• 한국생물환경조절학회:학술대회논문집
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• 한국생물환경조절학회 1997년도 봄 심포지움 및 학술논문발표요지
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• pp.62-64
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• 1997

작물생육은 근권 부근의 온도와 밀접한 관계가 있다. 따라서 외부환경의 영향을 받기 쉬운 단순 경량화된 순환형 무토양재배시스템내의 양액 또는 배지의 온도 변화를 파악하여 환경조절을 통한 적정 생육환경을 조성할 수 있다면, 작물의 생산성에 기여할 수 있다. 본 연구는 순환식 무토양재배시스템의 위치별 온도 분포 및 배양액의 공급 과 온도변화와의 관계를 분석하였다.

• 한국환경과학회지
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• 제14권9호
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• pp.861-871
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• 2005

This study was carried out to get more operational characteristics of Anoxic(anaerobic)-Oxic-Anoxic-Oxic $(AO)_2$ sequencing batch biofilm reactors (SBBRs) at the low TOC concentration, The operating time in anoxic (anaerobic) time to oxic time was I : I. Experiments were conducted to find the effects of the aeration time distribution on the organic matters and nutrients removal. Three lab-scale reactors were fed with synthetic wastewater based on glucose as carbon source. During studies, the operation mode was fixed. The first aeration time to the second aeration time in SBBR-I was 2 : 3, and those in SBBR-2 and SBBR-3 were I : 4 and 3 : 2, respectively. The organic removal efficiency didn't show large difference among three reactors of different aeration time distribution. However, from these study results, the optimum aeration time distribution in the first and the second aeration time for biological nutrient removal was shown as 3 : 2. The release of phosphorus was inhibited at the second non-aeration period because of the low TOC concentration and the nitrate produced by the nitrification at the first aeration period.

• The Korean Journal of Ecology
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• 제20권6호
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• pp.451-459
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• 1997

Seasonal and spatial distribution of vascular plants were examined and related to soil texture, pH, moisture and nutrient contents in the riparian zone of the Balan Stream. In spring the area was dominated by Alopecurus aequalis var. amurensis, was displaced by Persicaria thunbergii and Humulus japonicus in summer. From the stream channel to bank, soil texture and pH were not significantly differentiated, moisture decreased, organic matter and K increased, and TKN and available P increased in June and decreased in August. DCA ordination analysis by species distribution showed spatially and seasonally distinct patterns seasonal difference was evident on axis 1, and spatial difference according to the distance from stream channel was clear, too. Both axis 1 and axis 2 scores were significantly correlated with biomass, pH, and phosphate. Species richness increased were significantly correlated with biomass, pH, and phosphate. Species richness increaed with increasing organic matter and phosphate, and decreased with increasing soil moisture and K. Biomass increased with increasing organic matter, but was negatively related to pH, moisture, TKN, available P and K. Available P was significantly correlated with biomass, pH, and total soil nitrogen. In conclusion, the distribution of riparian vegetation was governed by soil physico-chemical properties, which are primarily determined by how far it is from the stream channel.

• Food Science and Biotechnology
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• 제15권2호
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• pp.232-237
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• 2006

Bacillus cereus group comprising B. cereus, B. thuringiensis, and B. mycoides was differentiated by polymerase chain reaction (PCR) and colony morphology. Prevalence of B. cereus group in rice and distribution of enterotoxin genes were determined as possible food poisoning agents. PCR using primers targeted for gyrB and cry genes could distinguish B. thuringiensis from B. cereus, and B. mycoides was differentiated by rhizoid morphological characteristics on nutrient agar. Among 136 rice and their processed products, prevalence of B. cereus group was 40%. B. cereus group consisted of 54 B. cereus, 11 B. thuringiensis, and 1 B. mycoides. Major isolates were B. cereus, with B. thuringiensis detected up to 10% among edible rice tested. Five enterotoxin genes, hbl, nhe, bceT, entFM, and cytK, were broadly distributed among B. cereus group, especially in B. cereus and B. thuringiensis. Prevalence of B. cereus group in rice and enterotoxin distribution suggest B. thuringiensis and B. cereus are toxigenic strain that should be controlled in rice and its products.

• Journal of the korean society of oceanography
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• 제32권3호
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• pp.145-155
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• 1997

The distribution of microzooplankton and hydrographic variables were measured in the Virginia portion of Chesapeake Bay and its major rivers. Samples were collected at 14 locations at monthly interval from September 1993 through December 1995. Ciliates were numerically dominated (>90%) and copepod nauplii comprised highest proportion of the total microzooplankton biomass (>77%). Copepod nauplii and ciliates were the most abundant at oligohaline water and rotifers at freshwater. Total microzooplankton density and biomass were usually higher at oligohaline stations than fresh water and polyhaline stations. Despite high nutrient concentration and phytoplankton density at eutrophic water, micro- and mesozooplankton biomass were low. Mesozooplankton were relatively abundant at polyhaline stations. The comparison between annual mean biomass of ciliates (12.7 ${\mu$}gC/1) and that of autotrophic picoplankton (13.5 {$\mu$}gC/1) revealed that ciliates were a major consumer of picoplankton production. The secondary production by ciliates was 12.7 ${\mu}$gC/1/day, representing 5% of the annual mean primary production in Chesapeake Bay, Total microzooplankton comprised 84% of the total zooplankton carbon content, representing five times higher than mesozooplankton biomass.

• The Korean Journal of Ecology
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• 제23권4호
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• pp.331-337
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• 2000

Fourteen different taxa of dictyostelid cellular slime molds were recovered from the alpine and subalpine zone in Mt. Paektu. In subalpine zone, six species were recovered : Dictyostelium minutum, D. brefeldianum, D. crassicaule, D. capitatum, Polysphondylium solitarium and P. pallidum. One of these species which were isolated from the soils of Larix olgensis community exhibited several distinctive features which differed from the published species. This species was designated as a new species, Polysphondylium solitarium Kang et Chang, sp. nov. When cultivated at 22~24$^{\circ}C$ on low-nutrient agar media with Escherichia coli, Polysphondylium solitarium is distinguishable from other species by the following combination of features: (ⅰ) the sorocarps with vinaceous pigmentation; (ⅱ) pseudoplasmodia radial. usually centralized and rarely subdivided; (ⅲ) the various number of whorls; (ⅳ) the spores with unconsolidated and nonconspicuous polar granules. Also, we confirmed this new species by analyzing ribosomal DNA (ITS1, ITS2 and 5.8s DNA) sequences of P. solitarium and P. violaceum.

• 한국패류학회지
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• 제26권2호
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• pp.107-114
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• 2010

To evaluate the culture conditions in oyster-farming waters, chemical and biological measurements were made in seawater and oysters from six bays around Tongyeong in November and December 2003. Nutrient levels in the seawater were higher in the western area than in the eastern area, in contrast to particulate organic matter and dissolved oxygen levels. The mean total polycyclic aromatic hydrocarbon ({\sum}PAH) content of the oysters was 194.5-375.9 ng/g dry weight, with four-ring compounds constituting 34.1%-79.6% of PAH. Despite wide temporal variations, a "western > eastern" spatial distribution of PAH was apparent. These low concentrations of PAHs indicate that Tongyeong waters are pristine in terms of PAH contamination. Among the hemocytic biomarkers, only lysosomal activity was significantly reduced in Hansan-Goje Bay, but did not correlate closely with PAH content. This finding indicates that the impact of PAH on cultured oysters is negligible around Tongyeong waters.

• 생명과학회지
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• 제10권1호
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• pp.74-78
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• 2000

This study was investigated to evaluate the distribution of airborne microorganisms at underground shops in Seomyun and Nampodong, Pusan. The number of bacterial colonies on the nutrient agar plate plates were calculated by the open petri dish method for 30 minutes in indoor air of underground shops at every seasons in a year. There was no statistically significant difference between Seomyun and Nampodong in mean colony counts. Isolation rates of Gram positive rods was highest, and Gram positive cocci and Gram negative rods were followed. In Nampodong underground shops, Enterobacteriaceae strains was isolated. Mean colony counts according to seasons was higher at summer and autumn in Seomyun, and spring and winter in Nampodong. In near future, a study on the distribution of bacteria causing respiratory infection should be followed.

• 농약과학회지
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• 제4권2호
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• pp.44-49
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• 2000

본 시험은 오이 양액재배시 배양액내 규산칼륨($K_{2}SiO_{3}$) 처리에 의한 생육단계별 규소의 흡수특성, 체내분표 병원균의 침입억제 효과를 검토하기 위하여 수행하였다. 잎에서의 규소 분포는 TEM, SEM 및 EDX-ray를 사용하여 4개(SEM, Ca, Si, K)의 구성원소를 각각 측정하였다. 흡수된 규소는 잎으로 이동하여 모용(毛茸, trichome, hair)을 둘러싸고 있는 기부 세포에 축적되었다. 모용에서의 규소는 고농도의 칼슘 및 칼륨과 혼재하여 분포하였고, 저농도 처리시에는 모용기부를 제외한 표피세포에서는 감지 할 수 없는 수준으로 분포하였다. 잎에서의 규소 축적은 처리 후 24시간에서 48시간 사이에 세포벽 주위에 가장 많이 축적되었고, 그 이후에도 다소 증가하는 경향이었다. 처리된 규소는 발아하고 있는 흰가루병 분생포자의 인접 조직의 세포벽과 병원균 흡기 주변에 다량 축적되어 물리적인 장벽으로 작용하였다. 고농도의 규산 처리된 잎 병반상의 발아관 길이는 낮은 농도의 처리구와 비교하여 현저히 짧았으며, 규산 처리농도와 부의 상관관계를 나타내었다. 배양액내 처리된 규산 농도는 오이가 생장함에 따라 감소하여 뿌리를 통하여 작물체내로 흡수되었으며, 저농도 처리구(0.85 mM이하)에서는 흡수되는 양이 현저히 적었다.

• Journal of Nutrition and Health
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• 제3권1호
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• pp.1-43
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• 1970

There is no any reports on nation-wide nutrition survey since 1947 in Korea, During the period only the small scaled nutrition surveys have been reported by several investigators. Authors, under the financial support from the Ministry of Health and Social Affairs, Republic of Korea, had conducted a nation-wide nutrition survey, including dietary, clinical, and socio-economical aspects, during the period from 29th of July to 15th of August, 1969. Number of households surveyed and population distribution are shown in Table II-2 and age and sex distribution of the population surveyed are also in Table II-3 in this report. Average food and nutrient intakes are shown in Tables II-6, II-7 and II-8 respectively. For the detailed discussions on food and nutrient intakes, see the Tables II-9 through II-11 and Figures II-1 through II-10 in this report. Anthropometric data are shown in Tables III-1 through III-4 and in Figures III-1 through III-4. Data of deficiency diseases are shown in Table III-5 and in Figure III-5 in this report. Socio-economical data are shown in Tables IV-1 through IV-26 and in Figures IV-1 through IV-3 in this report.