• Pediatric Infection and Vaccine
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• v.25 no.2
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• pp.61-71
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• 2018

Purpose: Research on the clinical role of Staphylococcus aureus as a pathogen in acute gastroenteritis (AGE) in children has been scarce. This study aimed to clarify the prevalence and clinical correlation of S. aureus detection in children with AGE. Methods: Fecal samples were collected from children with symptoms of AGE who visited a secondary hospital between January 2012 and December 2015. The samples were sent to the Seoul Metropolitan Government Research Institute of Public Health and Environment to test for pathogenic organisms. Clinical patterns were analyzed through medical record review. Results: Among the 663 participants, the bacteria detection rate was 26.2% (n=174), the virus detection rate was 29.7% (n=197), and the non-detection rate was 43.1% (n=286). S. aureus was tested positive from 102 cases and was confirmed as a single pathogen in 53 cases. It was the third most common pathogen. The prevalence by age was highest (45.3%) in 0-2 year-olds. Most cases occurred in summer. Symptoms included diarrhea (71.7%), vomiting (67.9%), fever (49.1%), and abdominal pain (37.7%). Only vomiting showed a significant difference between the S. aureus group and the non-detection group (67.9% vs. 43.0%; P=0.001). Among enterotoxins, the higher incidence of vomiting was associated with classical staphylococcal enterotoxins (SEA, SEB, SEC, SED, and SEE) and SEH (P=0.027). Conclusions: S. aureus was the bacteria commonly isolated from children with AGE. Our study identified cases of staphylococcal AGE in children based on fecal samples and confirmed the characteristic symptoms, affected age groups, seasonal distribution, and correlation with enterotoxins.

• Korean Journal of Poultry Science
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• v.39 no.2
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• pp.97-104
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• 2012

Newcastle disease virus (NDV) infects a variety of birds with a wide range of clinical signs from asymptomatic to severe. During a 10-month period in 2011, a total of 1,024 sera from wild birds including 42 species of birds in 8 orders were collected and the seroprevalence of NDV in wild birds was evaluated by hemagglutination inhibition (HI) test. Evidence of NDV infection was observed in 12.6% (129/1,024) of wild birds with a maximum prevalence reported in Mandarin duck (27.8%, 32/115) followed by Mallard duck (20.8%, 57/274), Spot-billed duck (11.9%, 36/303), Pintail (2.9%, 1/34), Black-tailed gull (2.9%, 1/34), White-fronted goose (1.8%, 1/56) and Common teal (1.4%, 1/69). None of the other 35 species of wild birds were antibody-positive for NDV. Mandarin duck, Mallard duck and Spot-billed duck showed high sero-prevalance of 12.2% to 42% during winter season (November to March). Our results indicate that Mandarin duck, Mallard duck and Spot-billed duck might be natural reservoirs for NDV in Korea and the prevalence of NDV infection in wild birds displayed a seasonal pattern with high prevalence of NDV in winter season (November to March).

• Journal of the Korean Society of Groundwater Environment
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• v.5 no.4
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• pp.177-191
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• 1998

For various kinds of waters including surface water, shallow groundwater (＜70 m deep) and deep groundwater (500∼810 m deep) from the Pungki area, an integrated study based on hydrochemical, multivariate statistical, thermodynamic, environmental isotopic (tritium, oxygen-hydrogen, carbon and sulfur), and mass-balance approaches was attempted to elucidate the hydrogeochemical and hydrologic characteristics of the groundwater system in the gneiss area. Shallow groundwaters are typified as the 'Ca-HCO$_3$'type with higher concentrations of Ca, Mg, SO$_4$and NO$_3$, whereas deep groundwaters are the 'Na-HCO$_3$'type with elevated concentrations of Na, Ba, Li, H$_2$S, F and Cl and are supersaturated with respect to calcite. The waters in the area are largely classified into two groups: 1) surface waters and most of shallow groundwaters, and 2) deep groundwaters and one sample of shallow groundwater. Seasonal compositional variations are recognized for the former. Multivariate statistical analysis indicates that three factors may explain about 86% of the compositional variations observed in deep groundwaters. These are: 1) plagioclase dissolution and calcite precipitation, 2) sulfate reduction, and 3) acid hydrolysis of hydroxyl-bearing minerals(mainly mica). By combining with results of thermodynamic calculation, four appropriate models of water/ rock interaction, each showing the dissolution of plagioclase, kaolinite and micas and the precipitation of calcite, illite, laumontite, chlorite and smectite, are proposed by mass balance modelling in order to explain the water quality of deep groundwaters. Oxygen-hydrogen isotope data indicate that deep groundwaters were originated from a local meteoric water recharged from distant, topograpically high mountainous region and underwent larger degrees of water/rock interaction during the regional deep circulation, whereas the shallow groundwaters were recharged from nearby, topograpically low region. Tritium data show that the recharge time was the pre-thermonuclear age for deep groundwaters (＜0.2 TU) but the post-thermonuclear age for shallow groundwaters (5.66∼7.79 TU). The $\delta$$\^$34/S values of dissolved sulfate indicate that high amounts of dissolved H$_2$S (up to 3.9 mg/1), a characteristic of deep groundwaters in this area, might be derived from the reduction of sulfate. The $\delta$$\^$13/C values of dissolved carbonates are controlled by not only the dissolution of carbonate minerals by dissolved soil CO$_2$(for shallow groundwaters) but also the reprecipitation of calcite (for deep groundwaters). An integrated model of the origin, flow and chemical evolution for the groundwaters in this area is proposed in this study.

• Korean Journal of Weed Science
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• v.3 no.2
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• pp.166-173
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• 1983

To investigate the varietal differences of weed competitive functions under the three different seasons of transplanting, rice cultivars Milyang 23 and Sadominori were used with seven weeding methods, namely, weedy check, weed-free, once weeding at 3, 6, 9, 12 weeks after transplanting, and two times weeding at 3 and 9 weeks after transplanting, respectively. As a result, weeding stages and times for the proper weeding efficacies and reasonable rice productivities by respective weed group and total weed flora were estimated. Also, the constructive characteristics for yield formations under the different competitive conditions as affected by various cropping patterns were discussed.

• Korean Journal of Weed Science
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• v.9 no.2
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• pp.130-140
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• 1989

1) Dormancy brocken weed seeds were planted in soil at 15 days interval from June to December in 1986 and 1987 and test of normality and normal distribution curve were made to determine seasonal distribution characteristics of weed emergence in fields. Monthly emergence distribution pattern of each species can be concluded as following normal distribution equations. E. crusgalli $y={\frac{1}{2.52{\sqrt{2{\pi}}}}}e^{-{\frac{(x-10.057)^2}{12.7}}}$ E. indica $y={\frac{1}{2.17{\sqrt{2{\pi}}}}}e^{-{\frac{(x-9.16)^2}{9.45}}}$ A. lividus $y={\frac{1}{7.74{\sqrt{2{\pi}}}}}e^{-{\frac{(x-10.06)^2}{15.46}}}$ S. nigrum $y={\frac{1}{2.7{\sqrt{2{\pi}}}}}e^{-{\frac{(x-9.695)^2}{14.58}}}$ C. busrsa-pastoris $y={\frac{1}{2.83{\sqrt{2{\pi}}}}}e^{-{\frac{(x-9.02)^2}{16.02}}}$ D. sanguinalis $y={\frac{1}{2.8{\sqrt{2{\pi}}}}}e^{-{\frac{(x-8.58)^2}{15.67}}}$ S. viridis $y={\frac{1}{2.72{\sqrt{2{\pi}}}}}e^{-{\frac{(x-9.36)^2}{14.8}}}$ C. album $y={\frac{1}{2.596{\sqrt{2{\pi}}}}}e^{-{\frac{(x-8.07)^2}{13.48}}}$ P. oleraeda $y={\frac{1}{2.45{\sqrt{2{\pi}}}}}e^{-{\frac{(x-10.83)^2}{12.01}}}$ 2) Emergence peak period of weed species tested were from the end of May to early August and yearly variation of emergence was observed in E. crus-galli, S. viridis, S, nigrum, and P. oleracea and this fact may more related to rainfall pattern rather than temperature.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.5
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• pp.402-410
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• 2009

Purpose: The aim of this study was to determine the incidence and malignant rate of incidental asymmetric palatine tonsillar uptake (ATU) on $^{18}F$-FDG PET/CT in various clinical indications and to evaluate the clinical and PET/CT findings suggesting malignancy. Materials and Methods: We retrospectively reviewed a total of 2,901 patients ($58.4{\pm}12.3$ yrs, range 20~88 yrs, M:F = 1,841:1,060) who underwent $^{18}F$-FDG PET/CT during an 1-year period with various indications except primary tonsillar cancer and lymphoma evaluation. On $^{18}F$-FDG PET/CT, metabolic abnormality of the palatine tonsil and cervical lymph node were visually assessed. ATU was defined as increased palatine tonsillar uptake with diffuse, focal, or irregular pattern compared to contralateral side. The incidence and malignant ratio of ATU were evaluated according to clinical and PET/CT findings. Results: Of 2,901 cases, 290(10,0%) showed ATU. The incidence of ATU showed seasonal variation and was high in the winter (12.1%). Of 209 cases with ATU confirmed pathologically and/or clinically, five (2.4%) were malignant lesions. ATU with irregular uptake pattern (2/2) and in cases referred for cervical lymph node metastasis of unknown origin (3/5) were frequently associated with malignant lesion (p<0.05). Conclusion: ATU was not infrequently observed on $^{18}F$-FDG PET/CT, and the malignant risk of ATU was low. However, ATU with cervical lymph node metastasis or with irregular pattern on PET/CT would be further evaluated by the histopathologic examination.

• Journal of Wetlands Research
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• v.18 no.3
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• pp.262-266
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• 2016

We investigated the characteristic demographics for visitors to Mujechi bog on Mt. Jungjok, with the purpose of developing a management strategy for the conservation and wise use of the montane wetland. Using daily visitor data from 2007, 2011, and 2015 we extracted and analyzed; visitation date, age, residential areas, purpose of visitation and the time allotted for the visit. The largest age cohort was the decade of the fifties(36.8%/total number of visitors) and followed by the decade of the forties(30.4%). The majority of visitors were from Ulsan(67%), Busan(16.6%), and Yangsan(10.8%). The visitors' primary objectives were to hike Mt. Jungjok(39-64.4%) or view Mujechi bog(18.7-51.8%) during the weekend. People visited more during the weekend than weekdays(F=6.19, p<0.002). In addition, there was a clear seasonality obvious in the monthly visits. The proportion of visitors were present in spring and fall, the month with the highest visitation rate was May at $15.6{\pm}2.8%$($mean{\pm}S.D.$). This increase in May was partly due to the desire to see the Korean azalea in bloom in the spring. Montane bog, like Mujechi, could be highly affected by disturbance(e.g. stamping, sediment inflow) caused by visitors. Therefore, it is suggested, based on the level of visitation that to reduce possible human disturbance effects, that either a seasonal restriction or a yearly alternation of trails be established. Visitors to the wetland should be restricted access to certain areas of the wetland, or be required to go in the accompaniment of a ranger or warden.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.9 no.2
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• pp.139-146
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• 2006

Purpose: Human astrovirus (HAstV) is known to be an important etiologic agent of acute gastroenteritis in infants worldwide. However, the prevalence of HAstV infection varies according to geographic region and patient age. The purpose of our study was to investigate the incidence of HAstV infection among hospitalized children at a tertiary hospital in Seoul. Methods: Fecal samples were collected from hospitalized children up to five years of age with acute gastroenteritis. A total of 812 fecal samples were collected from hospitalized children with acute gastroenteritis between February 2004 and January 2005. Fecal specimens were screened for rotavirus, enteric adenovirus and norovirus by enzyme immunoassay (EIA) or reverse transcriptase polymerase chain reaction (RT-PCR). HAstV positive samples were characterized by RT-PCR. Results: Rotavirus was detected in 16.9% (138/812), norovirus in 11.6% (94/812), and adenovirus in 4.0% (33/812) of the study population. HAstV was detected in 4.0% (33/812) samples by RT-PCR. The age distribution of HAstV positive patients was as follows: <12 month old, 82.0% (27/33); 1~2 years old, 6.0% (2/33); 2~5 years old, 12.0% (4/33). The seasonal distribution of HAstV positive samples was as follows; April (3), May (5), June (4), August (12), September (4), October (2), November (2), and December (1). The peak rate of HAstV infection was observed during the summer season, 2004. A mixed infection of viral agents was confirmed in 2.7% (22 /812) of the study population, most commonly with rotavirus and norovirus, and with rotavirus and HAstV. Genotype 1 was the predominant type (91%, 20/22) and genotype 8 was detected in two cases. Conclusion: The prevalence of HAstV infection was 4.0% in hospitalized children with acute gastroenteritis, and was especially high in infants. HAstV can be considered as an important etiologic agent of gastroenteritis in children.

• Analytical Science and Technology
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• v.23 no.4
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• pp.371-382
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• 2010

TSP and PM2.5 atmospheric aerosols have been collected at Gosan site of Jeju Island, and their compositions were analyzed to understand the pollution characteristics. The composition ratios of nss (non-sea salt)-$SO_4^{2-}$ and $NH_4^+$ were higher in Gosan site than those in other Korean background and urban sites. However the composition ratio of $NO_3^-$ was conversely lower in Gosan site. From the study of aerosol components according to particle sizes, the anthropogenic nss-$SO_4^{2-}$, $NO_3^-$ and $NH_4^+$ components were mostly existed in the fine particles. But the nss-$Ca^{2+}$, $Na^+$, $Cl^-$ and $Mg^{2+}$ originated from soil and marine sources were distributed relatively in the coarse particles. In the seasonal comparison, the concentrations of nss-$Ca^{2+}$, Al, Fe, Ca and $NO_3^-$ increased in spring season, and nss-$SO_4^{2-}$ showed higher concentration in summer and spring seasons. Based on the factor analysis, the atmospheric aerosols in Gosan site have been found to be influenced largely by anthropogenic sources, and next by marine and soil sources. The backward trajectory analyses showed that the concentrations of nss-$SO_4^{2-}$, $NO_3^-$, Pb and nss-$Ca^{2+}$ increased when the air mass moved from Chinese continent to Jeju area. On the other hand, their concentrations decreased when the air mass moved in from the North Pacific Ocean.

• Journal of the Korean association of regional geographers
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• v.2 no.1
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• pp.115-131
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• 1996

Tourism is multi-faceted phenomenon which involves movement to stay in destinations outside the normal place of residence. Thus, tourism is a composite phenomenon which incorporates the diversity of variables and relationships to be found in the tourist travel process. Tourism-behaviors are of major economic and social significance. With the growth of mass-tourism, the government departments of tourism is to provide many tourist facilities, to develop travel destination and tourism resources. At same time, the growth of mass-tourism has prompted perceptive travellers to raise many questions concerning the many travel destination and the tourism resources of encouraging further tourism demand. Most of tourism have a mental in their minds about various objects. This allowed him to choose tourism destination as a important rules. In tourism geography, behavioral approach to wildness, tourism resources and places has risen since 1960's. The tourist profile can be viewed under two major categories: the tourist social-economic and behavioral characteristic. Particulary, the motivations, attitude, need, values and preference of travel destinations are of crucial importance in contributing to their desion-making process. In this view, this paper is emprical study investigated travel patterns and behavioral characteristic of tourists and potential tourist in East Chonnam. The purpose of this paper is to show the spatial preference and tourism behavior of travel destinations. For this study, we are undertaken the questionary method employed by recreation geographers in order to collect research data for the East Chonnam-citizens functioned as a major tourist demand. The East Chonnam Province have many tourist-places including national park, provincial park, and local tourist-places. Thus, citizen of the East Chonnam evaluate many tourist-places very high, but evaluate the facilities of tourist place very low. The high ranks of preferences to travel destinations among tourist-places are Hyangilam, Geomoon island, Odongis land, Songkwang temple. The major travel destinations occurred the temporary travel trip are Odong island, Sunam temple, Songkwang temple. Heungkook temple, Hyangilam which are the type of mountainous in located inland. The relationship between the degree of preference and tourism behavior of travel trip for the travel destinations does not correlate each other. The result of analysis about the degree of seasonal preferences presented spatial differences according to characteristics of tourist-places. The typical travel destination are divided into seasons : Odong island. Mt. Backwoon, Goemoon island of spring, Goemoon island, Sungbul valley, Banggukpo beach of summer, Songkwang temple, Mt. Pal young of fall. The future of tourism will be rapidly grow with increase of personal mobility and leisure time, chang of tourism behavior. Thus, it is imperative that planning and development for tour-root, facilities of tourist-places should be implemented to increase tourism demand.