Ever since the Fukushima Daiichi nuclear power plant accident that caused the discharge of radionuclides from the power plant into the ocean, operators at the Tokyo Electric Power Company (TEPCO) have been implementing measures to reduce groundwater inflow into the damaged reactor buildings. TEPCO has also been pumping water into the reactors since the accident to cool them.

The cooled water is then treated using the Advanced Liquid Processing System (ALPS), which removes all radioactive materials from the water except for tritium – which is very difficult to remove and has a half-life of 12.32 ±0.02 years. This treated water ended up being accumulated and stored at the site, with limited space to store it.

To combat this storage issue, the Japanese government implemented a new policy in 2021 focused on discharging the ALPS-treated water into the ocean using a 1 km long tunnel. The release of the treated water (containing tritium) began on 24th August 2023, and the plan is to continue releasing it until 2050. The government set a threshold for tritium suspension levels of 700 Bq/L in the discharge outlet vicinity and 30 Bq/L in the ocean. If the concentrations exceed these thresholds, then the discharging must stop immediately.

Researchers at the University of Tokyo have now collaborated with Fukushima University to investigate the effects of discharging tritium into the local ocean environment, and whether the discharging of this treated water is actually having an adverse impact. The study used an ocean general circulation model known as COCO4.9 to look at the influence of climate conditions – such as long-term global warming – on the discharge scenarios of tritium from the power plant. The researchers examined multiple discharge scenarios (based on the amount of tritium released) up until 2099.

Previously, no modelling had been performed looking at long-term impacts relating to the changing environmental conditions of the planet. In a press release from the University of Tokyo, lead author Alexandre Cauqouin states that: “In our global ocean simulations, we could investigate how ocean circulation changes due to the global warming and representation of fine-scale ocean eddies influence the temporal and spatial distribution of tritium originating from these treated-water releases”.

It is important to find out how fast and far the tritium discharge spreads because both climate change and eddies in water currents can speed up the movement of tritium through the ocean.

The study revealed that in all but one of the modelled scenarios (and at the release location, which has a much higher concentration because the treated water hasn’t dissipated yet), the tritium concentration in the ocean remained almost the same, and at a very low concentration. This was true for both long- and short-term scenarios – showing that the discharge from the Fukushima Daiichi nuclear power plant has an almost negligible impact on the ocean.

Other than the worst-case scenario, the model discovered that the increase in tritium from the treated water is 0.1% or less of the tritium background concentration of 0.03–0.2 Bq/L within 25 km of the discharge site in the Pacific Ocean. This is well below detection limits – such a small amount that the presence of the added tritium from the treated water cannot be measured directly in the seawater. The results are also far below the safety standards of 10,000 Bq/L set by the World Health Organization and consistent with physical seawater monitoring being performed today.

Even in the worst-case scenario, the levels of tritium still fell well below the detection limits, but the model did find that in such a high-CO₂ emission scenario, there would be an increased concentration of tritium in the south of Japan due to the Kuroshio current – which could theoretically reach the western coast of the US, but in insufficient concentrations to have any adverse effects throughout the Pacific Ocean.

Overall, the study showed that the long-term safety threshold won’t be exceeded under the current treated water release plans. The study could also help with building future models to better understand how tritium moves through both water vapour and ocean water – as tritium could be used in the future as a chemical tracer to track atmospheric and oceanic circulation, precipitation patterns, river catchments, moisture sources and groundwater flow.

The research is published in Marine Pollution Bulletin.

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A mummy’s inked skin sheds light on the history of body art

Researchers say DOE report cherry-picks data to downplay threat of greenhouse gases

The Senate Commerce Committee advanced the nomination of Neil Jacobs to lead NOAA as that agency’s top satellite official remains on administrative leave.

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Learn how hundreds of “sinkites,” all around a kilometer across, are altering the strata in the North Sea.

Learn about cryovolcanism, which shapes the surface of icy moons in the outer Solar System by releasing water that simultaneously boils and freezes.

Learn more about the new language researchers uncovered at the Boğazköy-Hattusha site, indicating the city’s residents loved learning and writing in foreign languages.

A warming climate is enabling rodents to move north

International food security body issues rare alert about “worst-case scenario” unfolding

Slow-motion footage helps scientists predict flight paths of molten projectiles

A new Department of Energy report “fundamentally misrepresents” climate research and leaves out key context, multiple scientists cited in the report tell WIRED.

The acting administrator of NASA will meet with his Russian counterpart in the first face-to-face meeting between agency heads in several years.

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In this bonus edition of Space Minds, host David Ariosto moderates the panel "Mission to Market: The Evolution of CLPS" at the AIAA Ascend conference.

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SAN FRANCISCO — Kongsberg Satellite Services and Amazon Web Services are expanding their alliance to speed up the flow of satellite data to customers. KSAT announced plans July 30 to integrate AWS Ground Station capabilities into its network, which will include more than 200 antennas at 40 locations around the world. “That can really minimize […]

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China launched a sixth batch of Guowang megaconstellation satellites Wednesday, with a Long March 8A rocket launch from Hainan.

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It can be said with certainty that a lot went into Operation Midnight Hammer. The June 22 precision strike on Iranian strategic weapons production facilities was an airtight operation conducted with great execution, coordination and timing by the United States Air Force and the Navy. B-2 bombers dropped 14 Massive Ordnance Penetrator “bunker-buster” bombs on […]

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An Indian rocket placed into orbit a billion-dollar Earth science mission jointly developed by NASA and the Indian space agency ISRO.

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What is the gut microbiome? Learn more about why it's crucial for our health and wellness.

Glioblastoma is the most aggressive brain cancer and the hardest to treat, as it spreads and invades healthy brain tissue in a diffuse, microscopic way. Surgical treatment calls for a fine balance between excising all cancerous tissues and removing as little healthy brain tissue as possible. To help neurosurgeons more accurately remove glioblastoma, an international research collaboration has developed an optical imaging probe that identifies microscopic cancer cells in the margins of tumour-resected cavities in the brain.

The imaging probe works by exploiting the significantly increased fatty acid (FA) metabolism exhibited by glioblastoma cells. FA metabolism plays a key role in tumour progression and proliferation and is central to cancer immunity. To enable real-time, non-invasive imaging of FA absorption, the researchers – from Erasmus University Medical Center (Erasmus MC) in The Netherlands and the University of Missouri in the USA – covalently linked a long-chain saturated FA with the clinically approved near-infrared (NIR) dye indocyanine green (ICG).

ICG has intrinsic low autofluorescence, enables deep tissue imaging and exhibits a high signal-to-noise ratio compared with visible fluorophores. The team hypothesized that a probe combining ICG with a FA might specifically accumulate in tumours and enable efficient intraoperative visualization of tumour margins. Importantly, the spectral characteristics of ICG make it compatible with many existing intraoperative cameras and surgical microscopes.

The researchers initially investigated the uptake of the FA-ICG probe in living cells, confirming that the dye’s physiological uptake resembles that of natural FAs. They then used fluorescence imaging to assess FA-ICG uptake in mice with implanted glioblastoma, observing high accumulation in the brain tumours.

Comparing the fluorescence signal from mice administered with equivalent doses of FA-ICG and ICG revealed that the average radiance from FA-ICG was approximately 2.2 times higher than that from IGC. At 12 and 24 h post-injection, retention of the probe in the brain was approximately two to three times higher in the tumour-bearing than the non-tumour-bearing hemisphere.

Next, lead authors Meedie Ali and Pavlo Khodakivskyi and their colleagues investigated the application of FA-ICG as a preclinical imaging agent in a patient-derived model of glioblastoma. They showed that the probe could successfully image tumour growth at different time points in several mice.

“This finding is of importance for preclinical research since patient-derived xenograph models of glioblastoma are characterized by an unpredictable growth pattern and low tumour implantation rates,” explains principal investigator Elena Goun from the University of Missouri. “Thus, monitoring of tumour status by sensitive, non-invasive in vivo fluorescence imaging would be of high value as the introduction of optical imaging of reporter genes [an alternative monitoring approach] is known to result in tumour phenotypic alterations.”

Fluorescence-guided surgery

The researchers also demonstrated the feasibility of FA-ICG as a contrast agent for NIR image-guided cancer surgery, performing surgery on tumour-bearing mice using a standard NIR camera approved for use in surgical suites. Not only did the FA-ICG probe successfully image glioblastoma in the animals’ brains, but the brains also exhibited a considerably higher fluorescence signal than seen from similar mice injected with an ICG-only dye.

Subsequently, the team employed the probe during surgical resection of veterinarian-diagnosed symptomatic canine mastocytoma (a skin cancer) in a pet dog. Ten hours after injection with FA-ICG, the dog underwent surgery, with image-guided surgery performed successfully using an open-air NIR surgical camera.

If the probe transitions to routine clinical use, it could prove be of great benefit to neurosurgeons. If they can identify cancer cells, which are microscopic and resemble healthy brain tissue, outside the surgical margins, follow-up chemotherapy and radiation treatments should be more effective and cancer recurrence may be delayed. The probe also offers the practical features of a workable surgical procedure, an appropriate half-life and fluorescence that can be seen under normal operating room lights.

“Our results demonstrate that FA metabolism represents an excellent target for tumour imaging, leading to significantly enhanced uptake of the FA-ICG probe in tumours,” the researchers write. “[The probe] represents a promising candidate for a wide range of applications in the fields of metabolic imaging, drug development and most notably for translation in image-guided surgery.”

The researchers are now planning a Phase I clinical trial to examine the safety and efficacy of the probe. Specifically, they aim to determine how well patients tolerate the probe, what side effects may occur at an effective dose, and how the probe’s performance compares to existing optical imaging surgical tools.

“The upside of fluorescence-guided surgery is that you can make little remnants much more visible using the light emitting properties of these tumour cells when you give them a dye,” says Rutger Balvers, a neurosurgeon at Erasmus MC who is expected to lead the human clinical trials, in a press statement. “And we think that the upside of FA-ICG compared to what we have now is that it’s more select in targeting tumour cells. The visual properties of the probe are better than what we’ve used before.”

The study is described in npj Imaging.

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As a mother of two, I’ve read a lot of children’s books. While there are some so good that even parents don’t mind reading them again and again, it’s also very easy for them to miss the mark and end up “accidentally” hidden behind other books. They’ve not only got to have an exciting story, but also easy wording, a rhythmic pace, flowing language and captivating pictures.

Great non-fiction kids’ books are especially hard to find as they need to add in yet another ingredient: facts. As a result, they can often struggle to portray educational topics in an accessible and engaging way without being boring. So when I saw the ever impressive Jess Wade had published her second children’s book about physics, Light: the Extraordinary Energy That Illuminates Our World, I was intrigued.

Wade is a woman of many talents. She’s an accomplished physicist at Imperial College London, a trailblazing advocate for equality in science, and an enthusiastic science communicator. Her first book, Nano: the Spectacular Science of the Very (Very) Small, won the 2022 UK Literary Association (UKLA) Book Award for information books (3–14+ years).

And now, with the help of beautiful illustrations by Argentinian artist Ana Sanfelippo, Wade has created a clear, concise explanation of light, how it behaves and how we use it. The book starts by describing where light comes from and why we need it, and goes on to more complex topics like reflection, scattering and dispersion, the electromagnetic spectrum, and technologies that use light.

The language is clear, the sentences are simple, and there is a flow to the narrative that makes up for the lack of a story. Wade makes the science relatable for children by bringing in real-world examples – such as how your shadow changes length during the day, and how apples reflect red light so look red. And throughout, Sanfelippo’s gorgeous illustrations fill the pages with colourful images of a girl and her dog exploring the concepts discussed, keeping the content bright and cheerful.

Cats and secrets

Now obviously I am not the target audience for Light. So, as my own children are too young (the age range listed is 7–12 years), I asked my eight-year old-niece, Katie, to take a look.

Instantly, Katie loved the illustrations, which helped keep her engaged with the content as she read – her favourite was one of a cat using a desk lamp to create a shadow. She was intrigued by how fast light is – “you’d have to run seven and a half times around Planet Earth in a single second” – and liked being “let in on a secret” when Wade explains that white light actually contains a rainbow.

But as the book went on, she found some bits confusing, like the section on the electromagnetic spectrum. “It’s definitely a book someone Katie’s age should read with a grown up, and maybe in two sittings, because it’s very information heavy (in a good way),” said her mum, Nicci. Indeed, there are a couple of page spreads that stand out as being particularly busy and wordy, and these dense parts somewhat interrupt the book’s flow. “But overall, she found the topic very interesting, and it provoked a lot of questions,” Nicci continued. “I enjoyed sharing it with her!”

I think it’s safe to say that Wade can add another success to her list of many accomplishments. Light is beautiful and educational, and personally, I wouldn’t hesitate to give it as gift or keep it at the front of the bookshelf.

• 2025 Walker Books 32pp £12.99hb

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Once dismissed as just snoring, sleep apnea is now emerging as an early warning sign for serious conditions like Alzheimer’s, heart disease, and depression.

Patients with Ehlers-Danlos Syndrome are six times more at risk for the sleeping disorder. Now scientists are studying them in hopes of finding remedies beyond the CPAP machine.

Superconductors are materials that, below a certain critical temperature, exhibit zero electrical resistance and completely expel magnetic fields, a phenomenon known as the Meissner effect. They can be categorized into two types.

Type-I superconductors are what we typically think of as conventional superconductors. They entirely repel magnetic fields and abruptly lose their superconducting properties when the magnetic field exceeds a certain threshold, known as the critical field, which depends on both magnetic field strength and temperature.

In contrast, Type-II superconductors have two critical field values. As the magnetic field increases, the material transitions through different states. At low magnetic fields below the first critical field, magnetic flux is completely excluded. Between the first and second critical fields, some magnetic flux enters the material. Above the second critical field, superconductivity is destroyed.

In Type-II superconductors, when magnetic flux enters the material, it does so at discrete points, forming quantized vortices. These vortices repel each other and self-organize into a regular pattern known as the Abrikosov lattice. This effect has also been observed in Bose-Einstein condensates (bosons at extremely low temperatures) and chiral magnets (magnetic materials with spirally aligned magnetic moments). Interestingly, similar vortex self-organization is seen in liquid crystals, offering deeper insights into the underlying physics.

In this study, the researchers investigate vortex behaviour within a liquid crystal droplet, revealing a novel phenomenon termed Abrikosov clusters, which parallels the structures seen in Type-II superconductors. They examine the transition from an isotropic liquid phase to a chiral liquid phase upon cooling. Through a combination of experimental observations and theoretical modelling, the study demonstrates how chiral domains, in other words topological defects, cluster due to the interplay between vortex repulsion and the spatial confinement imposed by the droplet.

To model this behaviour, the researchers use a mathematical framework originally developed for superconductivity called the Ginzburg-Landau equation, which helps identify how certain vortex patterns emerge by minimizing the system’s energy. An interesting observation is that light passing through the chiral domains of the droplet can resultingly obtain chirality. This suggests that the research may offer innovative ways to steer and shape light, making it valuable for both data communication and astronomical imaging.

Do you want to learn more about this topic?

Vortex dynamics and mutual friction in superconductors and Fermi superfluids by N B Kopnin (2002)

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The quantum tangent kernel method is a mathematical approach used to understand how fast and how well quantum neural networks can learn. A quantum neural network is a machine learning model that runs on a quantum computer. Quantum tangent kernels help predict how the model will behave, particularly as it becomes very large – this is known as the infinite-width limit. This allows researchers to assess a model’s potential before training it, helping them design more efficient quantum circuits tailored to specific learning tasks.

A major challenge in quantum machine learning is the barren plateau problem, where the optimization landscape becomes flat, hiding the location of the minimum energy state. Imagine hiking in the mountains, searching for the lowest valley, but standing on a huge, flat plain. You wouldn’t know which direction to go. This is similar to trying to find the optimal solution in a quantum model when the learning signal disappears.

To address this, the researchers introduce the concept of quantum expressibility, which describes how well a quantum circuit can explore the space of possible quantum states. In the hiking analogy, quantum expressibility is like the detail level of your map. If expressibility is too low, the map lacks enough detail to guide you. If it’s too high, the map becomes overly complex and confusing.

The researchers investigate how quantum expressibility influences the value concentration of quantum tangent kernels. Value concentration refers to the tendency of kernel values to cluster around zero, which contributes to barren plateaus. Through numerical simulations, the authors validate their theory and show that quantum expressibility can help predict and understand the learning dynamics of quantum models.

In machine learning, loss functions measure the difference between predicted outputs and actual target values. These can relate to a global optimum (the best possible value across the entire system) or a local optimum (the best value within a small region or subset of qubits). The study shows that high expressibility can drastically reduce quantum tangent kernel values for global tasks, though this effect can be partially mitigated for local tasks.

The study establishes the first rigorous analytical link between the expressibility of quantum encodings and the behaviour of quantum neural tangent kernels. It offers valuable insights for improving quantum learning algorithms and supports the design of better quantum models, especially large, powerful quantum circuits, by showing how to balance expressiveness and learnability.

Do you want to learn more about this topic?

A comprehensive review of quantum machine learning: from NISQ to fault tolerance by Yunfei Wang and Junyu Liu (2024)

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