• The Korean Journal of Zoology
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• v.30 no.4
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• pp.379-386
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• 1987

Karyotype of the ricessh Orygias latipes (Temminck et Schlegel) was investigated using 151 specimens of eleven populations in the southern Korea. Based on the karyotype analysis, two distinct chromosomal groups were found. One group, occurring in the Kum River, the Mankyong River, the Dongjin River, the Ysngsan River and the SEmjin River had a diploid chromosome number of 46 and arm number of 70, which contained one pair of "large" metacentric chromosomes. The other group, occurring in the Tamjin River, the Hyongsan River andthe all four island populations observed had a diploid chromosome number of 48 and arm number of 68. These results showed that 0. latipes of 6 inland populations was identical with the Chinese population in diploid number, arm number and presence of "large" metacentric chromosome, while the present species of island populations ana populations of the Tamjn R. and Hyongsan R. was similar to the Japanese population in chromosome number and arm number. The karyotype variation in populations indicated that karyotypes will probably provide useful information in studying zoogeography of this species.phy of this species.

• Korean Journal of Plant Taxonomy
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• v.52 no.4
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• pp.251-254
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• 2022

Saxifraga cortusifolia Siebold & Zucc. (Saxifragaceae, sect. Irregulares, ser. Rufescentes), a species considered endemic along mountain streams throughout Honshu, Shikoku, and Kyushu in Japan, was discovered as a wild population in the Cheona Valley in Haean-dong, Jeju-si on Jeju-do Island of Korea. The population consisted of three subpopulations occupying narrow areas 10 × 10 m², 5 × 5 m², and 10 × 5 m² in size. The number of individuals in the three subpopulations was confirmed to exceed 100. Most of the individuals were on or below rocks at the edge of the valley. A morphological description, detailed photos, and a key to related taxa in Korea are presented.

• Journal of the Korean Society for Railway
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• v.20 no.3
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• pp.423-431
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• 2017

This study analyzed the educational background, career, and post-retirement activities of notable bureaucrats employed at Chosun Railway Bureau during the Japanese colonial period in Korea. First, significantly, most railway bureaucrats were of Japanese origin, being specialized in railway operations and adjusted to occupation in a reserved organizational environment for a considerable time period. Second, the Japanese showed explicit eagerness to work at the Chosun Railway, which fitted their ideology of railway bureaucrats. In addition, almost 60% of the bureaucrat population had strong educational experience from Tokyo Imperial University, which is equal to the percentage of graduates from other institutions operating during the Japanese colonial period. Moreover, in the very early period of building the railway system, the demand for specialists was higher than for other jobs and divisions because of the railroad's complex infrastructure, which resulted in high job appointment rates. In a similar sense, based on a strong affiliation of bureaucrats with railways, the number of bureaucrats from Japanese Railway Worker's Bureau was higher initially because of bureaucrats from South Manchurian Railway Company. These changes essentially contributed to alteration of bureaucrats' awareness and created a more positive attitude regarding the Chosun Railway. In the meantime, as opposed to the Taiwan and Manchurian Railways, both Chosun Railway and the Taiwan Railway were operated in compliance with strong bureaucratic traditions.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.5
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• pp.557-566
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• 2022

The Japanese eel Anguilla japonica is a highly valued research object that is important for aquaculture in Asia, including the Republic of Korea. However, few studies have been conducted analyzing parentage using microsatellite markers derived from the Japanese eel. We acquired Japanese eel genome data using next generation sequencing technology, and constructed a draft genome comprising 1,087 Mbp. Using the Simple Sequence Repeat Identification Tool program, 444,724 microsatellites were identified. Of these, 1,842 microsatellites located in the 3' untranslated region, which are stably inherited, were finally selected. Ninety-six primers were selected to validate polymorphism at these microsatellites, and 9 primers were finally identified for multiplex analysis. Using multiplex polymerase chain reaction with three different fluorescence chemistries, we performed parentage analysis of an artificial Japanese eel population. CERVUS software was used to calculate the logarithm of the odds (LOD) scores and the confidence of the parentage assignments. The results presented here show that 83 out of 85 paternity cases were assigned at 95% confidence to a candidate father and mother with LOD scores ranging from 4.79 to 28.2. This study provided a microsatellite marker-based assay for parentage analysis of Japanese eels, which will be useful for selective breeding and genetic diversity studies.

• Industrial Engineering and Management Systems
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• v.15 no.3
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• pp.197-205
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• 2016

The public services closely related to the daily lives of the Japanese people, such as firefighting, police or primary school education, are largely financed by the local governments. As the population as a whole in Japan declines, the population in local regions are forecasted to experience particularly rapid decline in the future, and it is inevitable to reduce the cost of public services provided by the local governments to keep their financial basis sustainable. In order to provide public services to the people properly and fairly, the local governments own and utilize their public facilities, such as fire stations, police stations or primary schools. On the other hand, we have to secure the accessibility, which is the condition of accessing a facility easily in a whole local city including the high population density area and low population density area. In this paper, we propose a method of determining the number of future facilities and its facility locations in which we maintain the present accessibility. In our proposed method, we determine them comparing the accessibility measurement calculated by facility location model using the present and future population. We adopted k-centdian model as the facility location model, which can secure the accessibility in a whole local city determining the weights of both areas. We applied our proposed method to fire station in Iwaki city, Japan. The results suggested that 7 facilities would be reduced in 2064, after 50 years from 2014. Additionally, we confirmed that the future facility location had secured accessibility in both high and low population density area.

• Animal cells and systems
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• v.14 no.1
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• pp.31-36
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• 2010

The pinewood nematode Bursaphelenchus xylophilus causes pine wilt disease and is a serious economic concern for the forest industry of South Korea. To achieve effective control with limited resources, it is necessary to clarify the transmission routes and mechanisms of dispersal of this organism. Highly polymorphic and easy-to-use molecular markers can be used for investigating this aspect. In this study, we evaluated the usefulness of amplified fragment length polymorphisms (AFLPs) for investigating the genetic variations of B. xylophilus and related individuals from China, Japan, and South Korea. The AFLP patterns obtained in our study were similar to the microsatellite patterns reported in a previous study; our AFLP patterns indicated high genetic variability and cryptic genetic structure, but did not indicate any peculiar geographic structure. Moreover, the genetic distances between individuals suggested that the Korean population was affected to a greater extent by the Chinese population than the Japanese population. Further, the gene flow among the related species appeared to be limited; however, there may be also the possibility of genetic introgression among species. These results confirm the usefulness of AFLPs for understanding the epidemiology of pine wilt disease, thereby contributing to the effective control of this disease.

• Journal of Ecology and Environment
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• v.35 no.4
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• pp.331-341
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• 2012

Using data sets for Japan as a whole, as arranged with approximately $10{\times}10$ km squares (a secondary grid), we investigated the relationship between population density and the habitats of threatened vascular plants listed in the Japanese Red Data Book; depopulated areas in the present and future, areas where under-use may be serious, and those with a predominance of elderly people; and the present state of the habitats in terms of a characteristic land use pattern. Regarding the habitats of threatened vascular plants, the progress of deterioration [$(N_{CR}+N_{EN})/(N_{CR}+N_{EN}+N_{VU})$] in depopulated areas has been confirmed, where $N_{CR}$, $N_{EN}$, and $N_{VU}$ are the numbers of species classified as critically endangered, endangered, and vulnerable, respectively. Moreover, in grid squares used by a human such as farmland, the progress of the deterioration simply increases when population density becomes low. However, for many vascular plants, they are particularly endangered in populous areas. Local populations will decrease throughout Japan with the rate of depopulation in and around large cities being relatively slow. We also propose some issues that need further study. The deterioration by human activity may be reduced. On the other hand, some vascular plants may be adversely influenced by depopulation. Additionally, we should keep a close watch on grasslands and water areas in large cities to preserve vascular plants.

• BMB Reports
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• v.35 no.3
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• pp.251-254
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• 2002

The genetic factors that contribute to the development of coronary artery disease (CAD) are poorly understood. It is likely that multiple genes that act independently or synergistically contribute to the development of CAD and the outcome. Recently, an insertion/deletion (I/D) polymorphism of the human angiotensin I-converting enzyme (ACE) gene, a major component of the renin-angiotensin system (RAS), was identified. The association of the ACE gene D allele with essential hypertension and CAD has been reported in the African-American, Chinese, and Japanese populations. However, other studies have failed to detect such an association. It has been suggested that these inconsistencies may be due to the difference in backgrounds of the population characteristics. In the present study, we investigated the I/D polymorphism of the ACE gene in 103 subjects of both sexes, consisting of 59 normal controls and 44 patients with hypertension. The allele and genotype frequency were significantly different between the hypertensive and control groups (p < 0.01). Among the three ACE I/D variants, the DD genotype was associated with the highest value of the mean systolic blood pressure [SBP] and mean diastolic blood pressure [DBP] (p = < 0.05) in men, but not in women. In the overall population, the mean SBP and DBP was highest in DD subjects, intermediate in I/D subjects, and the least in II subjects.

• Journal of the Korean Institute of Rural Architecture
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• v.22 no.4
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• pp.1-8
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• 2020

Recently, cultural property policies have changed from the preservation of cultural assets to the utilization of cultural assets. In historic villages, more and more traditional housings have been used as lodging facilities. On the other hand, low birth rates, aging population, declining population due to population outflow to the cities, increasing vacant houses, and aging buildings are tasks of historic villages. To be preserved the historic villages continuously, it is time to review how to regenerate and utilize the growing number of vacant houses. This study targets Tambasasayama city, which is drawing attention to the regeneration and utilization of vacant houses among historic Japanese villages. We want to analyze the operation systems and deregulation of a traditional housing regeneration project in Tambasasayama city and draw suggestions for the regeneration and utilization of vacant houses in traditional villages in South Korea.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.5
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• pp.597-602
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• 2001

This study was conducted to examine the relationships between the methods used to determine the number of transferable embryos collected per flush and the estimated cumulative genetic improvements in the Japanese Holstein MOET breeding population. Cumulative genetic improvements were predicted by Monte Carlo simulation using three different determination methods (MODEL 1, MODEL 2, and MODEL 3), for calculating the number of embryos collected per flush. Moreover EBVs were estimated including or ignoring coefficients of inbreeding in MME. Inbreeding coefficients were also predicted. The number of transferable embryos was determined using normal, gamma, and Poisson distributions in MODEL 1, gamma and Poisson distributions in MODEL 2, and only the Poisson distribution in MODEL 3. The fitness of MODEL 2 in relation to field data from Hokkaido Japan was the best, and the results for MODEL3 indicated that this model is unsuitable for determining the number of transferable embryos. The largest cumulative genetic improvement (3.11) in the 10th generation was predicted by MODEL 3 and the smallest (2.83) by MODEL 2. Mean coefficients of correlation between the true and estimated breeding values were 0.738, 0.729, and 0.773 in MODELS 1, 2, and 3, respectively. It is suggested that the smallest genetic improvement in MODEL 2 resulted from the smallest correlation coefficient between the true and estimated breeding values. The differences in milk, fat, and protein yields between MODELS 2 and 3 were 182.0, 7.0, and 5.6 kg, respectively, in real units when each trait was independently selected. The inbreeding coefficient was the highest (0.374) in MODEL 2 and the lowest (0.357) in MODEL 3. The effects of different methods for determining the number of transferable embryos per flush on genetic improvements and inbreeding coefficients of the simulated populations were remarkable. The effects of including coefficients of inbreeding in MME, however, were unclear.