• Journal of Microbiology and Biotechnology
• /
• v.18 no.4
• /
• pp.788-794
• /
• 2008

The aim of the present study is to estimate the overall prevalence and type distribution of human papillomavirus (HPV) in Korean women, through literature review and meta-analysis. We searched published data for the period between 1995 and 2007 using the following inclusion criteria; (1) studies using type-specific HPV tests, (2) data from Korean female, (3) with cytologic or pathologic results, (4) having more than 20 cases for each subgroup classified by cytologic results, and (5) HPV detection including types 16, 18, and at least one other type. In total, 18 studies (13,842 cases) published up to April 2007 were identified and selected. Adjusted overall HPV prevalence was 23.9% (95% CI: 23.8-24.1%) in women with normal cytology and 95.8% (95% CI: 95.4-96.2%) in women with cervical cancer. Type 16 was predominant regardless of cervical disease status, and type 58 occupied a significantly larger proportion in high-grade cervical intraepitheliallesions and cervical cancer in Korean women. HPV types 58, 33, and 52 together accounted for about 20% of infections in cervical cancer and high-grade intraepitheliallesions. After introduction of HPV prophylactic vaccines, extended protection, especially against types 58, 33, and 52, will be an important issue for cervical cancer prevention in Korea. The future dominant genotypes will require follow-up epidemiological studies with a large-scale, multicentered, and prospective design.

• Korean Journal of Environmental Biology
• /
• v.33 no.3
• /
• pp.330-337
• /
• 2015

Pre-monsoon dynamics of zooplankton community were investigated in Yongwol West River tributary; wetland shaped Korean Peninsula. Zooplankters were collected at three sites (stn 1: Yongwol West River, stn 2: Pyungchang River, stn 3: Jucheon River) monthly during the period between March and July 2014 except April. Totally 58 taxa of zooplankton occurred, consisting of 27 species of rotifer, 18 species of cladoceran, eight species of copepod, four kinds of aquatic insect larvae and one nematod. Lotic cladocerans of Alona spp. belonging to Chydoridae occurred frequently while typical lentic ones of Bosmina spp. and Daphnia spp. were not distributed, then sampling sites may be located in lotic waters. Zooplankton abundance recorded as $4,451-8,011indiv{\cdot}m^{-3}$ in Jucheon River but never exceeded $500indiv{\cdot}m^{-3}$ in other rivers. In Yongwol West River, dominant taxa were aquatic insect larvae from March through June and succeeded to cladocerans and copepods in July. Similar succession was observed in Jucheon River where aquatic insect larvae dominated in March and changed to cladocerans and copepods from May with high abundance. No such succession of zooplankton community was detected in Pyunchang River. Species diversity indices were the highest in Yongwol West River except in March. High values of dissolved oxygen ($9.0-11.0 mg{\cdot}liter^{-1}$) may show the characteristics of mountain streams. Water temperature increased gradually from $10.1^{\circ}C$ to $27.9^{\circ}C$ and pH varied within generally high range between 7.9-8.9, respectively. High value of pH seems to be derived from lime stone mines and cement factories around the studied area.

• Korean Journal of Environment and Ecology
• /
• v.28 no.3
• /
• pp.314-325
• /
• 2014

We studied fish fauna at 10 study sites in Ungcheon stream for 4 times from April to October, 2011 to investigate the influence of artificial structures such as dam (with fish-way) and weir (without fish-way), and abandoned mine on fish community. A total of 12 families, 36 species of fishes were collected. Dominant species was Zacco platypus (23.4%) and subdominant species was Zacco koreanus (20.5%). Ten species (27.8%) of Korean endemic species and Micropterus salmoides, exotic species, were observed during the study period. Endangered species of Korea such as Pseudopungtungia nigra and Liobagrus obesus, and Korean endemic species, Coreoperca herzi, which are vulnurable for water quality and had been observed in previous study, were not identified in this study. According to the cluster analysis, Ungcheon stream were divided into three groups consisting upstream (St.1, St.2, St.3), midstream (St.4, St.5, St.6, St.7), downstream (St.8, St.9, St.10). Community structure similarity between upper and lower site of Boryeong dam with fish-way (St.6-St.7) was high, whereas that of weir, lack of fish-way (St.7-St.8) showed little similarity indicating that fish-way was required. According to the canonical correlation analysis, high level of conductivity and salinity at upstream was detected and Misgurnus mizolepis, and endemic species of Korea such as Silurus microdorsalis, Coreoleuciscus splendidus and Iksookimia koreensis were observed at this part of the stream. Since Korean endemic species, Squalidus gracilis majimae cohabit with exotic species, M. Salmoides at downstream whose width is wide and water velocity is low, protection was needed for these endemic species.

• Journal of Wetlands Research
• /
• v.14 no.1
• /
• pp.21-33
• /
• 2012

The dominant land use at the Seonakdong river watershed is paddy and forest areas and the Seonakdong river stands still. Thus, the water pollution in the Seonakdong river is becoming more serious for the non-point source. In this study, SWAT(Soil and Water Assessment Tool) model was evaluated for simulation of flow and water quality behaviors in Seonakdong river. To perform the calibration and verification of the SWAT model, the measurements of discharge and water quality were performed for the period from 2006 to 2007 at 5 gauging stations in Seonakdong river. The $R^2$ value for discharge and water quality were 0.86 and 0.70 respectively for calibration after the sensitive analysis. The $R^2$ value for discharge and water quality were 0.81 and 0.51 respectively for verification. The simulation results show that BOD value in the river tends to decrease after the opening of gates and the patterns of TN and TP concentrations are similar as that of BOD. The gate operators need to determine how to supply water in drought season for effective water quality improvement. This study shows that the SWAT model, which is capable of simulating hydrologic and water quality behaviors temporarily and spatially at watershed scale, could be used to get the gate operation rule for the water quality management in Seonakdong river.

• Korean Journal of Environmental Agriculture
• /
• v.32 no.4
• /
• pp.304-314
• /
• 2013

BACKGROUND: Ecological functions of irrigation ponds were well known fact that important for biodiversity conservation in agricultural ecosystems. However, many irrigation ponds were destructed with changes of agricultural environment. The objective of this study is to appreciate the importance of ecological functions of irrigation pond. Furthermore, it presented to useful information for restorations of irrigation pond from analyses of correlations between benthic macroinvertebrate communities and locational factors of irrigation ponds. METHODS AND RESULTS: Benthic macroinvertebrate sampling was conducted from 2010 to 2012 at 15 study ponds. Comparisons of benthic macroinvertebrates diversity approached species richness and density, and statistical analyses were performed using independent t-test. A total of 131 species / 137,118 individuals of benthic macroinvertebrates were recorded during study period. Dominant taxa of benthic macroinvertebrates included Coleoptera, Hemiptera, and Odonata. Generally, benthic macroinvertebrate diversity in mountain region and existing ponds were showed higher than open field and created ponds, respectively. DCA ordination showed that benthic macroinvertebrate community was most correlated with locational characteristics of irrigation pond, and it correlated with bank type and age of pond. CONCLUSION(S): In conclusions, in order to restore ecological irrigation pond, it is necessary to consider environmental factors such as locational characteristics and bank types.

• Korean Journal of Environment and Ecology
• /
• v.20 no.3
• /
• pp.299-310
• /
• 2006

The germination period, the germination under different saline concentration and temperature condition, the survival percent several halophytes in cross-transplanting experiment of marsh type and the soil environment factor of five dominant species were investigated on the halophytes population formation strategies on the salt marsh of Mankyeong river estuary from February to October 2005. In terms of germination, Suaeda japonica appeared first followed by Aster tyipolium Salicornia herbacda, Atriplex gmelini and Suaeda asparagoides. The germination percent on the humidify conditions and saline concentrations of halophytes were that Suaeda japonica germinated well under inundation conditions, high temperature and low salinity; Salicornia herbacda under high salinity; Aster tripolium and Atriplex gmelini under dry or inundation conditions, and Suaeda aspar agoides under dry conditions and high salinity. The survival percent in cross-transplanting experiment of five halophytes were high with Suaeda japonica in the low marsh; Salicornia herbacda, Aster tripolium and Atriplex gmelini in the mid marsh, Suaeda asparagoides in the high marsh. The soil properties were similar for the five halophytes, but soil texture appeared high in order of silt, sand and clay. These results suggested that population formation strategies of five halphytes. Suaeda iaponica was distributed in the low tidal marsh, Salicornia herbacda, Aster tripolium, Atriplex gmelini in the mid tidal marsh and Suaeda asparagoides in the high tidal marsh.

• Korean Journal of Environment and Ecology
• /
• v.19 no.3
• /
• pp.305-311
• /
• 2005

For research of the wintering waterbirds we surveyed monthly from October 2000 to March 2001 on Gangjin Bay, Chollanam-do, Korea. During the study period, the waterbirds were observed 9,825 individuals and 36 species. The highest dominant species was Anaspiatyrhynchos which occupied the $48.42\%$, the one followings were Anas crecca $(10.8\%)$, Tadorna tadorna $(9.7\%)$, Anas poecilorhyncha $(9.5\%)$ and Cygnus cygnus $(4.8\%)$. A regularly observed species in every months were 3 species, Egretta garzetta, Anas pin tyrhynchos and Anas poecilorhyncha. The Cygnus cygnus of specially protected species was observed the 232 individuals maximumly in November and the 125 individuals to a minimum in December. The index of species diversity was minimum 1.24 at October and maximum 2.01 at March. This area has provided a suitable roosting and feeding place for waterbirds. The peak count of the wintering whooper swan was 232 individuals in Gangjin Bay. Therefore, We need the conservation and management of Gangjiun Bay.

• Korean Journal of Environment and Ecology
• /
• v.22 no.6
• /
• pp.616-624
• /
• 2008

The ichthyofauna and ecological community analysis in the Dong River, Korea, were investigated from May, 2006 to May, 2007. During the surveyed period, 31 species belonging 9 families were collected. Total of 31 species(primary freshwater: 26 species, peripheral freshwater: 5 species) were found with the primary freshwater fishes being highest. Dominant species was Zacco koreanus(55.73%), and subdominant species was Coreoleuciscus splendidus(7.15%). Also, Microphysogobio longidorsalis (6.12%), Hemibarbus mylodon(4.87%), Iksookimia koreensis(4.49%) were numerous. There were 19 Korean endemic species(61.29%), including Acheilognathus signifer, A. yamatsutae, Pseudopungtungia tenuicorpus, C. splendidus, Squalidus gracilis majimae, H. mylodon. Among them, 1 species was identified as qualifying for possible designation as a natural monument catergory, and 5 species were identified for designation required to protect under a wildlife category. As result of expected number of species according to rarefaction curve, the expected species of the Dong-river ranged from 19(51. 4, 5) to 22(51. 3) and result of similarity analysis ranged from 62.28%(51. 1 and 2) to 84.13%(51. 1 and 5). In conclusions, we could define that the Dong-river has a very good water conditions as habitat of fish, and habitat conditions also are very similar in every survey sites.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.22 no.3
• /
• pp.175-184
• /
• 2018

In this paper, comparative analysis of the 9.12 Gyeongju and 11.15 Pohang earthquakes was conducted in order to provide probable explanations and reasons for the damage observed in the 11.15 Pohang earthquake from both earthquake and structural engineering perspectives. The damage potentials like Arias intensity, effective peak ground acceleration, etc observed in the 11.15 Pohang earthquake were generally weaker than those of the 9.12 Gyeongju earthquake. However, in contrast to the high-frequency dominant nature of the 9.12 Gyeongju earthquake records, the spectral power of PHA2 record observed in the soft soil site was highly concentrated around 2Hz. The base shear around 2 Hz frequency was as high as 40% building weight. This frequency band is very close to the fundamental frequency of the piloti-type buildings severely damaged in the northern part of Pohang. Unfortunately, in addition to inherent vertical irregularity, most of the damaged piloti-type buildings had plan irregularity as well and were non-seismic. All these contributed to the fatal damage. Inelastic dynamic analysis indicated that PHA2 record demands system ductility capacity of 3.5 for a structure with a fundamental period of 0.5 sec and yield base shear strength of 10% building weight. The system ductility level of 3.5 seems very difficult to be achievable in non-seismic brittle piloti-type buildings. The soil profile of the PHA2 site was inversely estimated based on deconvolution technique and trial-error procedure with utilizing available records measured at several rock sites during the 11.15 Pohang earthquake. The soil profile estimated was very typical of soil class D, implying significant soil amplification in the 11.15 Pohang earthquake. The 11.15 Pohang earthquake gave us the expensive lesson that near-collapse damage to irregular and brittle buildings is highly possible when soil is soft and epicenter is close, although the earthquake magnitude is just minor to moderate (M 5+).

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.37 no.6
• /
• pp.1001-1008
• /
• 2017

This study was to evaluate the stream depletion rate from groundwater pumping with varying stream-well distance, aquifer transmissivity, storage coefficient, leakage coefficient, streambed hydraulic conductance using the Zlotnik and Tartakovsky analytical solution which considers a two-layer leaky aquifer-stream-well system. For the hydraulic conditions applied in this study, the streambed hydraulic conductance and the aquitard leakage coefficient were assessed to have a dominant influence on the stream depletion rate. In order to evaluate the applicability of Zlotnik and Tartakovsky analytical solution ignoring the change in the drawdown in the lower aquifer and applying the fixed head boundary condition, the solution was compared with Hunt analytical solution derived from the more practical conditions simultaneously taking into account the drawdown changes in the upper and lower aquifers. As a result, the Zlotnik and Tartakovsky analytical solution is suitable for predicting short-term effects of less than one year in the pumping period, and when the stream depletion factor (SDF) is greater than 2,500 days, or when the product of the leakage coefficient and the stream-well distance is less than 10 cm/s.