• Korea journal of population studies
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• v.17 no.2
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• pp.1-20
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• 1994

The main purpose of this paper is to examine changes in internal migration patterns during 1960 - 1990 period, and to analyze population movement to and from the Capital Region. The overall mobility rate of the whole Korean population has heen increasing since the 1960s, and reached to 24.6% in 1985 - 90 period. The most interesting changes in the migration pattern is that Seoul lost its population through migration during 1985 - 90, mainly due to heavy outmigration to Kyonggi province. The analysis of characteristics of inmigrants to the Capital Region reveals that those moved to Seoul are more likely to be young, better educated, never married and engage in service sector in comparison with migrants moved to the suburban districts and the outlying Kyonggi province. However, on the whole migrants moved to the Capital Region are overrepresented in manufacturing sector, which suggests that more effective policy measures to control the growth of manufacturing sector in the Capital Region is called for.

• Parasites, Hosts and Diseases
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• v.61 no.2
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• pp.103-126
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• 2023

In the l950s, under the legacy of traditional agriculture, Ascaris lumbricoides, spread epidemically in the war-bitten society of Korea. Consensus on the parasite control was drafted in the Parasite Disease Prevention Act, which passed a parliamentary agreement in 1966, and established safe disposal of feces and mass chemotherapy as control strategies. Biannual stool examinations and treating infected schoolchildren were basic scheme of the control activity through which revenue could be secured for organized business. In the 27 years following 1969, a maximum of 16 million stool examinations had been done every year. Cellophane thick smear enabled the task. The infection declined remarkably in the 1970s when industrialization and green revolution proceeded. A population study of A. lumbricoides in the late 1970s helped us better understand its epidemiology. The data also settled down the understandable protest of teachers against the repeated stool examinations. In the 9 years following 1987, the target population was gradually reduced when the egg positive rate was below 0.1%. An article in the Korean Law, stipulating obligatory stool examinations, was made optional. Although the long-term Korean effort of Ascaris control was a success, the effect of mass chemotherapy was not as succinct in terms of lowering reinfection. In the period of control, Korean agricultural technology changed, and the economy grew and supplied sanitary facilities by which the vicious cycle was disconnected. Reduction of morbidity was a benefit of mass chemotherapy, which is the only control method feasible in economically difficult countries. The most important hurdle of parasite control in the 1960s was poverty of general population and limited financial resources in Korea but the society formed a consensus on the priority of intestinal helminthiasis control during the ordeal period. The national consensus in the 1960s was the critical milestone for Ascaris control in Korea. Under the social agreement, application of timely technical and research advancements in parasitology achieved the success of ascariasis elimination. The successful experience of ascariasis elimination in Korea can be a benchmark for countries where neglected tropical diseases are endemically recycled.

• The Korean Journal of Nuclear Medicine Technology
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• v.20 no.1
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• pp.37-41
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• 2016

Purpose The importance of quality control by the error to a minimum, which for the purpose of enhancing the reliability of the examination is not be emphasized excess. Currently, most nuclear medicine laboratory are conducting the internal and external quality control, and they are applying the Levey-Jennings or Westgard Multi-Rules by using the commercialized quality control materials. The reliability of the nuclear medicine blood test which affects the diagnosis of patients and the treatment policy is being secured through this quality control activity. Therefore, researchers will evaluate the utility of the statistic quality control using the population distribution of the nuclear medicine blood test conducted targeting the checkup examinees by the additional technique of the reliability improvement. Materials and Methods A statistic analysis was performed about 12 items of the nuclear medicine blood test targeting 41,341 peoples who used the health screening and promotion center in Asan Medical Center from January, 2014 to December, 2014. The results of 12 items of the nuclear medicine blood test was divided into the monthly percentage of three groups: within reference values, over reference, and under reference to analyze the average value of the population distribution, standard deviation, and standard deviation index (SDI). Results The standard deviation of the population distribution mostly showed a result within ${\pm}2SD$ in all groups. However, When the standard deviation of the population distribution represented a result over ${\pm}2SD$, it was confirmed SDI was showing a result of SDI > -2 or SDI > 2. As a result of analyzing the population distribution of 12 items(AFP, CEA, CA19-9, CA125, PSA, TSH, FT4, Anti-Tg-Ab, Anti-TPO-Ab, Calcitonin, 25-OH-VitD3, Insulin) of the nuclear medicine blood part basic test, when SDI of the monthly percentage which deviated from the reference values was over ${\pm}2.0$, CA19-9 September was 2.2, Anti-Tg-Ab may was 2.2, Insulin January was 2.3, Insulin March was 2.4. It was confirmed these cases were attributed to the abnormality of the test reagent (maximum combination rate of isotope reagent declined) and the decline of the test response time. Conclusion The population distribution includes the entire attribute which becomes the study object. It is expected the statistic quality management using the population distribution which was conducted targeting the checkup examinees by dividing into three groups: within reference values, over reference, and under reference by means of this characteristics will be able to play a role of complementing the internal quality control program which is being carried out in the laboratory.

• Food Science and Preservation
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• v.30 no.1
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• pp.42-51
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• 2023

This study aimed to characterize a lytic Salmonella Typhimurium-specific (ST) phage and its biofilm control capability against S. Typhimurium biofilm on polypropylene surface. ST phage was isolated, propagated, and purified from water used in a slaughterhouse. The morphology of ST phage was observed via transmission electron microscopy. Its bactericidal effect was evaluated by determining bacterial concentrations after the phage treatment at various multiplicities of infection (MOIs) of 0.01, 1.0, and 100. Once the biofilm was formed on the polypropylene tube after incubation at 37℃ for 48 h, the phage was treated and its antibiofilm capability was determined using crystal violet staining and plate count method. The phage was isolated and purified at a final concentration of ~11 log PFU/mL. It was identified as a myophage with an icosahedral head (~104 nm) and contractile tail (~90-115 nm). ST phage could significantly decrease S. Typhimurium population by ~2.8 log CFU/mL at an MOI of 100. After incubation for 48 h, biofilm formation on polypropylene surface was confirmed with a bacterial population of ~6.9 log CFU/cm². After 1 h treatment with ST phage, the bacterial population in the biofilm was reduced by 2.8 log CFU/cm². Therefore, these results suggest that lytic ST phage as a promising biofilm control agent for eradicating S. Typhimurium biofilm formed on food contact surfaces.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.13
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• pp.5187-5194
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• 2014

Background: Numerous studies have suggested that selenium deficiency may be associated with an increased risk for several types of cancer, but few have focused on thyroid cancer. Materials and Methods: We examined the association between post-diagnostic fingernail selenium levels and differentiated thyroid cancer risk in a French Polynesian matched case-control study. Conditional logistic regression models were used to estimate odds ratios and 95% confidence intervals. Results: The median selenium concentration among controls was $0.76{\mu}g/g$. Significantly, we found no association between fingernail selenium levels and thyroid cancer risk after conditioning on year of birth and sex and additionally adjusting for date of birth (highest versus lowest quartile: odds-ratio=1.12, 95% confidence interval: 0.66-1.90; p-trend=0.30). After additional adjustment for other covariates, this association remained non-significant (p-trend=0.60). When restricting the analysis to thyroid cancer of 10 mm or more, selenium in nails was non-significantly positively linked to thyroid cancer risk (p-trend=0.09). Although no significant interaction was evidenced between iodine in nails and selenium in nails effect (p=0.70), a non-significant (p-trend =0.10) positive association between selenium and thyroid cancer risk was seen in patients with less than 3 ppm of iodine in nails. The highest fingernail selenium concentration in French Polynesia was in the Marquises Islands ($M=0.87{\mu}g/g$) and in the Tuamotu-Gambier Archipelago ($M=0.86{\mu}g/g$). Conclusions: Our results do not support, among individuals with sufficient levels of selenium, that greater long-term exposure to selenium may reduce thyroid cancer risk. Because these findings are based on post-diagnostic measures, studies with prediagnostic selenium are needed for corroboration.

• Korean journal of applied entomology
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• v.28 no.2
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• pp.61-68
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• 1989

To investigate the possibility of the BPH control by systematic application of insecticides, biological effects of buprofezin and isoprothiolane upon the BPH population was evaluated in the laboratory and pot. Both chemicals did not affect the developmental period of the nymphal stage with the applied dosages. When the buprofezin treated instar nymph was developed to the adult, adult's longevity was fairly reduced and such an effect of buprofezin was greater upon the younger instar nymphs. Residual effect of buprofezin was about 30 days in the pot. And it could suppress the BPH population when the younger instar nymphs were dominant age group in the population at the time of treatment. Isoprothiolane was also more effective for the suppression of the BPH population when the younger instar nymphs were dominant at the time of treatment. And it was expected that by buprofezin treatment in July the control effect of isoprothiolane against the BPH population could be maximized when it was treated to control the rice neck blast in late July or early August, because buprofezin could induce the biased population age distribution in which younger instar nymphs were main group at the time of isoprothiolane treatment.

• Korea journal of population studies
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• v.8 no.1
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• pp.118-138
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• 1985

This paper is aimed to analyse the recent changes in family planning as a step in an evaluation of the results of the population control policy which has been strenuously pursued by the government since December 1981. The data used in this analysis comes from the 1985 national fertility and family planning survey conducted by the Korea Institute for Population and Health (KIPH) in May 1985. According to the 1985 survey data, there have been great changes in both the contraceptive practice and fertility rates since the strengthening of the government's population control policy in 1 981. The contraceptive practice rate for married women aged 15-44 has increased from 57.7% in 1982 to 70.3% in 1985, an increase of 12.6% points in the short span of only 3 years. During the same period, the total fertility rate has declined from 2.7 in 1982 to the population replacement level which was planned to achieve by 1 988. More than 80% of women aged over 30 or with two children or more are practicing contraception, while the practice rates of women with 0-1 children are 14.0% and 45.1% respectively. The survey has revealed that the increase of contraceptive practice rate during 1982-1985 has mainly attributed to the high acceptance of sterilization procedures which practice rate of the married women has increased from 28.1% to 40.3% for the period. Also, the survey data shows that 24.7% of those women with only one child is practicing contraception for thepurpose of fertility termination. The government, taking into account of rapid changes in contraceptive practice and fertility rates, is formulating a population plan during the sixth fiveyear economic and social development plan (1987-1991) to achieve 1% ofpopulation growth rate by 1993, which was planned to realize by 2000. In order to meet this demographic goal, the existing population control policy measures should be improved to be suited to the recent contraceptive use and fertility changes. From this standpoint, the following considerations should be put forth; 1) improvement of the current program management systems including target allocation and evaluation schems for recruiting new acceptors in the young 20s groups to use contraceptives for birth spacing and to increase high continuation rates through the strengthening of follow-up services for the acceptors, 2) increase of self-supporting contraceptive users by promoting commercial advertisements on contraceptives through mass media including T.V. and radio, 3) development of social support policies including incentive schems, and strengthening of IE & C activities for increasing the proportion of the one-child family, 4) strengthening of population and family planning education in and out school youth, and 5) strengthening of management capabilities at the provincial and local program managers.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.9
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• pp.1223-1228
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• 2012

The population sizes of three Korean indigenous cattle populations have been drastically reduced over the past decades. In this study, we examined the extent to which reduction in populations influenced genetic diversity, population structure and demographic history using complete mitochondrial DNA (mtDNA) control region sequences. The complete mtDNA control region was sequenced in 56 individuals from Korean Black (KB), Jeju Black (JEB) and Korean Brindle (BRI) cattle populations. We included 27 mtDNA sequences of Korean Brown (BRO) from the GenBank database. Haplotype diversity estimate for the total population was high (0.870) while nucleotide diversity was low (0.004). The KB showed considerably low nucleotide (${\pi}$ = 0.001) and haplotype (h = 0.368) diversities. Analysis of molecular variance revealed a low level of genetic differentiation but this was highly significant (p<0.001) among the cattle populations. Of the total genetic diversity, 7.6% was attributable to among cattle populations diversity and the rest (92.4%) to differences within populations. The mismatch distribution analysis and neutrality tests revealed that KB population was in genetic equilibrium or decline. Indeed, unless an appropriate breeding management practice is developed, inbreeding and genetic drift will further impoverish genetic diversity of these cattle populations. Rational breed development and conservation strategy is needed to safeguard these cattle population.

• Animal Systematics, Evolution and Diversity
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• v.28 no.4
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• pp.279-290
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• 2012

Plecoglossus altivelis (ayu) is an amphidromous fish widely distributed in Northeastern Asia from the East China Sea to the northern Japanese coastal waters, encompassing the Korean Peninsula within its range. The shore lines of northeastern region in Asia have severely fluctuated following glaciations in the Quaternary. In the present study, we investigate the population genetic structure and historical demographic change of P. altivelis at a population level in East Asia. Analysis of molecular variance (AMOVA) based on 244 mitochondrial control region DNA sequences clearly showed that as the sampling scope extended to a larger geographic area, genetic differentiation began to become significant, particularly among Northeastern populations. A series of hierarchical AMOVA could detect the genetic relationship of three closely located islands between Korea and Japan that might have been tightly connected by the regional Tsushima current. Neutrality and mismatch distribution analyses revealed a strong signature of a recent population expansion of P. altivelis in East Asia, estimated at 126 to 391 thousand years ago during the late Pleistocene. Therefore it suggests that the present population of P. altivelis traces back to its approximate demographic change long before the last glacial maximum. This contrasts our a priori expectation that the most recent glacial event might have the most crucial effect on the present day demography of marine organisms through bottleneck and subsequent increase of effective population size in this region.

• Korea journal of population studies
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• v.17 no.1
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• pp.1-16
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• 1994

Since 1962, the population growth control has been one of the most important aims in the 5-Year So-cioeconomic Development Plans of Korea. The annual population growth rate has dropped to tess than 1 percent in 1990 from about 3 percents in 1960s, and projected to reach to $\ulcorner$0$\urcorner$ percent in 2021. From 2021, Korean population will decrease and the age structure will be distorted because birth rate will drop suddenly and continuously. Thus, we can consider $\ulcorner$0$\urcorner$ growth population for minimizing the prob- lems on the decreasing population. To discuss the problems caused from the changes of population size and age- sex composition, we projected three kinds of population including two kinds of $\ulcorner$0$\urcorner$ growth population under different as- sumptions. The first is the population which extended the projection of National Statistical Office up to 2090. Because the TFR is assumed and fixed as low as 1.63 after 1990, the population growth rate will be under $\ulcorner$0$\urcorner$ in 2021 and drop by about 1 percent every year from around 2050. This population trend results to old age population : 38.1 of old- age dependency ratio and 46.5 years of median age. The second is the population which the size in 2021 projected by the NOS continues after 2021. To change over from the decreasing population after 2021 to the $\ulcorner$0$\urcorner$ growth one, the TFR should be in-creased up to over 3.0 in 2040-2050, which fertility level would be too high to be accepted. The third is the population which approaches to the $\ulcorner$0$\urcorner$ growth population under the assumptions that the TFR increases from 1.63 to 2.1 in the period of 2010-2030 and then the same level continues. Although the maximum population size reaches 51, 503 thousand persons, the population will approach to the stationary population with about 42.4 million persons around 2090. In this projected population there is no more serious problems on population composition, on the rapid decrease of population, and on the increase TFR level. When the $\ulcorner$0$\urcorner$ growth population continues the problems of over population caused by the populationincrease wou]d be minimized, and the problems of unusual age composition resulted from the popula-tion decrease would not be found any more. Furthermore, when the changes of population size and composition is continuing slowly, the factors of population would effect moderately to socioeconomic development and help social changes. Therefore, with the attention of the present population changes, we should adapt new and detailde population policy which is able to get the $\ulcorner$0$\urcorner$ growth population.