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Influence of Fine Sediment on the Fluidity of Debris Flows

Journal of Mountain Science 2013年第2期10卷 233-238页

作者： Norifumi HOTTA Takahiro KANEKO Tomoyuki iwata Haruo NISHIMOTO Faculty of Life and Environmental Sciences University of Tsukuba3058577 IbarakiJapan Faculty of Agriculture The University of Tokyo1138657 TokyoJapan Graduate School of Agricultural and Life Sciences The University of Tokyo1138657 TokyoJapan

Debris flows include a great diversity of grain sizes with inherent features such as inverse grading, particle size segregation, and liquefaction of fine sediment. The liquefaction of fine sediment affects the fluidity of debris flows, although the behavior and influence of fine sediment in debris flows have not been examined sufficiently. This study used flume tests to detect the effect of fine sediment on the fluidity of laboratory debris flows consisting of particles with various diameters. From the experiments, the greatest sediment concentration and flow depth were observed in the debris flows mixed with fine sediment indicating increased flow resistance. The experimental friction coefficient was then compared with the theoretical friction coefficient derived by substituting the experimental values into the constitutive equations for debris flow. The theoretical friction coefficient was obtained from two models with different fine-sediment treatments： assuming that all of the fine sediments were solid particles or that the particles consisted of a fluid phase involving pore water liquefaction. From the comparison of the friction coefficients, a fully liquefaction state was detected for the fine particle mixture. When the mixing ratio and particle size of the fine sediment were different, some other eases were considered to be in a partially liquefied transition state. These results imply that the liquefaction of fine sediment in debris flows was induced not only by the geometric conditions such as particle sizes, but also by the flow conditions.

关键词： Debris flow Fine sediment Friction coefficient Liquefaction Open channel Reynolds stress

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Imbricate structure of the Otakeyama area, Okayama Permian Yoshii Group in the Prefecture, southwest Japan

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Frontiers of Earth Science 2015年第1期9卷 152-163页

作者： Tsuyoshi ITO atsushi MATSUOKA State Key Laboratory of Geo-processes and Mineral Resources China University of Geosciences Wuhan 430074 China Department of Geology Faculty of Science Niigata University Niigata 950-2181 Japan

The Yoshii Group of the Akiyoshi terrane is distributed over the Otakeyama area, Okayama Prefecture, southwest Japan. The Yoshii Group is composed of siliceous rocks and clastics, comprising chert-clastic sequences. The Yoshii Group is divided into four structural units （Units Ot 1, Ot 2, Ot 3, and Ot 4） in structurally ascending order. Lithological similarities and radiolarian age suggest that these units exhibit almost identical ocean plate stratigraphy. These units are structurally-repeated to form an imbricate structure. This structure was possibly formed by off-scrape accretion at a toe of an accretionary complex. Additionally, a review of previous studies indicates that an imbricate structure is common in the Akiyoshi terrane. The presence of an imbricate structure in the Akiyoshi terrane, Permian accretionary complex, indicates the possibility that a specific horizon of Permian pelagic sequences acted as a drcollement zone.

关键词： accretionary complex imbricate structure,Permian radiolafia Yoshii Group Okayama Prefecture,southwest Japan

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Balancing timber production and habitat conservation of Okinawa Rails(Gallirallus okinawae): Application of a harvest scheduling optimization model in subtropical forest in Okinawa, Japan

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Journal of Mountain Science 2019年第12期16卷 2770-2782页

作者： KONOSHIMA Masashi YOSHIMOTO atsushi Faculty of Agriculture University of the Ryukyusi SenbaruNishihara ChoOkinawa903-0213 Japan Institute of Statistical Mathematics(ISM) 10-3 Midori-choTachikawaTokyo 190-8562Japan

Finding the right balance between timber production and the management of forest-dependent wildlife species,present a difficult challenge for forest resource managers and policy makers in Okinawa,Japan.A possible explanation of this can be found in the unique nature of the forest management area which is populated with various kinds of rare and endangered *** issue has been brought to light as a result of the nomination of northern Okinawa Island in 2018 as a candidate for World Natural Heritage *** nomination has raised public awareness to the possibility of conflicting management objectives between timber extraction and the conservation of habitat for forest-dependent wildlife *** exclusively for one objective over the other may fail to meet the demand for both forest products and wildlife habitat,ultimately jeopardizing the stability of human and wildlife *** is therefore important to achieve a better balance between the objective of timber production and conservation of wildlife *** the significance of this subject area,current ongoing discussions on how to effectively manage for forest resources,often lack scientific basis to make sound judgement or evaluate tradeoffs between conflicting *** the effect of these forest management activities on wildlife habitat provides useful and important information needed to make forest management and policy *** this study we develop a spatial timber harvest scheduling model that incorporates habitat suitability index(HSI)models for the Okinawa Rail(Gallirallus okinawae),an endangered avian species found on Okinawa,*** illustrate how the proposed coupling model assembles spatial information,which ultimately aids the study of forest management effects on wildlife habitat,we apply these models to a forest area in Okinawa and conduct a simple simulation analysis.

关键词： Harvest scheduling Habitat suitability index model Optimization model Timber production Wildlife habitat

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Response of understory vegetation over 10 years after thinning in an old-growth cedar and cypress plantation overgrazed by sika deer in eastern Japan

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Forest Ecosystems 2017年第2期4卷 93-102页

作者： atsushi Tamura Masanobu Yamane Division of Forest Research and Nature Restoration Planning Kanagawa Prefecture Natural Environment Conservation Center 657 Nanasawa AtsugiKanagawa 243-072 Japan

Background： Forest management strategies such as thinning have long been used to enhance ecosystem functions, especially in *** in plantations with high deer density, however, may not yield a desired increase in understory vegetation because deer graze on germinating plants after ***, we examine the changes in understory vegetation after thinning in plantations that have been overgrazed by sika deer to provide insight into the effects of thinning on ecosystem functions such as soil conservation and biological ***： We conducted our survey in the Tanzawa Mountains of eastern *** surveyed the change in understory vegetation within and outside of three deer exclosures on a single slope with three levels of understory vegetation cover： sparse（1%, exclosure ＂US＂）, moderate（30%, exclosure ＂MM＂）, and dense（80%, exclosure ＂LD＂） over10 years after a 30% thinning of an old-growth cedar and cypress plantation which was overgrazed by sika ***： Understory vegetation cover, biomass and species richness increased within and outside the ＂US＂ and＂MM＂ exclosures after thinning, and biomass was greater within than outside the exclosures at 10 years after *** species dominated both ＂US＂ and ＂MM＂ exclosures before thinning, and trees and shrubs dominated within the exclosures over time after *** contrast, unpalatable, grazing-tolerant, perennial,and annual species increased outside the ＂US＂ and ＂MM＂ *** noticeable changes were observed within and outside the ＂LD＂ exclosure when compared with the ＂US＂ and ＂MM＂ ***： Our results suggest that thinning a stand by 30% based on volume resulted in an increase in understory vegetation cover mainly composed of both unpalatable and grazing-tolerant species in a plantation forest where understory vegetation is sparse or moderate and sika deer density is *** emphasize that establishing deer exclosures or controlling deer is essential to ma

关键词： Biomass Deer exclosure Grazing-tolerant species Understory cover Unpalatable species

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Effects of estradiol-17β and bisphenol A administered chronically to mice throughout pregnancy and lactation on the male pups＇ reproductive system

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Asian Journal of Andrology 2008年第2期10卷 271-276页

作者： atsushi Okada Osamu Kai College of Bioresource Sciences Nihon University Fujisawa 252-8510 Japan

Aim： To assess the effect of estradiol-17β （E2） and bisphenol A （BPA） administered chronically by implanting a silicone tube throughout pregnancy and lactation on male pups＇ reproductive system in ICR mice. Methods： Female mice were implanted with a tube filled with 10 ng, 500 ng, 1 μg, or 10 μg of E2, or 100 μg or 5 mg of BPA, before mating. The tube was kept in the mice throughout pregnancy and lactation, until the pups had weaned at 4 weeks of age. During the period, E2 was released from the tube at 120 pg or 6, 12 or 120 ng/day, and BPA at 1.2 or 60 μg/day. Results： Most of the mice given 1 μg and 10 lag of E2 did not maintain their pregnancy. However, the other groups showed high rates of birth, more than 70%. At age of 4 weeks, the male pups were killed. Body weight and reproductive organ weights （testes, epididymides and accessory reproductive glands） in the treated groups did not differ from the control values, whereas the percentage of seminiferous tubules in the testis with mature spermatids was significantly lower in the groups given 10 ng and 500 ng of E2 and 5 mg of BPA than that in the control. Conclusion： Chronic exposure to E2 and BPA might disrupt spermatogenesis in male pups. （Asian JAndrol 2008 Mar; 10： 271-276）

关键词： estradiol-17β bisphenol A chronic administration silicone tube spermatogenesis ICR mice

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Pouchitis and pre-pouch ileitis developed after restorative proctocolectomy for ulcerative colitis:A case report

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World Journal of Gastroenterology 2007年第4期13卷 643-646页

作者： Takashi iwata Takayuki Yamamoto Satoru Umegae Koichi Matsumoto Inflammatory Bowel Disease Center and Department of Surgery Yokkaichi Social Insurance Hospital 10-8 Hazuyamacho Yokkaichi Mie 510-0016 Japan

We report a case of pouchitis and pre-pouch ileitis, and inflammation in the neo-terminal ileum proximal to the pouch, developed after restorative proctocolectomy for ulcerative colitis. A 35-year old female presented with fever and abdominal pain five weeks after ileostomy closure following proctocolectomy. Computed tomography showed collection of feces in the pouch and proximal ileum. A drainage tube was placed in the pouch perianally, and purulent feces were discharged. With antibiotic treatment, her symptoms disappeared, but two weeks later, she repeatedly developed fever and abdominal pain along with anal bleeding. Pouchscopy showed mucosal inflammation in both the pouch and the pre-pouch ileum. The mucosal cytokine production was elevated in the pouch and pre-pouch ileum. With antibiotic and corticosteroid therapy, her symptoms were improved along with improvement of endoscopic inflammation and decrease of mucosal cytokine production. The fecal stasis with bacterial overgrowth is the major pathogenesis of pouchitis and pre-pouch ileitis in our case.

关键词： Mucosal cytokines Pouchitis Pre-pouchileitis Restorative proctocolectomy Ulcerative colitis

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Numerical investigation into pillar failure induced by time-dependent skin degradation

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International Journal of Mining Science and Technology 2017年第4期27卷 591-597页

作者： Sainoki atsushi Mitri Hani S. Department of Mining and Materials Engineering McGill University Montreal H3A0E8 Canada

This paper focuses on the instability mechanism of an isolated pillar, caused by time-dependent skin degradation and strength heterogeneity. The time-dependent skin degradation is simulated with a non-linear rheological model capable of simulating tertiary creep, whereby two different pillar failure cases are investigated. The first case is of an isolated pillar in a deep hard rock underground mine and subjected to high stresses. The results show that pillar degradation is limited to the regions near the surface or the skin until two months after ore extraction. Afterwards degradation starts to extend deeper into the pillar, eventually leaving a highly-stressed pillar core due to stress transfer from the failed *** potential indices show that the risk increases exponentially at the core as time goes by. It is then demonstrated that the progressive skin degradation cannot be simulated with conventional strain-softening model assuming brittle failure. The parametric study with respect to the degree of heterogeneity reveals that heterogeneity is key to the occurrence of progressive skin degradation. The second case investigated in this study is pillar failure taking place in a very long period. Such failure becomes significantly important when assessing the risk for ground subsidence caused by pillar collapse in an abandoned mine. The analysis results demonstrate that the employed non-linear rheological model can simulate gradual skin degradation taking place over several hundred years. The percentage of damage zone volume within the pillar is merely 1% after a lapse of one days and increases to 50% after one hundred years, indicating a high risk for pillar collapse in the long term. The vertical displacements within the pillar also indicate the risk of subsidence. The proposed method is suitable for evaluating the risk of ground surface subsidence above an abandoned mine.

关键词： Pillar stability Underground mine Skin degradation Rheological model Time-dependent failure

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Systematical Experiment for Optimal Design of Vibrating Flow Pump with Jelly-fish Valve

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Journal of Bionic Engineering 2016年第1期13卷 166-179页

作者： Satoyuki Kawano Saki Miyagawa atsushi Shirai Graduate School of Engineering Science Osaka University Osaka 560-8531 Japan Institute of Fluid Science Tohoku University Sendai 980-8577 Japan

The fundamental characteristics and the flow mechanism of a Vibrating Flow Pump （VFP） with a jelly-fish valve, which can be applied to a novel artificial heart, were studied theoretically and experimentally. By using water as the working fluid, the measurement methodology for the typical unsteady flow for VFP was developed here. The effects of the frequency, amplitude and inner diameter of the vibrating pipe, and thickness of the silicone rubber sheet of the jelly-fish valve on the basic per- formance of VFP were systematically investigated. A high-speed observation technique and simple theoretical model analysis were also introdueed for further detailed discussion. Quantitative contributions of the individual parameters to the pumping performance were shown through the experiment, which would give us essential knowledge for establishing design criteria of VFE The theoretical model, which agreed with the experiment and the high-speed observation, elucidated the pumping mechanism with respect to the role of inertia of the inner fluid.

关键词： vibrating flow pump artificial heart left ventricular assistance jelly-fish valve pump performance H-Q curve

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Multispectral Phenotyping and Genetic Analyses of Spring Appearance in Greening Plant, Phedimus spp.

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Plant Phenomics 2023年第2期5卷 353-367页

作者： Taeko Koji Hiroyoshi iwata Motoyuki Ishimori Hideki Takanashi Yuji Yamasaki Hisashi Tsujimoto The United Graduate School of Agricultural Sciences Tottori University4-101 Koyamacho minamiTottori-shiTottori 680-8553Japan Graduate School of Agricultural and Life Sciences The University of Tokyo1-1-1 Yayoi-chouBunkyoTokyo 113-8657Japan Arid Land Research Center Tottori University1390 HamasakaTottori-shiTottori 680-0001Japan

The change in appearance during the seasonal transitions in ornamental greening plants is an important *** particular,the early onset of green leaf color is a desirable trait for a *** this study,we established a method for phenotyping leaf color change by multispectral imaging and performed genetic analysis based on the phenotypes to clarify the potential of the approach in breeding greening *** performed multispectral phenotyping and quantitative trait locus(QTL)analysis of an F1 population derived from 2 parental lines of Phedimus takesimensis,known to be a drought and heat-tolerant rooftop plant *** imaging was conducted in April of 2019 and 2020 when dormancy breakage occurs and growth extension *** component analysis of 9 different wavelength values showed a high contribution from the first principal component(PC1),which captured variation in the visible light *** high interannual correlation in PC1 and in the intensity of visible light indicated that the multispectral phenotyping captured genetic variation in the color of *** also performed restriction site-associated DNA sequencing and obtained the first genetic linkage map of Phedimus *** analysis revealed 2 QTLs related to early dormancy *** on the genotypes of the markers underlying these 2 QTLs,the F1 phenotypes with early(late)dormancy break,green(red or brown)leaves,and a high(low)degree of vegetative growth were *** results suggest the potential of multispectral phenotyping in the genetic dissection of seasonal leaf color changes in greening plants.

关键词： breeding cultivar visible

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Acute Restraint Stress Augments 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine Neurotoxicity via Increased Toxin Uptake into the Brain in C57BL/6 Mice

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Neuroscience Bulletin 2018年第5期34卷 849-853页

作者： Yasuhide Mitsumoto atsushi Mori Laboratory of Alternative Medicine and Experimental Ther- apeutics Department of Clinical Pharmacy Faculty of Pharmaceutical Sciences Hokuriku University Ho-3 Kana- gawa-machi Kanazawa Ishikawa 920-1181 Japan Department of Perioperative Management System Nagoya University Graduate School of Medicine 65 Tsurumai-cho Showa-ku Nagoya Aichi 466-8550 Japan

As an environmental risk factor, psychological stress may trigger the onset or accelerate the progression of Parkinson＇s disease （PD）. Here, we evaluated the effects of acute restraint stress on striatal dopaminergic terminals and the brain metabolism of 1-methyl-4-phenyl-1,2,3,6-tetrahy- dropyridine （MPTP）, which has been widely used for creating a mouse model of PD. Exposure to 2 h of restraint stress immediately after injection of a low dose of MPTP caused a severe loss of striatal dopaminergic terminals as indicated by decreases in the dopamine transporter protein and dopamine levels compared with MPTP administration alone. Both striatal 1-methyl-4-phenylpyridinium ion （MPP＋） and MPTP concentrations were significantly increased by the application of restraint stress. Striatal monoamine oxidase-B, which catalyzes the oxidation of MPTP to MPP＋, was not changed by the restraint stress. Our results indicate that the enhanced striatal dopaminergic terminal loss in the stressed mice is associated with an increase in the transport of neurotoxin into the brain.

关键词： MPTP MPP+ Mouse model Restraint stress Dopaminergic neuron Degeneration Dopamine transporter Dopamine

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