• Applied Microscopy
• /
• v.26 no.3
• /
• pp.267-275
• /
• 1996

The internal ultrastructural changes of germ cells and external morphology of spermatozoon during the spermatogenesis in the rockfish, Sebastes inermis were studied using transmission and scanning electron microscope. The testis is seminiferous tubule type in internal structure. Seminiferous tubule consist of many cyst which contain numerous germ cells in same developmental stage. Spermatogonium contained a large nucleus with single nucleolus in interphase. Primary spermatocyte identified by the presence of synaptonemal complex in nucleus and the contained a number of mitochondria, endoplasmic reticula and Golgi bodies in cytoplasm. The nucleoplasm of secondary spermatocyte was more concentrated than that of the previous phase. Spermatids were more condensed in nucleus and cytoplasm, and show the long-spherical shape. In the cytoplasm of spermatid mitochondria located to lower portion of the nucleus and Golgi bodies located to upper portion, but proacrosomal granule is not appeared. The spermatozoon consist of the head and tail. No acrosome could be found in the head. The cytoplasmic collar of posterior part in sperm head contained mitochondria which surrounded axial filament. The well developed axonemal lateral fins were identified in sperm flagellum, and the axial filament of the flagellum consist of nine pairs of peripheral microtubules and one pair of central microtubules.

• The Korean Journal of Physiology and Pharmacology
• /
• v.13 no.3
• /
• pp.215-220
• /
• 2009

Chlorpheniramine is a potent first-generation histamine $H_1$ receptor antagonist that can increase action potential duration and induce QT prolongation in several animal models. Since block of cardiac human ether-a-go-go-related gene (hERG) channels is one of leading causes of acquired long QT syndrome, we investigated the acute effects of chlorpheniramine on hERG channels to determine the electrophysiological basis for its proarrhythmic potential. We examined the effects of chlorpheniramine on the hERG channels expressed in Xenopus oocytes using two-microelectrode voltage-clamp techniques. Chlorpheniramine induced a concentration-dependent decrease of the current amplitude at the end of the voltage steps and hERG tail currents. The $IC_{50}$ of chlorpheniramine-dependent hERG block in Xenopus oocytes decreased progressively relative to the degree of depolarization. Chlorpheniramine affected the channels in the activated and inactivated states but not in the closed states. The S6 domain mutations Y652A and F656A partially attenuated (Y652A) or abolished (F656A) the hERG current block. These results suggest that the $H_1$ antihistamine, chlorpheniramine is a blocker of the hERG channels, providing a molecular mechanism for the drug-induced arrhythmogenic side effects.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.4
• /
• pp.1603-1608
• /
• 2012

This paper aims to build a model of unemployment duration, in which each type of unemployment duration can be defined as a function of other exogenous variables. Recently, the so-called mismatch in the labor market has become a big issue in most countries. It is very obvious that 'mismatch' is deeply related to the long duration of unemployment status. Two problems may be head and tail of the same coin. Employing a simple analysis of Markov stochastic process, the model of unemployment duration developed here is useful for seeing the effects of shocks on unemployment duration. The model allows us to distinguish the determinants of different kinds of unemployment and to identify the nature of unemployment duration.

• Fisheries and Aquatic Sciences
• /
• v.8 no.1
• /
• pp.17-26
• /
• 2005

The ultrastructure of germ cells during spermatogenesis and the structural changes in the epithelial cells of the seminal vesicle with testicular development in male Neptunea (Barbitonia) arthritica cumingii were investigated monthly based on electron microscopic and histologic observations. N. arthritica cumingii (Gastropod: Buccinidae) undergoes internal fertilization and possesses a modified type of spermatozoon, which is approximately 20$\mu$m long. The axoneme of the tail flagellum consists of nine peripheral pairs of microtubules and one central pair. Many spermatozoa occur in the acini of the testis in the ripe stage and are transported to the seminal vesicles in the accumulating phase. In males, the monthly gonadosomatic index began to increase in September and reached a maximum in February. Subsequently, it decreased rapidly after April. The testis of this species can be classified into four developmental stages: the active (August to September), ripe (October to July), copulation (April to July), and recovery (July to August) stages. Structural changes in the epithelial cells of the seminal vesicles of this species could be classified into three phases: (1) S-I (resting), (2) S-II (accumulating), and (3) S-III (spent) phases. The morphology and structure of the epithelial cells of the seminal vesicle differed in each phase; the cells were cuboidal, squamous, or columnar in the resting, accumulating, or spent phases, respectively.

• International Journal of Internet, Broadcasting and Communication
• /
• v.7 no.2
• /
• pp.56-64
• /
• 2015

The personal image information compiled through closed-circuit television (CCTV) will be open to the internet with the technology such as Long-Tail, Mash-Up, Collective Intelligence, Tagging, Open Application Programming Interface (Open-API), Syndication, Podcasting and Asynchronous JavaScript and XML (AJAX). The movie User Created Contents (UCC) connected to the internet with the skill of web 2.0 has the effects of abuse and threat without precedent. The purpose of this research is to develop the institutional and technological method to reduce these effects. As a result of this research, in terms of technology this paper suggests Privacy Zone Masking, IP Filtering, Intrusion-detection System (IDS), Secure Sockets Layer (SSL), public key infrastructure (PKI), Hash and PDF Socket. While in terms of management this paper suggests Privacy Commons and Privacy Zone. Based on CCTV-UCC linked to the above network, the research regarding personal image information security is expected to aid in realizing insight and practical personal image information as a specific device in the following research.

• The Bulletin of The Korean Astronomical Society
• /
• v.41 no.2
• /
• pp.30.2-30.2
• /
• 2016

M104 (NGC 4594, the Sombrero) is an intriguing disk galaxy classified as an elliptical galaxy nowadays. It hosts a luminous bulge and a massive disk, but it is still mysterious how M104 acquired such peculiar structures. Globular clusters are an useful tracer to investigate the formation history of early-type galaxies. In this study we present a wide field imaging study of the globular clusters in M104. Using wide ($1^{\circ}{\times}1^{\circ}$) and deep ugi images of M104 obtained with the CFHT/MegaCam observations, we detect a large number of globular clusters. The color distribution of these globular clusters shows that there are two subpopulations: a metal-poor system and a metal-rich system. The radial number density of the metal-poor globular clusters shows a long tail reaching R ~ 30' (~ 80 kpc), indicating clearly the existence of a giant metal-poor halo in M104. This result is consistent with the previous studies on the dual halos of massive early-type galaxies. We will discuss implications of these results in relation with the formation history of M104.

• The Plant Pathology Journal
• /
• v.24 no.3
• /
• pp.361-364
• /
• 2008

The complete nucleotide sequences of a Korean isolate of Potato virus X(PVX-Kr) has been determined. Full-length cDNA of PVX-Kr has been directly amplified by long template reverse transcription and polymerase chain reaction(RT-PCR) using virus specific 5'-end primer and 3'-end primer, and then constructed in a plasmid vector. Consecutive subclones of a full-length cDNA clone were constructed to identify whole genome sequence of the virus. Total nucleotide sequences of genome of PVX-Kr were 6,435 excluding one adenine at poly A tail, and genome organization was identical with that of typical PVX species. Comparison of whole genome sequence of PVX-Kr with those of European and South American isolates showed 95.4-96.8% and 77.4-77.9%, in nucleotide similarity, respectively. Sequenced PVX-Kr in this study and twelve isolates already reported could be divided into two subgroups in phylogeny based on their complete nucleotide sequences. Phylogenetic tree analysis demonstrated that PVX-Kr was clustered with European and Asian isolates(Taiwan, os, bs, Kr, S, X3, UK3, ROTH1, Tula) in the same subgroup and South American isolates(CP, CP2, CP4, HB) were clustered in the other subgroup.

• The Bulletin of The Korean Astronomical Society
• /
• v.35 no.2
• /
• pp.34.1-34.1
• /
• 2010

Studies suggest that activities in luminous AGNs, residing mostly in early-type galaxies, are triggered by merging. However, the observational evidence for the connection between mergers and AGN activity is not clear yet because tracer of the past merging activities such as tidal tail, shell are often too faint. To see if we can reveal the merging features with a small telescope, we observed an AGN, MARK 478, at z=0.077 with long exposure time (7550 seconds) in V filter at Maidanak observatory. Our 2-D fitting analysis shows that the host galaxy of MARK 478 has the bulge to the total luminosity ratio of 0.3. And the residual image, after subtracting point spread function (PSF), bulge and disk components, shows that the host galaxy has an arm-like feature that could be a spiral arm or a feature from minor merging. We also show that the structural parameters obtained from our 2-D fitting match well with those derived from HST image. The promising result suggests that studies of low redshift AGN host galaxies are possible with data from a small telescope. In order to allow a statistical analysis, we hope to expand our sample size in future.

• The Bulletin of The Korean Astronomical Society
• /
• v.35 no.2
• /
• pp.41.1-41.1
• /
• 2010

It has been suggested that merging plays an important role in the formation and the evolution of early-type galaxies. Optical-NIR color gradients of early-type galaxies in high density environments are found to be less steep than those in low density environment, hinting frequent merger activities in early-type galaxies in high density environment. In order to confirm if the flat color gradient is the result of dry merger, we decided to look deeply to find merging features and get their relation with color gradient. We selected samples which show extreme values of optical-NIR color gradients based on the data of previous study, and observed them at Maidanak observatory 1.5m telescope with long exposure. After masking out overlaid sources, our analysis reveals that these galaxies do not have extreme color gradient values. High degree sky flat technique was used during observation to aid discovery of faint, extended features. However, flatness of detector (SNUCAM) was good enough, so we could not see any marked improvement in image quality compared to those using normal sky flats. Additionally we noticed a feature that looks like merging tidal tail in the CFHT archival image, but this does not show up on the image we obtained. This demonstrates that flatness and correct sky estimation is very important when we look for faint merging features. In future we plan to enlarge the number of the sample.

• Journal of architectural history
• /
• v.26 no.3
• /
• pp.19-30
• /
• 2017

This paper studies the style emergence of Liujin Dougong in the ancient Chinese architecture. Dougong is the bracket set of the ancient Chinese wood structural architecture, and Liujin Dougong is one of the late styles of Chinese Dougong. It emerged in the period of the Ming Dynasty and has been installed in imperial palaces and imperial temples till the late period of the Qing Dynasty. Through the long term field survey and documental investigation, this research found out the some prototypes of Liujin Dougong among the earlier Xia-ang style Dougongs in the Song and Yuan Dynasty architectures. The symptom of style change appeared in the bracket composition. In the beginning, because Shuatou, the horizontal member just on Xia-ang was needed to be fixed to the inner main structure system, it was changed to the diagonal member and replaced Xia-ang. It brought continuous changes, the other horizontal members of Dougong also began to change to the diagonal form. And in accordance with these compositional changes of Dougong members, the decoration of inner parts also began to change. This paper analyzed every step of the compositional and decorative changes from Xia-ang Dougong style to Liujin Dougong style. In the addition, it also proposed the typical model of Qing style Liujin Dougong of which tail end is not placed on the beam and is just placed under the purlin, based on the its own research and analysis.