SPACE/COSMOS
Mysterious glow in Milky Way could be evidence of dark matter
New simulations tilt the scales for competing theories about excess gamma ray light at the center of the galaxy
Johns Hopkins University
Johns Hopkins researchers may have identified what could be a compelling clue in the ongoing hunt to prove the existence of dark matter.
A mysterious diffuse glow of gamma rays near the center of the Milky Way has stumped researchers for decades, as they’ve tried to discern whether the light comes from colliding particles of dark matter or quickly spinning neutron stars.
It turns out that both theories are equally likely, according to new research published today in the journal Physical Review Letters.
If excess gamma light is not from dying stars, it could become the first proof that dark matter exists.
“Dark matter dominates the universe and holds galaxies together. It’s extremely consequential and we’re desperately thinking all the time of ideas as to how we could detect it,” said co-author Joseph Silk, a professor of physics and astronomy at Johns Hopkins and a researer at the Insitut d’Astrophyque de Paris and Sorbonne University. “Gamma rays, and specifically the excess light we’re observing at the center of our galaxy, could be our first clue.”
Silk and an international team of researchers used supercomputers to create maps of where dark matter should be located in the Milky Way, taking into account for the first time the history of how the galaxy formed.
Today, the Milky Way is a relatively closed system, without materials coming in or going out of it. But this hasn’t always been the case. During the first billion years, many smaller galaxy-like systems made of dark matter and other materials entered and became the building blocks of the young Milky Way. As dark matter particles gravitated toward the center of the galaxy and clustered, the number of dark matter collisions increased.
When the researchers factored in more realistic collisions, their simulated maps matched actual gamma ray maps taken by the Fermi Gamma-ray Space Telescope.
These matching maps round out a triad of evidence that suggests excess gamma rays in the center of the Milky Way could originate with dark matter. Gamma rays coming from dark matter particle collisions would produce the same signal and have the same properties as those observed in the real-world, the researchers said — though it’s not definitive proof.
Light emitted from reinvigorated, old neutron stars that spin quickly—called millisecond pulsars—could also explain the existing gamma ray map, measurements and signal signature. But, this millisecond pulsar theory is imperfect, the researchers said. To make those calculations work, researchers have to assume there are more millisecond pulsars in existence than what they’ve observed.
Answers may come with the construction of a huge new gamma ray telescope called the Cherenkov Telescope Array. Researchers believe data from the higher-resolution telescope, which has the capacity to measure high-energy signals, will help astrophysicists break the paradox.
The research team is planning a new experiment to test whether these gamma rays from the Milky Way have higher energies, meaning they are millisecond pulsars, or are the lower energy product of dark matter collisions.
“A clean signal would be a smoking gun, in my opinion,” Silk said.
In the meantime, the researchers will work on predictions about where they should find dark matter in several select dwarf galaxies that circle the Milky Way. Once they’ve mapped their predictions, they can compare them to the hi-res data.
“It’s possible we will see the new data and confirm one theory over the other,” Silk said. “Or maybe we’ll find nothing, in which case it’ll be an even greater mystery to resolve.”
Journal
Physical Review Letters
Article Title
Fermi-LAT Galactic Center Excess morphology of dark matter in simulations of the Milky Way galaxy
Article Publication Date
16-Oct-2025
Are there living microbes on Mars? Check the ice, researchers say
Study by researchers at Penn State and NASA reveals intact biomolecules from dormant microbes degrade far slower in pure water ice than mixed soil samples
Penn State
UNIVERSITY PARK, Pa. — Frozen in time, ancient microbes or their remains could be found in Martian ice deposits during future missions to the Red Planet. By recreating Mars-like conditions in the lab, a team of researchers from NASA Goddard Space Flight Center and Penn State demonstrated that fragments of the molecules that make up proteins in E. coli bacteria, if present in Mars’ permafrost and ice caps, could remain intact for over 50 million years, despite harsh and continuous exposure to cosmic radiation. In the study, published in Astrobiology, the researchers encouraged future missions searching for life on Mars to target locations with pure ice or ice-dominated permafrost for exploration, as opposed to studying rocks, clay or soil.
“Fifty million years is far greater than the expected age for some current surface ice deposits on Mars, which are often less than two million years old, meaning any organic life present within the ice would be preserved,” said co-author Christopher House, professor of geosciences, affiliate of the Huck Institutes of the Life Sciences and the Earth and Environment Systems Institute, and director of the Penn State Consortium for Planetary and Exoplanetary Science and Technology. “That means if there are bacteria near the surface of Mars, future missions can find it.”
The research team, led by corresponding author Alexander Pavlov, a space scientist at NASA Goddard — who completed a doctorate in geosciences at Penn State in 2001 — suspended and sealed E. coli bacteria in test tubes containing solutions of pure water ice. Other E. coli samples were mixed with water and ingredients found in Mars sediment, like silicate-based rocks and clay.
The researchers froze the samples and transferred them to a gamma radiation chamber at Penn State’s Radiation Science and Engineering Center, which was cooled to minus 60 degrees Fahrenheit, the temperature of icy regions on Mars. Then, the samples were blasted with radiation equivalent to 20 million years of cosmic ray exposure on Mars’ surface, vacuum sealed and transported back to NASA Goddard under cold conditions for amino acid analysis. Researchers modelled an additional 30 years of radiation for a total 50-million-year timespan.
In pure water ice, more than 10% of the amino acids — the molecular building blocks of proteins — from the E. coli sample survived the simulated 50-million-year timespan, while the samples containing Mars-like sediment degraded 10 times faster and did not survive. A 2022 study by the same group of researchers at NASA found that amino acids preserved in a 10% water ice and 90% Martian soil mixture were destroyed more rapidly than samples containing only sediment.
“Based on the 2022 study findings, it was thought that organic material in ice or water alone would be destroyed even more rapidly than the 10% water mixture,” Pavlov said. “So, it was surprising to find that the organic materials placed in water ice alone are destroyed at a much slower rate than the samples containing water and soil.”
That degradation could be due to a slippery film that forms in areas where ice touches minerals, the researchers hypothesized, allowing radiation to reach and destroy amino acids.
“While in solid ice, harmful particles created by radiation get frozen in place and may not be able to reach organic compounds,” Pavlov said. “These results suggest that pure ice or ice-dominated regions are an ideal place to look for recent biological material on Mars.”
In addition to testing for conditions on Mars, researchers also tested organic material in temperatures similar to those on Europa, an icy moon of Jupiter, and Enceladus, an icy moon of Saturn. They found that these even colder temperatures further reduced the rate of deterioration.
Those results are encouraging to NASA’s Europa Clipper mission, Pavlov said, which will explore the ice shell and ocean of Europa, the fourth largest of Jupiter’s of 95 moons. Europa Clipper launched in 2024 and is traveling 1.8 billion miles to reach Jupiter in 2030. It will conduct 49 close flybys of Europa to assess whether there are places below the surface that could support life.
For exploring ice on Mars, the 2008 NASA Mars Phoenix mission was the first to excavate down and capture photos of ice in the Mars equivalent of the Arctic Circle.
“There is a lot of ice on Mars, but most of it is just below the surface,” House said. “Future missions need a large enough drill or a powerful scoop to access it, similar to the design and capabilities of Phoenix.”
In addition to House and Pavlov, the co-authors include Zhidan Zhang, a retired lab technologist in the Penn State Department of Geosciences; and Hannah McLain, Kendra Farnsworth, Daniel Glavin, Jamie Elsila and Jason Dworkin, all researchers at NASA Goddard.
NASA’s Planetary Science Division Internal Scientist Funding Program through the Fundamental Laboratory Research work package at Goddard Space Flight Center supported this research.
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Learn more about the implications of federal funding cuts to our future at Research or Regress.
Journal
Astrobiology
Method of Research
Experimental study
Subject of Research
Cells
Article Title
Slow Radiolysis of Amino Acids in Mars-Like Permafrost Conditions: Applications to the Search for Extant Life on Mars
Planet formation depends on when it happens: UNLV model shows why
In new study, published in Astrophysical Journal Letters, collaboration of scientists detail recent observations explaining how planets form over time.
University of Nevada, Las Vegas
A new study led by UNLV scientists sheds light on how planets, including Earth, formed in our galaxy – and why the life and death of nearby stars are an important piece of the puzzle.
In a paper published Sept. 23 in the Astrophysical Journal Letters, researchers at UNLV in collaboration with scientists from the Open University of Israel for the first time modeled details about how the timing of planet formation in the history of the galaxy affects planetary composition and density.
“Materials that go into making planets are formed inside of stars that have different lifetimes,” says Jason Steffen, associate professor with the UNLV Department of Physics and Astronomy and the paper’s lead author. “These findings help explain why older, rocky planets are less dense than younger planets like the Earth, and also suggest that the necessary ingredients for life didn’t arrive all at once.”
Timing is Everything in Planetary Construction
All the basic elements that make up planets – like oxygen, silicon, iron, and nickel – are formed inside stars. Planets are essentially built from the debris of dying stars, but the stars die on vastly different timelines which can influence the structure of forming planets as a result.
High-mass stars burn out relatively quickly, typically within 10 million years, and when they explode they scatter lighter elements like oxygen, silicon, and magnesium into space. These materials are generally what make up the outer layers of rocky planets.
Low-mass stars live for billions of years and release heavier elements like iron and nickel, key elements for the formation of planetary cores.
Planets forming in solar systems where both high-mass and low-mass stars had time to contribute materials to the planetary disk will contain a greater variety of those elements. Those forming from the evolution and death of high-mass stars tend to have larger mantles and smaller cores. When time is allowed for low-mass stars to contribute heavier elements with greater abundance, such as iron and nickel, planet cores are larger.
Over the last decade, the research team had created software models for various niche projects, but only recently realized that it had all the pieces to create the first fully integrated planet formation model of this kind.
“It was like having the solution in hand, waiting for the right problem. When the new observations were published, we realized we could model the full system with just a small addition of code at the beginning,” says Steffen.
This simulation tracks the entire life cycle of planet formation from star birth and element synthesis to explosions, collisions, planet formation, and the planetary internal structure.
“One implication of these findings is that the conditions for life don’t start immediately,” says Steffen. “A lot of the elements needed for a habitable planet, and for living organisms, are made available at different times throughout galactic history.”
Publication Details
The paper, “Effect of Galactic Chemical Evolution on Exoplanet Properties,” was published Sept. 23, 2025 in the Astrophysical Journal Letters. In addition to Steffen, collaborators include Cody Shakespeare and Robert Royer with the Nevada Center for Astrophysics and UNLV Department of Physics and Astronomy; and David Rice and Allona Vazan with the Astrophysics Research Center at The Open University of Israel.
Journal
The Astrophysical Journal Letters
Article Title
Effect of Galactic Chemical Evolution on Exoplanet Properties
A hitchhiker's guide to the galaxy of space immunology
Buck scientists help define the scope of Astroimmunology
image:
In space, weakened immune function elevates disease risk. Continuous monitoring and targeted interventions are being proposed to protect astronaut immune health, while preventive measures aim to minimize long-term immune compromise.
view moreCredit: Huixan Du, Buck Institute for Research on Aging
With the advent of commercial spaceflight, an increasing number of people may be heading into space in the coming years. Some will even get a chance to fly to the Moon or live on Mars. One of the major health risks associated with spaceflight involves the immune system, which normally fights off viruses and cancer. It’s already established that spaceflight weakens immunity; current and past astronauts report clinical issues such as respiratory illnesses and skin rashes. These issues may become even more serious on longer-terms flights, such as to Mars.
To better understand the full scope of immunology during spaceflight, Buck Associate Professor Dan Winer, MD working with colleagues linked to the National Aeronautics and Space Administration (NASA), the European Space Agency (ESA), Cornell University, the University of Pittsburgh, the University of Toronto, Embry-Riddle Aeronautical University, and others, have put together a comprehensive guide describing a full array of science linking spaceflight and the immune system. Given the large, rapidly expanding knowledge base on the topic, the team used the name “astroimmunology” to define a subdiscipline of immunology dedicated to the study of the effects of spaceflight and its associated stressors on the immune system. The work is published online in the October16,2025 issue of Nature Reviews Immunology.
“The future of humanity will involve living in outer space or on distant worlds for some people. The larger goal of establishing this emerging subspecialty of astroimmunology is to develop countermeasures to protect the health of those exploring life off of Earth,” says Winer. “What’s special about this paper is that we provide integrated mechanistic insights into how all of these space-related stressors interface to alter immune physiology, and by doing so, we have defined the scope of an entire field, for the most part, in a single paper. As a bonus, many of these mechanisms may also have relevance in aging research.”
The stressors of spaceflight
The guide begins by describing how spaceflight stressors, including microgravity, cosmic radiation, changes in sleep-wake patterns and physiological stress (from mission-associated variables), are studied on Earth to mimic spaceflight, and what we have learned from these studies, paying special attention to the biological mechanisms by which these stressors adversely affect immune function.
Next, the authors discuss how spaceflight immune crosstalk changes the microbiome of space travelers and facilitates reactivation of latent viruses. The authors then focus their discussion to summarize how the immune system changes during and after actual spaceflight, harnessing findings from recent missions on the International Space Station, the NASA Twins’ study, and the SpaceX Inspiration 4 mission. Their discussion integrates data from contemporary multiomic analyses from these studies, providing comprehensive and modern insights of up-to-date mechanisms by which spaceflight adversely impacts immunity.
“Most of the classical human immunology data on spaceflight came from basic phenotyping studies - you could see that spaceflight perturbed the immune system, but there was very little known on why the immune system didn’t function well in space,” says Winer, who currently has multiple space-related projects going in his lab. “Now that investigators have brought multiomics into the work, we and others are able to identify mechanisms and hallmarks of space-related immune dysfunction.”
The paper then defines clinical risks of immune dysfunction in space, and defines avenues for countermeasures, including immune monitoring, the development of an immune countermeasure protocol, vaccinations, and the use of machine learning predicted space nutraceuticals. The work is informed by research published by the Winer lab last year in Nature Communications providing the first single cell atlas of the human immune system in simulated microgravity with spaceflight validation, and the identification of space nutraceutical countermeasures, such as Quercetin, that could be used to normalize immunity during space travel.
Finally, the authors look forward to new space stations, the Moon, and Mars, discussing issues surrounding biobanking approaches to study the immune system in space, including the Cornell Aerospace Medicine Biobank (CAMBank). The authors also highlight challenges inherent to living on Mars, such as how variable gravity, increased radiation and Lunar or Martian dust could impact immune cell function over time. “We can now track precisely how each cell of the immune system adapts to space and varied planetary environments, which can guide preparations for new missions and help keep astronauts safe,” Christopher Mason, PhD, the WorldQuant Professor of Genomics and Computational Biomedicine at Weill Cornell Medicine.
“The study of astroimmunology is still in a very early stage,” says Winer, who notes that more astronaut data will be coming soon from the field. “We think this paper sets the stage as a guide for future research in one of the body’s systems most impacted by spaceflight. It certainly is an exciting time to be involved in space research.”
Implications for aging research
The paper also highlights parallels between the impact of spaceflight and aging on the immune system, suggesting synergistic benefits to both fields of study. Huixun Du, a recent PhD graduate from the Winer lab, is a lead author of the study. “Spaceflight is an excellent model for accelerated aging,” she says, adding that researchers can now see the details of how mitochondria fail in space. “Mitochondria don’t work as efficiently in space and start producing free radicals. These same processes happen with aging.” Du is particularly excited about work that shows the cytoskeleton, which gives cells shape and coherence, becomes disorganized in microgravity. “What if that same disorganization happens in aging?” she asks. “Studying this phenomenon in space could jumpstart efforts aimed at keeping our cells healthy as we age.”
Other collaborators include Christopher Mason (corresponding author), Jang Keun Kim and Marrisa Burke, Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY; Alexander Chouker (corresponding author) Laboratory of Translational Research, Department of Anesthesiology, LMU University Hospital, Munich Germany; Brian Crucian (corresponding author), Clarence Sams, Honglu Wu, NASA, Johnson Space Center, Houston, TX, USA; Amber Paul, Embry-Riddle Aeronautical University, Daytona Beach, FL; Veronica Chang and Shawn Winer, Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada; Sylvain Costes, Space Biosciences Division, NASA Ames Research Center, Moffat Field, CA; Jean-Pol Fripplat, Stress Immunity Pathogens Laboratory, Lorrain University, Vandoeuvre-les-Nancy, France; Afshin Beheshti, McGowan Institute for Regenerative Medicine and Center for Space Biomedicine, University of Pittsburgh, Pittsburgh, PA, USA; Oliver Ullrich, Institute of Aerospace Medicine, University of Zurich, Zurich, Switzerland; and Sarah Baatout, Institute for Nuclear Medical Applications, Belgian Nuclear Research Centre, Mol, Belgium.
Citation: Astroimmunology: the effects of spaceflight and its associated stressors on the immune system
DOI: 10.1038/s41577-025-01226-6
Acknowledgments: This work was supported in part through funds derived from the Buck Institute for Research on Aging, Mount Sinai Hospital, NIH PO1CA272295 and NASA 80NSSC24K0728, the Natural Sciences and Engineering Research Council of Canada (NSERC, grant RGPIN-2024-05532, and the Huiying Memorial Foundation. Work has been supported and funded under the German National Space Program on behalf of the German Ministry of Economics and Energy and Ministry of Economics and Climate Action (50WB1317, 50WB1622 and 50WB2222). Research presented is also based on studies supported by the Alfred Wegener Institute, Institut polaire francais Paul-Emile-Victor, the Programma Nazionale di Ricerche in Antartide (PNRA), ROSCOSMOS and Institute of Biomedical Problems (IBMP), as well as by the European Space Agency (ESA) and the ESA Topical Team ‘Stress and Immunity’ as funded by the ESA ELIPS 4 and SciSpacE programmes. This work is also supported by ESA/BELSPO/PRODEX IMPULSE contract CO-90-11-2801-04 (S.B.). The authors also acknowledge support by the NASA Human Research Program, Human Health and Countermeasures Element, the Centre National d’Etudes Spatiales (CNES, the French Space Agency). C.E.M. thanks the WorldQuant and GI Research Foundation, NASA (NNX14AH50G, NNX17AB26G, NNH18ZTT001N-FG2, 80NSSC22K0254, 80NSSC23K0832, 24-24NSCOR_2-0008, 24- 24FLAG_2-0099 and 22-22SBR_2-0104), the National Institutes of Health (R01ES032638 and U54AG089334) and the LLS (MCL7001-18, LLS 9238-16, 7029-23).
COI disclosure: Christopher Mason and Daniel Winer are co-founders of Cosmica Biosciences, a company that studies altered biological ageing in spaceflight exposures.
About the Buck Institute for Research on Aging
At the Buck, we aim to end the threat of age-related diseases for this and future generations. We bring together the most capable and passionate scientists from a broad range of disciplines to study mechanisms of aging and to identify therapeutics that slow down aging. Our goal is to increase human healthspan, or the healthy years of life. Located just north of San Francisco, we are globally recognized as the pioneer and leader in efforts to target aging, the number one risk factor for serious diseases including Alzheimer’s, Parkinson’s, cancer, macular degeneration, heart disease, and diabetes. The Buck wants to help people live better longer. Our success will ultimately change healthcare. Learn more at: https://buckinstitute.org
Journal
Nature Reviews Immunology
Method of Research
Systematic review
Subject of Research
People
Article Title
Astroimmunology: the effects of spaceflight and its associated stressors on the immune system
Article Publication Date
16-Oct-2025
COI Statement
Christopher Mason and Daniel Winer are co-founders of Cosmica Biosciences, a company that studies altered biological ageing in spaceflight exposures.
Adaptive model shields real-time positioning from ionospheric chaos
Aerospace Information Research Institute, Chinese Academy of Sciences
As solar activity reaches its peak, disruptions in the ionosphere are severely degrading satellite navigation accuracy across the globe. To overcome this, scientists have unveiled a new adaptive Network Real-Time Kinematic (NRTK) positioning method that intelligently counters space weather interference. By combining ionospheric disturbance monitoring with dynamic error modeling, the method stabilizes Global Navigation Satellite System (GNSS) performance even in turbulent atmospheric conditions. Tests using Hong Kong's reference network data revealed that the adaptive approach raised positioning accuracy by more than 40% and boosted the signal-fixing rate from 58% to 84%. The breakthrough offers a powerful step toward uninterrupted, centimeter-level precision during solar storms.
The ionosphere, a charged layer of Earth's upper atmosphere, can fluctuate dramatically under solar radiation, distorting satellite signals vital for navigation and mapping. During solar maxima, these fluctuations cause sudden jumps in Total Electron Content (TEC), triggering ionospheric scintillation that weakens Global Navigation Satellite System (GNSS) positioning reliability. For users relying on centimeter-level accuracy—such as surveyors, engineers, and autonomous systems—these disturbances can mean system downtime and significant losses. Traditional Network Real-Time Kinematic (NRTK) positioning methods assume smooth ionospheric conditions and thus fail during active solar periods. Because of these challenges, researchers have sought adaptive techniques that can perceive and respond to ionospheric dynamics in real time, preserving GNSS stability even in stormy space-weather environments.
A research team from Wuhan University and Guangzhou Hi-Target Navigation Tech Co. Ltd. has developed a pioneering NRTK positioning model capable of maintaining centimeter-level accuracy under intense ionospheric disturbances. The study (DOI: 10.1186/s43020-025-00179-4), published in Satellite Navigation on October 6, 2025, introduces a dual-optimization framework that integrates real-time ionospheric indices with adaptive functional and stochastic models. By learning from disturbance patterns and automatically recalibrating user-side algorithms, the system dramatically enhances GNSS reliability during the ongoing solar cycle peak—offering a key safeguard for positioning technologies in low-latitude regions most vulnerable to ionospheric turbulence.
The innovation centers on leveraging the Rate of Total Electron Content Index (ROTI), a key indicator of ionospheric activity, to dynamically adjust both ionospheric residual estimation and observation weighting. When the system detects disturbances, it automatically reduces the influence of affected satellites and refines error models in real time. Using data from Hong Kong's Continuously Operating Reference Station (CORS) network—one of Asia's most active low-latitude regions—the researchers found that ROTI showed a strong positive correlation (0.91) with ionospheric interpolation errors and a negative correlation (–0.9) with signal-fixing rates.
Compared to conventional NRTK methods, their adaptive "Method B" improved horizontal and vertical positioning accuracy by 37.6% and 41.6%, respectively. Moreover, it achieved a stable 84% average fixing rate, even during equinoctial months when ionospheric scintillation is strongest. The results reveal not just a technical upgrade but a practical solution for real-time navigation across regions frequently affected by solar-induced ionospheric noise.
"Our method essentially teaches GNSS systems to think smarter under stress," said Dr. Xiaodong Ren, senior researcher at Wuhan University and lead author of the study. "By allowing the model to 'sense' and adapt to space-weather disturbances in real time, we've moved beyond static correction systems toward intelligent positioning. This is crucial not only for maintaining accuracy but also for ensuring resilience as solar activity intensifies." He added that this approach could serve as the foundation for next-generation, self-correcting navigation systems that operate reliably under any atmospheric condition.
This adaptive NRTK framework marks a significant leap forward for industries that depend on precise, real-time location data—from autonomous driving and drone surveying to precision agriculture and infrastructure monitoring. By integrating live ionospheric monitoring into everyday positioning workflows, it ensures continuous accuracy even when solar storms strike. Future developments may combine this model with artificial intelligence and multi-constellation GNSS networks to further enhance forecasting and resilience. As Earth moves through one of its most active solar cycles, such innovations will be essential to keeping our navigation, communication, and automation systems firmly on course.
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References
DOI
Original Source URL
https://doi.org/10.1186/s43020-025-00179-4
Funding information
This work was funded by the National Science Fund for Distinguished Young Scholars of China (Grant No. 42425003), the National Natural Science Founda tion of China (Grant No. 42388102, No. 42230104) and the Fundamental Research Funds for the Central Universities (No. 2042025kf0026).
About Satellite Navigation
Satellite Navigation (E-ISSN: 2662-1363; ISSN: 2662-9291) is the official journal of Aerospace Information Research Institute, Chinese Academy of Sciences. The journal aims to report innovative ideas, new results or progress on the theoretical techniques and applications of satellite navigation. The journal welcomes original articles, reviews and commentaries.
Journal
Satellite Navigation
Subject of Research
Not applicable
Article Title
Mitigating ionospheric disturbances impacts on NRTK positioning: an optimization method for adaptive functional and stochastic models
Article Publication Date
16-Oct-2025
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