古代湖琵琶湖産カワニナ属現生種の分類と多様化パターンの研究

京都大学新制・課程博士博士(理学)甲第25141号理博第5048号京都大学大学院理学研究科生物科学専攻(主査)准教授 中野 隆文, 教授 本川 雅治, 教授 森 哲学位規則第4条第1項該当Doctor of ScienceKyoto UniversityDGA

Gigantic Enhancement of Magneto-Chiral Effect in Photonic Crystals

We theoretically propose a method to enhance dramatically a magneto-chiral(MC) effect by using the photonic crystals composed of a multiferroic material. The MC effect, the directional birefringence even for unpolarized light, is so small that it has been difficult to observe experimentally. Two kinds of periodic structures are investigated; (a) a multilayer and (b) a stripe composed of a magneto-chiral material and air. In both cases, the difference in reflectivity between different magnetization directions is enhanced by a factor of hundreds compared with a bulk material.Comment: 3 pages, 3 figure

Systematic revision of the Japanese freshwater snail

琵琶湖から現生カワニナの2新種を発見 --140年にわたる分類の混乱を解決--. 京都大学プレスリリース. 2023-01-23.Not all snails of a feather: KyotoU discovers two new snail species in Lake Biwa after systematic revision. 京都大学プレスリリース. 2023-06-07.Semisulcospira is a freshwater snail genus highly divergent in the ancient Lake Biwa, Japan, with a history of ~4 million years. Although the shell morphology, karyotype and molecular phylogeny of the genus have been well studied, the systematic status of several non-monophyletic species remains uncertain. In this study, we have evaluated the taxonomic accounts of the species previously identified as Semisulcospira decipiens, S. habei and relatives. We examined the genetic relationships using genome-wide SNP data and elucidated morphological variation among these using Random Forest classification. Morphological relationships between the name-bearing type of S. decipiens and the newly collected specimens were also evaluated. Morphological characteristics effectively discriminated between the nine genetic clusters, and the correlation among morphology and substrates was elucidated. We revised taxonomic accounts of S. decipiens, S. habei, S. arenicola, S. nakasekoae and S. ourensis and synonymised S. multigranosa, S. habei yamaguchi, S. dilatata under S. decipiens and S. fluvialis under S. nakasekoae. We also described two new species, Semisulcospira elongata sp. nov. and Semisulcospira cryptica sp. nov., and redefined two phylogroups of the lacustrine species as the Semisulcospira niponica-group and the Semisulcospira nakasekoae-group. Traits of the species examined exhibiting intraspecific variation in the different substrates and flow velocity may indicate the morphological and trophic adaptations. The habitat-related variation has certainly caused the taxonomic confusion of the lacustrine species. Lake drainage contributes to increasing the species diversity of the genus, generating ecological isolation between the riverine and lacustrine habitats

First record of the terrestrial amphipod, Talitroides alluaudi (Chevreux, 1896) (Crustacea, Amphipoda, Brevitalitridae), from Japan

We report Talitroides alluaudi (Chevreux, 1896) from Miyako Island, Ryukyu Islands, Japan. Although this terrestrial amphipod is distributed worldwide, including Indo-Pacific islands, Europe, and North and South America, the present specimens represent the first record of this species from Japanese islands. The cytochrome c oxidase subunit I (COI) sequence of a Miyako Island specimen was unique compared with the known COI sequences from Taiwanese and Bermudan populations

Dynamical Diffraction Theory for Wave Packet Propagation in Deformed Crystals

We develop a theory for the trajectory of an x ray in the presence of a crystal deformation. A set of equations of motion for an x-ray wave packet including the dynamical diffraction is derived, taking into account the Berry phase as a correction to geometrical optics. The trajectory of the wave packet has a shift of the center position due to a crystal deformation. Remarkably, in the vicinity of the Bragg condition, the shift is enhanced by a factor $\omega /\Delta \omega$ ($\omega$: frequency of an x ray, $\Delta\omega$: gap frequency induced by the Bragg reflection). Comparison with the conventional dynamical diffraction theory is also made.Comment: 4 pages, 2 figures. Title change

Structural variation in the glycogen synthase kinase 3β and brain‐derived neurotrophic factor genes in Japanese patients with bipolar disorders

Background: Lithium is the first‐line drug for the treatment of bipolar disorders (BDs); however, not all patients responded. Glycogen synthase kinase (GSK) 3β and brain‐derived neurotrophic factor (BDNF) play a role in the therapeutic action of lithium. Since structural variations were reported in these genes, it is possible that these genomic variations may be involved in the therapeutic responses to lithium. Method: Fifty patients with BDs and 50 healthy subjects (mean age 55.0 ± 15.0 years; M/F 19/31) participated. We examined structural variation of the GSK3β and BDNF genes by real‐time PCR. We examined the influence of structural variation of these genes on the therapeutic responses to lithium and the occurrence of antidepressant‐emergent affective switch (AEAS). The efficacy of lithium was assessed using the Alda scale, and AEAS was evaluated using Young Mania Rating Scale. Results: Although we examined structural variations within intron II and VII of the GSK3® gene and from the end of exon IV to intron IV and within exon IX of the BDNF gene, no structural variation was found in BDs. Whereas 5 of 50 patients exhibited three copies of the genomic region within exon IV of the BDNF gene, all healthy subjects had two copies. No difference in the therapeutic efficacy of lithium was found between patients with three and two copies. No difference in the occurrence of AEAS was found between the two groups. Conclusion: The amplification of the BDNF gene influenced neither the therapeutic responses to lithium nor the occurrence of AEAS

Anisotropic Optic Conductivities due to Spin and Orbital Orderings in LaVO3 and YVO3: First-Principles Studies

The anisotropy of low energy (0$\sim$5eV) optical excitations in strongly correlated transition-metal oxides is closely related to the spin and orbital orderings. The recent successes of LDA+$U$ method in describing the magnetic and electronic structures enable us to calculate the optical conductivity from first-principles. The LaVO$_3$ and YVO$_3$, both of which have $3d^2$ configuration and have various spin and orbital ordered phases at low temperature, show distinct anisotropy in the optical spectra. The effects of spin and orbital ordering on the anisotropy are studied in detail based on our first-principles calculations. The experimental spectra of both compounds at low temperature phases can be qualitatively explained with our calculations, while the studies for the intermediate temperature phase of YVO$_3$ suggest the substantial persistence of the low temperature phase at elevated temperature.Comment: 6 pages, 3 figures, accepted by PR

A NEW OPERATIVE TECHNIQUE FOR ESOPHAGEAL RECONSTRUCTION USING A LONG GASTRIC TUBE OF 3 CM DIAMETER

The anthors have successfully prepared a 3 cm diameter gastric tube with a more favorable blood supply than the conventional one by performing interrupted suture each of the mucosal layers and seromuscular layers of the stomach separately with pyloromyotomy as a drainage procedure. This gastric tube caused no clavicular pressure on the anastomotic portion through a retrosternal route, so that we could perform end-to-end anastomosis between the cervical esophagus and the gastric tube in a region higher than the clavicle. We report in this paper the clinical findings of our procedure : it was effective in preventing postoperative complications such as suture insufficiency and passage disturbance other than postoperative complaints due to dumping and reflux esophagitis, etc

ER Stress Protein CHOP Mediates Insulin Resistance by Modulating Adipose Tissue Macrophage Polarity

Obesity represents chronic inflammatory states promoted by pro-inflammatory M1-macrophage infiltration into white adipose tissue (WAT), thereby inducing insulin resistance. Herein, we demonstrate the importance of an ER stress protein, CHOP, in determining adipose tissue macrophage (ATM) polarity and systemic insulin sensitivity. A high-fat diet (HFD) enhances ER stress with CHOP upregulation in adipocytes. CHOP deficiency prevents HFD-induced insulin resistance and glucose intolerance with ATM M2 predomination and Th2 cytokine upregulation in WAT. Whereas ER stress suppresses Th2 cytokine expression in cultured adipocytes, CHOP knockdown inhibits this downregulation. In contrast, macrophage responsiveness to Th1/Th2 cytokines is unchanged regardless of whether CHOP is expressed. Furthermore, bone marrow transplantation experiments showed recipient CHOP to be the major determinant of ATM polarity. Thus, CHOP in adipocytes plays important roles in ATM M1 polarization by altering WAT micro-environmental conditions, including Th2 cytokine downregulation. This molecular mechanism may link adipose ER stress with systemic insulin resistance