• Title/Summary/Keyword: population replacement level

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Relative Effectiveness of Replacement Diets for Mass Production of the Brackish Water Flea Diaphanosoma celebensis (기수산 물벼룩(Diaphanosoma celebensis)의 대량생산을 위한 대체 먹이원의 효과)

  • Park, Jin-Chul;Kwon, O-Nam;Park, Heum-Gi
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.45 no.2
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    • pp.146-153
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    • 2012
  • This study examined the effect of formulated diets (composed of condensed freshwater $Chlorella$ or $Schizochytrium$ sp., $Crypthecodinium$ sp., and EPA oil sources derived from baker's yeast) on the population growth and fatty acid composition of the brackish water flea ($Diaphanosoma$ $celebensis$) to determine diet effectiveness for mass production. Results indicated that the highest maximum density, fecundity, and population specific growth rate (SGR) of the flea were observed using a diet of $Tetraselmis$ $suecica$ (control). However, results using condensed freshwater $Chlorella$ and the mixed treatment of $Schizochytrium$ sp.+$Crypthecodinium$ sp.+EPA oil did not significantly differ from the control treatment ($P$>0.05). Thus, $T.$ $suecica$ could be replaced with a combination diet of $Schizochytrium$ sp., $Crypthecodinium$ sp., and EPA oil in condensed freshwater $Chlorella$ without growth interruption of $D.$ $celebensis$. As the percentage of combination diet (mix of $Schizochytrium$ sp., $Crypthecodinium$ sp., and EPA oil) in condensed freshwater $Chlorella$ increased, the level of ARA, EPA, DHA, and n-3 HUFA in $D.$ $celebensis$ also increased. However, the population density of $D.$ $celebensis$ sharply decreased with the use of treated supplements C5M5 (CHL [50%] and $Crypthecodinium$ sp.+ $Schizochytrium$ sp. + EPA oil [MIX 50%]). The optimum proportions of CHL and MIX for $D.$ $celebensis$ within the mixture were 70% and 30%, respectively. Based on the results, the combination of $Schizochytrium$ sp., $Crypthecodinium$ sp., and EPA oil in condensed freshwater $Chlorella$ appears to be a stable and effective food source for mass production of $D.$ $celebensis$.

Is Lowest-Low Fertility going to Continue in Korea? (초저출산은 지속될 것인가?)

  • Chung, Sung-Ho
    • Korea journal of population studies
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    • v.33 no.2
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    • pp.113-136
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    • 2010
  • Low fertility has become quite commonplace worldwide, and Europe has experienced below replacement fertility for several decades. In addition, lowest-low fertility, defined as period total fertility rate below 1.3, has rapidly spread in Europe during the 1990s and is likely to expand further. After the turn of century, lowest-low fertility started spreading in Eastern Asia. Korea's TFR of 1.19 in 2008 is lower than most European countries, although it is higher than the Hongkong(1.02) and Taiwan(1.09). The purpose of this paper is to examine the socioeconomic determinants of lowest-low fertility in Korea. In doing so, this paper discusses the effects of female labour force participation, labour instability on family formation and fertility. The data includes female labour force participation rate, unemployment rate, age at first marriage, and total fertility rate from 1980 to 2008. First, the economic recession hindered young people's economic independence and propensity to marry. Married couples were also depressed with uncertainty toward the future and avoided to have children. Second, the growth in female labor force participation had a negative impact on fertility, under the low level of compatibility between women's work and childrearing. Moreover, this paper argues that the rising cost of children including public and private educational costs is thought to be the main reason of the recent low fertility in Korea. Policy implications and some comments on population policies are also presented in the final section.

Ecological Replacement of Native Rapeseed Weevil (Ceutorhynchus albosuturalis) by Invasive Alien Species, Cabbage Seedpod Weevil (C. obstrictus) on Rapeseed Flowers in Korea (유채 꽃에서 자생종 유채좁쌀바구미(Ceutorhynchus albosuturalis)의 외래침입종 유럽좁쌀바구미(C. obstrictus)로의 생태적 대체)

  • Kim, Kyongyoung;Lee, Wonhoon;Hong, Ki-Jeong
    • Korean journal of applied entomology
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    • v.57 no.4
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    • pp.323-328
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    • 2018
  • Despite rising global concerns over the potential impacts of invasive alien species on indigenous species, the consequences of such introductions are lacking. The cabbage seedpod weevil (CSPW, Ceutorhynchus obstrictus) was found invaded into Korea in the early of 1990s. A large-scale survey in Korea reveals that, in about 20 years post-arrival, the invasive CSPW has become the most abundant on rape flowers and spread almost parts of South Korea including Is. Jeju and Is. Ulleung. Its spread is concurrent with the habitat retraction to cruciferous weeds of the native rapseed weevil (RSW, C. albosuturalis). However, Is. Yeoseo located between the mainland and Is. Jeju, showed their ratio with about 1:1. It suggests that the population of CSPW recently entered this island. Although underlying mechanisms of the decline of native species and increase of invaded species remain unknown, the potential roles of exploitative competition cannot be ruled out. Given that invasive weevil can rapidly replace native congeners, increased level of surveillances is demanding to discourage further invasion of othe alien pests.

The Relationship Between Son Preference and Fertility (남아 선호와 출산력간의 관계)

  • 이성용
    • Korea journal of population studies
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    • v.26 no.1
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    • pp.31-57
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    • 2003
  • This study is intended to examine (l)whether the value of son-for example, old age security and succession of family lineage- causing son preference in the traditional society can be explained at the individual level, (2)whether women without son in the son preference country continue her childbearing until having at least one son or give up the desire of having a son at a certain level. To accomplish these purposes, the 1974 Korean National Fertility Survey data are analyzed by the quadratic hazard models controlling unobserved heterogeneity. Unlike ordinary regression model, even omitted variables that affect hazard rates and are uncorrelated with the included independent variables can distort the parameter estimates in the hazard model. Therefore the nonparametric maximum likelihood estimator(NPMLE) of a mixing distribution developed by Heckman and Singer is used to control unobserved heterogeneity. Based on the statistical result in this study, the value of son causing son preference is determined at the societal level, not at the individual level. And Korean women without a son did not continue endlessly childbearing during child bearing ages until having a son. In general, they gave up the desire having a son when she had born six daughters continuously. Thus, 30-40 years ago, the number of daughters that women without a son giving up the desire of son was six, which is about the level of total fertility rate during 1960s. In these days, we can often see many women who have only two or three daughters and do not any son. This means that the level of giving up the desire of son, which is one factor representing the strength of son preference, becomes lower. If the strength of son preference did not become much weaker, then the fertility rates in Korea could not reach the below replacement level.

A Study on the Methodology of Acupuncture Clinical Trial on the Postmenopausal and Perimenopausal Hot Flashes (갱년기 안면홍조에 대한 침 임상시험 방법론 연구)

  • Roh, Jin-Ju;Kim, Dong-Il
    • The Journal of Korean Obstetrics and Gynecology
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    • v.21 no.4
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    • pp.193-206
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    • 2008
  • Purpose: In spite of many arguments on the result of WHI (Women's Health Initiative) study, no one can deny the necessity for researches on the alternative treatment to HRT (hormone replacement therapy). In this study, the author wanted to investigate the method of precedent acupuncture RCTs (randomized controlled trials) to make out the appropriate acupuncture study design on postmenopausal and perimenopausal hot flashes in Korea. Methods: Precedent studies were investigated using Pubmed search and key-words "acupuncture and hot flash", "acupuncture and menopause", "acupuncture and vasomotor", limited to RCT, from 2000 to 2008 April. Results: As a result. 10 studies were searched. In the hereafter studies, multi-center clinical trials which consist of population group of postmenopausal and perimenopausal women that would be pre-stratified and more than 50 patients per treatment arm seem adequate. Sham control study can make out the proper consequence because many people are get used to acupuncture in Korea. Flexible choice of acupoints addressed an individual's symptoms using standardized algorithm is recommended. Treatment consist of 4 weeks' observation, 11 acupuncture sessions during 7 weeks, follow-up of 3 months or more after treatment and hot flash score as a primary outcome measure seem appropriate. After all, higher level of description according to global standard must be obtained in the study report and publishing. Conclusion: The researchers should develope the methodology of acupuncture clinical trial on the postmenopausal and perimenopausal hot flashes.

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Analysis of the Effects of Job Policy Measures in Korea: Do the job policy measures impact the marriage and fertility of the youth in Korea?

  • Kang, Chang Ick;Lim, Kyung Eun;Kim, Junghak
    • Asian Journal for Public Opinion Research
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    • v.10 no.3
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    • pp.200-229
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    • 2022
  • The purpose of this study is to analyze the effects of youth job policy measures, set forth in Korea's 2016-2020 Third Basic Plan for Low Fertility and Aging Society (December 2015), on marriage and fertility among young people. Based on the results, we provide theoretical explanations for the findings and suggest policy alternatives to overcome the low fertility phenomenon in Korea. Previous studies have shown that employment is an important factor for marriage among youth, and a job policy could increase marriage and fertility rates. To test this assumption, we performed an exact matching between Statistics Korea's Employee-Enterprise Linkage DB and the Newlyweds DB from 2011 to 2019, in order to identify all young people aged 15-34. Then, linear spline regression analysis was used to examine the impact of the youth job policy on marriage and fertility. Comparing the period before the implementation of the employment policy (2011-2015) and after (2016-2019), the fertility rate increased as the number of young people looking for work increased. In addition, it was found that these impacts were greater after the implementation of the measures (2016-2019) than before (2011-2015). It is interesting to note that job growth among young people did not lead to an increase in marriage. However, the number of births significantly increased when young people who occupy jobs got married, which seems to be related to the delay in marriage among young people who are employed. Survey results about the intentions to marry and views on fertility are utilized for the explanation of the study results.

Below Replacement-level Fertility in Korea: A Myth or a Reality\ulcorner (한국의 대체출산이하 인구)

  • Lee, Hung-Tak
    • Korea journal of population studies
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    • v.11 no.1
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    • pp.146-158
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    • 1988
  • In order to examine differential mortality, the life tables for the insured persons in national pension scheme were estimated by sex and types of coverage(the insured in workplaces vs. the insured in rural areas). The averages of 1994-1996 data are used for insured in workplaces, but 1996 data are used for insured in rural areas. Life expectancies at the age of 18 are 59.5 years and 67.2 years each for insured males and females and thus 7.7 years longer for females than males in workplaces. Sex difference in mortality reduces as age increases, and more rapidly at younger ages than old ages. For insured in rural areas, life expectancies at the age of 18 are 51.4 years and 61.1 years each for insured males and females and thus sex difference is 9.7 years. The greater sex difference in mortality in rural areas can be explained by sex selective migration. The difference of life expectancy between insured in workplaces and insured in rural areas is 8.1 years for males, and 6.1 years for females. Because rural-urban difference in educational attainment is greater for males than females, the greater difference in life expectancy is observed for males than females.

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Clinical Efficacy and Safety of Gyebutang Granules Combined with Acupuncture for the Treatment of Knee Osteoarthritis: Protocol for a Multicenter, Randomized, Assessor-blinded, 2-armed Parallel, Controlled Trial

  • Lee, Cham-Kyul;Kang, Ha-Ra;Lee, Yeon-Sun;Sung, Won-Suk;Lim, Chi-Yeon;Jung, Chan-Yung;Kim, Eun-Jung;Seo, Byung-Kwan;Baek, Yong-Hyeon;Kim, Kyung-Ho;Lee, Eun-Young
    • Journal of Acupuncture Research
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    • v.37 no.2
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    • pp.102-109
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    • 2020
  • Background: Due to the aging population in Korea, knee osteoarthritis (KOA) has become an increasingly common condition. Many patients with KOA prefer analgesics, herbal medicines, acupuncture, or exercise, rather than arthroscopic surgery or a knee replacement. Gyebutang (GB) granules are a herbal extract widely used to treat KOA in traditional Korean medicine, but there is insufficient evidence of its efficacy and safety. Methods: A multicenter, randomized, assessor-blinded, 2-armed parallel, controlled clinical trial has been designed to investigate the efficacy and safety of GB combined with acupuncture for the treatment of KOA. There will be 100 patients with KOA enrolled in the study from 3 traditional Korean medicine hospitals. The participants will be randomly allocated to an experimental group (GB and acupuncture) or a control group (celecoxib and acupuncture) in a 1:1 ratio. Both groups will receive acupuncture treatment once a week for 6 weeks; one group will receive GB and the other will receive celecoxib for the same duration. Results: The primary outcome will be the change of knee osteoarthritic pain, based on scores on a 100 mm visual analog scale. The secondary outcomes will be scores on a numeric rating scale, the Western Ontario and McMaster Universities osteoarthritis index, patient global assessment, European quality of life 5-dimension 5-level scale, and adverse events. Conclusion: The results of this study will provide evidence of efficacy and safety of GB as a treatment for patients with KOA.

Innovative approaches to the health problems of rural Korea (한국농촌보건(韓國農村保健)의 문제점(問題點)과 개선방안(改善方案))

  • Loh, In-Kyu
    • Journal of agricultural medicine and community health
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    • v.1 no.1
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    • pp.5-9
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    • 1976
  • The categories of national health problems may be mainly divided into health promotion, problems of diseases, and population-economic problems which are indirectly related to health. Of them, the problems of diseases will be exclusively dealt with this speech. Rurality and Disease Problems There are many differences between rural and urban areas. In general, indicators of rurality are small size of towns, dispersion of the population, remoteness from urban centers, inadequacy of public transportation, poor communication, inadequate sanitation, poor housing, poverty, little education lack of health personnels and facilities, and in-accessibility to health services. The influence of such conditions creates, directly or indirectly, many problems of diseases in the rural areas. Those art the occurrence of preventable diseases, deterioration and prolongation of illness due to loss of chance to get early treatment, decreased or prolonged labour force loss, unnecessary death, doubling of medical cost, and economic loss. Some Considerations of Innovative Approach The followings art some considerations of innovative approaches to the problems of diseases in the rural Korea. 1. It would be essential goal of the innovative approaches that the damage and economic loss due to diseases will be maintained to minimum level by minimizing the absolute amount of the diseases, and by moderating the fee for medical cares. The goal of the minimization of the disease amount may be achieved by preventive services and early treatment, and the goal of moderating the medical fee may be achieved by lowering the prime cost and by adjusting the medical fees to reasonable level. 2. Community health service or community medicine will be adopted as a innovative means to disease problems. In this case, a community is defined as an unit area where supply and utilization of primary service activities can be accomplished within a day. The essential nature o the community health service should be such activities as health promotion, preventive measures, medical care, and rehabilitation performing efficiently through the organized efforts of the residents in a community. Each service activity should cover all members of the residents in a community in its plan and performance. The cooperation of the community peoples in one of the essential elements for success of the service program, The motivations of their cooperative mood may be activated through several ways: when the participation of the residents in service program of especially the direct participation of organized cooperation of the area leaders art achieved through a means of health education: when the residents get actual experience of having received the benefit of good quality services; and when the health personnels being armed with an idealism that they art working in the areas to help health problems of the residents, maintain good human relationships with them. For the success of a community health service program, a personnel who is in charge of leadership and has an able, a sincere and a steady characters seems to be required in a community. The government should lead and support the community health service programs of the nation under the basis of results appeared in the demonstrative programs so as to be carried out the programs efficiently. Moss of the health problems may be treated properly in the community levels through suitable community health service programs but there might be some problems which art beyond their abilities to be dealt with. To solve such problems each community health service program should be under the referral systems which are connected with health centers, hospitals, and so forth. 3. An approach should be intensively groped to have a physician in each community. The shortage of physicians in rural areas is world-wide problem and so is the Korean situation. In the past the government has initiated a system of area-limited physician, coercion, and a small scale of scholarship program with unsatisfactory results. But there might be ways of achieving the goal by intervice, broadened, and continuous approaches. There will be several ways of approach to motivate the physicians to be settled in a rural community. They are, for examples, to expos the students to the community health service programs during training, to be run community health service programs by every health or medical schools and other main medical facilities, communication activities and advertisement, desire of community peoples to invite a physician, scholarship program, payment of satisfactory level, fulfilment of military obligation in case of a future draft, economic growth and development of rural communities, sufficiency of health and medical facilities, provision of proper medical care system, coercion, and so forth. And, hopefully, more useful reference data on the motivations may be available when a survey be conducted to the physicians who are presently engaging in the rural community levels. 4. In communities where the availability of a physician is difficult, a trial to use physician extenders, under certain conditions, may be considered. The reason is that it would be beneficial for the health of the residents to give them the remedies of primary medical care through the extenders rather than to leave their medical problems out of management. The followings are the conditions to be considered when the physician extenders are used: their positions will be prescribed as a temporary one instead of permanent one so as to allow easy replacement of the position with a physician applicant; the extender will be under periodic direction and supervision of a physician, and also referral channel will be provided: legal constraints will be placed upon the extenders primary care practice, and the physician extenders will used only under the public medical care system. 5. For the balanced health care delivery, a greater investment to the rural areas is needed to compensate weak points of a rurality. The characteristics of a rurality has been already mentioned. The objective of balanced service for rural communities to level up that of urban areas will be hard to achieve without greater efforts and supports. For example, rural communities need mobile powers more than urban areas, communication network is extremely necessary at health delivery facilities in rural areas as well as the need of urban areas, health and medical facilities in rural areas should be provided more substantially than those of urban areas to minimize, in a sense, the amount of patient consultation and request of laboratory specimens through referral system of which procedures are more troublesome in rural areas, and more intensive control measures against communicable diseases are needed in rural areas where greater numbers of cases are occurred under the poor sanitary conditions.

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The Effects of Female Wage on Fertility in Korea (여성의 임금수준이 출산율에 미치는 영향 분석)

  • Kim, Jungho
    • KDI Journal of Economic Policy
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    • v.31 no.1
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    • pp.105-138
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    • 2009
  • Although the decline in fertility rate is generally observed along the history of economic development throughout the world, the continuing decline hitting below the replacement level in Korea over the recent years gathered serious social concerns on the ground that it accelerates the process of population aging. The total fertility rate in Koreareached 2.08 in 1983, and gradually fell to the levels of 1.08 in 2005 and 1.26 in 2007. The policy debate over the role of the government has been focused mainly on the level of theoretical discussion without substantial basis on firm empirical evidence and the determinants of fertility. The objective of the paper is to empirically investigate the fertility effect of the female wage, which is understood as one of the most important determinants of fertility in Koreasince 1980 focusing on one aspect of fertility, namely birth spacing. Using the Korean National Fertility Survey conducted in 2006, I estimate a duration model of first and second births taking into account individual heterogeneity, which turned out to be an important factor to control for. Compared with previous studies in the literature on the Korean fertility, the study has an advantage of using the complete pregnancy history of women in a more representative sample. Unlike the previous studies, the analysis also deals with the endogeneity of marriage by treating a certain age, rather than age at marriage, as the time in which a woman becomes exposed to the risk of pregnancy. The study shares the common problem in the literature on birth spacing of lacking relevant wage information for respondents in a retrospective survey. I estimate the wage series as a function of the basic characteristics using the annual Wage Structure Survey from 1980 to 2005, which is considered as a nationally representative sample for wage information of employees. The results suggest that the increase in female wage by 10 percent leads to a decrease in second birth hazard by 0.56~0.92 percentage points and that the increase in spouse's wage by the equal amount is accompanied by the increase in second birth hazard by 0.36~1.13 percentage points. These estimates are more precisely estimated and of smaller magnitude than those presented by the previous studies. The results are robust to the different specifications of the wage equation. The simulation analysis based on the predicted values shows that about 17% of the change in the second birth hazard over the period 1980 to 2005 was due to the change in the female wage. Although there is some limitation in data, the results can be viewed as one estimate of the role of female wage on the recent fertility decline in Korea. The question raised by the paper is not a normative one of whether a government should promote childbearing but a positive one thatexplains fertility decline. Therefore, if there is a wide consensus on promoting childbearing, the finding suggests that the policies designed to reduce the opportunity cost of women in the labor market would be effective. The recent movement of implementing a wide range of family-friendly policies including child care support, maternity leave, parental leave and tax benefit in developed countries should be understood in this context.

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