• Korean Journal of Environment and Ecology
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• v.38 no.3
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• pp.246-262
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• 2024

The survey conducted from 2018 to 2020 aimed to investigate the changes in fish fauna and community characteristics in the upper reaches of the Seomgang River, Korea. During the survey period, 35 sites were selected, resulting in the collection of 7,817 fish belonging to 12 families and 40 species. The dominant species was Zacco koreanus, with a relative abundance of 34.5%, followed by Z. platypus at 28.7%. Other significant species included Rhynchocypris oxycephalus (10.2%), Pungtungia herzi (5.3%), and Squalidus gracilis majimae (4.3%). Notably, four protected species - Acheilognathus signifer, Gobiobotia brevibarba, and Cottus koreanus, designated as class II endangered wildlife by the Ministry of Environment- were identified. These species predominantly inhabit the middle and lower reaches, except for Gobiobotia brevibarba, which is found in the upper reaches. Nineteen species, accounting for a 47.5% endemism rate, were endemic to Korea. The study also noted the presence of one climate-sensitive species, Cottus koreanus, and two exotic species, Carassius cuvieri and Micropterus salmoides. Community analysis indicated a trend of decreasing dominance and increasing diversity and richness from upstream to downstream, with a distinct division into uppermost reaches, upper reaches, middle and lower reaches, and lakes. The construction of the Hwaseong Dam has had a significant direct and indirect impact on the fish community. The habitat and abundance of endangered species such as R. pseudosericeus, A. signifer, and G. brevibarba decreased dramatically immediately after the dam's construction, transforming the submerged area from lotic to lentic environments. Approximately 20 years later, the habitats have stabilized, leading to an increase in the fish population and a recovery of the previously diminished endangered species. The river health (FAI) was also evaluated, with 27 sites rated as very good (A), seven as good (B), and one as fair (C). However, endangered species such as A. signifer continue to face threats from dam and river construction, while C. Koreanus has experienced a severe population decline due to river works. Additionally, the presence of the ecosystem-disrupting species M. salmoides in Hwaseong Lake raises concerns. To ensure a stable habitat for fish in the upper reaches of the Seomgang River, it is crucial to avoid indiscriminate river construction, urgently implement restoration policies for endangered species such as A. signifer, and develop management strategies to control the spread of invasive species such as bass.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.32 no.1
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• pp.93-106
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• 2014

In this study, Analyze environment of location, investigation into vegetation resources, survey management status and establish to classify the management area for Natural monument No.374 Pyengdae-ri Torreya nucifera forest. The results were as follows: First, Torreya nucifera forest is concerned about influence of development caused by utilization of land changes to agricultural region. Thus, establish to preservation management plan for preservation of prototypical and should be excluded development activity to cause the change of terrain that Gotjawal in the Torreya nucifera forest is factor of base for generating species diversity. Secondly, Torreya nucifera forest summarized as 402 taxa composed 91 familly 263 genus, 353 species, 41 varieties and 8 forms. The distribution of plants for the first grade & second grade appear of endangered plant to Ministry of Environment specify. But, critically endangered in forest by changes in habitat, diseases and illegal overcatching. Therefore, when establishing forest management plan should be considered for put priority on protection. Thirdly, Torreya nucifera representing the upper layer of the vegetation structure. But, old tree oriented management and conservation strategy result in poor age structure. Furthermore, desiccation of forest on artificial management and decline in Torreya nucifera habitat on ecological succession can indicate a problem in forest. Therefore, establish plan such as regulation of population density and sapling tree proliferation for sustainable characteristics of the Torreya nucifera forest. Fourth, Appear to damaged of trails caused by use. Especially, Scoria way occurs a lot of damaged and higher than the share ratio of each section. Therefore, share ratio reduction Plan should be considered through the additional development of tourism routes rather than the replacement of Scoria. Fifth, Representing high preference of the Torreya nucifera forest tourist factor confirmed the plant elements. It is sensitive to usage pressure. And requires continuous monitoring by characteristic of Non-permanent. In addition, need an additional plan such as additional development of tourism elements and active utilizing an element of high preference. Sixth, Strength of protected should be differently accordance with importance. First grade area have to maintenance of plant population and natural habitats. Set the direction of the management. Second grade areas focus on annual regeneration of the forest. Third grade area should be utilized demonstration forest or set to the area for proliferate sapling. Fourth grade areas require the introduced of partial rest system that disturbance are often found in proper vegetation. Fifth grade area appropriate to the service area for promoting tourism by utilizing natural resources in Torreya nucifera forest. Furthermore, installation of a buffer zone in relatively low ratings area and periodic monitoring to the improvement of edge effect that adjacent areas of different class.

• Tuberculosis and Respiratory Diseases
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• v.67 no.6
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• pp.506-511
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• 2009

Background: The smoking prevalence in asthma patients are similar to those in the general population. Asthma and active cigarette smoking can interact to create more severe symptoms, an accelerated decline in lung function and impaired therapeutic responses. Accordingly, asthmatics with a history of smoking were examined to define the clinical characteristics and lung function of smoking asthmatics. Methods: The medical records of 142 asthmatics with a known smoking history were reviewed. The patients were divided into three groups according to their smoking history - current smokers, former smokers and non-smokers. The clinical characteristics, lung function, and annual declines of the forced expiratory volume in one second ($FEV_1$) were compared. Results: Fifty-three of the 142 patients (37%) were current smokers, 24 were former smokers (17%) and 65 were non-smokers (45%). The patients with a hospital admission history during the previous year included 16 current smokers (30%), 4 former smokers (17%) and 7 non-smokers (11%) (p=0.02). The mean $FEV_1$ (% predicted) was 76.8${\pm}$19.8%, 71.6${\pm}$21.1% and 87.9${\pm}$18.7% for current smokers, former smokers and non-smokers, respectively (p< 0.001). The $FEV_1$/forced vital capacity (FVC) (ratio, %) values were 63.6${\pm}$12.6%, 59.3${\pm}$14.9% and 72.1${\pm}$11.8% in current smokers, former smokers and non-smokers, respectively (p<0.001). The corresponding mean values for the individual $FEV_1$ slopes were not significant (p=0.33). Conclusion: Asthmatic smokers demonstrated higher hospital admission rates and lower lung function. These findings suggest that the smoking history is an important predictor of a poor clinical outcome in asthma patients.

• Korean Journal of Health Education and Promotion
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• v.15 no.2
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• pp.163-183
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• 1998

To evaluate the impacts of the health education programs including smoking cessation, pap smear and breast self-examination(BSE), a community trial was conducted during one year from December 1996 to December 1997 in Kyongju City. Before health education, a base-line survey was implemented and the target population was allocated randomly to case and control groups. The case and control groups were divided into three categories which were smoking cessation, pap smear and BSE. The series of health education leaflets about anti-smoking, pap smear and BSE were mailed to case group and the evaluation survey was conducted at the end of this trial to compare the change of health related behaviours of case and control groups. Smoking prevalence of case group did not decline significantly after anti-smoking education but the cessation rates of the elderly and low educated were higher than others. The knowledge level of case group on the health risk associated with smoking was higher than that of control group and the willingness of case group to quit smoking was higher than the control group. The case group's compliance with pap smear for cervical cancer was more increased compared to control group after health education. Of the case group, the younger and lower educated women were screened at a higher rate than others. The knowledge level of case group on the risk factors of cervical cancer and how to prevent it was higher than that of control group. Nearly 60 percent of case group reported that the health education leaflet influenced them to have the pap smear. The unscreened cases were highly motivated to get the pap smear test in the future.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.2
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• pp.277-281
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• 1997

The cell density changes of Vibrio mimicus K-1 in sea water and arkshell feeding it were examined at various temperature. The strain was suspended in sterilized sea water and storaged at experimental temperature $(5,\;10,\;15,\;20,\;and\;28^{\circ}C)$). At intervals of up to 10 days, aliquots of each suspension were plated onto BHI agar. At 5 and $10^{\circ}C$, the plate counts of V. mimicus K-1 showed a rapid decline, which 3s known to be a reault of this bacterium's entering into the viable but non culturable state. At 20 and $28^{\circ}C$, however, V. mimicus K-1 are stable over the 10 days experimental periods. V. mimicus K-1 was fed to arkshell, which was subsequently stored at temperatures ranging from 5 to $20^{\circ}C$ for 10 days. The samples of arkshell were homogenized and plated at intervals to determine the cell density of V. mimicus K-1 and total aerobic population of bacteria present. At 5 and $10^{\circ}C$, the numbers of V. mimicus K-1 in sea water rapid decreased over the 10 days experimental periods. However, little change of V. mimicus K-1 density was observed in shellstock arkshell at 5 and $10^{\circ}C$. While, V. mimicus K-1 density was decreased more rapidly to level below limit of dectection in shucked arkshell at same temperature. Incubation at the higher temperature $(20^{\circ}C)$ resulted in large increase in total aerobic bacterial number of shellstock arkshell. These results suggest that even with proper storage, indigenous levels of V. mimicus may remain sufficiently high in shellstock arkshell to produce infection in compromise hosts.

• Korean Journal of Soil Science and Fertilizer
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• v.9 no.3
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• pp.149-163
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• 1976

In Korea, the ever-increasing population has become a serious problem and the decreasing of cultivated lard area per person has become a major concern. Therefore, today we are implementing a green revolution using miracle varieties which require more fertilizer. The increased use of fertilizer along with development and adoption of high yielding varieties is the key to carrying out this green revolution. Fertilizer consumption in Korea is mainly influenced by agricultural techniques, fertilizer prices and government policies for increasing food production. If there are no special change, such as a cataclysm or an exhaustion of resources, it is quite clear that the fertilizer demand will increase to the near maximum ceiling point of optimum levels for crops in the year 2000. Fertilizer demand is not the amount of fertilizer that will be used by the farmer, but the actual optimum amount of plant nutrients required for maximum production. In this report, two alternative strategies are consideded in forecasting the future feitilizer demands. Alternative I is projected by reviewing consumption amounts over the last 10 years (1966~75) in Korea. The annual rate of increase in fertilizer consumption for the last 10 years was approximately 8.7% (table 1). Plant nutrient consumption rates in later years have been more balanced, and also fertilizer consumption per total acreage is considerably higher in Korea than in other countries (table 11), consequently the rate of increase in the future is expected to decline. Looking at the long term projections, the average annual rate of increase is expected to be 7% for 1976~80, 2.5% for 1981~90, 1.5% for 1991~2000. Thus, total projected fertilizer demands are estimated at 1,208,000M/T by 1980, 1,547,000M/T by 1990, 1,795,000M/T by 2000 (table 16). Alternative II is based on projected optimum fertilizer levels for crops and on increased crop acreage. The government recommended fertilizer rate has increased by a factor of 0.99 to 5.49 over the past twelve years depending on the specific crops (table 4). Levels of fertilizer demand recommended by government (table 7) in 1976 are still low compared with actual optimum fertilizer demands for crops (table 5). Therefore, future incaeases in fertilizer usage are anticipated. Thus, total projected fertilizer demands are estimated at 1,229,000M/T by 1980, 1,493,000M/T by 1990 and 1,898,000M/T by 2000(table 16).

• Spatial Information Research
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• v.23 no.3
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• pp.11-21
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• 2015

While the number of total population in Seoul has been on the constant decline for the last few years, the number of household has increased due to the rising tendency of the smaller households. In 2010, the small households in the metropolitan areas accounted for 44% of the entire households, and Statistics Korea has reported that one person household, which will take up more than 30% of the whole household, will have been the most common type of household by 2020. This reason of rise will be differently shown according to age like the preferred housing type or surrounding environments, this research is suggest to research hypothesis that distinction of age leads to the spatial distribution of one person household. Therefore, this research is to exercise a multiple regression analysis targeting on the facilities, which become the spatial distribution factor of one person household, with the independent variable gained from the concluded area calculated with the area ratio of the spatial unit followed by the service area analysis based on network. The spatial unit is the census output of Seoul, and based on this the interaction between the number of one person household according to age and the factors of its distribution. Also, the spatial regions - downtown, northeast, southeast, northwest, southwest - are designed as dummy variables and the results of each region are found out. As a result, the spatial regions occupied according to age are found to be varied - people in their 20s prefer housings near the college, 30s lease or the monthly rental housings, 40s the monthly rental housings, and over 60s the housing with the floor area of less than $40m^2$. Likewise, one person household has different types of housing environments preferred according to age, and thus a housing policy concerning this will have to be suggested.

• Korean Journal of Environment and Ecology
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• v.30 no.4
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• pp.694-704
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• 2016

Various infectious and parasitic diseases are known to be the main factors that cause decline in the global amphibian population. In Korea, commercial frog farms have been running since 2005. However, until now, studies on diseases including studies on parasitic diseases that occur in farm frogs have not been conducted. In this study, we studied and compared the acanthocephalan infection rates and the number of parasites in the body cavity, stomach, and small and large intestines of the Dybowskii's brown frogs collected from inside and outside the frog farms in Inje, Goesan, Gongju and Boryeong. In addition, we classified the acanthocephalan parasites into genera by analyzing their nuclear 18S rRNA genes. On an average, 51.7% of the investigated frogs were infected by acanthocephalans, which belong to the Centrorhynchus genus. The infection rate of the frogs collected in the Inje farm was 15%, significantly lower than those from the Goesan, Gongju and Boryeong farms. The rate in Goesan was 55%, which is lower than Gongju (80%) and Boryeong (90%) although it is not statistically significant. No difference was found in the infection rate and in the number of parasites in male and female frogs and between the groups collected from inside and outside of the farms. The number of infected parasites negatively correlated with the body condition of the frogs. The most parasites were found in the stomach followed by the small and large intestines and the body cavity. This study is the first report on the Centrorhynchus acanthocephalan infection of amphibians in Korea and it suggests the necessity for acanthocephalan parasite management and for conducting further disease-related studies in commercial frog farms.

• 한국환경농학회:학술대회논문집
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• 2009.07a
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• pp.273-282
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• 2009

The transmissible spongiform encephalopathies (TSEs) disease group are fatal neurodegenerative disorders affecting a wide range of hosts. The group includes kuru and Creutzfeldt-Jakob disease (CJD) in humans, scrapie in sheep and goats and Bovine spongiform encephalopathy (BSE) in cattle. The exact nature of the infectious agent involved in the transmission of these diseases remains controversial. However, a central event in their pathogenesis is the accumulation in infected tissues of an abnormal form of a host-encoded protein, the prion protein (PrP). Whereas the normal cellular protein is fully sensitive to protease ($PrP^{sen}$), the disease-associated prion protein ($PrP^d$) is only partly degraded ($PrP^{res}$), its amino-terminal end being removed. BSE was first reported in the mid-80s in the UK. Ten years later, a new form of human prion disease, variant CJD (vCJD) developed in the wake of the BSE epidemic, and there is now strong scientific evidence that vCJD was initiated by the exposure of humans to BSE-infected tissues, thus indicating a zoonotic disease. However, the ban on the feeding of animal-derived proteins to ruminants, and the apparent lack of vertical transmission of BSE, have led to a decline in the incidence of the disease within cattle herd and therefore, an assumed decreased risk for human contacting vCJD. The origin of the original case(s) of BSE still remains an enigma even though three hypotheses have been raised. Hypotheses are i) sheep- or goat-derived scrapie-infected tissues included in meat and bone meal fed to cattle, ii) a previously undetected sporadic or genetic bovine TSE contaminating cattle feed or iii) originating from a human TSE through animal feed contaminated with human remains. A host cellular membrane protein ($PrP^C$), which is abundant in central nervous system tissue, appear to be conformationally altered in the diseased host into a prion protein ($PrP^{Sc}$). This $PrP^{Sc}$ is detergent insoluble and partially protease-resistant ($PrP^{res}$). The term $PrP^{res}$ is normally used to describe the protein detected after protease treatment, in techniques such as Western immunoblotting, and enzyme-linked immunosorbant assay using fresh/frozen tissue. Immunohistochemistry may performed with formalin-fixed tissues. Also, clinical signs of the BSE are one of the major diagnostic indicators. Recently, atypical forms (known as H- and L-type) of BSE have appeared in several European countries, Japan, Canada and the United States. An unusual case was also reported in a miniature zebu. The atypical BSE fall into two groups based on the relative molecular mass (Mm) of the unglycosylated $PrP^{res}$ band relative to that of classical BSE, one of the higher Mm (H-type) and the other lower (L-type). Both types have been detected worldwide as rare cases in older animals, at a low prevalence consistent with the possibility of sporadic forms of prion diseases in cattle. This raises the unwelcome possibility that vCJD could increase in the human population. Now, active surveillance program against BSE is going on in Korea. In regional veterinary service lab, ELISA is applied to screen the BSE in slaughter and confirmatory tests by Western immunoblotting and immunohistochemisty are carried out if there are positive or suspect in the screening test. Also, the ruminant feed ban is rigorously enforced. Removal of specified risk materials such as brain and spinal cord from cattle is mandatory process at slaughter to prevent the infected material from entering the human food chain.

• Journal of Animal Science and Technology
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• v.54 no.1
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• pp.9-14
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• 2012

The purpose of this study was to estimate heritabilities and genetic correlations for reproductive and productive traits and to apply their estimates to selection strategies in a swine population. Reproductive and productive traits considered in this study were number of born alive piglet (NBA), number of weaned piglet (NW), loin eye area (LEA), days to 90 kg (D90KG), back fat thickness (BF), and lean meat content (LEAN). Data were collected from 9,886 litters on 2,447 sows for reproductive traits and 10,181 gilts and boars for productive traits from Jan. 2000 to Dec. 2008 in a swine GGP farm. The statistical model to estimate genetic parameters for considering traits was a multiple traits animal model with including animal and maternal additive effects and litter effects on reproductive traits and animal additive effects on productive traits as random as well as some of fixed effects. For estimating (co) variance components of several random effects, restricted maximum likelihood methodology was used on this assumed model. The estimated heritabilities by animal additive effects and maternal effects were 0.07 and 0.02 for NBA and 0.03 and 0.02 for NW, respectively. Genetic correlation estimate for direct genetic effects between NBA and NW was 0.14. Heritability estimates for direct genetic effects were 0.19, 0.39, 0.36, and 0.43 for LEA, D90KG, BF and LEAN, respectively. The genetic correlation of LEA with LEAN was 0.35. Productive traits were antagonistically correlated with reproductive traits. From these results it is concluded that, if selection is done for strong positive effects of reproductive traits, then this would decline productive performance.