• Korean Journal of Clinical Laboratory Science
• /
• v.48 no.3
• /
• pp.230-236
• /
• 2016

Economic growth has increased the living standards around the world. Water pollution, in particular, is a public relations issue because it poses a direct threat to everyone's lives. As of recently, the production of taste and odor (T&O) compounds has been a common problem in the water industry. The adsorption process using granular activated carbon (GAC) has been the most widely used process. The objectives of this study were to evaluate the microorganisms before and after the backwashing of GAC and to identify the species of the microorganisms found. Five dominants microorganisms were confirmed after the microfiltration process from backwashing of GAC, and the dominant bacterial species were found to be ${\beta}$-proteobacterium species, Porphyrobacter donghaensis, Polaromonas rhizophaerae, Hydrogenophaga species, and Pseudonocardia species. However, when UV treatment after microfiltration was performed, Hydrogenophaga species and Psedonocardia species were eliminated. Herein, I conclude that the UV treatment post microfiltration process is more efficient than microfiltration process alone. The findings of this study may provide useful information regarding the management of microfiltration process.

• Korean Journal of Ecology and Environment
• /
• v.52 no.4
• /
• pp.366-377
• /
• 2019

Paddy wetlands are a critical habitat for a variety of wild animals, and their rapid development and environmental changes pose a threat to the conservation of agrobiodiversity. The objectives of this study were to evaluate the habitat characteristics of anuran inhabiting paddy wetlands and identify major environmental variables affecting their distributions. The study was conducted in the Daeho reclaimed area in Dangjin, from March to October 2018. In this study, we found three anuran species (Pelophylax nigromaculatus, Hyla japonica and Pelophylax chosenicus). The environmental factors affecting the three species were identified as air temperature, humidity, water-depth, and micro-habitats. H. japonica were affected by water temperature, and P. chosenicus were affected by rice height and types of farming practices. All the three species richness was correlated with air temperature, humidity, and water-depth positively, and the three species used rice transplanted paddy fields the most. It was also found that paddy is the most preferred of the micro-habitats during the breeding season, so the survey area is considered to be used as the major breeding sites for the three species. P. chosenicus were more observed on environmental-friendly paddy fields than conventional paddy fields, which appears to be differences in their surroundings environment caused by predators and weeding. It will be needed to identify their relationship with predators, their preferred food resources and the richness and diversity of wild vegetation around paddy wetlands.

• Journal of Wetlands Research
• /
• v.22 no.2
• /
• pp.73-80
• /
• 2020

Polygonatum stenophyllum Maxim. is a native perennial herb to Korea belonging to family Liliaceae. Although it was removed from the endangered species list, since it inhabits the riverside, it has been threatened with damage to its populations due to frequent disturbances. In order to reveal the basic ecological characteristics of P. stenophyllum, This study was identified the life cycle of the aboveground part and was measured the number of flowers and fruits, which are reproductive organs of P. stenophyllum in riverside in Paju - si during the two years. As a result, aboveground part of P. stenophyllum appeared and grew rapidly until the end of May to about 1m. In early May, two buds per one peduncle were formed up to six pairs per floor. The flowers bloomed in turn from the base of the stem and to the top floor and the blooming occurred when the number of leaves was at least three. Fruits were formed in mid-June and matured by the end of September. The numbers of flowers and fruits were revealed that flowers bloomed in turn from the bottom of the stem to the top floor, the most intensively bloomed in the center part of the stem, and did not bloom from the floor closest to the ground and above the highest 5th node. This basic ecological characteristics of the P. stenophllyum grown in riverside identified in this study will be useful as basic data for their conservation.

• Journal of Life Science
• /
• v.30 no.2
• /
• pp.191-201
• /
• 2020

As society develops rapidly, environmental pollution is becoming a greater risk factor threatening human health. One of the major causes of air pollution that affects human health is particulate matter (PM), which contains a heterogeneous mixture of different particle sizes and chemical compositions. PM is classified by size into general PM (PM₁₀; diameter below 10 ㎛) and fine PM (PM_2.5; diameter below 2.5 ㎛). PM_2.5 can pass through the respiratory tract into the circulatory system and thence throughout the body. PM_2.5 is known to stimulate oxidative stress and inflammatory responses to cells, promoting diseases such as asthma, chronic respiratory disease, cardiovascular disease, diabetes mellitus, and immunological disorders. Although detailed molecular mechanisms for how PM stimulates disease progression still need to be elucidated, together with national efforts to reduce PM production, significant research has been conducted that demonstrates the harmfulness of PM in disease progression through in vitro and in vivo experiments. This review focuses on the harmfulness of PM in disease progression; we also introduce a biological verification method for determining the hazards of PM.

• Journal of Korea Water Resources Association
• /
• v.49 no.2
• /
• pp.155-164
• /
• 2016

Algal blooms not only destroy fish habitats but also diminish biological diversity of ecosystem which results into water quality deterioration of 4 major rivers in South Korea. The relationship between algal bloom and environmental factors had been analyzed through the cross-correlation function between concentration of chlorophyll a and other environmental factors. However, time series of cross-correlations can be affected by the stochastic structure such auto-correlated feature of other controllers. In order to remove external effect in the correlation analysis, the pre-whitening procedure was implemented into the cross correlation analysis. The modeling process is consisted of a series of procedure (e.g., model identification, parameter estimation, and diagnostic checking of selected models). This study provides the exclusive correlation relationship between algae concentration and other environmental factors. The difference between the conventional correlation using raw data and that of pre-whitened series was discussed. The process implemented in this paper is useful not only to identify exclusive environmental variables to model Chl-a concentration but also in further extensive application to configure causality in the environment.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2007.05a
• /
• pp.1063-1069
• /
• 2007

우리나라의 하천환경은 1990년대 이전의 산업화와 인구증가를 수반한 고도성장기를 거치면서 이수성 및 치수성만을 강조하며 개수되고 관리되었다. 그 결과 하천은 획일적인 단면과 저수로 및 제방이 콘크리트화되면서 하천의 자정능력은 감소되었고, 하천을 중심으로 생활하는 동물들의 서식처 기능을 상실해 하천생태계가 위협받고 있다. 하천공사에 자연형 하천공법이 도입되기 시작하여 자연형 하천공사가 이루어지고 있지만 생태환경의 관점보다는 조경 및 경관적, 그리고 위락적인 관점에서 공원화에 주안점을 두고 있어 하천의 생태적 특성의 반영이 부족하다는 평가를 듣고 있는 실정이다. 따라서 본 연구에서는 향후의 하천공법이 자연적 기능들 중 생물서식처 기능을 보다 깊이 다루어야 한다는 필요성을 고려하여, 먹이사슬의 최상위에 있을 뿐만 아니라 하천환경의 건강도를 판단할 수 있는 수환경의 지표종이라 불리는 수달(Lutra lutra)을 대상으로 배설물에 의한 출현빈도와 하천환경 요인들에 대한 상관관계를 분석하여 수달 서식지 복원을 위한 하천정비의 기초자료를 제공하는 데 그 목적이 있다. 이를 위해 현재 수달이 서식하고 있는 섬진강 지류인 서시천을 연구 대상지점으로 하여 5개 구간을 선정하였으며, 각 구간에 대한 계절별 수달의 배설물 분포를 조사하여 출현빈도를 나타내었다. 또한 먹이, 지형, 식생, 기상인자를 포함한 하천환경 요인들에 대한 자료를 각 계절별로 구축하였으며, 이를 수달의 출현빈도와의 상관관계를 조사하는데 활용하였다. 본 연구의 결과는 환경 기술적으로는 멸종위기종의 복원, 사회경제적으로는 하천정비사업의 방향제시 등의 기대효과를 가져올 수 있으리라 생각되며 분석된 인자들은 수달 서식지를 위한 하천정비의 기초자료에 유용할 것으로 보인다.따른 유량측정망을 구축하는 것이다.의 의사결정 지원 도구가 될 것이다. 따라서, 본 연구에서는 도시유역의 물순환 해석을 위한 일련의 과정, 즉 자료의 조사 및 취득에서부터 물순환 해석 모형을 이용한 정량적 현황파악, 물순환 개선 기법 및 평가를 수행함에 있어 주요 착안점 및 실무에서의 기술적 가이드를 제공하고자 하였으며, 보다 세밀한 도시유역의 물순환 해석을 위하여 우리나라와 일본에서 적용이 활발한 물리적 기반의 분포형 모형(WEP, SHER, SWMM)의 적용사례를 통하여 국내 도시하천의 물순환 해석에 활용함에 있어서의 실질적인 적용절차 등을 제시하고자 하였다. 한다.호강유역의 급격한 수질개선을 알 수 있다.世宗實錄) $\ulcorner$지리지$\lrcorner$(地理志)와 동년대에 동일한 목적으로 찬술되었음을 알 수 있다. $\ulcorner$경상도실록지리지$\lrcorner$(慶尙道實錄地理志)에는 $\ulcorner$세종실록$\lrcorner$(世宗實錄) $\ulcorner$지리지$\lrcorner$(地理志)와의 비교를 해보면 상 중 하품의 통합 9개소가 삭제되어 있고, $\ulcorner$동국여지승람$\lrcorner$(東國與地勝覽) 에서는 자기소와 도기소의 위치가 완전히 삭제되어 있다. 이러한 현상은 첫째, 15세기 중엽 경제적 태평과 함께 백자의 수요 생산이 증가하자 군신의 변별(辨別)과 사치를 이유로 강력하게 규제하여 백자의 확대와 발전에 걸림돌이 되었다. 둘째, 동기(銅器)의 대체품으로 자기를 만들어 충당해야할 강제성 당

• Ecology and Resilient Infrastructure
• /
• v.2 no.1
• /
• pp.80-92
• /
• 2015

Some of alien plants, which were introduced from foreign countries, have caused problems in Korea. Invasion of these alien plants in the ecosystem threatens the habitat of endemic species, reducing biodiversity, and causing a disturbance in the ecological system. In urbanized areas of campus universities, a diverse range of organisms were found and a comparison between the sites, near roads or housing sites were made because the campuses provided a large biotope. Although the campus had been exposed to interferences like gardening, it was also a place for most organisms to live in an active floating population due to free access. This research investigated the flora of alien plants that appeared in Beakseok University, Sangmyung University, Hoseo University and Dankook University, and relationship between the distribution of alien plants and the campus and green areas and distance from the highway. The total number of plant species and naturalized species found in the four universities was 189 and 43 species. Those of Dankook University were 136 and 35 species, Hoseo 108 and 25 species, Sangmyung 103 and 31 species, and Baekseok 97 and 26 species, respectively. The abundance of natural plants for each respective university tended to be higher as it became closer to the highway. Also, the closer the walking distance to the university, the greater the tendency for the degree of similarity to be higher. As a result, we may conclude that the distribution of alien plants and anthropogenic activities may be closely related.

• Korean Journal of Ecology and Environment
• /
• v.48 no.1
• /
• pp.32-37
• /
• 2015

Naturalized plants are invaded through various routes and distributed throughout the nation. They are also invaded in the sand dune ecosystem and poses a threat ecological niche of indigenous sand dune plants. We studied the effects of salt stress on the plant growth to suggest the management plans of naturalized plants in the sand dune ecosystem. As a result of germination experiment according to the salt gradient, germination rate decreased as the higher concentration and tolerance range was up to 160 mM. As a result of seedling experiment according to salt gradient, mortality rate was up to 90% from 0 mM to 200 mM and 100% over 300 mM. The day of first death with different concentration was 18.5 days in 100 mM and 6 days in 800 mM since the experiment has started. In addition, the day of last death with different concentration was 29.5 days in 100 mM and 6 days in 800 mM. Therefore, two stages of management plans would be effective. The first one is to suppress the germination by salt spray over 170 mM before germination. The other one is to wither seedlings in a short period by salt spray over 600 mM.

• Journal of Wetlands Research
• /
• v.17 no.4
• /
• pp.359-369
• /
• 2015

Stream ecosystems are highly valued natural resources, however, stream environments are currently under threat in several respects. We evaluated vegetation and ecological characteristics according to different revetment types. The distribution of vegetation differed with revetment type, with a 42~45 taxa found in natural revetments, and 23~38 taxa in vertical revetments. Thus, natural revetments host more diverse vegetation than vertical revetments. We also found more plants belonging to the families Labiatae and Cyperaceae growing in natural revetments than in vertical revetments. We proposed that habitat space be apportioned to introduce annual plants as part of stream restoration projects. And, we identified 7 families and 18 taxa of naturalized plants, majority taxa were either biennial or perennial. Moreover, naturalized ratio was higher in vertical(14.3%) than natural(12.1%), we proposed a plan to promote and improve natural streams and revetments. Furthermore, we applied a waterfront evaluation method developed by the Natural Resources Conservation Service of the USDA-NRCS, which confirmed that stream health can be improved in most regions by controlling naturalized plants and ensuring shrub and tree growth. We adopted a new method to remove naturalized plants and establish natural revetments to ensure shrub and tree growth to aid in small-stream restoration and improvement. In future studies, we hope to develop methods for small-stream restoration projects in rural areas.

• Journal of Life Science
• /
• v.27 no.12
• /
• pp.1494-1499
• /
• 2017

Oral infection due to Candida albicans is a widely recognized and frequent cause of superficial infections of the oral mucosa (oral candidiasis). Although oral candidiasis is not a life-threatening fungemia, it can cause severe problems in individuals under certain conditions. MicroRNAs (miRNAs) are noncoding, small RNA molecules, which regulate the expression of other genes by inhibiting the translation of target mRNAs. The present study was designed to identify miRNAs in C. albicans and determine their possible roles in this organism. miRNA-sized small RNAs (msRNAs) were cloned in C. albicans by deep sequencing, and their secondary structures were analyzed. All the cloned msRNAs satisfied conditions required to qualify them as miRNAs. Bioinformatics analysis revealed that two of the most highly expressed C. albicans msRNAs, Ca-363 and Ca-2019, were located in the 3' untranslated region of the corticosteroid-binding protein 1 (CBP1) gene in a reverse orientation. miRNA mimics were transformed into C. albicans to investigate their RNA-inhibitory functions. RNA oligonucleotide-transformed C. albicans was then observed by fluorescent microscopy. Quantitative PCR analysis showed that these msRNAs did not inhibit CBP1 gene expression 4 hr and 8 hr after ectopic miRNA transformation. These results suggest that msRNAs in C. albicans possess an miRNA-triggered RNA interference gene-silencing function, which is distinct from that exhibited by other eukaryotic systems.