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        검색결과 20

        1.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A sediment control dam is an artificial structure built to prolong sedimentation in the main dam by reducing the inflow of suspended solids. These dams can affect changes in dissolved organic matter (DOM) in the water body by changing the river flow regime. The main DOM component for Yeongju Dam sediment control of the Naeseongcheon River was analyzed through 3D excitation-emission matrix (EEM) and parallel factor (PARAFAC) analyses. As a result, four humic-like components (C1~C3, C5), and three proteins, tryptophan-like components (C2, C6~C7) were detected. Among DOM components, humic-like components (autochthonous: C1, allochthonous: C2~C3) were found to be dominant during the sampling period. The total amount of DOM components and the composition ratio of each component did not show a difference for each depth according to the amount of available light (100%, 12%, and 1%). Throughout the study period, the allochthonous organic matter was continuously decomposing and converting into autochthonous organic matter; the DOM indices (fluorescence index, humification index, and freshness index) indicated the dominance of autochthonous organic matter in the river. Considering the relative abundance of cyanobacteria and that the number of bacteria cells and rotifers increased as autochthonous organic matter increased, it was suggested that the algal bloom and consequent activation of the microbial food web was affected by the composition of DOM in the water body. Research on DOM characteristics is important not only for water quality management but also for understanding the cycling of matter through microbial food web activity.
        5,100원
        2.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, we estimated the applicability of length-weight relationship-based biomass calculations by comparison of body length of genus Polyarthra collected from different habitats. Through the comparison, we also tested availability of representative species-specific biomass value of Polyarthra which is often used without length measurement. Polyarthra samples were collected from rivers (Han River and Nakdong River) and reservoir (Paldang Reservoir), and the body length was measured for statistical comparison among habitats and biomass calculations using different equations suggested previously. According to the results, the body length of Polyarthra spp. was significantly different among sampling sites, and the necessity of body length measurement for rotifer species in each situation has been suggested rather than using the representative biomass values which is fixed without considering time and space. Comparison of suggested biomass calculations based on our measured Polyarthra body length, the equation suggested by McCauley showed more reasonable range of biomass values than that suggested by EPA. In addition, in order to calculate more accurate biomass, it is necessary to measure the body length of rotifers, at least more than 44 individuals to reduce error probability to less than 5% with 99% probability. However, since direct measurement of rotifers biomass is limited, it is considered that further analyses are required for more precise application of rotifer biomass of which has high variability due to complex morphologies and species-specific cyclomorphosis often induced by biotic and abiotic factors in the habitats.
        4,000원
        3.
        2017.04 구독 인증기관·개인회원 무료
        The green peach aphid, Myzus persicae, is one of the most important pests of vegetable crops worldwide. This species cause direct damage by feeding on plant nutrients and indirect damage as transmits many virus vectors. The control of aphid has relied on the use of chemical insecticides and their intensive use over many years has led to the development of resistance. To surmount or avoid these problems, we screened the entomopathogenic fungi against green peach aphid and evaluated their virulences. Several entomopathogenic fungal isolates were selected with high virulence to green peach aphid. Additionally, the antimicrobial activity of the selected fungal isolates was tested and analyzed to phytopathogens. Consequently, these entomopathogenic fungi would be used effectively for dual control agents for the green peach aphid and phytopathogen.
        7.
        2008.02 구독 인증기관 무료, 개인회원 유료
        This paper describes the traditional Ondol medical care, the specific combination of ancient and contemporary examples to be articulated. As a traditional Korean culture, to be extracted from the historical perspective, it described the relationship and origins between them, From a health perspective, in accordance with the logic and pharmacologyit introduced Ondol as the important principle of health care equipment. The modern architecture of some common harmful to the body, from the perspective of Ondol, it should be improved and based on scientific proof to the theory.
        4,000원
        9.
        2004.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        원형질체 융합에 의한 화합성 및 불화합성 종간 체세포잡종을 얻었다. 화합성 종간인 Pleurotus ostreatus 와 P. florida 의 융합체는 이질핵체 (heterokaryon) 를 형성하였고, 불화합성 종간인 P. cornucopiae + P. florida , P. ostreatus + Ganoderma applanatum, P. florida + Ganoderma lucidum, 그리고 P. ostreatus + Flammulina velutipes 는 합핵체(synkaryon) 를 형성하였다. 이질이핵체는 동일한 양상의 자실체를 형성하는데 비해 합핵체는 유사분열상의 꺽쇠연결체 형성, 한쪽 친과 유사한 자실체 형성, 비정상적 유전형질 분리 및 유전자재조합 현상을 나타내었다. 화합성 및 불화합성 계통간 융합체의 RAPD 분석결과 화합성 종간 융합체는 동일한 DNA 패턴을 나타내었고, 불화합성 종간 융합체는 한쪽 친과 유사한 DNA 양상이면서 비양친 DNA 밴드도 형성하였다. 합핵체의 패턴은 microgenome insertion type 과 macrogenome insertion type 으로 구분되었다. 합핵체의 자실체 발생은 융합 모균주 양친의 자가임성에 의존하는데 이는 느타리의 동형핵체 자가임성과 유사한 양상이었고, 교배형 전환과 관련이 있는 것으로 사료된다. 여기서는 이러한 관점에서 논할 것이다.
        4,300원
        11.
        2001.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        4,000원
        14.
        2016.06 KCI 등재 서비스 종료(열람 제한)
        The effect of sudden changes of water temperature (WT) on the survival rate and physiological responses of the red spotted grouper (Epinephelus akaara) were examined by manipulating WT control system for 9 days. Experimental condition was divided in two different regimes at low (from 10°C to 4°C, decreased 1℃/d) and high (from 28°C to 34°C, increased 1°C/d) WT. Survival rate of experimental fishes were observed, and determined the changes of hematological characteristics by analyzing plasma levels of cortisol, glucose, total protein, and electrolytes (Na+, Cl–, K+). No mortality was observed until low WT 6°C (144 h) and high WT 32°C (96 h), and 100% mortality was observed at low WT 4°C (216 h) and high WT 35°C (171 h). Plasma levels of cortisol and glucose increased rapidly as decreasing WT, and the loss of swimming ability and respiration response was observed at low WT 7°C and high WT 34°C conditions.
        15.
        2016.06 KCI 등재 서비스 종료(열람 제한)
        We observed the osteological development of larval and juvenile red spotted grouper (Epinephelus akaara) in order to generate data for the assessment of skeletal deformities and to inform phylogenetic systematics research. Larvae and juveniles were obtained from a aquafarm in Muan-gun, Jeolla-namdo Province, Korea. The average water temperature at the time of breeding was 23.0°C and average water salinity was 33.0 psu. Freshly hatched fish larvae had not undergone any ossification, but ossification of the parasphenoid bone, which forms the base of the cranium, occurred as the juveniles reached an average body length (BL) of 2.49 mm. At the same time, ossification of the preopercle and opercle occurred in the operculum, and ossification of the maxilla, which forms the upper jaw, and the dentary bones, which form the lower jaw, began. In addition, ossification of the vertebra occurred by formation of 7 vertebral centra and the neural spine in the abdominal vertebra. When the juveniles reached an average (BL) of 5.22 mm, ossification of the nasal, lateral ethmoid, and alisphenoid bones occurred in the cranium; ossification of the endopterygoid and metapterygoid bones began in the palatine region; and ossification of the hypohyal and interhyal bones occurred in the hyoid arch. At an average (BL) of 20.9 mm, ossification of the basisphenoid bone in the cranium and the suborbital bone in the orbital region occurred. Ossification of the vertebra then occurred by the formation of long pairs of ribs from the third to the ninth abdominal vertebrae, completing osteological development.
        16.
        2016.03 KCI 등재 서비스 종료(열람 제한)
        This study was conducted in order to examine the egg development in red spotted grouper, Epinephelus akaara and the morphological development of its larvae and juveniles, and to obtain data for taxonomic research. This study was conducted in June 2013, and 50 male and female fish were used for the study. One hundred μg/kg of LHRHa was injected into the body of the fish for inducing spawning, and the fish were kept in a small-sized fish holder (2×2×2 m). Eggs were colorless transparent free pelagic eggs, 0.71–0.77 mm large (mean 0.74±0.02 mm, n=30), and had an oil globule. Hatching started within 27 h after fertilization. Pre-larvae that emerged just after hatching were 2.02–2.17 mm in total length (mean 2.10±0.11 mm), their mouth and anus were not opened yet, and the whole body was covered with a membrane fin. Post-larvae that emerged 15 days post hatching were 3.88–4.07 mm in total length (mean 3.98±0.13 mm), and had a ventral fin with two rays and a caudal fin with eight rays. Juveniles that were formed at 55 d post hatching, were 31.9–35.2 mm in total length (mean 33.6±2.33 mm), with red color deposited over the entire body, and black chromophores deposited in a spotted pattern. The number of fin rays, body color, and shape were the same as that in the adult fish.
        20.
        2002.12 KCI 등재 서비스 종료(열람 제한)
        A new covered barley variety, 'Daeyeonbori' was developed from the cross between Milyangketbori, a stabile for machine harvest, and Olbori by the barley breeding team in the National Yeongnam Agricultural Experiment Station (NYAES) in 1999. An elite line,