The Regulator RamA Influences cmytA Transcription and Cell Morphology of Corynebacterium ammoniagenes

Lee, Seok-Myung,Lee, Joo-Young,Park, Kwang-Jin,Park, Jun-Sung,Ha, Un-Hwan,Kim, Younhee,Lee, Heung-Shick Springer-Verlag 2010 Current microbiology Vol.61 No.2

Synteny Portal: a web-based application portal for synteny block analysis

Lee, Jongin,Hong, Woon-young,Cho, Minah,Sim, Mikang,Lee, Daehwan,Ko, Younhee,Kim, Jaebum Oxford University Press 2016 Nucleic acids research Vol.44 No.w1

<P>Recent advances in next-generation sequencing technologies and genome assembly algorithms have enabled the accumulation of a huge volume of genome sequences from various species. This has provided new opportunities for large-scale comparative genomics studies. Identifying and utilizing synteny blocks, which are genomic regions conserved among multiple species, is key to understanding genomic architecture and the evolutionary history of genomes. However, the construction and visualization of such synteny blocks from multiple species are very challenging, especially for biologists with a lack of computational skills. Here, we present Synteny Portal, a versatile web-based application portal for constructing, visualizing and browsing synteny blocks. With Synteny Portal, users can easily (i) construct synteny blocks among multiple species by using prebuilt alignments in the UCSC genome browser database, (ii) visualize and download syntenic relationships as high-quality images, (iii) browse synteny blocks with genetic information and (iv) download the details of synteny blocks to be used as input for downstream synteny-based analyses, all in an intuitive and easy-to-use web-based interface. We believe that Synteny Portal will serve as a highly valuable tool that will enable biologists to easily perform comparative genomics studies by compensating limitations of existing tools. Synteny Portal is freely available at http://bioinfo.konkuk.ac.kr/synteny_portal.</P>

The whcD gene of Corynebacterium glutamicum plays roles in cell division and envelope formation

Lee, Dong-Seok,Kim, Younhee,Lee, Heung-Shick Microbiology Society 2017 Microbiology Vol.163 No.2

<P>In this study, we analysed the whcD gene from Corynebacteriumglutamicum, which encodes a homologue of whiB, a Streptomycescoelicolor gene required for the sporulation of aerial hyphae. Deletion of the gene (Delta whcD) severely affected cell growth in C. glutamicum. The Delta whcD strain exhibited a large filamentous, branched and bud-shaped morphology with multiple septa. The transcription levels of the cell division genes involved in Z-ring assembly and septal peptidoglycan synthesis, including ftsZ, sepF, ftsQ and ftsI, were markedly decreased in the Delta whcD strain. The divIVA gene, which is responsible for apical growth, also showed decreased transcription in the Delta whcD strain. However, genes involved in the later stages of cell division, such as cell separation and chromosome segregation, did not show notable changes in their transcription levels. Moreover, the mutant strain was susceptible to inhibitors of transpeptidation, including penicillin and vancomycin. In addition, the transcription of genes fas-IA, fas-IB and accD1, which participate in the synthesis of fatty acid and cell envelope component mycolic acid, was altered in the Delta whcD strain. This increased the cell surface hydrophobicity in the mutant strain, apparently leading to cell aggregation in liquid media. These findings indicate that whcD is a whiB-like gene with roles in the early stages of cell division and fatty acid synthesis, and the pleiotropic phenotypes of the Delta whcD strain suggest that whcD may be a global regulatory gene.</P>

Corynebacterium glutamicum WhcD interacts with WhiA to exert a regulatory effect on cell division genes

Lee, Dong-Seok,Kim, Pil,Kim, Eung-Soo,Kim, Younhee,Lee, Heung-Shick Springer-Verlag 2018 Antonie van Leeuwenhoek Vol.111 No.5

Verdi and Risorgimento

Younhee Lee The Pianissimo 음악예술학회 2011 음악예술연구 Vol.1 No.-

Risorgimento, which can be translated as “Rise again,” is a period in Italian political and social history that roughly spans the 19th century. It was essentially a movement for the reunification of Italy as a single nation that took over centuries. Giuseppe Verdi (1813-1901) was a composer who actively composed and influenced politically and socially during this period. This study will focus on the overall process of Risorgimento and how Verdi dissolved his political agenda in his operas; Nabuco, I Lombardi alla prima corciata (The Lombards in the First Crusade), Attila, Macbethe, La battaglia di Legnano(The battle of Legnano), Un ballo di maschiera(A masked Ball,) and Don Carlos.

Predicting Arbitrage-free American Option Prices Using Artificial Neural Network with Pseudo Inputs

Younhee Lee,Youngdoo Son 대한산업공학회 2021 Industrial Engineeering & Management Systems Vol.20 No.2

Machine learning models, which have recently been applied to evaluate financial variables, have a major difficulty to accomplish arbitrage-free valuation. We propose an American style option pricing method using multilayer artificial neural networks with arbitrage-free pseudo inputs. The proposed neural network model was trained with samples composed of market data and pseudo grid points generated by the calibrated parametric models. The trained model found arbitrage-free price or nearest price for each strike price and expiration date. We compared the proposed model with a conventional multilayer neural network model in terms of model prediction using S&P 100 American put options from 2012. The proposed model achieved better prediction performance than the conventional neural network model. In addition, prices obtained from the proposed method were much closer to the arbitrage-free prices from the parametric model.

COMPARISON OF NUMERICAL METHODS FOR OPTION PRICING UNDER THE CGMY MODEL

Lee, Ahram,Lee, Younhee Chungcheong Mathematical Society 2016 충청수학회지 Vol.29 No.3

We propose a number of finite difference methods for the prices of a European option under the CGMY model. These numerical methods to solve a partial integro-differential equation (PIDE) are based on three time levels in order to avoid fixed point iterations arising from an integral operator. Numerical simulations are carried out to compare these methods with each other for pricing the European option under the CGMY model.

IMEX METHODS FOR PRICING FIXED STRIKE ASIAN OPTIONS WITH JUMP-DIFFUSION MODELS

Lee, Sunju,Lee, Younhee The Youngnam Mathematical Society 2019 East Asian mathematical journal Vol.35 No.1

In this paper we study implicit-explicit (IMEX) methods combined with a semi-Lagrangian scheme to evaluate the prices of fixed strike arithmetic Asian options under jump-diffusion models. An Asian option is described by a two-dimensional partial integro-differential equation (PIDE) that has no diffusion term in the arithmetic average direction. The IMEX methods with the semi-Lagrangian scheme to solve the PIDE are discretized along characteristic curves and performed without any fixed point iteration techniques at each time step. We implement numerical simulations for the prices of a European fixed strike arithmetic Asian put option under the Merton model to demonstrate the second-order convergence rate.

mySyntenyPortal: an application package to construct websites for synteny block analysis

Lee, Jongin,Lee, Daehwan,Sim, Mikang,Kwon, Daehong,Kim, Juyeon,Ko, Younhee,Kim, Jaebum BioMed Central 2018 BMC bioinformatics Vol.19 No.-

<P><B>Background</B></P><P>Advances in sequencing technologies have facilitated large-scale comparative genomics based on whole genome sequencing. Constructing and investigating conserved genomic regions among multiple species (called synteny blocks) are essential in the comparative genomics. However, they require significant amounts of computational resources and time in addition to bioinformatics skills. Many web interfaces have been developed to make such tasks easier. However, these web interfaces cannot be customized for users who want to use their own set of genome sequences or definition of synteny blocks.</P><P><B>Results</B></P><P>To resolve this limitation, we present mySyntenyPortal, a stand-alone application package to construct websites for synteny block analyses by using users’ own genome data. mySyntenyPortal provides both command line and web-based interfaces to build and manage websites for large-scale comparative genomic analyses. The websites can be also easily published and accessed by other users. To demonstrate the usability of mySyntenyPortal, we present an example study for building websites to compare genomes of three mammalian species (human, mouse, and cow) and show how they can be easily utilized to identify potential genes affected by genome rearrangements.</P><P><B>Conclusions</B></P><P>mySyntenyPortal will contribute for extended comparative genomic analyses based on large-scale whole genome sequences by providing unique functionality to support the easy creation of interactive websites for synteny block analyses from user’s own genome data.</P>

A comparison of dementia care and policy in five Asian regions: A literature review

Younhee Kang(Younhee Kang),Dukyoo Jung(Dukyoo Jung),Jung Jae Lee(Jung Jae Lee),Sumalee Lirtmunlikaporn(Sumalee Lirtmunlikaporn ),Huei-Chuan Sung(Huei-Chuan Sung),Miyae Yamakawa(Miyae Yamakawa ),Yujin 한국노인간호학회 2023 노인간호학회지 Vol.25 No.2

Purpose: This review was comprised of an integrative analysis of the literature on the current state of dementia and related issues in Hong Kong, Japan, South Korea, Taiwan, and Thailand. Methods: Published reports and policy documents from MEDLINE, CINAHL, PubMed, and each government’s database were used in this review. Results: All five Asian regions are projected to become super-aged societies within 12 years, and the number of people with dementia has increased in these regions. All five regions have established dementia policies, which include improving dementia awareness, risk reduction, early diagnosis, and support programs for caregivers. However, there is a lack of information systems for sharing dementia data and research funding for dementia. Conclusion: It is necessary to establish a dementia committee for Asian regions to actively address the challenges posed by the upcoming super-aged societies and to complement the insufficient research. This review provides future directions for dealing with diverse dementia-related issues and can serve as the basis for forming an Asian dementia committee.