nature of the accretion disk, namely the rotating structure of hot gas and other matter spiraling inward towards a black hole, can “confuse” the measurement, Wong notes. Light echoes provide an independent measurement of the mass and spin, however, and having multiple measurements allows us to produce an estimate for those parameters “that we can really believe in,” states Medeiros.

Detecting light echoes might also enable scientists to better test Albert Einstein’s theories of gravity. “Using this technique, we might find things that make us think ‘hey, this is weird!'” adds Medeiros. “The analysis of such data could help us to verify whether black holes are indeed consistent with general relativity.”

The team’s results suggest that it may be possible to detect echoes with a pair of telescopes — one on Earth and one in space — working together to perform what can be described as “very long baseline interferometry.” Such an interferometric mission need only be “modest,” states Wong. Their technique provides a tractable, practical method to gather important, reliable information about black holes.

The research was published online September 28 in the journal Nature Communications.

Deep in a tumor, full of rapidly dividing cells, cancer cells are faced with a lack of oxygen, a condition called hypoxia. Cancer cells that survive these tough environments end up seeking what they missed, slowly making their way to the oxygen-rich bloodstream and often seeding metastasis elsewhere in the body, explains lead study author Daniele Gilkes, Ph.D., an assistant professor of oncology at Johns Hopkins.

The team identified 16 genes responsible for this protection from reactive oxygen species, “which is a stress that occurs when the cells enter the bloodstream,” Gilkes says. “Although the hypoxic cells are localized in what we call the perinecrotic region of a tumor — meaning they’re sitting right next to dead cells — we think that they’re able to migrate into higher [oxygen] levels where they can actually find the bloodstream,” she says. “Cells able to survive super-low oxygen concentrations do a better job of surviving in the bloodstream. This is how, even after a tumor is removed, we sometimes find that cancer cells have set up elsewhere in the body. Lower levels of oxygen in a tumor correlate with worse prognosis.”

The scientists sought to learn what helps these post-hypoxic cells survive in an environment that would kill other cancer cells, and which genes were being turned on to facilitate survival.

In laboratory studies, Gilkes’ team color-coded hypoxic cells green, then applied a technique called spatial transcriptomics to identify which genes were turned on in the perinecrotic region, and that stayed on when the cells migrated to more oxygenated tumor regions. They compared cells in the primary tumors of mice with those that had entered the blood stream or the lungs. A subset of hypoxia-induced genes continued to be expressed long after cancer cells escaped the initial tumor.

“The results suggest the potential for a sort of memory of exposure to hypoxic conditions,” says Gilkes.

The new research showed a disparity between what occurs in laboratory models and what happens in the human body, solving a mystery that was puzzling scientists. When cells in a dish are hypoxic and returned to high levels of oxygen in a short time, they tend to stop expressing the (hypoxia-induced) genes and go back to normal. However, in tumors, hypoxia can be more of a chronic condition, not acute. When Gilkes’ team exposed cells to hypoxia for a longer period — five days was usually enough — they mimicked what was happening in the mouse models.

Results were particularly predictive for triple-negative breast cancer (TNBC), which has a high rate of recurrence. The researchers found that patient biopsies from TNBC that had recurred within three years had higher levels of a protein called MUC1.

As part of their research model, Gilkes and team blocked MUC1 using a compound called GO-203 to see if it would reduce the spread of breast cancer cells to the lung. Their aim was to specifically eliminate aggressive, post-hypoxic metastatic cells.

“If we reduced the level of MUC1 in these hypoxic cells, they were no longer able to survive in the bloodstream or in presence of reactive oxygen species, and they formed fewer metastases in mice,” Gilkes says. However, there are other factors at play, she says, and additional research will be needed to see if this finding is true across cancer types.

A phase I/II clinical trial targeting MUC1 for patients with advanced cancers across a variety of solid tumor types — including those found in breast, ovarian, and colorectal cancer — is ongoing, Gilkes says.

Study co-authors were Inês Godet, Harsh Oza, Yi Shi, Natalie Joe, Alyssa Weinstein, Jeanette Johnson, Michael Considine, Swathi Talluri, Jingyuan Zhang, Reid Xu, Steven Doctorman, Genevieve Stein-O’Brien, Luciane Kagohara, Cesar Santa-Maria and Elana Fertig, from Johns Hopkins, and Delma Mbulaiteye from the NIDDK STEP-UP Program at the National Institutes of Health.

The work was funded by The Jayne Koskinas Ted Giovanis Foundation for Health and Policy, the NCI/ SKCCC Core grant number P50CA006973, NCI grant number 5U01CA253403-03, and the National Cancer Center.

Santa-Maria has received research funds from AstraZeneca, GSK/ Tesaro, Merck, Gilead, Celldex, BMS and Pfizer, and consulting fees from Seattle Genetics. Fertig serves on the scientific advisory board of Resistance Bio, is a consultant for Merck and Mestag Therapeutics, and has received research funding from Abbvie, Inc. and Roche/Genentech. These relationships are managed by The Johns Hopkins University in accordance with its conflict-of-interest policies.

A campuswide collaboration is using sewage surveillance as a vital strategy in the fight against diseases that spread through the water such as legionella and shigella. The ones that are most difficult to combat are diseases with antimicrobial resistance, which means they are able to survive against antibiotics that are intended to kill them.

A recent paper in Nature Water offers an encouraging insight: Monitoring sewage for antimicrobial resistance indicators is proving to be more efficient and more comprehensive than testing individuals. This approach not only detects antimicrobial resistance more effectively but also reveals its connection to socioeconomic factors, which are often key drivers of the spread of resistance.

The team is collaborating across Virginia Tech with experts such as Leigh-Anne Krometis in biological systems engineering and Alasdair Cohen and Julia Gohlke in population health sciences to focus on serving rural communities where the issues are most acute.

Globally, low-to middle-income communities bear the brunt of infectious diseases and the challenges of antimicrobial resistance. Sewage surveillance could be a game changer in addressing these disparities. This method not only captures a snapshot of antimicrobial resistance at the community level, but also reveals how socioeconomic factors drive the issue.

The National Science Foundation Research Traineeship focuses on advancing sewage surveillance to combat antimicrobial resistance. The work is integral to broader efforts led by Vikesland and the Fralin Life Sciences Institute program for technology enabled environmental surveillance and control to sense and monitor waterborne health threats.

The study analyzed data from 275 human fecal samples across 23 countries and 234 urban sewage samples from 62 countries to investigate antibiotic resistance gene levels. Socio-economic data, including health and governance indicators from World Bank databases, were incorporated to explore links between antibiotic resistance genes and socio-economic factors. The group utilized machine learning to assess antibiotic resistance gene abundance in relation to socio-economic factors, revealing significant correlations. Statistical methods supported the finding that within country antibiotic resistance gene variation was lower than between countries.

Big picture, the team’s findings show sewage surveillance is emerging as a powerful tool in the fight against antimicrobial resistance. It even has the potential to protect vulnerable communities more effectively.

The study led by Xuehua Zhong, a professor of biology in Arts & Sciences, was published Nov. 6 in Science Advances.

Zhong’s new research focuses on DNA methylation, a normal biological process in living cells wherein small chemical groups called methyl groups are added to DNA. This activity controls which genes are turned on and off, which in turn affects different traits — including how organisms respond to their environments.

Part of this job involves silencing, or turning off, certain snippets of DNA that move around within an organism’s genome. These so-called jumping genes, or transposons, can cause damage if not controlled. The entire process is regulated by enzymes, but mammals and plants have developed different enzymes to add methyl groups.

“Mammals only have two major enzymes that add methyl groups in one DNA context, but plants actually have multiple enzymes that do that in three DNA contexts,” said Zhong, who is the Dean’s Distinguished Professorial Scholar and program director for plant and microbial biosciences at WashU. “This is the focus of our study. The question is — why do plants need extra methylation enzymes?”

Looking forward, Zhong’s research could pave the way for innovations in agriculture by improving crop resilience. “Certain genes or combinations of genes are contributing to certain features or traits,” Zhong explained. “If we find precisely how they are regulated, then we can find a way to innovate our technology for crop improvement.”

Evolving differernt functions

The new study is centered around two enzymes specifically found in plants: CMT3 and CMT2. Both enzymes are responsible for adding methyl groups to DNA, but CMT3 specializes in the parts of DNA called the CHG sequences, while CMT2 specializes in different parts called CHH sequences. Despite their functional differences, both enzymes are a part of the same chromomethylase (CMT) family, which evolved through duplication events that provide plants with additional copies of genetic information.

Using a common model plant called Arabidopsis thaliana, or thale cress, Zhong and her team investigated how these duplicated enzymes evolved different functions over time. They discovered that somewhere along the evolutionary timeline, CMT2 lost its ability to methylate CHG sequences. This is because it’s missing an important amino acid called arginine.

“Arginine is special because it has charge,” said Jia Gwee, a graduate student in biology and co-first author of the study. “In a cell, it’s positively charged and thus can form hydrogen bonds or other chemical interactions with, for example, the negatively charged DNA.”

However, CMT2 has a different amino acid — valine. “Valine is not charged, so it is unable to recognize the CHG context like CMT3. That’s what we think contributes to the differences between the two enzymes,” said Gwee, winner of the Dean’s Award for Graduate Research Excellence in Arts & Sciences.

To confirm this evolutionary change, the Zhong lab used a mutation to switch arginine back into CMT2. As they expected, CMT2 was able to perform both CHG and CHH methylation. This suggests that CMT2 was originally a duplicate of CMT3, a backup system to help lighten the load as DNA became more complex: “But instead of simply copying the original function, it developed something new,” Zhong explained.

This research also provided insights about CMT2’s unique structure. The enzyme has a long, flexible N-terminal that controls its own protein stability. “This is one of the ways plants evolved for genome stability and to fight environmental stresses,” Zhong said. This feature may explain why CMT2 evolved in plants growing in such a wide variety of conditions worldwide.

Much of the data for this study came from the 1001 Genomes Project, which aims to discover whole-genome sequence variation in A. thaliana strains from around the globe.

“We’re going beyond laboratory conditions,” Zhong said. “We’re looking at all of the wild accessions in plants using this larger data set.” She believes part of the reason A. thaliana has evolved to thrive despite environmental stresses is because of the diversification that happens during the methylation process, including those jumping transposons: “One jump might help species deal with harsh environmental conditions.”