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Kongju, South Korea

Yoo H.-J.,Gyeonggi Science High School | Chung O.-S.,Chungnam Development Institute | Seo M.,Dankook University
Korean Journal of Parasitology | Year: 2012

Migratory birds have been suspected as playing a central role in transmission of various trematodes, but few surveys have been undertaken in the Republic of Korea. In the present study, we describe new fauna of microphallid flukes in Korea. Two species of microphallids were found in the intestines of 2 migratory bird species, namely the red necked stints (Calidris ruficollis) and the terek sandpiper (Xenus cinereus), in a coastal area of Gunsan-si, Jeollabuk-do. The microphallids recovered from the latter were 451 μm in length and 217 μm in width, and the eggs were very small, 13 μm by 8 μm. They had the characteristic extracecal vitellaria intruding into the median posttesticular area, belonging to Endocotyle incana. Another microphallids were discovered from both migratory birds, 417 μm in length and 249 μm in width. The cirrus was projecting into the genital atrium in form of male papilla, and bounded by a muscular flap, termed pseudogonotyl. They were identified as Spelotrema pseudogonotyla in consideration of the distinctive male papilla and pseudogonotyl. Besides these flukes, Maritrema obstipum and Gynaecotyla squatarolae also were recovered. This paper is in fact the first report on the presence of Spelotrema and Endocotyle in Korea. © 2012, Korean Society for Parasitology. Source

Chung O.-S.,Chungnam Development Institute | Lee H.-J.,Dankook University | Kim Y.-M.,Dankook University | Sohn W.-M.,National University of Health Sciences | And 2 more authors.
Parasitology International | Year: 2011

Gynaecotyla squatarolae (Digenea: Microphallidae) is a minute intestinal trematode whose natural hosts are aves. We conducted a feces screening survey in a coastal village of Muan-gun, where the residents routinely consume brackish water crabs as a food. Through this survey, a 50-year-old female was found to shed gymnophallid and heterophyid eggs in her stool, and 845 adult flukes were collected from her purged stool. The adult worms were morphologically grouped into three species. A total of 841 worms were Gymnophalloides seoi. Three worms were identified as G. squatarolae, and the last one proven to be Haplorchis pumilio. This is the first worldwide report of G. squatarolae infection in humans, and the first H. pumilio infection in Korean people. © 2010 Elsevier Ireland Ltd. Source

Chung O.S.,Chungnam Development Institute | Jang G.S.,Yeungnam University | Oh J.H.,Korea forest Research Institute
Animal Cells and Systems | Year: 2011

Estimating the habitat potential of inland forest patches for birds requires the modeling of species-area relationships, or relationships between habitat size and numbers of bird species in each patch. The accurate estimation of species-area relationships significantly reduces the effort required to recognize the number of species living in each patch. The objective of this study was to estimate the relationship between forest patch size and bird species diversity in Dangjin County, in northwest South Korea, based on the sizes of inland forest patches. KOMPSAT-2 images were obtained and ortho-rectified to construct a map of the target forest patches. The numbers of birds per patch were surveyed four times: August 2008, September 2008, February 2009 and May 2009. Regression models were derived to explain the relationships between the numbers of bird species and patch size. A model that was derived using data from all four observation periods had the highest coefficient of determination (R2). According to these models, the numbers of bird species at first increased linearly with increasing patch size; however, the curve then plateaued. Our model including observations from four seasons will be useful for estimating the numbers of bird species in other inland forest patches in South Korea. © 2011 Korean Society for Integrative Biology. Source

Chen B.,Harbin Institute of Technology | Kim Y.,Chungnam Development Institute | Westerhoff P.,Arizona State University
Water Research | Year: 2011

Dissolved organic nitrogen (DON) derived from wastewater effluent can participate in reactions that lead to formation of nitrogenous chlorination by-products, membrane fouling, eutrophication, and nitrification issues, so management of DON is important for both wastewater reuse applications and nutrient-sensitive watersheds that receive discharges from treated wastewater. This study documents DON occurrence in full-scale water/wastewater (W/WW) treatment plant effluents and assesses the removal of wastewater-derived DON by several processes (biodegradation, coagulation, softening, and powdered activated carbon [PAC] adsorption) used for advanced treatment in wastewater reuse applications. After varying levels of wastewater treatment, the dominant aqueous nitrogenous species shifts from ammonia to nitrate after aerobic processes and nitrate to DON in tertiary treatment effluents. The fraction of DON in total dissolved nitrogen (TDN) accounts for at most 52% in tertiary treated effluents (median = 13%) and 54% in surface waters impacted by upstream wastewater discharges (median = 31%). The 5-day biodegradability/bioavailability of DON (39%) was higher, on average, than that of dissolved organic carbon (DOC, 26%); however, upon chlorination, the DON removal (3%) decreased significantly. Alum coagulation (with ≥8 mg/L alum per mg/L DOC) and lime softening (with pH 11.3-11.5) removed <25% of DON and DOC without selectivity. PAC adsorption preferentially removed more DOC than DON by 10% on average. The results provided herein hence shed light on approaches for reducing organic nitrogen content in treated wastewater. © 2011 Elsevier Ltd. Source

Yoon J.-J.,Chungnam Development Institute | Jun K.-C.,KIOST
Ocean Science Journal | Year: 2015

An integrated model system was developed to apply surge-wave coupled simulations to the southern coast of Korea during Typhoon Sanba in 2012. Numerical experiments were carried out to examine the effects of land-dissipated wind on storm surges and the influence of wave-surge coupled simulations on storm surges and surface waves. These numerical experiments used a finite volume ocean model, FVCOM, coupled with a wave model SWAVE. Due to the complex geometry of the coastal area investigated, a high-resolution terrain-following unstructured grid was employed. Atmospheric forcing was generated by a planetary boundary layer model, which was revised by incorporating the effect of the land’s roughness on the typhoon wind. A detailed comparison shows generally good agreement between the measured and simulated wind, surge, and waves. In particular, improved results have been found for the simulation of storm winds and surges when considering the effect of land-dissipated wind. In addition, clearly improved results for storm surges were obtained when adding the coupling effect between waves and surges. The results show a maximum contribution of ~40% by the waveinduced surge to the peak surge height along the coasts. The mean rate of error for peak surge heights decreased from 29.6% to 21.3% after considering the effects of wind dissipation, and decreased again to 17.9% when adding the effects of the waves. These results imply that the effect of wind dissipation caused by land roughness and waves should be taken into account when determining storm surge heights. The results also show the effects of wave-current coupling influences the generation of waves. However, the magnitude of this coupling effect on wave heights was found to be relatively insignificant. © 2015, Korea Ocean Research & Development Institute (KORDI) and the Korean Society of Oceanography (KSO) and Springer Science+Business Media Dordrecht. Source

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