• Journal of Cerebrovascular and Endovascular Neurosurgery
• /
• v.25 no.3
• /
• pp.347-351
• /
• 2023

Intracranial aneurysms arise in 1-2% of the population and usually present as hemorrhagic strokes. Spontaneous thrombosis of a ruptured intracranial aneurysm occurs in 1-3% and most commonly in giant aneurysms, with complete thrombosis in just 13-20% of the cases. Thrombosis of smaller aneurysms is rare. Here we present a case of a patient who presented with a ruptured intracranial aneurysm that subsequently thrombosed, discovering a neighboring de-novo aneurysm during follow-up. We hypothesized that after thrombosis, the hemodynamic characteristics that contributed to the formation of the first aneurysm were replicated.

• Journal of the Korean housing association
• /
• v.22 no.1
• /
• pp.85-93
• /
• 2011

As passing through the Japanese colonial period, Daegu has been changed into a modern city. In addition, the nature of the city had changed a lot by withdrawal of Eup-sung and the opening of the road and the increase of population in Japan. Of course, the expansion of the city was caused by the increase of the Japanese population. To understand the current city, it is most important to understand the past city's characteristics and especially the formation and change of city must be considered with understanding the situation of city. And now the city reflects the role of the city in the past. In fact, the effect of the street constitution in Daegu Eup-sung during Japanese colonial period on the present time was very big and continues. Especially, in order to understand the situation of the city and consider the direction in the future, the analysis of the development process has important implications.This study aimed to consider the change of Daegu Eup-sung Street and Formation of Dwelling Site focusing on the Buksung Street. The purpose of this study is to investigate the nature of the city and changing process of the city by the past Buksung street and the current Buksung street as time goes by.

• The Bulletin of The Korean Astronomical Society
• /
• v.42 no.2
• /
• pp.64.2-64.2
• /
• 2017

The Population III (Pop III) stars are thought to be massive. If massive Pop III stars form binary system and they experience mass transfer via the Roche lobe overflow, this may significantly change the properties of the system. For example, mass transfer in such system may shorten the period of the system, forming short period binary black hole (BBH) system, which is the most promising candidate for recently detected gravitational wave radiation sources. Also, there is an expectation that due to the stripped envelope of donor star by mass transfer, this system can play a significant role in the cosmic reionization by emitting more UV photons. However, this outcome highly depends on the initial properties of the system. We perform grid calculation on Pop III binary models with various initial primary masses (20 ~ 100 solar mass), initial separations, and initial mass ratios (q = 0.5 ~ 0.9). We find that 1) in most cases binary models show no increase in the number of ionizing photons and 2) formation of short period BBH system via mass transfer is highly unlikely.

• Korea journal of population studies
• /
• v.14 no.1
• /
• pp.1-25
• /
• 1991

The Purpose of this study is to analyze the contribution of the total human capital formation to economic growth in Korea. In order to assess the contribution of the total human capital formation to economic growth, aggregate production functions are estimated using two ways of ordinary least squares and polynomial distributed lags based on 1955 - 1988 time series data in Korea. The total amount of investment in human capital is calculated by adding each amount of investment in formal education, vocational training, inter-provincial migration, and health in pecuniary terms. The findings of this study could be summarized as follows ; (1) If we enumerate the variables in good order according to the importance, we get the following ; namely, total number of labor force, inter-provincial migration, vocational training, health, physical capital, and formal education. (2) The contribution of the human capital to economic growth is much more larger than that of physical capital. In particular, it appears that inter-provincial migration and vocational training make a great contribution to economic growth. (3) It appears that investment in formal education has a continuous effect for fifteen years and maximum effect is observed approximately eight years later. In the case of vocational training, the effect of investment lasts for about 12-14 years and its effect on economic growth reaches maximum with the passage of seven to eight years after initial investment. (4) Investment in vocational training contributes more in the long run compared with investment in formal education. The effect of investment in formal education lasts longer than that of vocational training, while the effect of investment in vocational training is considerably larger in the short run compared with the investment in formal education.

• Clinical and Experimental Reproductive Medicine
• /
• v.27 no.1
• /
• pp.47-57
• /
• 2000

Objective: The effects of cryopreservation with or without coculture on the in vitro development of blastomere-biopsied 8-cell mouse embryos were investigated. This experimental study was originally designed for the setup of a preclinical mouse model for the preimplantation genetic diagnosis (PGD) in human. Methods: Eight-cell embryos were obtained after in vitro fertilization (IVF) from F1 hybrid mice (C57BL(표현불가)/CBA(표현불가)). Using micromanipulation, one to four blastomeres were aspirated through a hole made in the zona pellucida by zona drilling (ZD) with acid Tyrode's solution (ATS). A slow-freezing and rapid-thawing protocol with 1.5M dimethyl sulfoxide (DMSO) and 0.1M sucrose as cryoprotectant was used for the cryopreservation of blastomere- biopsied 8-cell mouse embryos. After thawing, embryos were cultured for 110 hours in Ham's F-10 supplemented with 0.4% bovine serum albumin (BSA). In the coculture group, embryos were cultured for 110 hours on the monolayer of Vero cells in the same medium. The blastocyst formation was recorded, and the embryos developed beyond blastocyst stage were stained with 10% Giemsa to count the total number of nuclei in each embryo. Results: The survival rate of embryos after cryopreservation was significantly lower in the blastomere-biopsied (7/8, 6/8, 5/8, and 4/8 embryos) groups than in the non-biopsied, zona intact (ZI) group. Without the coculture, the blastocyst formation rate of embryos after cryopreservation was not significantly different among ZI, the zona drilling only (ZD), and the balstomere-biopsied groups, but it was significantly lower than in the non-cryopreserved control group. The mean number of cells in embryos beyond blastocyst stage was significantly higher in the control group ($50.2{\pm}14.0$) than in 6/8 ($26.5{\pm}6.2$), 5/8 ($25.0{\pm}5.5$), and 4/8 ($17.8{\pm}7.8$) groups. With the coculture using Vero cells, the blastocyst formation rate of embryos after cryopreservation was significantly lower in 5/8 and 4/8 groups, compared with the control, 7/8, and 6/8 groups. The mean number of cells in embryos beyond blastocyst stage was also significantly lower in 4/8 group ($25.9{\pm}10.2$), compared with the control ($50.2{\pm}14.0$), 7/8 ($56.0{\pm}22.2$), and 6/8 ($55.3{\pm}25.5$) groups. Conclusion: After cryopreservation, blastomere-biopsied mouse embryos have a significantly impaired developmental competence in vitro, but this detrimental effect might be prevented by the coculture with Vero cells in 8-cell mouse embryos biopsied one or two blastomeres. Biopsy of mouse embryos after ZD with ATS is a safe and highly efficient preclinical model for PGD of human embryos.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.11 no.3
• /
• pp.108-116
• /
• 2006

To investigate the factors controlling the spring population of Acartia hongi, egg production, hatching time of egg and predation pressure were measured. Egg production was maintained the superior position between winter and spring. Egg production was positively correlated with not only water temperature when water temperature was below $7^{\circ}C$ but also chlorophyll-a concentration when it was from $7^{\circ}C$ to $21^{\circ}C$. A regressive equation of development time$(D_e,\;day)$ of eggs derived from water temperature$(T,\;^{\circ}C)$ was obtained as $D_e=18.9(T-0.4)^{-1.0}$, showing longer development time at water temperature below $5^{\circ}C$. In Cross Correlation Analysis(CCA) to examine the time-lag relationship among abundances of developmental stages of A. hongi, egg production rate calculated by multiplying population egg production rate by hatching time showed more significant correlation with nauplii abundance than population egg production rate. Therefore, it suggests that hatching time is also recognized by a factor controlling formation of population and especially, in winter, high abundance of egg derived from high daily egg production rate and delayed hatch by low water temperature become the origin of initial spring population of nauplii. Egg predation by Noctiluca scintillans, suggesting a negative factor in formation of A. hongi spring population, was observed. During spring, A. hongi eggs were found in $2.9\sim21.1%$ of individuals of N. scintillans. It was deduced that $1.2\sim49.5%$ of the eggs produced by A. hongi was preyed on by N. scintillans. In conclusion, the factors controlling spring population of A. hongi were regarded as high egg production by winter generation, the delayed development time of egg by low temperature, and egg predation of N. scintillans.

• Fisheries and Aquatic Sciences
• /
• v.22 no.6
• /
• pp.12.1-12.8
• /
• 2019

Background: Wild fish populations stock is continuously diminishing in the Indo-Ganges river basin, and the population status of most fishes is unidentified. The identification of the population status and the conservation of commercially important and endemic wild fish populations in this region are crucial for the management. The aim of this paper was to identify the population status of Cirrhinus reba, a promising aquaculture but vulnerable species in the Indo-Ganges river basin in Bangladesh. Methods: C. reba samples were collected from four isolated populations of the Brahmaputra (n = 30), the Padma (33), the Karatoya (31), and the Jamuna Rivers (30) in Bangladesh, and the population status was evaluated using morphometric and landmark comparisons. Data were analyzed with the Kruskal-Wallis test, univariate analysis, discriminant function analysis, and the formation of a dendrogram. Results: Three meristic characters (Pectoral fin rays, caudal fin rays, scale in lateral lines), four morphometric characters (head length, pre-orbital length, post-orbital length, maximum body depth), and truss measurement (4-7) were significantly different among the stocks. The step-wise discriminant function analysis retained 15 variables from morphometric and landmark measurements that significantly differentiated the populations based on the constructed DFI and DFII. Discriminate function analysis also showed that 91.2% of the original groups were classified into their correct samples. The cluster analysis of Euclidean distances placed the Jamuna population in one cluster and the Brahmaputra, the Padma, and the Karatoya populations in the second one. Conclusion : Morphological differences among the stock were probably due to different ancestral origin. This is the first report about population status of C. reba in their natural habitat of the Indian subcontinent. Further genetic studies and the evaluation of environmental impact on C. reba populations in Bangladesh are suggested to support our findings.

• The Korean Journal of Ecology
• /
• v.17 no.2
• /
• pp.203-211
• /
• 1994

The establishment by seeds and the maintenance by ramets of the autumn olive (Elaeagnus umbellata) population were investigated in the Namhansansung Provincial Park, Jungbu-myun, Kwangju-gun, Kyunggi-do. Seed production and germination rate were 3, 300 $seeds{\cdot}m^{-2}{\cdot}yr^{-1}$ and 52%, respectively. The ramet formation in the population was classified into 4 types: stump type, creeping root type, lateral root type and secondary creeping root type. The subterranean creeping roots were 0.1~1.0 m in length, 4.5~14.0 mm in diameter and 0.06~0.2 m in soil depth. The number of ramets formed from a node was 1~21. The subterranean roots spread $5~509cm^2{\cdot}plant^{-1}{\cdot}yr^{-1}$, which began to be produced from 7~9 year-old individuals. The number of stems was 1~67 per stump, which was reduced by self-thinning from 2 to 14 year-old trees. The frequency distribution of stem diameter$(D_{30})$ showed a reverse J-shaped curve, suggesting that this population be maintained perpetually by their own ramets.

• Journal of Korean Society of Rural Planning
• /
• v.22 no.4
• /
• pp.159-169
• /
• 2016

In recent years, the population structure has been changed by the progresses of 6th-industrialization and transportation in farming areas. This study aims to suggest a regional development plan of farming areas in accordance with the demographic changes. Population structure indicators were derived from previous studies and literature review in order to identify the types of farming areas. Demographic indicators separated to depopulation and population growth in farming areas through a standardized scoring method. This research found that the division of economy is not only the most important division in any other regional development divisions but also necessary to develop new sources of non-farm income through traditional culture, natural environment. In the social division, it is necessary to secure the facilities for the formation of a sense of community to multicultural families and existing residents in farming areas. In the environmental division, it is desirable to improve the quality and satisfaction of life for residents such as the sidewalk and park that utilize ecological environment, culture, history for both depopulation and population region. In the physical division, there is a need for improvement of the facilities of basic living infrastructure service such as roads, water supply and sewerage systems. In the institution division, sustainable financial support of the central government policy for farming areas is crucial for the improvement of residential environment in the farming areas of depopulation and population region.

• The Bulletin of The Korean Astronomical Society
• /
• v.40 no.1
• /
• pp.77.2-77.2
• /
• 2015

Galaxies are known to evolve passively in the cluster environment. Indeed, much evidence for HI stripping has been found in cluster galaxies to date, which is likely to be connected to their low star formation rate. What is still puzzling however, is that the molecular gas, which is believed to be more directly related to star formation, shows no significant difference in its fraction between the cluster population and the field galaxies. Therefore, HI stripping alone does not seem to be enough to fully understand how galaxies become passive in galaxy clusters. Intriguingly, our recent high resolution CO study of a subsample of Virgo spirals which are undergoing strong ICM pressure has revealed a highly disturbed molecular gas morphology and kinematics. The morphological and kinematical peculiarities in their CO data have many properties in common with those of HI gas in the sample, indicating that strong ICM pressure in fact can have impacts on dense gas deep inside of a galaxy. This implies that it is the molecular gas conditions rather than the molecular gas stripping which is more responsible for quenching of star formation in cluster galaxies. In this study, using multi transitions of 12CO and 13CO, we investigate the density and temperature distributions of CO gas of a Virgo spiral galaxy, NGC 4402 to probe the physical and chemical properties of molecular gas and their relations to star formation activities.