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        검색결과 20

        1.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Paddy fields provide important habitats for biodiversity conservation within the agricultural ecosystem. Their importance is gradually increasing as their ecological value is better understood. Benthic macroinvertebrates dominate paddy fields. They play an essential role in maintaining the biodiversity of paddy ecosystems. This study aimed to analyze characteristics of benthic macroinvertebrate communities and main environmental factors affecting the distribution of golden apple snails (Pomacea canaliculata). Results showed that the diversity index (H ′) of the benthic macroinvertebrate community was the highest at the Sangju site (St. 12) but the lowest at the Sancheong site (St. 18). Total Dissolved Solids (TDS), salinity, and Electrical Conductivity (EC) values were the highest in Gimhae and Yeongam based on Canonical Correspondence Analysis (CCA). Numbers of P. canaliculata (m-2) were relatively low in Gunsan and Iksan where water temperatures were high. Therefore, changes in geographical characteristics and environmental factors might affect the distribution of P. canaliculata and characteristics of benthic macroinvertebrate communities. Results of this study can be used as primary data for biodiversity conservation and ecosystem service evaluation in agroecosystems.
        4,300원
        2.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to verify the mediating effect of Korean language ability on the effect of marriage immigrants’ safety education attitude on safety awareness. A survey was conducted on marriage immigrants living in the Daejeon and Chungcheong regions, and the responses of 109 people were used for the analysis. After controlling for gender, nationality, age, educational background, period of stay, region of residence, and presence or absence of safety accidents, the analysis was performed according to the step-by-step approach of Baron and Kenny(1986). In order to verify the statistical significance of the mediating effect of Korean proficiency, the Sobel test was conducted. As a result of the study, it was confirmed that marriage immigrants’ safety education attitude had a significant positive (+) effect on safety awareness, and Korean language ability had a partial mediating effect on the relationship between marriage immigrants’ safety education attitude and safety awareness.
        4,000원
        3.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적: 안경사 직무를 분석하여 국가시험 교과목과의 연계성을 확인하고 대학의 시험과목 비율과 교육과정 개발에 기초자료를 제공한다. 방법 : 안경사 872명과 안경광학과 교수 99명을 대상으로 5개의 직무영역과 18개의 일로 구성된 설문을 조사하여 분석하였다. 결과 : 안경사 직무분석에서 작업의 중요도와 필요도가 모두 높은 영역에서 필요능력인 지식과 기술을 도출하여 안경조제가공(39.1%), 시력검사(27.5%) 및 콘택트렌즈(14.8%), 기타(18.6%)의 비중을 통해 안경사 1차 직무 분석(2000년)과 비교해 검안안경사 분야로 안경사의 직무가 이동된 것으로 나타났다. 결론: 안경사 직무에서의 변화는 안경사 국가시험과 대학의 교육과정에 적절히 반영되어야 할 것으로 생각된다.
        4,000원
        5.
        2017.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 실험에서는 냉동 새우(Litopenaeus vannamei)를 4oC에서 12일동안 저온 저장하며, 키토산 코팅과 천연보존제의 병행처리(0.05% carvacrol, 0.05% thymol)가 미생물(중 온균, 저온균, Pseudomonas spp., H2S 생성균)의 성장과 새우의 이화학적 특징(총 휘발성 질소화합물, pH) 및 관능적 품질(외관, 냄새, 전반적 수용도)에 미치는 영향을 살펴보았다. 키토산 코팅과 carvacrol 병행 처리, 키토산 코팅과 thymol 병행 처리는 모든 대상 미생물의 성장을 억제하였고 특히 중온균, 저온균, H2S 생성균의 경우 실험 의 마지막 날인 12일째까지 유의적인 항균효과(p < 0.05)를 보였다. 이 처리구들은 총 휘발성 질소화합물과 관능적 특성(외관, 냄새, 전반적 수용도)에서도 12일째까지 유의적인 차이(p < 0.05)를 보였으나 pH에서는 유의적 차이 가 없었다. 따라서 키토산 코팅과 carvacrol 병행 처리, 키토산 코팅과 thymol 병행 처리는 새우의 주요 부패 미생 물의 성장을 효과적으로 억제하는 것으로 보이며 냉장 새우의 유통기간 연장에 활용할 수 있을 것으로 보여진다.
        4,000원
        6.
        2017.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to investigate the effect of cold plasma combined with UV-C irradiation against Escherichia coli O157:H7, Salmonella enterica serovar Typhimurium, and Listeria monocytogenes on lettuce. E. coli O157:H7, S. Typhimurium, and L. monocytogenes, corresponding to approximately 5.82, 5.09, 5.65 log CFU/ g, were inoculated on lettuce, respectively. Then, the lettuce was treated with cold plasma, UV-C and combination (cold plasma + UV-C), respectively. The treated lettuce was stored for 9 days at 4oC for microbiological analysis and sensory evaluation. Cold plasma reduced the populations of E. coli O157:H7, S. Typhimurium, and L. monocytogenes by 0.26, 0.65, and 0.93 log CFU/g, respectively. Each microorganism were reduced by 0.87, 0.88, and 1.14 log CFU/ g after UV-C treatment. And, the combined treatment that was treated by cold plasma after UV-C treatment reduced the populations of inoculated microorganisms by 1.44, 2.70, 1.62 log CFU/g, respectively. The all treatment significantly (p < 0.05) reduced the populations of all inoculated bacteria compared to untreated lettuce. UV-C combined with cold plasma was the most effective for reducing the pathogenic bacteria on lettuce, by showing log-reductions of ≥ 2.0 log CFU/g. All treatment was not significantly different until 6 day storage compared to control group in terms of appearance, texture and overall acceptability. Therefore, the combined treatment will be an effective intervention method to control the bacteria on lettuce.
        4,000원
        8.
        2015.10 구독 인증기관·개인회원 무료
        Headwater streams are the main sources of water sediment and organic material for downstream reaches and their small catchments coupled terrestrial-aquatic linkages. Because headwater streams provide valuable habitats for unique and diverse assemblages of aquatic fauna, they are also essential for sustaining the structure and function of the watersheds. Therefore, it has been recently supported that headwaters are important areas for maintaining biodiversity. In this study, we surveyed four different headwater streams in different watersheds to characterize differences of benthic macroinvertebrate assemblages among study streams. Benthic macroinvertebrates were collected seasonally with a Surber net at four different streams. In addition, hydrological and physicochemical environmental factors including temperature, discharge, width, conductivity, dissolved oxygen and pH were also measured at each sampling site. Community indices were used to differentiate spatiotemporal changes of macrointertebrate communities. Multivariate analysis were used to characterize the relationships between communities and environmental factors. Differences of their environmental condition such as meteorological factors and stream hydromorphological factors were reflected in the ordination with macroinvertebrate communities.
        9.
        2015.04 구독 인증기관·개인회원 무료
        Benthic macroinvertebrates are sedentary and have an intermediate life span ranging from months to a few years. They play a key role as consumers in the food trophic structure by linking producers, top carnivores, and decomposers in aquatic communities. Therefore, they have been widely used for ecological assessment of aquatic ecosystem health in an integrative and continuous manner. In this study, we characterized benthic macroinvertebrate communities at reference sites, which are not disturbed. Benthic macroinvertebrates were collected seasonally with a Surber net at three different streams (Pocheon, Hongcheon, and Namhae). In addition, hydrological and physicochemical environmental factors including temperature, discharge, width, conductivity, dissolved oxygen and pH were also measured at each sampling site. Spatial and temporal differences of benthic macrointertebrate communities were analyzed based on community indices, functional guilds, etc. relating to their environmental factors. Multivariate analysis were used to characterize the relationships between communities and environmental factors. Benthic macroinvertebrates were significantly different among sampling sites reflecting differences of their environmental condition such as hydromorphological factors, meteorological factors, etc.
        10.
        2014.04 구독 인증기관·개인회원 무료
        Distribution of aquatic organisms is governed by various environmental factors Hydromorphological characteristics which are heavily affected by heavy rains in stream are one of the fundamental factors to influence the distribution of aquatic organisms. In this study we evaluated the difference response of two aquatic species Chironomus yoshimatisui and Limnodrilus hoffmesteri habiting to changes of discharge due to heavy rains. We compared the differences in their resilience and recover to disturbances. Our results showed that after a heavy rain during the sampling periods, the proportion of macrosubstrate highly increased and was not recovered into the previous states. Nonmetric Multi-dimensional scaling based on Chironomidae and Oligochaeta biota well represented annual and seasonal differences with heavy rain effects. Random forest model showed that the abundance of C. yoshimatisui were mainly influenced by microsubstrate, precipitation and Reynolds number, whereas stream roughness, mesosubstrate and macrosubstrate much more influenced the abundance of L. hoffmesteri.
        11.
        2013.10 구독 인증기관·개인회원 무료
        This study was carried out to investigate the changes of guilds in benthic macroinvertebrate community in a undisturbed headwater stream. Samples were collected seasonally with a Surber sampler (30×30cm) at three different sampling sites (five replicates in each sampling sites) at Bongsunsa stream in Korean National Arboretum in Gyeonggi-do for 7 years from 2006 to 2012. Physicochemical environmental factors including discharge, water width, substrate composition, dissolved oxygen, pH and conductivity were also measured at each sampling sites. Changes of community indices and functional guilds such as functional feeding groups and trophic groups were evaluated in each sampling sites during study periods. In the samples, 84 species (9 order, 36 family) were identified, and Gammarus sobuegensis, Chironomidae spp, Ephemera strigata and Ecdyonurus kibunensis were dominant taxa. Considering the changes of functional feeding groups, shredder tended to decrease from upstream to downstream, whereas collector-gatherer and collector-filterer became higher. In addition, shredder was higher during autumn seasons. Self-Organizing Map was also applied to find out the temporal changes of benthic macroinvertebrate community composition, displaying the effects of seasonal variations in reference stream ecosystems.
        12.
        2013.10 구독 인증기관·개인회원 무료
        This study was conducted to evaluate the seasonal changes of benthic macroinvertebrate communities in a reference stream as well as the effects of physicochemical environmental factors on benthic macroinvertebrate communities in a study stream. Benthic macroinvertebrates were sampled seasonally at five different sampling sites with five replicates at Changjeon stream in Mountain Gariwang from spring to winter in 2011. Physicochemical environmental factors (e.g., discharge, width, substrate, conductivity, dissolved oxygen, pH and water temperature) were measured at each sampling sites. Water quality factors such as conductivity, dissolved oxygen and pH were similar among the sampling sites, whereas hydrological factors including discharge and width tended to be higher from upstream to downstream. In substrate composition, the relative ratio of large substrate such as cobbles was higher in summer season. In macroinvertebrate samples, 79 species with 2 phylum, 5 order and 9 family were identified during the sampling periods. Gammarus sp. was higher in upstream (sites 1 and 2), whereas Chironomidae spp. tended to be higher in downstream. In functional feeding groups, shredder was higher in upstream, whereas predator and collector-gatherer were higher in downstream. The ratios of Gammarus sp. and Plecopetera were higher in summer. Nonmetric multidimensional scaling was applied to figure out the differences of macroinvertebrate communities during the survey periods, representing the seasonal changes as well as hydrological gradients.
        13.
        2013.04 구독 인증기관·개인회원 무료
        Pomacea canaliculata (golden apple snail) as an invasive species in Asia has become a serious agricultural pest, especially in young rice, and makes significant environmental changes resulting from the depletion of macrophytes in natural wetlands. Even though various environmental factors influence to growth rate, reproduction, survival and behavior in apple snail, water temperature is one of the overwhelming effect on freshwater snails in general. In this sense, the objective of this study was to examine the changes of individual behavior in the apple snail according to the temperature changes. The snails were acclimated at 25℃, and 9 behavior categories were examined in each temperature regime (25℃ to 30℃, 2 5℃ to 20℃, and 25℃ to 15℃) for three days. Autocorrelation function (ACF) was applied to characterize the presence or absence of periodic behaviors in apple snails. The snails’ behavior in the treatment of elevated temperature were irregularly fluctuated or decayed in most behavior categories. On the other hands, in decreasing temperature from 25℃ to 15℃, the snails were nonstationary, especially in clinging behavior. The snails showed periodicity and some of them were decayed in clinging behavior in temperature changing from 25℃ to 20℃.
        14.
        2011.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적: 콘택트렌즈 착용자들이 느끼는 건성안과 관련된 안구증상을 알아보고자 한다. 방법: 하루 평균 8시간 이상, 주 3일 이상 콘택트렌즈를 착용하는 대학생들에게 콘택트렌즈 착용과 관련된 건성안설문지(CLDEQ)를 작성하도록 하여 성별, 착용렌즈에 따른 안구증상의 정도를 0점에서 5점 척도로 하여, 건조감과 기타 안구증상들과의 상관성을 알아보았으며 콘택트렌즈로 인해 유발되는 안구증상을 관리하는 방법과 비용 등에 대해 알아보았다. 결과: 콘택트렌즈 착용과 관련된 안구증상의 정도를 점수화한 결과, 안구건조감(dryness) 2.53±0.86점, 안구불편감(discomfort) 2.35±0.81점, 흐려보임(blurry vision)이 2.27±0.86점으로 높게 나왔고 눈부심(light sensitivity) 1.49±0.79점, 작열감(burning/stinging)이 1.43±0.78점으로 낮게 나왔다. 착용시간이 길어질수록 증상이 심해져 건조감은 렌즈착용 2시간 동안 1.81±0.93점에서 렌즈를 제거하기 전에는 3.63±1.13점(t=-27.755, p=0.000)으로 증가하였고 안구불편감은 1.84±1.10점에서 3.28±1.33점(t= -17.897, p=0.000)으로 증가하였다. 안구건조감과 다른 안구증상들 사이에서도 상관성이 있었다. 남자보다 여자에서, 정기교체렌즈나 일회용 렌즈보다는 연속착용렌즈에서 안구증상과 관련된 점수가 높았다. 결론: 건조감이나 안구불편감과 같은 증상이 콘택트렌즈 착용자들에게 흔하게 발생하는 것으로 보여지며 저녁이 될수록 그 증상이 심해지는 것으로 나타났다.
        4,200원
        15.
        2016.06 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        참취로부터 phenolic compounds를 추출 후 항산화 효과, 건강 기능성 식품 및 미용식품 활성을 검정하여 기능성 소재로 활용 가능성을 살펴보았다. 참취에 함유되어 있는 페놀성 물질은 물과 60% ethanol을 용매로 하여 추출하였을 때 각각 11.1 mg/g, 4.18 mg/g 함량을 나타내었다. 추출물의 phenolic 농도를 50~200 μg/mL로 조절하여 DPPH를 측정한 결과, 물 추출물과 ethanol 추출물 50 μg/mL phenolics 농도 에서 각각 87%, 91%였고, ABTS radical decolorization도 50 μg/mL phenolics 농도에서 각각 99%, 99%였다. Antioxidant protection factor는 200 μg/mL phenolics 농도에 서 물 추출물과 ethanol 추출물에서 각각 1.87 PF와 2.22 PF로 측정되었으며, TBARs값은 50 μg/mL phenolics농도에 서 물 추출물이 95%, ethanol 추출물에서 97%를 나타내었 다. Angiotensin converting enzyme(ACE) 저해능은 물 추출 물에서 50.8%, ethanol 추출물에서 69.4%의 저해율을 나타 내었으며, xanthine oxidase 저해능은 물 추출물은 50 μg/mL phenolics농도에서 91%, ethanol 추출물은 200 μg/mL phenolics농도에서 80%의 높은 효능을 보였다. α-Amylase 저해능은 물 추출물과 ethanol 추출물에서 각각 24%, 89% 로 ethanol 추출물에서 높은 효능을 보였다. Tyrosinase 저해 능을 측정한 결과 물 추출물과 ethanol 추출물에서 각각 47%, 25%의 미백 효과를 나타내었다. Elastase 저해능 측정 결과 물 추출물과 ethanol 추출물에서 각각 46%, 14%로 물 추출물에서 주름 개선 효과가 상대적으로 높게 나타내었 다. 이러한 결과로 보아 참취 추출물은 항산화 고혈압억제, 통풍억제, 당분해억제, 미백효과, 주름개선효과 등의 건강 기능성 식품 및 미용식품 활성 소재로서 활용 가능성이 큰 것으로 판단되었다.
        16.
        2016.02 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        In this study, the antioxidative activity and functional food activities of water and ethanol extracts from Pinus densiflora root were examined. It was more effective to use ethanol than water when extracting phenolic compounds. The extracted phenolic compounds from Pinus densiflora root for biological activities were examined. The phenolic compounds extracted with water and 80% EtOH were 1.86±0.04 mg/g and 6.85±0.16 mg/g, respectively. DPPH free radical scavenging activity of water and EtOH were each 86% and 85% at 100 μg/mL phenolics, respectively. ABTS radical decolorization activity was 48% in water and 68% in EtOH at 200 μg/mL. Antioxidant Protection Factor (PF) were 1.74 PF in water and 1.96 PF in EtOH at 50 μg/mL. TBARs of water and EtOH were 93% and 98%, respectively at 100 μg/mL. The inhibition activity on xanthine oxidase was 83.7% in water extracts and 79.6% in ethanol extracts. Inhibition on xanthine oxidase of water and ethanol extracts showed a higher inhibition effect than allopurinol. The inhibition activity on α-glucosidase was 14.8% in water extracts and 91.6% in ethanol extracts. The result suggests that P. densiflora root extracts may be useful as as functional food material.
        20.
        2008.10 KCI 등재 서비스 종료(열람 제한)
        The purple and blue grain of barley have anthocyanins that is good sources of antioxidant. Thus we investigated the malt and wort characteristic of purple and blue barley for brewing. During steeping period, anthocyanins content reduced both materials. However the lost content was different from 80% and 20% in purple and blue barley, respectively. Also the anyhocyanin content was different both malt comparing to raw grain from 0.4~4.2% in purple but 50% in blue grain. The wort and beer color(EBC unit) and content of polyphenol and soluble nitrogen from malt of purple and blue were higher than control malt(Hopum). There was no anthocyanins in wort and beer of malt in purple and blue. In these results, it was identified that the anthocyanins from raw grain lost during malting and brewing processing with conventional method.