Kyoto, Japan -- In nature, ecosystems are tightly linked through the flow of organisms, detritus, and nutrients across boundaries arbitrarily imagined by humans. These systems are deeply in tune with seasonal changes, fostering a harmonious ebb and flow of resources.

Many of these connections remain poorly understood, especially the mechanisms responsible for maintaining biodiversity at the landscape level. One important example is the environmental drivers underlying variations in life-histories, or how organisms grow, survive, and reproduce in natural ecosystems. But as human activities ravage biodiversity on a global scale, elucidating the factors that cause variations in an organism's life-history is fundamental for understanding not only population persistence and adaptation to fluctuating environments, but also effective conservation and management.

Motivated to shed light on these factors, a team of researchers at Kyoto University is studying how seasonally recurring resource subsidies affect life-histories. Via a large-scale field experiment in a temperate forest-stream ecosystem, they are testing whether the seasonal timing of terrestrial subsidies contributes to maintaining variations in life-history traits of red-spotted masu salmon, a common freshwater fish in Japan.

Researchers from The University of Osaka found that the Wnt5a protein, secreted by inflammatory fibroblasts within cancerous tumors, inhibits angiogenesis and consequently promotes hypoxia within tumors. Hypoxic conditions help sustain the inflammatory fibroblasts, which also secrete the growth factor epiregulin, thereby promoting tumor growth. This newly proposed mechanism for tumor growth offers a promising new target for cancer therapies and possibly other conditions linked to inflammation, such as inflammatory bowel disease.

Kyoto, Japan -- Diabetes is characterized by the pancreas producing too little insulin, but there is a rarer condition in which it produces too much. A hormone-producing tumor originating in the pancreas -- an insulinoma -- is the cause. Patients with the condition often experience severe hypoglycemia, resulting in convulsions, impaired consciousness, and sometimes even death.

The definitive treatment for an insulinoma is surgical removal, which depends on precise localization. However, existing diagnostic methods are limited by low sensitivity or high invasiveness, resulting in urgent clinical demand for a new means of detection.

"As endocrinologists and researchers, we frequently encountered patients experiencing severe hypoglycemia who faced delays or difficulties in obtaining an accurate diagnosis, negatively impacting their quality of life," says first author Takaaki Murakami of Kyoto University.

Plants that reproduce exclusively by self-pollination arise from populations with extremely low diversity to begin with. The Kobe University research not only adds a facet to possible evolutionary strategies, but also lends weight to Darwin’s suspicion that this strategy might be a path to extinction.

The Arctic is one of the coldest places on Earth, but in recent decades, the region has been rapidly warming, at a rate three to four times faster than the global average. However, current climate models have been unable to account for this increased pace. Now, researchers at Kyushu University have reported in a study, published April 29 in Ocean-Land-Atmosphere Research, that clouds may be to blame.

In regional and urban economics, theoretical models are developed to predict patterns of regional development based on real-world factors. Such models in economic geography can inform regional and urban development policies aimed at promoting economic growth and fostering sustainable regional development. 

Researchers from the Institute of Industrial Science, The University of Tokyo have developed a filter that effectively blocks small particles while allowing unrestricted air flow. Such a filter is attractive for use in face masks that are highly effective while maintaining wearer comfort. The filter is constructed from nanosheets consisting of a mesh containing tiny pores supported on a nanofiber-coated fabric with larger pores. This hierarchical pore structure blocks nanoparticles while allowing air flow.

A research group led by Dr. Kento Yoshioka, Dr. Keisuke Obara, and Professor Yoshio Tanaka from the Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University, has discovered that a natural substance in the body, known as platelet-activating factor (PAF), can strongly stimulate muscle movements in parts of the digestive system, especially the esophagus and the upper part of the stomach.

A research group led by Dr. Keisuke Obara, Dr. Kento Yoshioka, and Professor Yoshio Tanaka from the Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University, has discovered that certain naturally occurring peptides in the body can trigger contractions in the vas deferens—a muscular tube that carries sperm in the male reproductive system. These peptides, known as bombesin-like peptides (neuromedin B, gastrin-releasing peptide, and neuromedin C), were found to play an active role in smooth muscle movement in this organ. The team also found that the mRNA for a specific receptor, the bombesin BB₂. receptor—which responds to these peptides—is highly expressed in the tissue. This suggests that the peptides likely act through this receptor to induce contractions. This discovery provides new insights into the regulation of the reproductive system and may contribute to the development of novel treatments for urogenital disorders. The findings were published in the scientific journal Biological and Pharmaceutical Bulletin in March 2025.

Researchers at Nagoya University in Japan have developed an interface that creates "virtual sorting nanomachines" without the need to manufacture actual devices. By projecting electron beams onto thin silicon nitride membranes, they generated programmable electric fields that function like microfluidic devices—systems that move very small amounts of fluids through microscopic channels. This allows them to move and sort nanomaterials by size at any desired location and time.