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        검색결과 15

        3.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, newly improved Ferron assay test haved on timed spectrometry was used for the determination of hyolrolytic Al species presented in PACl coagulant. The color development reagent ferron was prepared by using conventional method and two newly developed methods. Then the ferron assay test was used to compare and analyze the distribution of Al(III) hydrolyzed species presented in the prepared PACl and alum. The preparing method of reagent A required an aging period of 7 days by adding a hydroxylamine hydroxide and a 1,10-phenanthroline monohydrate reagent, whereas the preparing method of reagent B was used as a coloring agent immediately without aging time. The regression analysis between UV absorbance and Al concentrations of conventional method and newly developed method of ferron reagents in low-concentration aluminum solutions and high-concentration aluminum solutions, showed the correlation coefficients of 0.999 or higher, as showing high correlations of conventional method and newly developed method. Applying Ferron assay test, Al species in the PACls and alum were classified as Ala(monomeric Al), Alb (polymeric Al), and Alc (colloidal and precipitated Al). Distribution of Al(III) hydrolyzed species according to the preparation of ferron colorimetric reagents was similar.
        4,000원
        5.
        2019.04 구독 인증기관·개인회원 무료
        점착트랩은 특정 광파장에 유인되는 곤충의 반응을 이용하여 비행 곤충의 유살 및 모니터링에 널리 이용되고 있다. 그러나 유색 점착트랩은 해당 색상에 반응을 보이는 모든 곤충을 유인하기 때문에 비표적곤충(Non target insect)이 부착되는 문제가 발생한다. 비표적곤충은 부착면을 차지하여 표적곤충의 유인을 방해하며, 해충밀도 모니터링에 필요한 노력과 시간 소요를 증대시킨다. 본 연구에서는 비표적 곤충과 이물질의 부착을 물리적으로 방지하기 위하여 내경 5mm, 10mm의 방지망을 설치하였을 때, 각 처리에 따른 유입 곤충의 종다양성 지수를 분석하여 방지망의 현장 적용 가능성을 검정하였다. 그 결과 망을 처리하지 않은 트랩과 5mm, 10mm 방지망을 설치한 트랩 간 종다양성 지수에서 유의한 차이를 보이지 않았다. 그러나 포획된 총 종의 수는 망을 처리하지 않은 트랩에서 높게 나타났는데 이는 대형 비표적 곤충의 포획수가 높은 것이 주 요인이었다. 표적 해충인 총채벌레, 가루이 등 미소해충의 유입 빈도 또한 무처리, 5mm, 10mm 간에 유의한 차이를 보이지 않아 방지망의 설치가 표적곤충인 미소해충의 유입에 악영향이 없으며, 5mm 망을 적용하여도 무방하다는 결과를 얻었다.
        7.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Aquatic ecosystems are receiving various harmful effects due to anthropogenic chemical pollutions. To protect wildlife, risk assessments of the chemicals are conducted using reference indexes of toxicity estimated by species-level laboratory tests and/or micro-/mesocosm community-level studies. However, the existing micro-/mesocosm communities are structurally too complicated, and it is also difficult to compare the experimental results directly with those from species-level tests. Here, we developed a procedure of a simple bi-trophic microcosm experiment which contains the common species (a green algae, Pseudokirchneriella subcapitata and a cladoceran, Daphnia magna) for testing chemical toxicities. For the proper operation of bitrophic microcosm experiment, the minimum required concentration of primary producer (P. subcapitata) is 5×105 cells mL-1. The microcosm system showed higher stability when the initially introduced D. magna population was composed of neonates (<24-h old) than adults and those mixture. This simple microcosm system would be an applicable tool to estimate the disturbing impacts of pollutants on plant-herbivore interactions, and linking the species- and population-/community level risk assessments in the future studies.
        4,000원
        8.
        2014.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, two commercial PCR and ELISA test kits were examined for identification of eight animal species (beef, pork, chicken, duck, turkey, goat, lamb, and horse) from raw meat and meat products in Korea. The detection limit in RAW meat ELISA kit® on three types of meat samples blended with beef, pork and chicken, demonstrated that all meat species were differentiable down to 0.2%. RAW meat ELISA kit® on animal species resulted in differentiation rate of 94.5% for beef, 93.3% for pork, 90% for lamb, and 100% for chicken, duck, turkey, goat, and horse. In contrast, Powercheck Animal Species ID PCR kitTM resulted in 100% specificity at 0.05% limit of detection for all meat species. The detection limit of Cooked Meat ELISA kit® on mixed meat samples heat-treated with different temperatures and times, resulted in 0.1% for all heat-treated mixed meat except for chicken at 1.0%. Additionally, ELISA kit on sixty meat products resulted in specificity of 31.8% for ham, 13.6% for sausages, and 12.5% for ground processed products, and relatively low rate for more than 2 types of mixed meats. On the contrary, meat species differentiation using PCR kit showed higher percentage than that using ELISA kit®: 50.0% for ham, 41.7% for sausages, and 28.6% for ground processed meat. Futhermore, PCR kit on 54 dried beef meats detected pork genes in 13 products whereas ELISA kit showed negative results for all products. Hence, the possibility of cross-contamination during manufacturing process was investigated, and it was found that identical tumblers, straining trays, cutters and dryers were used in both beef and pork jerky production line, suggesting the inclusion of pork genes in beef products due to cross-contamination. In this study, PCR and ELISA test kits were found to be excellent methods for meat species differentiation in raw meat and heat-processed mixed meat. However, lower differentiation rate demonstrated in case of meat processed products raised the possibility of inclusion of other species due to cross-contamination during manufacturing process.
        4,000원
        9.
        2012.12 구독 인증기관 무료, 개인회원 유료
        LIVE/DEAD® BacLight™ and alamarBlue® are fluorescent materials used for the enumeration of live and dead bacteria. LIVE/DEAD® BacLight™ is generally used for confocal microscopy applications to differentiate live from dead bacteria in a biofilm or planktonic state. AlamarBlue® has also been used widely to assay live and dead bacteria in a planktonic state. Whilst these materials are successfully utilized in experiments to discriminate live from dead bacteria for several species of bacteria, the application of these techniques to oral bacteria is limited to the use of LIVE/DEAD® BacLight™ in biofilm studies. In our present study, we assessed whether these two methods could enumerate live and dead oral bacterial species in a planktonic state. We tested the reagents on Streptococcus mutans, Streptococcus sobrinus, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans and Enterococcus faecalis and found that only LIVE/DEAD® BacLight™ could differentiate live from dead cells for all five of these oral strains. AlamarBlue® was not effective in this regard for P. gingivalis or A. actinomycetemcomitans. In addition, the differentiation of live and dead bacterial cells by alamarBlue® could not be performed for concentrations lower than 2 × 106 cells/ml. Our data thus indicate that LIVE/DEAD® BacLight™ is a more effective reagent for this analysis.
        4,000원
        10.
        2010.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The effect of altitude and latitude on biodiversity (or species richness) has been a topic of great interest for many biogeographers for a long time. This study was conducted to examine the dynamics of species richness of aquatic insects along the altitudinal gradient in 24 wetlands on Mt. Halla, Jeju and test the Rapoport’s rule. The species richness of aquatic insects monotonically decreased with increasing altitude, showing a significant inverse correlation (r = -0.64). However, the pattern of species richness with altitude showed a hump-shaped relationship, with a peak in species richness at intermediate elevations when the effects of area were removed. The altitudinal range of species tended to increase with increasing altitude, as Rapoport’s rule predicts. There was a positive correlation between the altitudinal range size and the midpoint of the range size (Median) except for Hemiptera (Odonata: r = 0.75, Hemiptera: r = -0.22, Coleoptera: r = 0.72, Total: r = 0.55). Also, the extent of average altitudinal range of high-altitude species was 904.3m, and it was significantly wider than a 469.5m of low-altitude species. Consequently, the species richness of aquatic insects in wetlands on Mt. Halla along the altitudinal gradient well supported Rapoport’s rule.
        4,200원
        11.
        1998.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We studied behaviour pattern of anchovy (Engraulis japonicus) shoal by a method of shoal echo integration and tested species identification by a method of artificial neural network using the acoustic data collected in the East China Sea in March 1994 and in the southern coastal waters of the East Sea of Korea in March 1995. Between areas, frequency distribution of 10 shoal descriptors was different, which showed characteristics of shoal behaviour in size, bathymetric position and acoustic strength. The range and mean of shoal size distribution in length and height was wider and bigger in the southern coastal waters of the East Sea than in the East China Sea. Relative shoal size of China Sea. Fractal dimension of shoal was almost same in both areas. Mean volume reverbration index of shoal was 3 dB higher in the southern coastal waters of the East Sea than in the East China Sea. The depth layer of shoal distribution was related to bottom depth in the southern coastal waters of the East Sea, while it was between near surface and central layer in the East China Sea. Principal component analysis of shoal descriptors showed the correlation between shoal size and acoustic strength which was higher in the southern coastal waters of the East Sea, than in the East China Sea. Correlation was also found among the bathymetric positions of shoal to some degree higher in the southern coastal waters of the East Sea than in the East China Sea. The anchovy shoal of two areas was identified by artificial neural network. The contribution factor index (Cio) of the shoal descriptors between two areas were almost identical feature. The shoal volume reverberation index (Rv) was showed the highest contribution to the species identification, while shoal length and shoal height showed relatively high negative contribution to the species identification.
        4,000원
        12.
        2011.09 KCI 등재 서비스 종료(열람 제한)
        The mixotrophic marine ciliate Mesodinium rubrum possesses a highly modified algal endosymbiont as a nutrition source for the species. Accordingly, we assumed that the species can reflect the ecotoxicity on marine producer (as phytoplankton) and consumer (as zooplankton) both. A series of experiments were conducted to identify the potential of the species as a standard test species for marine ecotoxicological study. The comparison of species sensitivity on reference toxic materials was made using potassium dichromate for phytoplankton and copper chloride for zooplankton. The ciliate revealed the highest sensitivity on both reference materials among the seven test species including phytoplankton, benthic copepod and rotifer species. The toxicity end point of the species was 72hr-EC50=1.52 mg/L (as potassium dichromate) estimated by population growth inhibition (PGI), which is more sensitive than the most sensitive phytoplankton Skeletonema costatum (72hr-EC50=3.05 mg/L). As comparison to rotifer, it also revealed higher sensitivity on copper chloride; 72hr-EC50=0.38 mg/L for ciliate and 48hr-EC50=0.48 mg/L for rotifer. Also, the elutriate toxicity test of various ocean disposal wastes were conducted to identify the potential of ciliate toxicity test application using industrial waste sludges. The toxicity of leather processing waste sludge was highest on the ciliate, followed by dyeing waste sludge and dye production waste sludge as an increasing order of toxicity. 72h-EC50 of ciliate PGI test was 1.83% and that of S. costatum 3.84% for leather waste sludge which showed highest toxicity. The toxicity test results also revealed that the highest sensitivity was observed on ciliate species on ocean disposed sludge wastes. Also, ciliate toxicity test well discriminated the degree of toxicity between sludge sources; 72h-EC50 values were 1.83% for leather processing waste sludge, 16.75% for dye production waste sludge and 27.75% for textile production waste sludge. Even the laboratory culture methods of the species were not generally established yet, the species has high potential as the standard test species for marine toxicity test in terms of the dual reflection of phyto- and zooplankton toxicity from single test, sensitivity and test replicability.
        13.
        2010.04 KCI 등재 서비스 종료(열람 제한)
        The genus Allium which is one of the biggest plant genera comprises around 750 species that show the various morphological and ecological diversity with various taxonomic and geographical groups. The species of genus Allium has not been clearly distinguished because of extraordinary large amount of variation. We developed 8 simple sequence repeat markers (SSRs) which showed polymorphism within A. sativum accessions, but it was insufficient in transferability analysis of other Allium species. In this regard, we finally selected 50 primer pairs which was applicable to other Allium species adding to 8 primer pairs. According to results from application of 50 SSR markers to 9 Allium species, the average number of alleles ranged from 1.400 (A. porrum) to 1.889 (A. tuberrosum) and A. tuberosum (2n=32) has maximum 9 alleles. The lowest transferability value was 42.0% ( A. cepa and A. chinense) while A. sativum showed 96.7%. The A. porrum conceived to be close relationship to A. sativum as Allium subgenera revealed higher transferability (73%) rather than other Allium species. According to PCA analysis, three groups were divergent, and the A. fistulosum and A. sativum revealed the distinct groups and the rest 7 species formed another group.
        14.
        2005.12 KCI 등재 서비스 종료(열람 제한)
        A series of experiments was conducted to identify the potential of five phytoplankton species as standard test species for marine ecotoxicological tests. The candidate phytoplankton species are Skeletonema costatum, Heterosigma akashiwo, Prorocentrum micans, Isochrysis galbana, and Tetraselmis suecica. Salinity tolerance and sensitivity on potassium dichromate as a reference material were identified. Toxicity of eleven ocean-dumped sewage sludges and four red tide expellent extracts were estimated by the inhibition of population growth rates (PGR) of marine diatom S. costatum. While most species revealed relatively weak tolerance on salinity, T. suecica demonstrated the highest salinity tolerance ranged from 5~35 psu and the others 15~35 psu. H. akashiwo revealed the highest sensitivity as 72h IC50=0.76mg/L and T. suecica the lowest as 72h IC50=8.89mg/L on potassium dichromate. Sludge extracts from industrial waste, domestic sewage and livestock farm waste sludge showed high toxicity as 72h IC50<2% and lowest toxicity from filtration bed sludge as 72h IC50=30.50%. NOEC (No Observed Effective Concentration) of sludge extract ranged from <0.4% to 1.6% and this indicated high phytotoxicity of ocean dumped sewage sludge. The test sensitivity of phytoplankton PGR inhibition was much higher than those of marine rotifer Brachionus plicatilis mortality test and bioluminescent inhibition test by marine bacteria Vibrio fischeri, and comparable with the sea urchin (Strongylocentrotus intermedius) fertilization test. As a result the phytotoxicity test using phytoplankton PGR inhibition (IC50) must be a useful tool for marine phyto-toxicological evaluation of ocean dumped materials.