Molecular phylogeny and taxonomy of the Hydrangea serrata complex (Hydrangeaceae) in western Japan, including a new subspecies of H. acuminata from Yakushima

According to the contemporary classification of Hydrangea native to Japan, H. serrata is a polymorphic species including six varieties. We discovered a plant identified as H. serrata, but morphologically distinct from previously known varieties, in Yakushima island where approximately 50 endemic species are known. To determine the relationship of this plant with previously known varieties, we examined morphology and constructed a highly resolved phylogeny of H. serrata and its relatives using three chloroplast genomic regions, rbcL, trnL intron, psbA-trnH, and two nuclear genomic regions, ITS1 and ITS2, and Multiplex ISSR genotyping by sequencing (MIG-seq). Based on these morphological and phylogenetic observations, we describe Hydrangea acuminata subsp. yakushimensissubsp. nov. as a newly discovered lineage in Yakushima, Japan and propose Hydrangea minamitaniistat. nov. and Hydrangea acuminata subsp. australisstat. nov. which were previously treated as varieties of H. serrata.

Vaccination Strategy for the COVID-19 Pandemic in Early 2021 Based on Differences in People's Behavior Between Tokyo and Osaka, Japan

Background: During the fourth COVID-19 wave in Japan, a marked difference was apparent in the scale of the epidemic between Metropolitan Tokyo in eastern Japan and Osaka prefecture in western Japan.Methods: Public epidemic data were analyzed, with performance of mathematical simulations using simplified SEIR models.Results: The increase in the number of infected persons per 100,000 population during the fourth wave of expansion was greater in Osaka than in Tokyo. The basic reproduction number in Osaka was greater than in Tokyo. Particularly, the number of infected people in their 20s increased during the fourth wave: the generation-specific reproduction number of people in their 20s was higher than people of other generations. Both Tokyo and Osaka had strong correlation between the increase in the number of infected people and the average number of people using the main downtown stations at night. Simulations showed vaccination of people in their 60s and older reduced the number of infected people among the high-risk elderly population in the fourth wave. However, age-specific vaccination of people in their 20s reduced the number of infected people more than vaccination of people in their 60s and older.Conclusions: Differences in the epidemic between Tokyo and Osaka are explainable by different behaviors of the most socially active generation. When vaccine supplies are adequate, priority should be assigned to high-risk older adults, but if vaccine supplies are scarce, simulation results suggest consideration of vaccinating specific groups among whom the epidemic is spreading rapidly.

Where do overseas Filipinos intend to retire? The case of Filipinos in Chugoku region, Japan

Migrants nearing retirement age face issues and challenges distinct from those of migrants in their working age. Yet, their well-being has not been fully addressed because of lack of data. Drawing from the results of a survey of Filipinos residing in the Chugoku region in Western Japan ( n = 481), this study contributes to the literature on the aging-migration nexus by exploring migrants’ anxiety toward retirement and intended country of retirement. The results have crucial implications not only on migrants’ plans for retirement but also on the provision of social protection in both the host and the origin countries.

The Role of Civil Society Sector in the Development of Art-Driven Regional Social Innovation: The Case of Benesse Art Site Naoshima and Art Setouchi

Recently art is increasing its presence as an “creative industry” to sustain local communities, by generating socio-economic values. Still, whether art can be a tool for social innovation to regenerate communities, especially in rural areas in aging societies, is an unanswered question. In this paper, we take the example of Benesse Art Site Naoshima and Art Setouchi in the island area of Western Japan, viewing how it transformed from a corporate-established museum to a regional initiative involving various stakeholders, including local residents and thus creating the process of dialogues and collaboration. By reconstructing the existing evidence with supplementary fieldwork and interviews and applying a tri-sectoral analysis of the processes, we present how the art sites developed to become a social innovation. We then illustrate the role of two key individuals, Soichiro Fukutake and Fram Kitagawa, and shed light on the different values and methodologies they brought into these art sites. We argue that such contributions from the civil society and philanthropy sector made a critical contribution to characterize BASN and Art Setouchi, in addition to the well-documented and recognized efforts from local government and business sectors. Finally, we propose that such values, methodologies, and persons who can embody and implement such values are crucial if other countries and areas are to replicate the model.

Reproduction of the Marine Debris Distribution in the Seto Inland Sea Immediately after the July 2018 Heavy Rains in Western Japan Using Multidate Landsat-8 Data

Understanding the spatiotemporal environment of the ocean after a heavy rain disaster is critical for satellite remote sensing research and disaster prevention. We attempted to reproduce changes in marine debris distributions using multidate data of Landsat-8 spectral reflectance acquired immediately after a heavy rain disaster in western Japan in July 2018. Data from cleaning ships were used for screening the marine debris area. As most of the target marine debris consisted of plant fragments, a method based on the corrected floating algae index (cFAI) was applied to Landsat-8 data. Data from cleaning ships clarify that most of the marine debris accumulated in the waters in the northern part of Aki Nada, a part of the Seto Inland Sea. The spectral characteristics of the corresponding marine debris spectral reflectance obtained from the Landsat-8 data were explained by the FAI with band 5 (central wavelength: 865 nm) as the maximum value. Unlike traditional FAI, cFAI eliminated the effect of background water turbidity. The Otsu method was effective for the automatic threshold determination for cFAI. Although Landsat-8 data have limited spatial resolution and observation frequency, these data were useful for understanding marine debris distribution after a heavy rain disaster.

Annual variability in sound acorn production was regulated by a generalist seed predator weevil in Quercus serrata

Highly variable and synchronous seed production within a population (‘masting’) could be from either synchronised high annual variability in floral initiation (‘flower masting’) or synchronised floral abortion until maturity (‘fruit maturation masting’). We investigated the demographic processes of the female organs from flowering to seed maturity, including each type of insect damage identified, in Quercus serrata in six individuals within a stand from 2014 to 2020, western Japan. Although the annual production of sound acorns was significantly correlated with that of female flowers, the annual variability in sound acorn production within an individual was significantly higher and their synchrony increased, compared to those of female flowers. The annual production of female flowers was positively correlated with the temperature difference in April between the previous and flowering years. However, their fluctuation was low, which was neither affected by seed and flower production in the previous year nor contributed to predator starvation. Key-factor analyses revealed that reproductive loss due to oviposition and sap suction by Mechoris ursulus , a generalist seed predator weevil for oak species, was the largest and most important factor that contributed to the annual variation in the total pre-dispersal loss of Q. serrata . The survival rate from female flowers to sound acorns was strongly predicted by the temperature in June, corresponding to the emergence of adult M. ursulus . This study suggests that highly variable and synchronous sound seed production can be proximately regulated by seed predation when the main predator is a generalist.