• Korean Journal of Ecology and Environment
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• v.52 no.3
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• pp.274-283
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• 2019

Beta diversity is an efficient means of assessing the spatial variation in community composition among sites. To present fish community variation and LCBD (Local Contribution to Beta Diversity) among sites in stream, 6 sampling sites were selected in Cheonggye stream. Fish communities, environmental and habitat variables were collected at sites from April 2014 to October 2015. We used the total variance of the fish community data table (site-by-species community table) based on different forms, presence-absence, abundance, and Hellinger transformation, to estimate and compare beta diversity and LCBD. Fish community data table transformed by Hellinger distance showed the higher values of beta diversity than presence-absence and abundance data table. A similar patterns of LCBD were observed with presence-absence and Hellinger transformed data table. Low value of beta diversity calculated by community data table with abundance was due to the non-normality of fish assemblage data. Additionally, correlation coefficients were calculated to evaluate the relationships among LCBD, community indices and physicochemical variables. LCBD showed negative correlation coefficients with Shannon diversity. Overall, application of beta diversity analysis is an efficient method of addressing spatial variation of fish communities and ecological uniqueness of the sites in stream.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.12
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• pp.7761-7762
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• 2013

Alternative strategies such as visual inspection of cervix with acetic acid, are real time, economical and easily implemented methods for cervical cancer screening. However, variable sensitivity and specificity have been observed in various community based studies. The possible reasons could include variation in man power training, light source used for visualization, and preparation of diluted (4-5%) acetic acid and its storage. A standardized protocol for training, teaching material (easy to understand in the local language) for trainees, supervision and reinforcement by intermittent and supplementary training to check the quality of their observation, a standard protocol for preparation dilute acetic acid and its storage and a standard good light source (equivalent to day light) are needed to minimize the variation in sensitivity and specificity of VIA in community settings.

• Journal of Microbiology and Biotechnology
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• v.27 no.10
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• pp.1808-1819
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• 2017

Knowledge on the functional characteristics and temporal variation of anaerobic bacterial populations is important for better understanding of the microbial process of two-stage anaerobic reactors. However, owing to the high diversity of anaerobic bacteria, close attention should be prioritized to the frequently abundant bacteria that were defined as core bacteria and putatively functionally important. In this study, using MiSeq sequencing technology, the core bacterial community of 98 operational taxonomic units (OTUs) was determined in a two-stage upflow blanket filter reactor treating pharmaceutical wastewater. The core bacterial community accounted for 61.66% of the total sequences and accurately predicted the sample location in the principal coordinates analysis scatter plot as the total bacterial OTUs did. The core bacterial community in the first-stage (FS) and second-stage (SS) reactors were generally distinct, in that the FS core bacterial community was indicated to be more related to a higher-level fermentation process, and the SS core bacterial community contained more microbes in syntrophic cooperation with methanogens. Moreover, the different responses of the FS and SS core bacterial communities to the temperature shock and influent disturbance caused by solid contamination were fully investigated. Co-occurring analysis at the Order level implied that Bacteroidales, Selenomonadales, Anaerolineales, Syneristales, and Thermotogales might play key roles in anaerobic digestion due to their high abundance and tight correlation with other microbes. These findings advance our knowledge about the core bacterial community and its temporal variability for future comparative research and improvement of the two-stage anaerobic system operation.

• Ocean and Polar Research
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• v.31 no.1
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• pp.71-76
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• 2009

Drastic changes in the water quality and phytoplankton community of the new Saemankeum Lakeduring the first decade following the construction of the Saemankeum Sea Wall has been considered to be unavoidable. Input of eutrophicated water through the Mankyeong River and Dongjin River might produce more direct effects on the water quality and phytoplankton community, which lead us to launch a long-term semi-weekly investigation at the "Mankyeong Bridge" monitoring point to resolve its short-term effect as well as long-term stabilization of the ecosystem in the new Saemankeum Lake. During 15 months starting from June 2006, the water temperature varied in accordance with the typical seasonal variations in temperate on the coasts, and no significant daily variations evoked by tidal cycle could be detected. However, there was an inverse relationship between seasonal precipitation and salinity even though the range in annual variation was drastically reduced right after the construction of the Saemankeum Sea Wall. Species richness in the phytoplankton community was also reduced due to the narrowed annual range of salinity, which would eliminate the mid-high salinity species from the Mankyeong Bridge monitoring point. Similarly, species diversity was decreased with increased dominance of the phytoplankton community after the construction. Between the two summer seasons during the present study, species diversity was higher in 2007 than in 2006, which might indicate the early stage of a gradual stabilization in the ecosystem including the phytoplankton community at the monitoring station. The phytoplankton community thus needs to be monitored on a long-term basis to identify indirect signals that can be used to assess the stability of the ecosystem in the young Saemankeum Lake.

• Korean Journal of Child Studies
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• v.18 no.1
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• pp.5-21
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• 1997

This study compared children's daily activities In the preschools of middle-and lower-income communities. 22 children, evenly divided by community and children's gender, were observed for 3 hours on 5 consecutive days. The observers followed the target child, gathering data during 30-second "windows" every 4 1/2 minutes. A total of 750 observations were used in the analyses. The findings show the variation in children's activities as a function of community differences. In the case of academic activities, children of middle-income community were more exposed to and engaged in play with academic objects more than children of the of low-income community. A reverse tendency, however, was found in academic lessons. Children of low-income community were more exposed to work than their counterparts. Children of middle-income community were engaged in child-adult conversation more than those of low-income community. In addition, children of the middle-income community initiated their involvement in play and conversation more than their counterparts, though no difference was found in children's initiation of activities.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.3
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• pp.1234-1243
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• 2011

Our study was carried out to develop the severity-adjustment model for length of stay in hospital for community-acquired pneumonia so that we analysed the factors on the variation in length of stay(LOS). The subjects were 5,353 community-acquired pneumonia inpatients of the Korean National Hospital Discharge In-depth Injury Survey data from 2004 through 2006. The data were analyzed using t-test and ANOVA and the severity-adjustment model was developed using data mining technique. There are differences according to gender, age, type of insurance, type of admission, but there is no difference of whether patients died in hospital. After yielding the standardized value of the difference between crude and expected length of stay, we analysed the variation of length of stay for community-acquired pneumonia. There was variation of LOS in regional differences and insurance type, though there was no variation according whether patients receive their care in their residences. The variation of length of stay controlling the case mix or severity of illness can be explained the factors of provider. This supply factors in LOS variations should be more studied for individual practice style or patient management practices and healthcare resources or environment. We expect that the severity-adjustment model using administrative databases should be more adapted in other diseases in practical.

• Journal of the Korean earth science society
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• v.36 no.1
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• pp.59-67
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• 2015

An electrical resistivity survey is widely conducted for the safety management of embankment. In this study we investigated how a tidal variation affects the interpretation of electrical resistivity monitoring data of the embankment located in west coast. We monitored the variation of electrical resistivity on the coastal embankment where there was a high tidal variation for 3 days in every 3 hours. Electrical resistivity monitoring data showed a variation of resistivity distribution in specific area according to the time, which demonstrated some correlation with a tidal height variation. Therefore, we highly recommend that a tidal effect be considered when electrical resistivity survey is conducted on the embankment where there is a high tidal variation. For further study, we need a long term electrical resistivity monitoring and analyzing on tidal variation.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.13
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• pp.5237-5242
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• 2015

Background: Socioeconomic factors are associated with screening in terms of reducing the risk of cervical cancer. This study aimed to clearly establish the effect of screening on variation in socio-economic factor-specific survival estimates. Materials and Methods: Survival estimates were calculated using the life table method for 165 women from the routine care control arm and 67 from the visual inspection with acetic acid screening arm diagnosed with cervical cancer during 2000-2006 in rural south India. Kaplan-Meier survival curves were plotted to compare the variation in survival by socioeconomic factors. Results: Whereas there was a significant variation in survival estimates of the different categories of age at diagnosis among the screen-detected cancers with women aged<50 years having an improved survival, no significant variation was noted among women diagnosed with cervical cancer from the control arm. Compared to the variation among the cancer cases detected in the unscreened control group, screening widened the variation in survival estimates by age and type of house, and reduced the variation by education. The direction of the magnitude of the survival estimates was reversed within the different categories of occupation, marital status and household income in the screen-detected cancer cases compared to control group cancer cases. Also, women diagnosed with stage 1 disease had a very good survival. Conclusions: Screening changed the pattern of survival by socio-economic factors. We found improved survival rates in screened women aged <50 years, with no formal education, manual workers and married women.

• Ocean and Polar Research
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• v.35 no.3
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• pp.219-228
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• 2013

In Korea, more than 300 oil spill accidents occur every year. Despite the frequency, only a small pool of data is available on the initial effect of oil spill on macrobenthic fauna inhabiting rocky shores. The aim of this study was to analyze the variation of macrobenthic fauna composition and community structure on rocky shores, and understand the impact of oil on rocky shore organisms after the Hebei Spirit oil spill. Field surveys were carried out in five regions dose to the wreck site in January, April and September 2008. Polluted sites after the Hebei Spirit oil spill showed that biological index consistently decreased for 9 months limited to breeding and recruitment of organisms by spilled oil. Macrobenthic community was subdivided into 3 groups by species elimination and differences between density of major dominant species: enriched biota community under a relatively stable environment, the second with relatively low ecological index and the last with poor community. In this study, species number did not clearly reflect the effect of oil on the rare and mobile species. However, mean density, biomass and community structure showed the effect of oil by considering breeding activity, decline in recruitment and variation pattern with time.

• Korean Journal of Microbiology
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• v.27 no.4
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• pp.378-384
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• 1989

The numerical taxonomy of heterotrophic bacterial community in Lake Soyang was analysed. 95, 115, 88 and 75 strains which were isolated at each season from spring in 1987 to winter in 1988 were clustered by single matching coefficient. The diversity indices (H') were in the range of 0.511-1.684, and the community was most diverse in spring. THe seasonal variation of generic composition was significant. Of the domonant genera, Acinetobacter, Pseudomonas, and Flavobacterium were representative.