148 research outputs found
The "Yin-Yang Grid": An Overset Grid in Spherical Geometry
A new kind of overset grid, named Yin-Yang grid, for spherical geometry is
proposed. The Yin-Yang grid is composed of two identical component grids that
are combined in a complemental way to cover a spherical surface with partial
overlap on their boundaries. Each component grid is a low latitude part of the
latitude-longitude grid. Therefore the grid spacing is quasi-uniform and the
metric tensors are simple and analytically known. One can directly apply
mathematical and numerical resources that have been written in the spherical
polar coordinates or latitude-longitude grid. The complemental combination of
the two identical component grids enables us to make efficient and concise
programs. Simulation codes for geodynamo and mantle convection simulations
using finite difference scheme based on the Yin-Yang grid are developed and
tested. The Yin-Yang grid is suitable for massively parallel computers.Comment: 9 figure
Relationship of Cognitive Style and Job Level: First Demonstration of Cultural Differences
Higher-level managers are said to have a more intuitive cognitive style. To verify this hypothesis, we must consider three factors that have often been left out of account. Previous studies, related to managerial cognitive style and job level, used a unidimensional model of cognitive style, did not consider age, and have mainly been conducted in the UK. Our study replicated previous studies on a population of 1,533 Japanese fulltime workers, using a questionnaire based on a two-dimensional model of cognitive style and setting a frame by age for each job level. Our results showed that higher job levels are associated with more rational cognitive styles. There were significant main effects of the interaction of job level and job level by age in rational thinking style. There was no correlation between intuition and job level. Our findings are the first demonstration that the relationship between job level and cognitive style likely depends on culture
Properdin inhibition ameliorates hepatic ischemia/reperfusion injury without interfering with liver regeneration in mice
Hepatic ischemia/reperfusion injury (IRI) often causes serious complications in liver surgeries, including transplantation. Complement activation seems to be involved in hepatic IRI; however, no complement-targeted intervention has been clinically applied. We investigated the therapeutic potential of Properdin-targeted complement regulation in hepatic IRI. Male wild-type mice (B10D2/nSn) were exposed to 90-minute partial hepatic IRI to the left and median lobes with either monoclonal anti-Properdin-antibody (Ab) or control-immunoglobulin (IgG) administration. Since the complement system is closely involved in liver regeneration, the influence of anti-Properdin-Ab on liver regeneration was also evaluated in a mouse model of 70% partial hepatectomy. Anti-Properdin-Ab significantly reduced serum transaminases and histopathological damages at 2 and 6 hours after reperfusion (P <0.001, respectively). These improvements at 2 hours was accompanied by significant reductions in CD41+ platelet aggregation (P =0.010) and ssDNA+ cells (P <0.001), indicating significant amelioration in hepatic microcirculation and apoptosis, respectively. Characteristically, F4/80+ cells representing macrophages, mainly Kupffer cells, were maintained by anti-Properdin-Ab (P <0.001). Western blot showed decreased phosphorylation of only Erk1/2 among MAPKs (P =0.004). After 6 hours of reperfusion, anti-Properdin-Ab significantly attenuated the release of HMGB-1, which provokes the release of proinflammatory cytokines/chemokines (P =0.002). Infiltration of CD11b+ and Ly6-G+ cells, representing infiltrating macrophages and neutrophils, respectively, were significantly alleviated by anti-Properdin-Ab (both P <0.001). Notably, anti-Properdin-Ab did not affect remnant liver weight and BrdU+ cells at 48 hours after 70% partial hepatectomy (P =0.13 and 0.31, respectively). In conclusion, Properdin inhibition significantly ameliorates hepatic IRI without interfering with liver regeneration
Enhanced pressor response in spontaneously hypertensive rats induced by stimulation of vasopressin-V1 receptors.
To elucidate the effect of the arginine vasopressin (AVP) system in vivo, especially V1 and V2 activity, on blood pressure, we measured the acute changes in blood pressure and heart rate after AVP, OPC-21,268 (a V1 receptor antagonist), and OPC-31,260 (a V2 receptor antagonist) were injected intravenously in anesthetized spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats at the age of 15 weeks. Compared with the control period, single injection of AVP 5 ng/kg significantly increased systolic blood pressure in WKY rats without a concomitant increase in heart rate, but there was no significant increase in blood pressure in SHR. In contrast, single injection of either OPC-21,268 3 mg/kg or OPC-31,260 3 mg/kg did not affect blood pressure or heart rate in either SHR or WKY rats. Injection of AVP after the administration of OPC-31,260 induced a greater increase in blood pressure in SHR than in WKY rats, whereas injection of AVP after the administration of OPC-21,268 did not induce any clear increase in blood pressure in SHR or WKY rats. These results suggest that SHR have enhanced pressor activity mediated by V1 receptors and that this increase may be due to an increase in their number. In conclusion, enhancement of V1 activity may contribute to the development of high blood pressure in SHR.</p
初学者によるデジタル画像を用いた角度測定の精度および信頼性
研究論文Original article〔目的〕本研究の目的は,0.5 度刻みで設定した被写体に対し,学生が検査者となった場合,デジタル画像解析による角度測定の精度を検証することである.〔対象と方法〕検査者は大学生10 名とした.デジタルカメラで撮影した被写体は,89.0 度,89.5 度,90.0 度,90.5 度,91.0 度の5 条件を設定したモデルとした.得られたデジタル画像に対し,各条件で3 回の角度測定を行った.〔結果〕すべての検査者において,測定値は,いずれの設定条件でも設定角度の大きい条件は小さい条件より大きかった.また,各条件間で有意な差を認めた.絶対誤差は,平均0.16 ± 0.05 度であった.級内相関係数ICC(1,3)は0.981-0.987 であった.〔結語〕この研究では,デジタル画像解析が,大学生が測定しても,小さな変化を検出できる精度をもっていることが示唆された.[Purpose] The purpose of this study is to verify the accuracy of angle measurement by digital image analysis for subjects set at 0.5-degree increments.[Methods] The examiners were 10 university students. The subjects were photographed with a digital camera, and the model was set to five conditions: 89.0, 89.5, 90.0, 90.5, and 91.0 degrees. The examiner performed angle measurements in each condition using the digital images obtained.[Results] In all examiners, measurements were greater for the larger set angle condition than for the smaller set angle condition for all conditions. In addition, measurements were significantly different between conditions. Absolute errors averaged 0.16 ± 0.05 degrees. The intraclass correlation coefficient ICC (1, 3) was 0.981-0.987.[Conclusion] This study suggests that digital image analysis has the accuracy to detect small changes even when measured by university students
2.6 仮想現実空間における立体音響システムの開発と数値シミュレーションモデルへの適用
仮想現実空間における立体音響システムの開発と数値シミュレーションモデルへの適用田村祐一[核融合科学研究所]陰山聡[核融合科学専攻・核融合科学研究所]佐藤哲也[核融合科学専攻・核融合科学研究所]*所属は当時のものを記
The impact of human leukocyte antigen mismatch on recipient outcomes in living‐donor liver transplantation
Donor–recipient human leukocyte antigen (HLA) compatibility has not been considered to significantly affect liver transplantation (LT) outcomes; however, its significance in living-donor LT (LDLT), which is mostly performed between blood relatives, remains unclear. This retrospective cohort study included 1954 LDLTs at our institution (1990–2020). The primary and secondary endpoints were recipient survival and the incidence of T cell–mediated rejection (TCMR) after LDLT, respectively, according to the number of HLA mismatches at all five loci: HLA-A, HLA-B, HLA-C, HLA-DR, and HLA-DQ. Subgroup analyses were also performed in between-siblings that characteristically have widely distributed 0–10 HLA mismatches. A total of 1304 cases of primary LDLTs were finally enrolled, including 631 adults (recipient age at LT ≥18 years) and 673 children (<18 years). In adult-to-adult LDLT, the more HLA mismatches at each locus, the significantly worse the recipient survival was (p = 0.03, 0.01, 0.03, 0.001, and <0.001 for HLA-A, HLA-B, HLA-C, HLA-DR, and HLA-DQ, respectively). This trend was more pronounced when multiple loci were combined (all p < 0.001 for A + B + DR, A + B + C, DR + DQ, and A + B + C + DR + DQ). Notably, a total of three or more HLA-B + DR mismatches was an independent risk factor for both TCMR (hazard ratio [HR] 2.66, 95% confidence interval [CI] 1.21–5.87; p = 0.02) and recipient survival (HR 2.44, 95% CI 1.11–5.35; p = 0.03) in between-siblings. By contrast, HLA mismatch did not affect pediatric LDLT outcomes at any locus or in any combinations; however, it should be noted that all donor–recipient relationships are parent-to-child that characteristically possesses one or less HLA mismatch at each locus and maximally five or less mismatches in total. In conclusion, HLA mismatch significantly affects not only TCMR development but also recipient survival in adult LDLT, but not in children
Intramolecular Regulation of Phosphorylation Status of the Circadian Clock Protein KaiC
KaiC, a central clock protein in cyanobacteria, undergoes circadian oscillations between hypophosphorylated and hyperphosphorylated forms in vivo and in vitro. Structural analyses of KaiC crystals have identified threonine and serine residues in KaiC at three residues (T426, S431, and T432) as potential sites at which KaiC is phosphorylated; mutation of any of these three sites to alanine abolishes rhythmicity, revealing an essential clock role for each residue separately and for KaiC phosphorylation in general. Mass spectrometry studies confirmed that the S431 and T432 residues are key phosphorylation sites, however, the role of the threonine residue at position 426 was not clear from the mass spectrometry measurements.Mutational approaches and biochemical analyses of KaiC support a key role for T426 in control of the KaiC phosphorylation status in vivo and in vitro and demonstrates that alternative amino acids at residue 426 dramatically affect KaiC's properties in vivo and in vitro, especially genetic dominance/recessive relationships, KaiC dephosphorylation, and the formation of complexes of KaiC with KaiA and KaiB. These mutations alter key circadian properties, including period, amplitude, robustness, and temperature compensation. Crystallographic analyses indicate that the T426 site is phosphorylatible under some conditions, and in vitro phosphorylation assays of KaiC demonstrate labile phosphorylation of KaiC when the primary S431 and T432 sites are blocked.T426 is a crucial site that regulates KaiC phosphorylation status in vivo and in vitro and these studies underscore the importance of KaiC phosphorylation status in the essential cyanobacterial circadian functions. The regulatory roles of these phosphorylation sites--including T426--within KaiC enhance our understanding of the molecular mechanism underlying circadian rhythm generation in cyanobacteria
Activation of AMPK-Regulated CRH Neurons in the PVH is Sufficient and Necessary to Induce Dietary Preference for Carbohydrate over Fat
Food selection is essential for metabolic homeostasis and is influenced by nutritional state, food palatability, and social factors such as stress. However, the mechanism responsible for selection between a high-carbohydrate diet (HCD) and a high-fat diet (HFD) remains unknown. Here, we show that activation of a subset of corticotropin-releasing hormone (CRH)-positive neurons in the rostral region of the paraventricular hypothalamus (PVH) induces selection of an HCD over an HFD in mice during refeeding after fasting, resulting in a rapid recovery from the change in ketone metabolism. These neurons manifest activation of AMP-activated protein kinase (AMPK) during food deprivation, and this activation is necessary and sufficient for selection of an HCD over an HFD. Furthermore, this effect is mediated by carnitine palmitoyltransferase 1c (CPT1c). Thus, our results identify the specific neurons and intracellular signaling pathway responsible for regulation of the complex behavior of selection between an HCD and an HFD
Strain-induced creation and switching of anion vacancy layers in perovskite oxynitrides
Using strain to control oxynitride properties. 京都大学プレスリリース. 2020-12-01.原子空孔の配列を制御する新手法の発見. 京都大学プレスリリース. 2020-12-02.Perovskite oxides can host various anion-vacancy orders, which greatly change their properties, but the order pattern is still difficult to manipulate. Separately, lattice strain between thin film oxides and a substrate induces improved functions and novel states of matter, while little attention has been paid to changes in chemical composition. Here we combine these two aspects to achieve strain-induced creation and switching of anion-vacancy patterns in perovskite films. Epitaxial SrVO3 films are topochemically converted to anion-deficient oxynitrides by ammonia treatment, where the direction or periodicity of defect planes is altered depending on the substrate employed, unlike the known change in crystal orientation. First-principles calculations verified its biaxial strain effect. Like oxide heterostructures, the oxynitride has a superlattice of insulating and metallic blocks. Given the abundance of perovskite families, this study provides new opportunities to design superlattices by chemically modifying simple perovskite oxides with tunable anion-vacancy patterns through epitaxial lattice strain
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