• 한국발생생물학회지:발생과생식
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• 제23권4호
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• pp.377-384
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• 2019

Genomic DNA extracted from representatives of two populations, Gunsan and Chinese, of Urechis spp. was amplified using PCR with several primers. The band-sharing (BS) value between individuals no. 05 from the Gunsan population and no. 22 from the Chinese population was 0.206, which was the lowest recognized value. Oligonucleotides primer OPC-04 revealed 44 unique loci, which distinguished the Chinese population. Primer OPB-17 allowed the discovery of 22 loci shared by the two populations, which were present in all samples. Based on the average BS results, individuals from the Gunsan population demonstrated lower BS values (0.661±0.012) than did those from the Chinese population (0.788±0.014; p<0.05). The shortest genetic distance (GD) displaying a noteworthy molecular difference was between individuals CHINESE no. 12 and no. 13 (GD=0.027). Individual no. 06 from the Gunsan population was most distantly related to CHINESE no. 22 (GD=0.703). A group tree of the two populations was constructed by UPGMA Euclidean GD analysis based on a total of 543 fragments generated using six primers. The explicit markers recognized in this study will be used for genetic analysis, as well as to evaluate the species security and proliferation of echiuran individuals in intertidal regions of the Korean Peninsula.

• 농촌계획
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• 제19권4호
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• pp.203-212
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• 2013

The aging of farm households has caused serious problems such as productivity slowdown and aggravated income polarization in South Korea. Urban-to-rural migration has been recently suggested as a measure to attenuate the aging of rural population and other related problems. The inflow of migrants for farming can have a substantial effect on agriculture and rural communities while the natural adjustment of rural population caused by birth and death is slow. This paper forecasts population distribution of different provinces using the Origin-Destination (OD) analysis, taking into account both the size and directions of migration. In the analysis, nodes where the migration takes place are divided by the industrial sectors (agriculture and non-agriculture), regions, and ages. The results of a ten-year forecast shows that the aging of total population in most provinces will be intensified, but the portion of people over sixty will decrease in the agricultural sector. This finding implies that migration into rural areas, when occurring by a large extent, can mitigate the aging process and attendant problems.

• 한국인구학
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• 제2권1호
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• pp.5-16
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• 1978

The main purpose of this study is to examine the recent level of fertility and potentiality of the Korean population in Japan and to investigate some forces which influence the fertility of them using survey data. Some estimates of the level of fertility for the Korean population in Japan in 1974 are presented in Table 1. Comparing the some estimates for 1974 with those for 1969, the level of fertility in 1974 was realistically declined. It also indicated that potentiality of Koreans in Japan showed decreasing population. For investigating some factors affecting fertility, total births is selected which regressed on some variables believed in general to be influential in determiaing fertility. It was used a step-wise multiple regression to determine the independent as well as the combined effects of each of the variables. The SPSS computer program was used to perform the anlysis. Result from this data reveals that wife's family size preference as relevant predictor does influence the fertility of Koreans in Japan at this point considering that the age group of 20-29 is very much related. By employing multiple classification analysis, the analysis is concluded by nothing that the wi 3 family size preference has an even stronger relationship with economic factors than any other facto 3.

• 한국인구학
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• 제11권1호
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• pp.117-130
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• 1988

Though most of East European coutries seem to hold a pronatalist policy, they approve of family planning and provide contraceptive services. One of the most popular contraceptive method has traditionally been the coitus interruptus in these countries. One of the major reasons for adopting family planning is to decrease the incidence of induced abortion has been closely related to the popular use of coitus interruptus in these countries. Most of the East European countries liberalized induce abortion legally mainly to neutralize the wide practice of illegal abortion. However, the practice of induced abortion is under the strict control of the public health authorities in these countries. Migration and redistribution of population of population are mostly under the control of the state in these socialist countries. Policies on migration and redistribution are usually carried out to achieve the general goal of socio-economic development plan of the states. Both incentive measures and control measures are mobilized to affect the internal migration and redistribution of population. With respect to public health East European countries are characterized by the socialized medicine following the Soviet model. Public health measures and medical practice are controlled by the state and highly centralized in many countries except Yugoslavia. They place much emphasis on preventive medicine, primary health care, occupatinal and industrial medicine, and health education. Private sectors in medical practice do not exist in these countries of Eastern Europe.

• 한국발생생물학회지:발생과생식
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• 제25권1호
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• pp.59-65
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• 2021

The author established a PCR-based genetic platform to examine the hierarchical polar dendrogram of Euclidean genetic distances of one tailfin anchovy population, especially for Coilia nasus, which was further associated with other fish population, by connecting with specifically designed oligonucleotide primer sets. Five oligonucleotide primers were used to generate a total of 260 and 211 scorable fragments in Coilia populations I and II, respectively. The DNA fragments ranged from greater than (approximately) 100 to more than 2,000 bp. The average bandsharing values (BS) of individuals from the anchovy population I (0.693) displayed higher values than individuals from population II (0.675). The genetic distance between individuals established the existence of a close relationship in group II. Comparatively, individuals of one anchovy population were fairly related to other fish populations, as shown in the polar hierarchical dendrogram of Euclidean genetic distances. The noteworthy genetic distance determined between two Coilia nasus populations demonstrates that this PCR technique can be applied as one of the several devices for individuals and/or population biological DNA researches undertaken for safeguarding species and for production of anchovies in the littoral area of Korea.

• 한국발생생물학회지:발생과생식
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• 제24권4호
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• pp.327-335
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• 2020

Genomic DNA (gDNA) extracted from two populations of natural and cultured river pufferfish (Takifugu obscurus) was amplified by polymerase chain reaction (PCR). The complexity of the fragments derived from the two locations varied dramatically. The genetic distances (GDs) between individuals numbered 15 and 12 in the cultured population was 0.053, which was the lowest acknowledged. The oligonucleotide primer OPC-11 identified 88 unique loci shared within each population reflecting the natural population. The OPC-05 primer identified 44 loci shared by the two populations. The average band-sharing (BS) values of individuals in the natural population (0.683±0.014) were lower than in those derived from the cultured population (0.759±0.009) (p<0.05). The shortest GD demonstrating a significant molecular difference was found between the cultured individuals # 15 and # 12 (GD=0.053). Individual # 02 of the natural population was most distantly related to cultured individual # 22 (GD=0.827). A cluster tree was built using the unweighted pair group method with arithmetic mean (UPGMA) Euclidean GD analysis based on a total of 578 various fragments derived from five primers in the two populations. Obvious markers identified in this study represent the genetic structure, species security, and proliferation of river pufferfish in the rivers of the Korean peninsula.

• Animal Systematics, Evolution and Diversity
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• 제39권4호
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• pp.264-271
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• 2023

The edible jellyfish Rhopilema esculentum occurs in waters throughout northeastern Asia, including in Korea, China, and Japan. In Korean waters, R. esculentum has appeared in two regions (Gangwha and Muan). Based on the appearance of young medusae and coastal distribution records, these two regions may be key R. esculentum breeding sites. In the present study, we investigate and compare the genetic structure of R. esculentum in the two regions using mitochondrial sequences (16S ribosomal RNA and cytochrome c oxidase subunit I). The genetic diversity of the R. esculentum population at Ganghwa exceeded that of the population at Muan. Despite considerable geographic separation (400 km) between the two regions(Gangwha and Muan), our haplotype network suggests that the Gangwha and Muan populations of R. esculentum are related. The simple and monotonous genetic structure of the Muan population shows that R. esculentum emergence is relatively recent. In contrast, the Gangwha population shows evolution. Moreover, jellyfish of the Gangwha population are genetically diverse and remain constant despite environmental fluctuations in the Han River. The Gangwha area is considered to be the old origin of R. esculentum in Korea.

• 한국콘텐츠학회논문지
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• 제10권3호
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• pp.347-354
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• 2010

여행시장에 있어 인구의 고령화는 새로운 표적시장의 증가라는 점에서 의미가 있고 국가정책 측면에서는 복지관광수요의 증가라는 의미를 갖는다. 날로 첨예화되는 시장경쟁과 새로운 시장 창출이라는 당면과제를 안고 있는 여행업계의 입장에서는 새로운 수익창출 대안으로서 노인관광시장을 주목할 필요가 있다. 한편, 향후 우리사회에 심각한 문제가 될 수 있는 노인문제를 해결하기 위한 방안으로 복지관광 측면에서 노인관광에 접근할 수 있는데, 이는 여러 가지 노인 여가활동 중 관광이 노인들의 생활만족도에 미치는 영향이 타 여가활동보다 상대적으로 높다는 점에 착안한다. 본 연구에서는 청주지역 노인들을 대상으로 인구통계적 특성 및 여행활동 특성이 생활만족에 어떠한 영향을 미치는가를 실증적으로 분석하였다. 분석의 결과, 생활수준, 건강상태, 용돈수준이 높은 노인 집단일수록 생활만족도가 높은 것으로 나타났으나 여행형태에 따른 생활만족의 차이는 없는 것으로 나타났다. 이와 같은 결과를 토대로 본 논문에서는 실무적 시사점과 정책과제에 대한 시사점을 제시하였다.

• Journal of Ginseng Research
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• 제5권1호
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• pp.73-84
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• 1981

Effect of environmental factors and host on the growth and outbreak of various ginseng diseases was reviewed Environmental lectors included hydrogen ion concentration, moisture content, temperature, nutrition, and microbiol populations. Age of the ginseng plants in relation to several ginseng disease occurrence was also included in order to formulate the effective control measure for ginseng diseases. Damping-off caused by Rhizoctonia, Pythium, and Phytophthora, greymold by Botrytis, sclerotinia by Scleretinia, and phytophthora blight caused by Phytophthora were usually prevalent during the early growing season of ginseng when temperature is below 20$^{\circ}C$, while anthrac se caused by Colletotrichum, alternaria blight by Alternaria, and bacterial soft rot by Erwinia were so during the latter growing season when temperature is above 25$^{\circ}C$. However, the root rot incited by Fnarium and Cylindrocarpon caused severe damages throughout the growing season. Growth range of the temperature for a pathogen was highly related to the corresponding disease outbreak. Hydrogen ion concentration was highly related to the outbreak of sclerotinia, root rot, and red rot. Most severe outbreak of those diseases where the soil acidity was pH 4.7, pH 6.5- 7.5, and pH6.0-6.5, respectively. Nitrogen content in the soil was also related to outbreak of root rot and red rot. More red rot occurred where NH,-nitrogen is above 30 ppm and more root rot obtained when excessive nitrogen fertilizer applied. Yellow necrosis apparently was related to magnesium especially its ratio with potassium or calcium content in a soil. Fusarium Population showed significant .relations to missing rate of ginseng Plants in a Implanting ginseng field, while that of total bacteria showed similar relations in all ginseng field, However, in six year old ginseng fields, the more the Streptomyces population was, the less the Fusarium obtained. Consequently, less missing rate observed in a field where Streptomyces population was high. Damping-off, root rot, Rhytophthor a blight were mose severe on the nursery and on 2-3 years old ginseng plants, whereas sclerotinia, and grey cod, alteraria blight, anthracnose were severe on 4-6 years old ginseng plants. Root rot caused by Fusarium and Erwinia, however, was also severe regardless of the age of the plants when the roots were injured. Therefore, for the effective control of ginseng root rot most careful control of the disease during the early year should be rendered.

• 한국인구학
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• 제3권1호
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• pp.5-41
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• 1979

Vast volumes of studies of the medical and public health aspects of fertility and family planning have been published by the various institutes of health related research and university scholars in Korea. None of them, however, have dealed with the population problems associated with biologically and mentally handicapped people. It must be emphasized that the purpose of Korea's population policy should be to improve the quality of the population rather than to decrease its rate of increase. In this spirit, the first report of this study is to identify problems related with mentally and physically less fitted population, and to attempt to offer the possible solutions to the health planners and policy-makers. Several nation-wide surveys of the handicapped people in Korea have been compared. Each survey shows a wide range of difference in the prevalence of the handicaps(see Table 13). In this study, the data on the handicaps are collected by two independent system ; one by the nation-wide survey and the other by the reporting system existing at the Seoul National University Demonstration Health Project. The Chandrasekar-Deming technique was used to estimate the total number of handicaps. The estimates are summarized in the tables 8, 9 and 10. Estimate of total number of handicapped people in Korea is 601, 400 with the prevalence rate of 16.1 per thousand persons. Even if taking a number of conditions which may result in a biased estimate of the total number of the handicaps into consideration, the proportion of handicapped people in Korea has increased in the past two decade as the result of the rapid decline in fertility and childhood mortality, which consequently prolonged life expectancy of persons with congenital or acquired impediment. An increase in the proportion of handicapped people will eventually bring about serious problems of social welfare, medical care, and population qualities from various aspects including eugenics. To tackle the problem, there must be an increased emphasis on the prevention of handicaps from the government and private sector. Based on the amount and quality of data, and from the practical point of view, this study prepared a set of recommendations for the government to strengthen its programs of the preventive activities during the prenatal period and early childhood, early finding from routine examinations, and proper social and medical rehabilitation.