Statistical analysis of foreign exchange rates: application of cointegration model and regime-switching stochastic volatility model

The dissertation discusses an application of two statistical models to foreign exchange rate data and consists of two main parts. The first part is an application of the partial cointegration model developed by Johansen (1990) and uses the concept of weak exogeneity. While a direct application of the cointegration approach with many variables is not easy to handle, the partial model can reduce the number of the parameters to be estimated by identifying weakly exogenous variables. The method is illustrated utilizing a theoretical long-run model based on Dornbusch\u27s sticky price model. The small country assumption is relaxed to that both countries are taken to be large. Furthermore the model is also extended to include a third country. The data set consists of monthly exchange rates, countries\u27 money supplies, and GNPs. The three countries are Germany, Japan and the United States, thus giving a total of eight equations to be estimated. Three variables out of eight are identified as weakly exogenous variables and only five questions are estimated. Results show that there exist three cointegrating relations among the variables. One relation can be interpreted as long-run money market equilibrium while the other two relations, though considered to be long-run in nature, can not be interpreted in an economically meaningful way. Variance decomposition and impulse response analysis are conducted to investigate the dynamic of the system;In the second part of the dissertation a regime-switching stochastic volatility (RSV) model is applied to daily exchange rate data. The model is used to capture possible changing volatility of the exchange rate over time. The RSV model recommends itself since it is the more natural method to apply, as opposed to using ARCH and GARCH models. The main drawback however, is that it is the more complicated to implement. A Markov chain technique is used as an estimation method. By imposing interest rate parity, the relationship between exchange rate and foreign and domestic interest rate difference is also simultaneously examined. The results indicate that interest rate difference does not affect the level and the volatility of exchange rates. This finding supports the random walk theory of exchange rates. On the other hand two different regimes, a high-volatility regime and a low-volatility regime, are discovered and well modeled. The development of a forecasting model will be the subject for future studies

The effect of explicit instruction and error correction on learners’ grammatical accuracy in the case of japanese learners of English as a second language

Este estudio afirma que la instrucción explicita (EI) con la corrección de error explicito (EEC) pueden ser eficaces para adquirir elementos lingüísticos que no se hayan enseñado lo suficiente y que mayormente expresen significado léxico. Por otra parte, EI con EEC no pueden ser eficaces para los elementos lingüísticos que mayormente expresen funciones gramaticales formales, que los aprendices ya conocen muy bien. El estudio asume que el orden linear fijo para algunos elementos (e. g., morfemas gramaticales) no es influenciado por estímulos externos (i. e. , EC con EEC): como L1, el proceso de la adquisición de la L2 no es al azar, sino ordenado. Sin embargo, el estudio no necesariamente niega el rol de la instrucción explicita del profesor para cada uno de los aspectos de la adquisición de la L2. El estudio también afirma que EI y EEC son más eficaces para aquellos aprendices quienes tengan sus niveles de competencia general de la L2 altos. Apoyamos estas suposiciones presentando tres experimentos con respecto a la adquisición de los sujetos de la oración y los morfemas gramaticales en inglés por japoneses adultos, aprendices del idioma Inglés.This study claims that explicit instruction (EI) with explicit error correction (EEC) can be effective for acquiring linguistic items which mainly convey lexical meaning, and have not been taught enough. On the other hand, EI with EEC cannot be effective for linguistic items which mainly convey formal grammatical functions, which are already well known to the learners. The study assumes that the fixed linear order for some grammatical items (e.g., grammatical morphemes) is not influenced by external stimuli (i.e., EC with EEC): Like L1, the L2 acquisition process is not random, but orderly. However, the study does not necessarily deny the role of teacher’s explicit instructions for every aspect of L2 acquisition. The study also claims that EI with EEC are more effective for those learners whose general L2 proficiency levels are high. We support these assumptions by presenting three experiments concerning the acquisition of English sentential subjects and grammatical morphemes by Japanese adult learners of English

Numerical analysis of the eutectic melting and relocation of the b4c control rod materials by the MPFI-MPS method

Eutectic melting and subsequent relocation of the boron-carbide (B4C) control rod materials were simulated by a particle method. In the past, it was difficult to simulate the eutectic melting by a particle method because the melting starts at the interface between two different materials, which leads to the instability of the particle motion due to the small amount of fluid particles and lack of the thermodynamic consistency of the particle system. Thus, the Moving Particle Full Implicit (MPFI)-Moving Particle Semi-implicit (MPS) method was developed and introduced in the current study. Specifically, the MPFI method was introduced for the momentum transfer calculation, and the MPS method was introduced for the heat and mass transfer calculation. The MPFIMPS method realized the simulation of the eutectic melting and subsequent relocation behaviour

A Study on the Stress Analysis and the Sealing Performance Evaluation of Bolted Pipe Flange Connections with Metallic Gaskets Subjected to Internal Pressure

広島大学(Hiroshima University)博士(工学)Doctor of Engineering in Mechanical System Engineeringdoctora

Detection of the Viruses Occurring in Oriental Cymbidium in Japan

A survey of virus diseases occurring in Oriental Cymbidium collected from a commerical nursery and home garden in Japan was conducted in 1991-1994. Identification of the vurus was based on partcle morphology, symptomatology in indicator plants, ultrastructure of infected cells and serology. Four viruses, odontoglossum ringspot tabamovirus(ORSV), cymbidium mosaic potexvirus(CyMV), orchid fleck virus (ORV) and a previously underscribed spherical virus, were found in 27 out of 37 Cymbidium plants tested. ORSV was detected from 11 plants belinging to Cym. ensifolium, Cym. forrestii, Cym. goeringii, Cym. kanran, Cym. sinense and Cymbidium spp. showing chlorotic streaks and/or mild mosaic. CyMV was isolated from only one plant of Cymbidium sp. showing mosaic and necrotic spots on leaves. In negatibvely stained dip preparations from plants infected with ORSV and CyMV, rod shaped particles of ca. 310 nm and flexuous rod-shaped ca. 475 nm in length were observed, respectively. The viruses were reacted strongly with respective antiserum to each virus in immunosorbent electron microcopy and inderect ELISA. OFV was isolated from four plants of Cym. formosanum, Cym. kanran, Cym. sinense and Cymbidium sp. showing mosaic and necrotic flecks. The virus had non-enveloped, bullet-shaped particles about 40×120～150 nm in dip preparation. The undescribed spherical virus, ca. 28 nm diameter, was isolated from 11 plants of Cym. forrestii, Cym. goeringii and Cymbidium spp. showing stunting and chlorotic streaks on newly developed leaves. The virus was mechanically transmitted only to Cymbidium orchids. Previously, we designated it as cymbidium chlorotic mosaic sobemovirus(CyCMV)(Kondo et al,1994),as the virus was considered to be a new member of the genus Sobemovirsu.1991～1994年にかけ山口県ならびに岡山県下を中心に東洋ラン（シンビジウム属）のウイルス病の発生調査を行った。ウイルス病様の症状を示していた37株の東洋ランを採集し、これらから病原ウイルスの分離、同定を試みた結果、オドントグロッサムリングスポットウイルス（ORSV）、シンビジウムモザイクウイルス（CyMV）、ランえそ斑紋ウイルス（OFV）ならびにソベモウイルス属の新ウイルスであるシュンラン退緑ウイルス（CyCMV）の発生が認められた。ORSVは退緑条斑や軽いモザイク症状を示すスルガラン、カンラン、コラン、ホウサイランなどから分離された。CyMVは明瞭なえそ斑を伴うモザイクを呈した東洋ラン（品種不祥、赤芽素心）から分離された。ORSVならびにCyMVに感染した植物のDN法試料中には電顕観察でそれぞれ長さ約310nmの棒状粒子と約475nmのひも状粒子が観察され、免疫電顕法と間接ELISA法では、これらのウイルスはそれぞれのウイルスに対する抗血清とよく反応した。OFVは退緑斑あるいはえそ斑点を生じているイトラン、カンラン、ホウサイランなどから検出された。その粒子形態は長さ約120～150nm、幅約40nmの被膜のない弾丸状あるいは桿菌状であった。CyCMVは新芽に明瞭な退緑斑や退緑状斑症状を示すシナシュンラン、シュンランなどから分離された。この球状ウイルスは直径約28nmで、シンビジウム属以外の植物には感染が認められなかった。今回の発生調査では、東洋ランからはORSVならびに新ウイルスのCyCMVがもっとも多く分離され、OFVは4株から、CyMVは1株から検出された。またこれらのウイルスによる重複感染は認められなかった

ラットの膀胱内圧測定及び摘出膀胱収縮力に対する虚血の影響

ラットの両側内腸骨動脈を結紮し虚血ラット膀胱を作成し, この虚血膀胱におけるurethane麻酔下の膀胱内圧測定及び摘出膀胱の電気刺激, bethanechol, ATP, KClに対する収縮力を検討した.次いで一定速度で生理食塩水を膀胱内に注入しながら電気刺激を繰り返しvolume-pressure studyを実施した.膀胱の重量は虚血により有意に増大した.膀胱内圧曲線を分析した結果, 膀胱容量, 残尿量は増大し, 排尿筋収縮圧は減少した.この結果, 虚血に伴い排尿効率(排尿量/膀胱容量)は有意に減少した.摘出膀胱における排尿収縮力は, 全ての刺激に対して虚血後に低下した.volume-pressure studyの結果からin vitroの膀胱complianceは7日後減少し14日後は逆に増大したIschemia induced by atherosclerosis is a common cause of organ failure in the elderly. We investigated the effects of in vivo ischemia created by ligation of the internal iliac arteries on the parameters of in vivo infusion cystometry under urethane anesthesia and on in vitro whole bladder contractility of the rat. Bladder weight significantly increased after ischemia for 14 days. Infusion cystometry demonstrated that in the ischemic bladders the capacity increased, the voiding pressure decreased, and the volume of residual urine increased, which resulted in deteriorated voiding efficacy. The in vitro whole bladder contractility to field stimulation, bethanechol, ATP, and KCl was reduced by ischemia. The passive pressure increased as the bladder volume enlarged and the bladder compliance once decreased by ischemia on the 7th day, but increased on the 14th day. In an active volume-pressure relationship study the peak response was decreased by ischemia. The volume at which response reached a peak value shifted to a larger volume 14 days after surgery. In conclusion, ischemia impaired in vivo rat detrusor power to empty. Since detrusor contractility in vitro decreased in response to various kinds of stimulation, this deteriorated bladder function was supposed to be caused by muscle degeneration

Identification of lactate dehydrogenase as a mammalian pyrroloquinoline quinone (PQQ)-binding protein

Pyrroloquinoline quinone (PQQ), a redox-active o-quinone, is an important nutrient involved in numerous physiological and biochemical processes in mammals. Despite such beneficial functions, the underlying molecular mechanisms remain to be established. In the present study, using PQQ-immobilized Sepharose beads as a probe, we examined the presence of protein(s) that are capable of binding PQQ in mouse NIH/3T3 fibroblasts and identified five cellular proteins, including l-lactate dehydrogenase (LDH) A chain, as potential mammalian PQQ-binding proteins. In vitro studies using a purified rabbit muscle LDH show that PQQ inhibits the formation of lactate from pyruvate in the presence of NADH (forward reaction), whereas it enhances the conversion of lactate to pyruvate in the presence of NAD+ (reverse reaction). The molecular mechanism underlying PQQ-mediated regulation of LDH activity is attributed to the oxidation of NADH to NAD+ by PQQ. Indeed, the PQQ-bound LDH oxidizes NADH, generating NAD+, and significantly catalyzes the conversion of lactate to pyruvate. Furthermore, PQQ attenuates cellular lactate release and increases intracellular ATP levels in the NIH/3T3 fibroblasts. Our results suggest that PQQ, modulating LDH activity to facilitate pyruvate formation through its redox-cycling activity, may be involved in the enhanced energy production via mitochondrial TCA cycle and oxidative phosphorylation

Blockade of the CXCR3/CXCL10 axis ameliorates inflammation caused by immunoproteasome dysfunction

Immunoproteasomes regulate the degradation of ubiquitin-coupled proteins and generate peptides that are preferentially presented by MHC class I. Mutations in immunoproteasome subunits lead to immunoproteasome dysfunction, which causes proteasome-associated autoinflammatory syndromes (PRAAS) characterized by nodular erythema and partial lipodystrophy. It remains unclear, however, how immunoproteasome dysfunction leads to inflammatory symptoms. Here, we established mice harboring a mutation in Psmb8 (Psmb8-KI mice) and addressed this question. Psmb8-KI mice showed higher susceptibility to imiquimod-induced skin inflammation (IMS). Blockade of IL-6 or TNF-α partially suppressed IMS in both control and Psmb8-KI mice, but there was still more residual inflammation in the Psmb8-KI mice than in the control mice. DNA microarray analysis showed that treatment of J774 cells with proteasome inhibitors increased the expression of the Cxcl9 and Cxcl10 genes. Deficiency in Cxcr3, the gene encoding the receptor of CXCL9 and CXCL10, in control mice did not change IMS susceptibility, while deficiency in Cxcr3 in Psmb8-KI mice ameliorated IMS. Taken together, these findings demonstrate that this mutation in Psmb8 leads to hyperactivation of the CXCR3 pathway, which is responsible for the increased susceptibility of Psmb8-KI mice to IMS. These data suggest the CXCR3/CXCL10 axis as a new molecular target for treating PRAAS

Stand-to-sit motion in older women

Objectives : The aims of this study were to examine the biomechanics of StandTS movements in older adults and to identify their optimal StandTS motion by measuring sitting impact forces. Methods : Healthy older women (n = 17) and healthy young women (n = 18) were asked to perform SitTS and StandTS motions at a natural speed using a chair. We measured the ground reaction forces from the participants’ feet and the chair, the angle of the trunk and ankle, vertical velocity, and postural muscle activities using a force plate, motion analyzer, and electromyography, respectively. Results : Sitting impact force was significantly greater in the older women than in the young women during the StandTS motion. There was a significant difference between the trunk angle and the ankle angle during the StandTS motion and sitting impact force had a significant negative correlation with the ankle joint motion in the older women. Conclusions : The ankle joint strategy was characterized by body sway resembling a single-segment-inverted pendulum and suggests that this response is less developed in the older adult. These results indicate that the ankle joint strategy may be an important factor involved in the sitting impact force