The new study, led by Artemis Tsantiri, who conducted the work as a graduate student at the Facility for Rare Isotope Beams (FRIB) and is now a postdoctoral fellow at the University of Regina in Canada, achieved a milestone. For the first time, researchers directly measured how arsenic-73 captures a proton to form selenium-74 using a rare isotope beam. This result places new limits on how the lightest p-nucleus is created and destroyed in space.

The findings were published in Physical Review Letters (“Constraining the Synthesis of the Lightest 𝑝 Nucleus ⁷⁴Se”) and involved more than 45 scientists from 20 institutions across the United States, Canada, and Europe.

Why Some Elements Remain a Mystery

A key goal in nuclear astrophysics is to understand where the elements come from. Many elements heavier than iron are formed through slow and rapid neutron-capture processes. In these reactions, atomic nuclei repeatedly absorb neutrons and then undergo radioactive decay until they reach stable forms.

However, this explanation does not apply to a special group of proton-rich isotopes. These p-nuclei cannot be produced through neutron capture. They span a range from selenium-74, the lightest, to mercury-196, the heaviest, and their origin has remained unclear for decades.

Supernova Explosions and the Gamma Process

One leading explanation for the creation of p-nuclei is the gamma process, which takes place in certain types of supernova explosions. In these extreme environments, intense heat produces gamma rays that strip neutrons and other particles from existing heavy nuclei.

After this process, the remaining nuclei contain more protons than neutrons. Over time, some of these nuclei convert protons into neutrons, moving toward a more stable balance and eventually forming p-nuclei.

Many of the isotopes involved in this process are short-lived and difficult to produce in the lab. Because of this, scientists have had to rely heavily on theoretical models rather than direct measurements.

“Even though the origin of the p-nuclei has been a topic of study for over 60 years, measurements of important reactions on short-lived isotopes are almost non-existent,” said Tsantiri. “Experiments of this kind are only now possible with facilities like FRIB.”

Recreating a Stellar Reaction in the Lab

In this study, researchers successfully recreated a key step in the process by observing proton capture on radioactive arsenic-73 for the first time. To do this, they generated a beam of arsenic-73 specifically for the experiment and directed it into a chamber filled with hydrogen gas. The hydrogen served as a source of protons and was positioned at the center of the Summing Nal (SuN) detector.

The team produced the arsenic-73 using FRIB’s ReA accelerator, which they operated in a standalone configuration rather than relying on the main linear accelerator. The radiochemistry group, led by Katharina Domnanich, prepared the material in a form suitable for use in the experiment. The isotope was then placed into a batch-mode ion source, where it was ionized, accelerated to high energies, and delivered to the target. This setup demonstrated the flexibility of ReA for producing and studying rare isotopes.

Tracking How Selenium-74 Is Formed and Destroyed

During the reaction, arsenic-73 absorbs a proton and becomes selenium-74 in an excited state. It then releases a gamma ray to reach a stable state. The researchers focused on the reverse reaction because it plays a key role in the gamma process inside stars. By measuring the forward reaction, they could determine how quickly the reverse process occurs.

To understand how much selenium-74 exists in the solar system, scientists must consider both its creation and its destruction. One of the biggest remaining uncertainties has been how often selenium-74 is broken apart by gamma rays during stellar explosions.

Improved Models but New Questions Remain

When the researchers incorporated their measurements into astrophysical models, they reduced the uncertainty in the predicted abundance of selenium-74 by half. This marks a significant improvement in understanding how this isotope is produced.

Even so, the updated models still do not fully match what is observed in nature. This gap suggests that scientists may need to refine their assumptions about the conditions inside supernova explosions.

“These results bring us a step closer to understanding the origins of some of the rarest isotopes in the universe,” said Artemis Spyrou, professor of physics at FRIB and in the Michigan State University Department of Physics and Astronomy, research advisor to Tsantiri, and original architect of the experiment. “Tsantiri’s work is a nice example of the multidisciplinary collaborations needed for advancing the field, and of the kind of professional development opportunities for early career researchers at FRIB.”

Collaboration and Support

This research was supported in part by the U.S. Department of Energy Office of Science Office of Nuclear Physics; the U.S. National Science Foundation; the U.S. National Nuclear Security Administration; and the Natural Sciences and Engineering Research Council of Canada.

The isotope(s) used in this research was supplied by the U.S. Department of Energy Isotope Program, managed by the Office of Isotope R&D and Production.

The research team found no signs of widespread overhunting. Instead, they point to a combination of factors, including climate change, invasive species, and shifts in land use. Many of these changes occurred either before Polynesians arrived in Hawaiʻi or after traditional Indigenous land management practices were disrupted. The study also suggests that several waterbird species now considered endangered may have reached their highest numbers just before European contact, when wetland management was a central part of Kānaka ʻŌiwi (Native Hawaiian) society.

Rethinking Conservation Assumptions

“So much of science is biased by the notion that humans are inevitable agents of ecocide, and we destroy nature wherever we go. This idea has shaped the dominant narrative in conservation, which automatically places the blame for extinctions on the first people — the Indigenous People — of a place. Even where there is zero scientific evidence to support it, the myth of Hawaiians hunting birds to extinctions took root in Hawaiʻi and for decades has been taught as if it was a scientific fact,” shares Kawika Winter, associate professor at UH Mānoa Hawaiʻi Institute of Marine Biology (HIMB), director of the Heʻeia National Estuarine Research Reserve (NERR), and co-author of the paper. “Our study not only dispels this myth, but also contributes to a growing body of evidence that Indigenous stewardship represents the best ways for native birds to thrive in a world where humans are not going away.”

The study revisits existing data while setting aside a common assumption that humans are inherently harmful to natural systems. By doing so, it offers a more detailed and balanced view of ecological history and highlights the need for more careful interpretation in conservation science.

“Science has matured to a point where graduate students are being trained to challenge its own long-standing world view,” notes Kristen Harmon, lead author on the paper who recently earned a PhD from UH Mānoa College of Tropical Agriculture and Human Resilience (CTAHR) Department of Natural Resources and Environmental Management. “Our interpretation of historical ecology, how ecological systems change over time, influences our approaches to solving global-scale ecological problems. Bringing together information from different disciplines and knowledge systems can yield a more accurate picture of reality, which is ultimately the goal of every scientist.”

Indigenous Stewardship and Bird Recovery

The findings could play an important role in shaping conservation strategies across Hawaiʻi, especially for endangered waterbirds such as ʻalae ʻula (Gallinula chloropus) and ʻaeʻo (Himantopus mexicanus knudseni). Researchers say that restoring traditional systems may be key to helping these species recover.

“Recent studies support what Hawaiians have always known — that restoration of loʻi (wetland agro-ecosystems) is critically important to bring these waterbirds into abundance again,” said Melissa Price, an Associate Professor who runs the Wildlife Ecology Lab at CTAHR. “If we wish to transform our islands from the ‘Extinction Capital of the World’ into the ‘Recovery Capital of the World,’ we need to restore relationships between nature and communities.”

This updated understanding may also help resolve tensions that have existed between conservation groups and Native Hawaiian communities, opening the door to more inclusive approaches.

Ulalia Woodside Lee, who was not a part of this research project, offered some reflections as the Hawai’i and Palmyra Executive Director for The Nature Conservancy, “For generations, Native Hawaiians have been criticized for causing the extinctions of our precious native birds. This has contributed to a breakdown in trust between the Hawaiian community and conservationists, and the exclusion of Native Hawaiians from important conservation decisions. This study will help us to move past those untruths, so that we can all move together into a brighter future where our native species are thriving again.”

A new study suggests a path toward next-generation cancer treatments by training the immune system to respond more efficiently and aggressively. The research was led by PhD student Omri Yosef and Prof. Michael Berger from the Faculty of Medicine at Hebrew University, working with Prof. Magdalena Huber of Philipps University of Marburg and Prof. Eyal Gottlieb of the University of Texas MD Anderson Cancer Center. Together, the international team found that adjusting how immune cells handle energy can greatly improve their ability to eliminate cancer.

At the center of this work is a key idea: when T cells, which play a central role in immune defense, are forced to alter how they convert energy, they become much better at detecting and attacking cancer cells.

Blocking Ant2 Boosts T Cell Power

“By disabling Ant2, we triggered a complete shift in how T cells produce and use energy,” explains Prof. Berger. “This reprogramming made them significantly better at recognizing and killing cancer cells.” In simpler terms, shutting down this protein pushes immune cells to adapt their metabolism, transforming them into stronger, faster, and more aggressive cancer fighters.

Mitochondria and Cellular Energy Rewiring

Published in Nature Communications, the study focuses on the mitochondria, the “metabolic hub” of cells. By intentionally disrupting a specific energy pathway inside T cells, the researchers effectively rewired the cells’ internal engines, placing them in a heightened state of readiness. These modified T cells showed improved endurance, multiplied more quickly, and targeted cancer cells with greater precision.

From Lab Discovery to Potential Treatments

One of the most important findings is that this metabolic shift can be triggered not only through genetic changes but also with drugs. This raises the possibility of translating the discovery into real-world therapies.

This research is part of a broader trend in cancer immunotherapy that goes beyond guiding the immune system and instead focuses on upgrading how it functions at a fundamental level. While further studies and clinical trials are still needed, the results highlight the potential for treatments that harness and enhance the body’s own defenses.

“This work highlights how deeply interconnected metabolism and immunity truly are,” says Prof. Berger. “By learning how to control the power source of our immune cells, we may be able to unlock therapies that are both more natural and more effective.”