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Doubling Construction of Calabi-Yau Fourfolds from Toric Fano Fourfolds

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Communications in Mathematics and Statistics 2015年第3期3卷 423-447页

作者： Mamoru doi Naoto Yotsutani 11-9-302 Yumoto-cho TakarazukaHyogo 665-0003Japan School of Mathematical Sciences at Fudan University Shanghai 200433People’s Republic of China

We give a differential-geometric construction of Calabi-Yau fourfolds by the‘doubling’method,which was introduced in doi and Yotsutani(N Y J Math 20:1203-1235,2014)to construct Calabi-Yau *** also give examples of Calabi-Yau fourfolds from toric Fano *** in our construction are admissible pairs,which were first dealt with by Kovalev(J Reine Angew Math 565:125-160,2003).Here in this paper an admissible pair(X,D)consists of a compact Kähler manifold X and a smooth anticanonical divisor D on *** two admissible pairs(X_(1),D_(1))and(X_(2),D_(2))with dimC X_(i)=4 satisfy the gluing condition,we can glue X_(1)\D_(1)and X_(2)\D_(2)together to obtain a compact Riemannian 8-manifold(M,g)whose holonomy group Hol(g)is contained in Spin(7).Furthermore,if theA-genus of M equals 2,then M is a Calabi-Yau fourfold,i.e.,a compact Ricci-flat Kähler fourfold with holonomy SU(4).In particular,if(X_(1),D_(1))and(X_(2),D_(2))are identical to an admissible pair(X,D),then the gluing condition holds automatically,so that we obtain a compact Riemannian 8-manifold M with holonomy contained in Spin(7).Moreover,we show that if the admissible pair is obtained from any of the toric Fano fourfolds,then the resulting manifold M is a Calabi-Yau fourfold by computing^A(M)=2.

关键词： Ricci-flat metrics Calabi-Yau manifolds Spin(7)-structures Gluing Doubling Toric geometry

Leaf Positioning of Arabidopsis in Response to Blue Light

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Molecular Plant 2008年第1期1卷 15-26页

作者： Shin-ichiro Inoue Toshinori Kinoshit Atsushi Takemiya Michio doi Ken-ichiro Shimazaki Department of Biology Faculty of Science Kyushu University Ropponmatsu Fukuoka 810-8560 Japan Research and Development Center for Higher Education Kyushu University Ropponmatsu Fukuoka 810-8560 Japan

Appropriate leaf positioning is essential for optimizing photosynthesis and plant growth. However, it has not been elucidated how green leaves reach and maintain their position for capturing light. We show here the regulation of leaf positioning under blue light stimuli. When 1-week-old Arabidopsis seedlings grown under white light were transferred to red light （25 i, mol m^-2 s^-1） for 5 d, new petioles that appeared were almost horizontal and their leaves were curled and slanted downward. However, when a weak blue light from above （0.1 i, mol m^-2 s^-1） was superimposed on red light, the new petioles grew obliquely upward and the leaves were flat and horizontal. The leaf positioning required both phototropinl （photl） and nonphototropic hypocotyl 3 （NPH3）, and resulted in enhanced plant growth. In an nph3 mutant, neither optimal leaf positioning nor leaf flattening by blue light was found, and blue light-induced growth enhancement was drastically reduced. When blue light was increased from 0.1 to 5 i, mol m^-2 s^-1, normal leaf positioning and leaf flattening were induced in both photl and nph3 mutants, suggesting that phot2 signaling became functional and that the signaling was independent of photl and NPH3 in these responses. When plants were irradiated with blue light （0.1 i, mol m^-2 s^- 1） from the side and red light from above, the new leaves became oriented toward the source of blue light. When we transferred these plants to both blue light and red light from above, the leaf surface changed its orientation to the new blue light source within a few hours, whereas the petioles initially were unchanged but then gradually rotated, suggesting the plasticity of leaf positioning in response to blue light. We showed the tissue expression of NPH3 and its plasma membrane localization via the coiled-coil domain and the C-terminal region. We conclude that NPH3-mediated phototropin signaling optimizes the efficiency of light perception by inducing both optimal leaf posit

关键词： Leaf Positioning of Arabidopsis Response Blue Light

Thin film dynamics in coating problems using Onsager principle

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Chinese Physics B 2018年第2期27卷 51-55页

作者：邸亚娜许现民周嘉嘉 Masao doi LSEC ICMSEC Academy of Mathematics and Systems Science Chinese Academy of Sciences School of Mathematical Sciences University of Chinese Academy of Sciences Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of Ministry of Education School of ChemistryBeihang University Center of Soft Matter Physics and Its Applications Beihang University Beijing Advanced Innovation Center for Biomedical Engineering Beihang University

A new variational method is proposed to investigate the dynamics of the thin film in a coating flow where a liquid is delivered through a fixed slot gap onto a moving substrate. A simplified ODE system has also been derived for the evolution of the thin film whose thickness hf is asymptotically constant behind the coating front. We calculate the phase diagram as well as the film profiles and approximate the film thickness theoretically, and agreement with the well-known scaling law as Ca2/3 is found.

关键词： Onsager principle thin films coating flows interfacial flows

Distinctive Precursory Air–Sea Signals between Regular and Super El Ni os

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Advances in Atmospheric Sciences 2016年第8期33卷 996-1004页

作者： Lin CHEN Tim LI Swadhin K.BEHERA Takeshi doi Key Laboratory of Meteorological Disaster Joint International Research Laboratory of Climate and Environmental Changeand Collaborative Innovation Center on Forecast and Evaluation of Meteorological DisastersNanjing University of Information Science and Technology International Pacific Research Center School of Ocean and Earth Science and Technology University of Hawaii Application Laboratory Japan Agency for Marine-Earth Science and Technology

Statistically different precursory air–sea signals between a super and a regular El Ni no group are investigated, using observed SST and rainfall data, and oceanic and atmospheric reanalysis data. The El Ni no events during 1958–2008 are first separated into two groups： a super El Ni no group（S-group） and a regular El Ni no group（R-group）. Composite analysis shows that a significantly larger SST anomaly（SSTA） tendency appears in S-group than in R-group during the onset phase[April–May（0）], when the positive SSTA is very small. A mixed-layer heat budget analysis indicates that the tendency difference arises primarily from the difference in zonal advective feedback and the associated zonal current anomaly（u）.This is attributed to the difference in the thermocline depth anomaly（D） over the off-equatorial western Pacific prior to the onset phase, as revealed by three ocean assimilation products. Such a difference in D is caused by the difference in the wind stress curl anomaly in situ, which is mainly regulated by the anomalous SST and precipitation over the Maritime Continent and equatorial Pacific.

关键词： super El Ni no precursory air–sea signals thermocline depth anomaly ENSO

Production of Ergot Alkaloids by the Japanese Isolate Claviceps purpurea var. agropyri on Rice Medium

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Advances in Microbiology 2022年第4期12卷 254-269页

作者： Yuji doi Daigo Wakana Hisashi Takeda Eiji Tanaka Tomoo Hosoe Faculty of Pharmaceutical Sciences Hoshi University Shinagawa Japan Department of Environmental Science Ishikawa Prefectural University Nonoichi Japan

Ergot alkaloids (EAs) are secondary metabolites produced by ergot fungi (e.g., Claviceps purpurea), which are parasites of Gramineae grasses. EAs and their analogs are used to treat migraine, postpartum uterine bleeding, and Parkinson's syndrome. Recent studies have reported additional new bioactive activities of EAs and their analogs, making them essential compounds for drug development, drug repositioning, and clinical applications. EAs are produced industrially by field cultivation of ergot or liquid fermentation in the mycelial phase, but there are few published studies of the production of EAs by cereal culture and thus this approach is poorly understood. This study searched for Claviceps strains that produce EAs cultured artificially in the mycelial phase, then the selected strains were cultured on cereal media (white rice, brown rice, and rye) to examine their ability to produce EAs on each medium. C. purpurea var. agropyri produced the Clavine-type EAs pyroclavine (1), festuclavine (2), and agroclavine (3) in the mycelial phase. When cultured with white rice, brown rice, or rye, C. purpurea var. agropyri produced 1 - 3 on all cereal media. The total amount of 1 - 3 in each cereal medium (150 g of cereal per Roux flask) was 2220.5 ± 564.1 μg for white rice, 920.0 ± 463.6 μg for brown rice, and 595.4 ± 52.1 μg for rye. The white rice medium supported the highest production of 1 - 3, with the total amount of EAs (150 g of white rice per Roux flask) being about 34 times higher than that in the T25 liquid medium (190 mL per 1 L Erlenmeyer flask) (equivalent amount per flask).

关键词： Claviceps Ergot Alkaloid Rice Culture Pyroclavine Festuclavine Agroclavine

Modelling drying pathways of an evaporating soft matter droplet

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Communications in Theoretical Physics 2022年第9期74卷 194-198页

作者： Guangle Du Fangfu Ye Hao Luo Guangyin Jing Masao doi Fanlong Meng CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China Wenzhou Institute University of Chinese Academy of SciencesWenzhou 325001China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China Songshan Lake Materials Laboratory Dongguan 523808China School of Physics and State Key Laboratory of Photon-Technology in Western China EnergyNorthwest UniversityXi’an 710069China Center of Soft Matter Physics and its Applications Beihang UniversityBeijing 100191China

Micro-droplets of soft matter solutions have different morphologies upon drying,and can become wrinkled,buckled or cavitated *** investigate the morphology evolution of a drying soft matter droplet in this work:at the early stage of drying,wrinkling or cavitation instability can occur in the droplet,depending on the comparison between the critical wrinkling and cavitation pressure;at a later stage of drying,no wrinkles will appear if cavitation happens first,while cavitation can still occur if wrinkling happens first.A three-dimensional phase diagram in the space of elastic length,gel layer thickness and weight loss is provided to illustrate the drying pathways of a soft matter *** diagram can help guide future fabrications of micro-particles with desired morphologies.

关键词： soft matter solution drying instabilities

Secalonic Acid and Benzoic Acid Analogues Exhibiting Cyto toxicity against Cancer Cells Isolated from Claviceps yanagawaensis

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Advances in Microbiology 2022年第12期12卷 649-670页

作者： Yuji doi Daigo Wakana Satoshi Kitaoka Hisashi Takeda Eiji Tanaka Tomoo Hosoe Faculty of Pharmaceutical Sciences Hoshi University Tokyo Japan Faculty of Pharmacy and Pharmaceutical Sciences Josai University Sakado Japan Department of Environmental Science Ishikawa Prefectural University Nonoichi Japan

The genus Claviceps (Clavicipitaceae) is noted for producing ergot alkaloids that cause ergotism. Claviceps yanagawaensis, a parasite of Zoysia japonica (family: Poaceae), has been isolated in Japan. Bioactivity screening showed that a methanol extract from a rice culture of C. yanagawaensis was cytotoxic to cancer cells. In our search for active substances, the new secalonic acid analogues (-)-5-epi-F-7 (1) and ergochrysin C (2) and a new benzoic acid analogue, dimethyl bigutol (3), were isolated along with the known compounds 3,4-dihydroxy-5-(3-methyl-2-buten-1-yl)benzoic acid (4) and methyl veratrate (5). The structures of 1 - 3 were elucidated by NMR, MS, and circular dichroism spectroscopy. MTT assays of 1 - 5 using cancer cell lines (HepG2, HL60, HT29, PANC-1, and T98G) showed that 1 - 4 exhibited cytotoxicity against cancer cells.

关键词： Claviceps Secalonic Acid MTT Assay

Examination of in vivo mutagenicity of sodium arsenite and dimethylarsinic acid in gpt delta rats

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Journal of Environmental Sciences 2016年第11期28卷 125-130页

作者： Masaki Fujioka Min Gi Satoko Kawachi Kumiko Tatsumi Naomi Ishii Kenichiro doi Anna Kakehashi Hideki Wanibuchi Department of Molecular Pathology Osaka City University Graduate School of Medicine

Arsenic is a well-known human bladder and liver carcinogen, but its exact mechanism of carcinogenicity is not fully understood. Dimethylarsinic acid（DMAV） is a major urinary metabolite of sodium arsenite（i As~Ⅲ） and induces urinary bladder cancers in rats. DMAVand i As~Ⅲare negative in in vitro mutagenicity tests. However, their in vivo mutagenicities have not been determined. The purpose of present study is to evaluate the in vivo mutagenicities of DMAVand i As~Ⅲin rat urinary bladder epithelium and liver using gpt delta F344 ***-week old male gpt delta F344 rats were randomized into 3 groups and administered 0,92 mg/L DMAV, or 87 mg/L i As~Ⅲ（each 50 mg/L As） for 13 weeks in the drinking water. In the mutation assay, point mutations are detected in the gpt gene by 6-thioguanine selection（gpt assay） and deletion mutations are identified in the red/gam genes by Spi-selection（Spi-assay）. Results of the gpt and Spi-assays showed that DMAVand i As~Ⅲhad no effects on the mutant frequencies or mutation spectrum in urinary bladder epithelium or liver. These findings indicate that DMAVand i As~Ⅲare not mutagenic in urinary bladder epithelium or liver in rats.

关键词： Dimethylarsinic acid Sodium arsenite In vivo mutagenicity Urinary bladder epithelium gpt delta rat

γ-Irradiation Effect:Variation of Photosynthetic Activity of Euglena

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Biomedical and Environmental Sciences 2002年第3期15卷 261-267页

作者： T·SAKASHITA M·doi 等 NationalInstituteofRadinologicalSciences

Objective To study the effects of gamma-ray irradiation on carbon fixation (Specific production rate: SPR), CO2 utilization efficiency (CUE) and electron transfer rate (ETR) in the photosynthetic flagellate Euglena gracilis strain Z in a dose-response dependent manner. Methods Euglena cells were cultured in an inorganic nutrient medium containing ammonium chloride or proteose peptone. Cells were exposed to gamma-ray at 5 doses (0, 100, 250, 350, 500 Gy for water). Five days after irradiation, three photosynthetic activities were measured. SPR, which is a carbon uptake rate per unit carbon mass, was determined by 13C tracer methodology. CUE was evaluated using a relation of carbon isotope fractionation in Calvin cycle. ETR in photosystem II (PS II) was measured by a chlorophyll fluorescence analysis. Results Even at a dose of 500 Gy, 80 % of ETR of the non-irradiated control (0 Gy) was sustained, while SPR and CUE were about half the level in the non-irradiated control at 500 Gy. Furthermore, the dose response of ETR was considerably different from the others. Conclusion Our findings suggest that not only PS II but also the Calvin cycle in the photosynthetic system is affected by gamma ray irradiation.

关键词： Gamma-ray irradiation Euglena gracilis Photosynthetic activities