極限補償光学のための点回折干渉計型波面センサの開発

京都大学新制・課程博士博士(理学)甲第24416号理博第4915号新制||理||1702(附属図書館)京都大学大学院理学研究科物理学・宇宙物理学専攻(主査)准教授 栗田 光樹夫, 准教授 岩室 史英, 教授 太田 耕司学位規則第4条第1項該当Doctor of ScienceKyoto UniversityDFA

Paleomagnetism of Eocene volcanic tuffs from Laramide foreland basins: Implications for the Geomagnetic Polarity Time Scale

Volcanic tuff samples were collected from twenty-nine tuff horizons in Laramide foreland basins and measured for their paleomagnetism. The results were combined with high precision radiometric ages of the same tuffs to evaluate eight competing calibration models for the Eocene part of the Geomagnetic Polarity Time Scale (GPTS) by comparing the measured polarity to that predicted by each age model. Of the eight models, the New Willwood model is tentatively favored and recommended as the best alternative yet available to the current GPTS calibration. It not only removes an ongoing chronostratigraphic discrepancy in the Greater Green River Basin, but also provides a new temporal framework to which regional chronostratigraphic data are correlated most coherently. This new calibration model implies a shorter duration for the early Eocene and the Early Eocene Climatic Optimum and also suggests that rates of seafloor spreading were more variable than traditionally modeled in the GPTS

Geometry of tropical moduli spaces and linkage of graphs

We prove the following "linkage" theorem: two p-regular graphs of the same genus can be obtained from one another by a finite alternating sequence of one-edge-contractions; moreover this preserves 3-edge-connectivity. We use the linkage theorem to prove that various moduli spaces of tropical curves are connected through codimension one.Comment: Final version incorporating the referees correction

Relation between reflux of bile acids into the stomach and gastric mucosal atrophy, intestinal metaplasia in biopsy specimens

During endoscopic examinations we collected fluid in the stomach that included reflux fluid from the duodenum, and assessed the effect of quantitatively determined bile acids on glandular atrophy and intestinal metaplasia using biopsy specimens. A total of 294 outpatients were enrolled in this study. Total bile acid concentration was measured by an enzyme immunoassay. Glandular atrophy and intestinal metaplasia scores were graded according to the Updated Sydney System. An effect of refluxed bile acids on atrophy and intestinal metaplasia was shown in the high-concentration reflux group in comparison with the control group. However, when the odds ratios (ORs) were calculated according to whether Helicobacter pylori (H. pylori) infection was present, no significant associations were shown between reflux bile acids and atrophy in either the H. pylori-positive cases or -negative cases. The same was true for intestinal metaplasia in the H. pylori-positive cases, whereas intestinal metaplasia was more pronounced in the high-concentration reflux group in the H. pylori-negative cases (OR 2.4, 95%CI 1.1–5.6). We could not clarify the effect of the reflux of bile acids into the stomach in the progression of atrophy. High-concentration bile acids had an effect on the progression of intestinal metaplasia in the H. pylori-negative cases

Novel Transmembrane Receptor Involved in Phagosome Transport of Lysozymes and β-Hexosaminidase in the Enteric Protozoan Entamoeba histolytica

Lysozymes and hexosaminidases are ubiquitous hydrolases in bacteria and eukaryotes. In phagocytic lower eukaryotes and professional phagocytes from higher eukaryotes, they are involved in the degradation of ingested bacteria in phagosomes. In Entamoeba histolytica, which is the intestinal protozoan parasite that causes amoebiasis, phagocytosis plays a pivotal role in the nutrient acquisition and the evasion from the host defense systems. While the content of phagosomes and biochemical and physiological roles of the major phagosomal proteins have been established in E. histolytica, the mechanisms of trafficking of these phagosomal proteins, in general, remain largely unknown. In this study, we identified and characterized for the first time the putative receptor/carrier involved in the transport of the above-mentioned hydrolases to phagosomes. We have shown that the receptor, designated as cysteine protease binding protein family 8 (CPBF8), is localized in lysosomes and mediates transport of lysozymes and β-hexosaminidase α-subunit to phagosomes when the amoeba ingests mammalian cells or Gram-positive bacillus Clostridium perfringens. We have also shown that the binding of CPBF8 to the cargos is mediated by the serine-rich domain, more specifically three serine residues of the domain, which likely contains trifluoroacetic acid-sensitive O-phosphodiester-linked glycan modifications, of CPBF8. We further showed that the repression of CPBF8 by gene silencing reduced the lysozyme and β-hexosaminidase activity in phagosomes and delayed the degradation of C. perfringens. Repression of CPBF8 also resulted in decrease in the cytopathy against the mammalian cells, suggesting that CPBF8 may also be involved in, besides the degradation of ingested bacteria, the pathogenesis against the mammalian hosts. This work represents the first case of the identification of a transport receptor of hydrolytic enzymes responsible for the degradation of microorganisms in phagosomes

経済的行動の心理学的分析に関する基本的問題の考察

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