古田織部三畳大目茶室の研究

内容の要約広島大学(Hiroshima University)博士(文学)Doctor of Philosophydoctora

Linalool odor stimulation improves heat stress tolerance and decreases fat accumulation in nematodes

Aromatherapy uses plant essential oils and fragrant ingredients for relaxation, sleep assistance, and improvement of restlessness related to dementia. Certain aromatic substances increase the life span and stress tolerance of nematodes. We investigated effects of exposure to linalool, a linear chain monoterpenic alcohol that is present in the essential oils of many plants, and its optical isomer, l-linalool, in Caenorhabditis elegans. Nematodes were repelled by the odor of both linalool and l-linalool; however, linalool odor stimulation decreased fat accumulation and increased motility after thermal stress. Analysis of a gene-deficient mutant revealed that the DAF-16 insulin-signaling pathway, which is involved in heat stress tolerance, was enhanced by linalool treatment. Linalool stimulation increased the expression of downstream genes such as sod-3 and hsp-12.6 via DAF-16. We conclude that linalool odor induces a repelling behavior in nematodes, improves heat stress tolerance through the DAF-16 signaling pathway, and affects fat accumulation

The Impact of Phenological Gaps on Leaf Characteristics and Foliage Dynamics of an Understory Dwarf Bamboo, Sasa kurilensis

Phenological gaps exert a significant influence on the growth of dwarf bamboos. However, how dwarf bamboos respond to and exploit these phenological gaps remain enigmatic. The light environment, soil nutrients, leaf morphology, maximum photosynthetic rate, foliage dynamics, and branching characteristics of Sasa kurilensis were examined under the canopies of Fagus crenata and Magnolia obovata. The goal was to elucidate the adaptive responses of S. kurilensis to phenological gaps in the forest understory. The findings suggest that phenological gaps under an M. obovata canopy augment the available biomass of S. kurilensis, enhancing leaf area, leaf thickness, and carbon content per unit area. However, these gaps do not appreciably influence the maximum photosynthetic rate, total leaf number, leaf lifespan, branch number, and average branch length. These findings underscore the significant impact of annually recurring phenological gaps on various aspects of S. kurilensis growth, such as its aboveground biomass, leaf morphology, and leaf biochemical characteristics. It appears that leaf morphology is a pivotal trait in the response of S. kurilensis to phenological gaps. Given the potential ubiquity of the influence of phenological gaps on dwarf bamboos across most deciduous broadleaf forests, this canopy phenomenon should not be overlooked

日本におけるがん罹患率の動向（1975-2005）

要旨ありがん統計データおよびその解析研究ノー

Conceptual model study using origami for membrane space structures : a perspective of origami-based engineering

This paper discusses what has been found and what will be found using conceptual “origami” models to develop deployable space structures. The study covers the following: (i) one-dimensional structural elements, which are axially buckled inflatable tubes; (ii) two-dimensional elements, which are deployable membranes, such as solar arrays and solar sails; and (iii) deployable elements in nature. The study clarifies what design considerations are necessary to adapt the basic concepts to actual space structural hardware, and several limitations of origami models are discussed. Regarding the last subject, this study envisions future space structures using conceptual origami models that imitate three-dimensional deployable structures in nature, such as flowers and insect wings

The Role of Estrogen Receptor β in the Dorsal Raphe Nucleus on the Expression of Female Sexual Behavior in C57BL/6J Mice

17β-Estradiol (E2) regulates the expression of female sexual behavior by acting through estrogen receptor (ER) α and β. Previously, we have shown that ERβ knockout female mice maintain high level of lordosis expression on the day after behavioral estrus when wild-type mice show a clear decline of the behavior, suggesting ERβ may be involved in inhibitory regulation of lordosis. However, it is not identified yet in which brain region(s) ERβ may mediate an inhibitory action of E2. In this study, we have focused on the dorsal raphe nucleus (DRN) that expresses ERβ in higher density than ERα. We site specifically knocked down ERβ in the DRN in ovariectomized mice with virally mediated RNA interference method. All mice were tested weekly for a total of 3 weeks for their lordosis expression against a stud male in two consecutive days: day 1 with the hormonal condition mimicking the day of behavioral estrus, and day 2 under the hormonal condition mimicking the day after behavioral estrus. We found that the level of lordosis expression in ERβ knockdown (βERKD) mice was not different from that of control mice on day 1. However, βERKD mice continuously showed elevated levels of lordosis behavior on day 2 tests, whereas control mice showed a clear decline of the behavior on day 2. These results suggest that the expression of ERβ in the DRN may be involved in the inhibitory regulation of sexual behavior on the day after behavioral estrus in cycling female mice

Virological characterization of the 2022 outbreak-causing monkeypox virus using human keratinocytes and colon organoids

ヒトiPS細胞由来大腸オルガノイドおよびヒトケラチノサイトを用いたmpoxウイルス2022年株の解析. 京都大学プレスリリース. 2023-06-07.The outbreak-causing monkeypox virus of 2022 (2022 MPXV) is classified as a clade IIb strain and phylogenetically distinct from prior endemic MPXV strains (clades I or IIa), suggesting that its virological properties may also differ. Here, we used human keratinocytes and induced pluripotent stem cell-derived colon organoids to examine the efficiency of viral growth in these cells and the MPXV infection-mediated host responses. MPXV replication was much more productive in keratinocytes than in colon organoids. We observed that MPXV infections, regardless of strain, caused cellular dysfunction and mitochondrial damage in keratinocytes. Notably, a significant increase in the expression of hypoxia-related genes was observed specifically in 2022 MPXV-infected keratinocytes. Our comparison of virological features between 2022 MPXV and prior endemic MPXV strains revealed signaling pathways potentially involved with the cellular damages caused by MPXV infections and highlights host vulnerabilities that could be utilized as protective therapeutic strategies against human mpox in the future