The National Institute of Polar Research (NIPR) publishes Polar Science, a peer-reviewed quarterly journal dealing with polar science, in collaboration with Elsevier B.V. In the latest issue, it features “Sustainable development in the Arctic for Indigenous peoples”, published as part of its regular issue (Vol. 44, June 2025). The full text of featured articles will be freely accessible worldwide until 14 January 2026.

Osaka Metropolitan University researchers analyzed the interactions between two bacteria that make up intestinal microbiota. 

Joint research led by Sosuke Ito of the University of Tokyo has shown that nonequilibrium thermodynamics, a branch of physics that deals with constantly changing systems, explains why optimal transport theory, a mathematical framework for the optimal change of distribution to reduce the cost, makes generative models optimal. As nonequilibrium thermodynamics has yet to be fully leveraged in designing generative models, the discovery offers a novel thermodynamic approach to machine learning research. The findings were published in the journal Physical Review X.

Industrial anomaly detection is crucial for maintaining quality control and reducing production errors, but traditional supervised models require extensive datasets. While embedding-based methods are promising for unsupervised anomaly detection, they are highly memory-intensive and unsuited to low-light conditions. In a new study, researchers developed a new unsupervised model that utilizes both well-lit and low-light images to achieve computationally efficient and memory-friendly industrial anomaly detection.

Fluorescent markers are extremely useful in science as tools to track molecules or processes as they carry out their unique activities, revealing unknown facts along the way. However, physically introducing fluorescent markers into targets can result in strong background signals, and even when chemically bound, the target’s hydrophobicity may increase, making the process far from straightforward. Moreover, fluorescent markers are often affected by the properties of the solvent in which they operate. To address these challenges, researchers have developed a method to track the behavior of cellulose nanofibers (CNFs) by conjugating water-compatible fluorescent amino acids to the CNFs. As a result, observers can now microscopically visualize CNFs by following the blue fluorescence emitted from them.

Japanese researchers have developed a human cytokine-based designer enzyme. Relying on their rational design workflow, they demonstrated that proteins can serve as ligands with the same precision as synthetic organic ligands. The resulting designer enzyme maintains its original biological functions while gaining new catalytic abilities.

Kyoto, Japan -- In 1978, cane toads, which are native to South and Central America, were introduced for pest control to Ishigaki island in Okinawa prefecture in Japan. These poisonous toads secrete deadly toxins, killing enough of the predators in their new territories that they have been designated an invasive species.

However, one predator on Ishigaki has proven resistant to the cane toads' poison. The crested serpent eagle, common across Asia but considered critically endangered in Japan where only about 200 individuals reside, has been observed feeding on the toads on the island without showing signs of poisoning.

This inspired a team of researchers at Kyoto University to investigate the crested serpent eagle's potential toxin resistance to the cane toad's toxins. Several species that prey on toxin-secreting animals exhibit genetic resistance, particularly in a gene known as ATP1A. These previous findings prompted the team to investigate whether the crested serpent eagle also possesses this genetic resistance, and to explore the evolutionary background of this trait.

Kyoto, Japan -- Black holes embody the ultimate abyss. They are the most powerful sources of gravity in the universe, capable of dramatically distorting space and time around them. When disturbed, they begin to "ring" in a distinctive pattern known as quasinormal modes: ripples in space-time that produce detectable gravitational waves.

In events like black hole mergers, these waves can be strong enough to detect from Earth, offering a unique opportunity to measure a black hole's mass and shape. However, precise calculation of these vibrations through theoretical methods has proven a major challenge, particularly for vibrations that are rapidly weakening.

This inspired a team of researchers at Kyoto University to try a new method of calculating the vibrations of black holes. The scientists applied a mathematical technique called the exact Wentzel-Kramers-Brillouin, or exact WKB analysis to carefully trace the behavior of waves from a black hole out into distant space. While this method has long been studied in mathematics, its application to physics -- especially to black holes -- is still a newly developing area.