84 research outputs found
Impact of Sea Surface Temperature and Surface Air Temperature on Maximizing Typhoon Rainfall: Focusing on Typhoon Maemi in Korea
In this study, the effects of surface air temperature (SAT) and sea surface temperature (SST) changes on typhoon rainfall maximization are analysed. Based on the numerically reproduced Typhoon Maemi, this study tried to maximize the typhoon-induced rainfall by increasing the amount of saturated water vapour in the atmosphere and the amount of water vapour entering the typhoon. Using the Weather Research and Forecasting (WRF) model, which is one of the regional climate models (RCMs), the rainfall simulated by WRF while increasing the SAT and SST to various sizes at initial conditions and boundary conditions of the model was analysed. As a result of the simulated typhoon rainfall, the spatial distribution of total rainfall depth on the land due to the increase combination of SAT and SST showed a wide variety without showing a certain pattern. This is attributed to the geographical location of the Korean peninsula, which is a peninsula between the continent and the ocean. In other words, under certain conditions, typhoons may drop most of the rainfall on the southern sea of the peninsula before landing on the peninsula. For instance, the 6-hour duration maximum precipitation (MP) in Busan Metropolitan City was 472.1 mm when the SST increased by 2.0°C. However, when the SST increased by 4.0°C, the MP was found to be 395.3 mm, despite the further increase in SST. This indicates that the MP at a particular area and the increase in temperature do not have a linear relationship. Therefore, in order to maximize typhoon rainfall, it is necessary to repeat the numerical experiment on various conditions and search for the combination of SAT and SST increase which is most suitable for the target typhoon
The boundary of Rauzy fractal and discrete tilings
The Rauzy fractal is a domain in the two-dimensional plane constructed by the
Rauzy substitution, a substitution rule on three letters. The Rauzy fractal has
a fractal-like boundary, and the currently known its constructions is not only
for its boundary but also for the entire domain. In this paper, we show that
all points in the Rauzy fractal have a layered structure. We propose two
methods of constructing the Rauzy fractal using layered structures. We show how
such layered structures can be used to construct the boundary of the Rauzy
fractal with less computation than conventional methods. There is a
self-replicating pattern in one of the layered structure in the Rauzy fractal.
We introduce a notion of self-replicating word and visualize how some
self-replicating words on three letters creates discrete tiling of the two
dimensional plane
Regulation of Dendritic Spine Morphogenesis by Insulin Receptor Substrate 53, a Downstream Effector of Rac1 and Cdc42 Small GTPases
The small GTPases Rac1 and Cdc42 are key regulators of the morphogenesis of actin-rich dendritic spines in neurons. However, little is known about how activated Rac1/Cdc42 regulates dendritic spines. Insulin receptor substrate 53 (IRSp53), which is highly expressed in the postsynaptic density (PSD), is known to link activated Rac1/Cdc42 to downstream effectors for actin regulation in non-neural cells. Here, we report that IRSp53 interacts with two specific members of the PSD-95 family, PSD-95 and chapsyn-110/PSD-93, in brain. An IRSp53 mutant lacking the C-terminal PSD-95-binding motif shows significant loss of synaptic localization in cultured neurons. Overexpression of IRSp53 in cultured neurons increases the density of dendritic spines but does not affect their length or width. Conversely, short-interfering RNA-mediated knock-down of IRSp53 reduces the density, length, and width of spines. In addition, the density and size of spines are decreased by a dominant-negative IRSp53 with a point mutation in the Src homology 3 (SH3) domain and a dominant-negative proline-rich region of WAVE2 (Wiskott-Aldrich syndrome protein family Verprolin-homologous protein), a downstream effector of IRSp53 that binds to the SH3 domain of IRSp53. These results suggest that PSD-95 interaction is an important determinant of synaptic IRSp53 localization and that the SH3 domain of IRSp53 links activated Rac1/Cdc42 to downstream effectors for the regulation of spine morphogenesis
Regulation of synaptic Rac1 activity, long-term potentiation maintenance, and learning and memory by BCR and ABR Rac GTPase-activating proteins
Rho family small GTPases are important regulators of neuronal development. Defective Rho regulation causes nervous system dysfunctions including mental retardation and Alzheimer's disease. Rac1, a member of the Rho family, regulates dendritic spines and excitatory synapses, but relatively little is known about how synaptic Rac1 is negatively regulated. Breakpoint cluster region (BCR) is a Rac GTPase-activating protein known to form a fusion protein with the c-Abl tyrosine kinase in Philadelphia chromosome-positive chronic myelogenous leukemia. Despite the fact that BCR mRNAs are abundantly expressed in the brain, the neural functions of BCR protein have remained obscure. We report here that BCR and its close relative active BCR-related (ABR) localize at excitatory synapses and directly interact with PSD-95, an abundant postsynaptic scaffolding protein. Mice deficient for BCR or ABR show enhanced basal Rac1 activity but only a small increase in spine density. Importantly, mice lacking BCR or ABR exhibit a marked decrease in the maintenance, but not induction, of long-term potentiation, and show impaired spatial and object recognition memory. These results suggest that BCR and ABR have novel roles in the regulation of synaptic Rac1 signaling, synaptic plasticity, and learning and memory, and that excessive Rac1 activity negatively affects synaptic and cognitive functions.This work was supported by the National Creative Research Initiative Program of the Korean Ministry of Education,
Science and Technology (E.K.), Neuroscience Program Grant 2009-0081468 (S.-Y.C.), 21st Century Frontier R&D Program in Neuroscience Grant 2009K001284 (H.K.), Basic Science Research Program Grant R13-2008-009-01001-0
(Y.C.B.), and United States Public Health Service Grants HL071945 (J.G.) and HL060231 (J.G., N.H.)
The genome of the freshwater monogonont rotifer Brachionus calyciflorus
Monogononta is the most speciose class of rotifers, with more than 2,000 species. The monogonont genus Brachionus is widely distributed at a global scale, and a few of its species are commonly used as ecological and evolutionary models to address questions related to aquatic ecology, cryptic speciation, evolutionary ecology, the evolution of sex and ecotoxicology. With the importance of Brachionus species in many areas of research, it is remarkable that the genome has not been characterized. This study aims to address this lacuna by presenting, for the first time, the whole‐genome assembly of the freshwater species Brachionus calyciflorus. The total length of the assembled genome was 129.6 Mb, with 1,041 scaffolds. The N50 value was 786.6 kb, and the GC content was 24%. A total of 16,114 genes were annotated with repeat sequences, accounting for 21% of the assembled genome. This assembled genome may form a basis for future studies addressing key questions on the evolution of monogonont rotifers. It will also provide the necessary molecular resources to mechanistically investigate ecophysiological and ecotoxicological responses. </p
2023 Korean Endocrine Society Consensus Guidelines for the Diagnosis and Management of Primary Aldosteronism
Primary aldosteronism (PA) is a common, yet underdiagnosed cause of secondary hypertension. It is characterized by an overproduction of aldosterone, leading to hypertension and/or hypokalemia. Despite affecting between 5.9% and 34% of patients with hypertension, PA is frequently missed due to a lack of clinical awareness and systematic screening, which can result in significant cardiovascular complications. To address this, medical societies have developed clinical practice guidelines to improve the management of hypertension and PA. The Korean Endocrine Society, drawing on a wealth of research, has formulated new guidelines for PA. A task force has been established to prepare PA guidelines, which encompass epidemiology, pathophysiology, clinical presentation, diagnosis, treatment, and follow-up care. The Korean clinical guidelines for PA aim to deliver an evidence-based protocol for PA diagnosis, treatment, and patient monitoring. These guidelines are anticipated to ease the burden of this potentially curable condition
Advanced analysis of battery material and effect of doping on potential of molecules.
Compared to common batteries, lithium-ion batteries have higher energy and power density, longer life, and more environmentally friendly; thus, it is applied to wide electronical area. However, lithium-ion batteries for cars have high capacity and huge serial-parallel numbers, which, involved with such problems as protection, robustness, consistency and cost, levies boundaries on the varied request of lithium-ion batteries in the vehicle. (Ogihara, T., 2010) The fine area in which lithium-ion batteries activate with safety and reliability requires the efficient control and administration of battery supervision system. The paper will use softwares to compute potentials of molecules and change of potential as a result of doping. The paper will show how different location of doping will affect the potential of battery. This present paper gives a summarized introduction to the structure and potential of molecule that can be used in lithium ion battery in the hope of providing some stimuli to the design and research of the battery system through the inspection of literature with practical experience.Undergraduat
동아시아 통화 및 환율정책에 관한 연구: 개방경제 DSGE 모형을 이용한 베이지안 추정
학위논문 (박사)-- 서울대학교 대학원 : 사회과학대학 경제학부, 2018. 8. 김소영.This dissertation consists of two chapters. Chapter I analyzes the mone- tary policy conducted by the central bank of Korea in relation to the 2008–2009 global financial crisis focusing on the reaction of the policy interest rate to nominal exchange rate movements. In chapter II, I additionally experiment the role of central banks foreign exchange intervention (FX-Intervention) policy considering two more countries in East Asia1. Estimation and Assessment of the Monetary Policy in Korea Before and After the Global Financial Crisis . . . . . . . . . . . . . 1
1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Simple Small Open Economy Model . . . . . . . . . . . . . . . 5
1.3 Bayesian Approach . . . . . . . . . . . . . . . . . . . . . . . . 9
1.4 Data and Prior Distributions . . . . . . . . . . . . . . . . . . . . 11
1.5 Estimation of the Korean Monetary Policy . . . . . . . . . . . . 16
1.5.1 Models best supported by the data . . . . . . . . . . . . 16
1.5.2 Different features of the two periods policy rules . . . . 20
1.6 Assessment of the Change . . . . . . . . . . . . . . . . . . . . . 25
1.6.1 Impulse Response Functions . . . . . . . . . . . . . . . 26
1.6.2 Stochastic Simulation . . . . . . . . . . . . . . . . . . . 28
1.7 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
A Korean Monetary Policy Before and After the Crisis . . 34
B Impulse Response Functions in Pre- and Post Crisis . . . 36
C Robustness . . . . . . . . . . . . . . . . . . . . . . . . 37
2. Estimation and Assessment of Monetary and Exchange Rate Policies in East Asia . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
2.2 Small Open Economy New Keynesian Model . . . . . . . . . . . 49
2.2.1 Households . . . . . . . . . . . . . . . . . . . . . . . . 49
2.2.2 Domestic producers . . . . . . . . . . . . . . . . . . . . 54
2.2.3 Retailers . . . . . . . . . . . . . . . . . . . . . . . . . . 56
2.2.4 Market clearing . . . . . . . . . . . . . . . . . . . . . . 59
2.2.5 Central bank . . . . . . . . . . . . . . . . . . . . . . . 59
2.2.6 Domestic net foreign asset position . . . . . . . . . . . 61
2.2.7 Exogenous shock and the rest of the world . . . . . . . . 61
2.3 Methodology and Data . . . . . . . . . . . . . . . . . . . . . . . 62
2.3.1 Bayesian approach . . . . . . . . . . . . . . . . . . . . 62
2.3.2 Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
2.3.3 Priors . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
2.4 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
2.4.1 Estimated posterior distributions . . . . . . . . . . . . . 67
2.4.2 Macroeconomic effects of the FX-intervention . . . . . 73
2.5 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
A Estimation results under alternative prior for χcb . . . . . 82
B Bayesian IRFs under the benchmark prior . . . . . . . . 86
C Bayesian IRFs under the alternative prior . . . . . . . . 89
D Theoretical moments . . . . . . . . . . . . . . . . . . . 92
Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
국문초록 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101Docto
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