• 제목/요약/키워드: Limiting nutrient

검색결과 142건 처리시간 0.024초

완도해역에서 유기물의 생산량 평가 (Assessment for Production of Organic Matter in the Wando Costal Area.)

  • 김우항
    • 해양환경안전학회지
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    • 제12권3호
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    • pp.165-170
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    • 2006
  • 육상 오염원의 영향을 적게 받는 완도 해역에서 약 10년간의 월별 수질자료를 이용하여 식물성플랑크톤의 증가에 의한 유기물의 증가에 대하여 분석하였다. 그 결과 DIN의 경우 겨울철인 2월에는 상대적으로 높은 농도인 0.138mg/L를 나타내고 있으며 여름철인 8월에는 0.052mg/L로 매우 낮은 값을 나타내고 있다. DIP의 경우도 DIN과 비슷한 경향을 나타내고 있으며 겨울철인 2월의 농도가 가장 높은 0.015 mg/1이고 여름철인 8월이 가장 낮은 값인 0.011 mg/1를 나타내고 있다. 식물성플랑크톤의 제한영양염을 알아보기 위하여 Redfield ratio(N:P=16:1)를 이용하여 제한영양염을 평가하여 보면 완도해역은 질소가 제한 영양염으로 나타나고 있다. 가장 제한이 되고 있는 계절은 여름으로 N/P의 비가 10.5로 나타났다 Chl.-a는 겨울철인 2월에 비해 봄과 여름인 5월과 8월에 79%, 97%가 증가하는 것으로 나타났다. 유기물의 농도는 COD로 나타내었으며 2월에는 0.84 mg/1로서 가장 낮은 값을 나타내었으며 8월인 여름철에 가장 높은 1.10 mg/1를 나타내었다. 영양염과 Chl.-a의 상관관계는 DIN과의 상관에서 $r^2$M가 0.93, DIP과의 상관에서 $r^2$M가 0.89로 매우 높게 나타났다. 이와 같은 결과는 식물성플랑크톤의 증식이 영양염의 감소에 주요 원인이라고 할 수 있다. 또한 Chl.-a와 COD의 회귀분석에서 상관계수 $r^2$M가 0.78로서 상관관계가 있는 것으로 나타났으며 회귀식을 이용하여 분석한 결과 유기물의 생산량은 겨울철에는 17%, 여름철에는 37%가 증가하는 것으로 나타났다. 위의 결과를 종합하면 완도의 해역에서 수온이 증가하는 여름철에 용존성 영양염의 농도는 감소하고 있으나 식물성플랑크톤의 지표가 되는 Chl.-a와 유기물의 지표가 되는 COD는 증가하는 것으로 나타났다. 또한 이들을 회귀분석을 통하여 분석한 결과 상관성이 매우 높은 것으로 나타났다.

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Primary Production System in the Southern Waters of the East Sea, Korea III. Vertical Distribution of the Phytoplankton in Relation to Chlorophyll Maximum Layer

  • Shim, Jae-Hyung;Park, Jong-Gyu
    • Journal of the korean society of oceanography
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    • 제31권4호
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    • pp.196-206
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    • 1996
  • Vertical profiles of the chlorophyll ${\alpha}$, phytoplankton abundance, nutrients and sigma-t were compared with the vertical distribution of phytoplankton species in conjunction with $^{14}$C primary production in the Southern Waters of the East Sea, Korea. In the upper mixed layer the water column was only weakly stratified and ambient nitrogenic nutrient concentrations were markedly depleted. Dissolved silicate seemed to be another limiting nutrient in the surface layer. The occupation of different water depths by several dominant diatom species was well explained by the degree of silicification of each cell and the silicate concentration of ambient seawater. Subsurface chlorophyll maxima were continuously observed in the lower parts of the euphotic layer and the depth coincided with nutricline, supporting our view that chlorophyll maximum was sustained partially by enhancement of in situ growth of phytoplankton and partially by increase of cellular chlorophyll content. The persistence of chlorophyll maximum layer was attributed to the physiological adaptation of the phytoplankters to low light intensities and to the utilization of regenerated nutrients. Integrated water column production of organic matter by photosynthesis appeared to be better related to phytoplankton cell division than to the cell growth in terms of biosynthesis of pigments and other intracellular components.

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Fundamental Structure in Simultaneous Removal for Phytoplankton and Nutrient Salt in Lakes

  • SEKI, Tatsuhiro;ISHII, Yuuichi;ISHII, Toshio;TAKI, Kazuo
    • Environmental Engineering Research
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    • 제14권4호
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    • pp.220-225
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    • 2009
  • The water quality in eutrophic lakes is affected by serious problems, such as abnormal increasing of Cyanobacteria. The purpose of this study was to investigate the possibility of a modified flotation system using a hybrid technique formed by chemical compounds and an electrostatic bridge. Therefore, experiments using the hybrid technique were performed to measure the zeta potential value on the phytoplankton surface and the removal efficiencies of phytoplankton, ammonia nitrogen, nitrate nitrogen and phosphoric acid. The results were as follows: Firstly, the zeta potential of M.aeruginosa was observed to approach charge neutralization due to adhesion of magnesium hydroxide precipitate on the phytoplankton surface in the pH range 10.5 to 11. Secondly, the concentration of chlorophyll-a decreased from about 150 to 20${\mu}g$g/L, with a maximum removal efficiency of 84% due to coagulation with pH values higher than 10. Thirdly, the N$H_4$-N concentration was observed to decrease from 0.62 to 0.54mg-N/L (13%), and the P$O_4$-P concentration, which is a limiting factor to the formation of algae blooms, decreased from 0.27 to 0.02mg-P/L (92%). These findings suggest that the modified flotation system can be applied for the purification of the raw water of numerous lakes containing high phytoplankton populations and elevated pH.

시아해의 수질환경과 식물플랑크톤 생물량의 시ㆍ공간적 분포특성과 기초생물량변동에 영향을 미치는 환경특성 (On the Spatio-temporal Distributions of Nutrients and Chlorophyll a Concentration, and the Environmental Factors on the Variation of Phytoplankton Biomass in the Shiahae, Southwestern Part of Korean Peninsula)

  • 윤양호
    • 환경생물
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    • 제18권1호
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    • pp.77-93
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    • 2000
  • 시아해의 수질환경과 식물플랑크톤 생물량의 계절변동 특성 및 식물플랑크톤 생물량변동에 영향을 미치는 환경요인을 파악하기 위해 1995년 2월,4월,7월과 10월 4회에 걸쳐 계절별로 23개 관측점의 표층과 저층 해수를 대상으로 현장조사를 실시하였다. 결과, 시아해는 2월에 최저수온, 8월에 최고 수온을 나타내나, 염분은 6, 7월에 높고 겨울에 낮은 특성을 나타내었으며, 연중 빠른 유속과 조석혼합 등으로 수층 간 혼합된 양상과 매우 낮은 투명도를 나타내고 있었다. 영양염류 중 질소는 여름을 제외하고는 비교적 높은 값을 나타내며, 인은 연중 0.5$\mu\textrm{g}$ㆍat./l내외의 값을 보이고 있는 반면, 규소는 봄철 규조류 대발생시를 제외하고는 연중 높은 농도를 유지하고 있었다. Chl-a는 연중 2$\mu\textrm{g}$/l 이상의 높은 값을 나타내고 있으며, 특히 규조류의 대발생이 보여지는 봄철에 높은 값을 나타내었다. 다만, 연중 높은 생물량은 생물의 성장과 활성에 의하기보다는 조석혼합 등에 의해 해저표층퇴적물에 침강된 표영생태계 중의 생물량 상당부분이 수중으로 재 부유한 결과로 보여져, 높은 부유물질 등 제한된 광 조건으로 시아해 식물플랑크톤 생물활성은 그다지 높지 않을 것으로 추정되었다. 기초생산을 제한하는 영양염은 시아해 북쪽해역에서는 인에 의해, 남쪽해역에서는 질소에 의해 지배되고 있는 것으로 나타났으며, 겨울철은 인의 존재량에 비해 질소가 과잉으로 존재하는 것으로 나타났다. 그리고 규소는 봄철 규조의 대발생시를 제외하고는 식물플랑크톤 군집에 크게 영향을 주지 앓는 것으로 나타났다. 또한, 영양염류 중 규소는 담수 등 복잡한 주변 수괴의 유입에 의존하는 비율이 높고, 질소는 여름에는 담수 유입에 의존하나 시기에 따라서는 저층 해수의 공급에 의존하는 것으로 나타났다. 인은 담수유입에 의한 부분보다 저층 해수 및 주변 수괴로부터 유입하는 비율이 높은 것으로 판단되었다. 시아해의 식물플랑크톤에 영향을 미치는 환경요인은 시간과 공간에 따라 다르게 나타나고 있으며, 여름철 극심한 질소의 부족이나 봄철 규조 대발생시의 규산염 고갈 등을 제외하면 영양염류보다도 높은 부유물질, 즉 광량 등 물리학적 요인에 의해 영향을 받는 것으로 판단되었다.

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알코올을 섭취하는 일부 성인 남성에 있어 흡연여부에 따른 식사의 질 및 혈중 지질농도에 관한 비교 연구 (A Comparative Study on the Diet Quality Evaluation and Blood Lipid Profiles in Adult Male Drinkers according to the Smoking)

  • 강명희;최인선;노희경
    • Journal of Nutrition and Health
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    • 제42권6호
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    • pp.547-558
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    • 2009
  • This study was carried out to compare the effect of smoking on dietary habits, nutrient intakes and blood lipid profiles in 173 adult male drinkers. Subjects were classified by two groups, alcohol-only and alcohol-smoking, based on their alcohol or smoking habits. The BMI of the alcohol-smoking group was significantly lower than those of alcohol-only group. In dietary habits, the alcohol-smoking group had higher irregular breakfast and dinner intakes than alcoholonly group (p < 0.05). Plant lipid intake of the alcohol-smoking group was higher than those of alcohol-only group (p < 0.05) and the vitamin C intake of the alcohol-smoking group was lower than those of alcohol-only group (p < 0.05). With regard to the diet quality evaluation of subjects, the alcohol-smoking group showed significantly lower values than alcohol-only group in the nutrient density of carbohydrate, dietary fiber, sodium, potassium, vitamin $B_6$, and vitamin C. Also, with regard to the index of nutrition quality (INQ) and the nutrient adequacy ratio (NAR), the alcohol-smoking group showed significantly lower value than alcohol-only group in vitamin C. With these results, we found that the alcohol-smoking group had lower diet quality evaluation. The results of blood analysis showed that HDL-cholesterol in the alcohol-smoking group was significantly lower than that in the alcohol-only group. In conclusion, the alcohol-smoking group had greater health risk than the alcohol-only group. Particularly, alcohol-smoking caused irregular eating patterns and unbalanced nutrition intakes compared to alcohol-only and also changed blood composition as shown in the decrease of HDL-cholesterol. Besides, the index of coronary heart disease such as AI was higher in both groups suggesting that alcohol-only or alcohol-smoking cause health problems. Since there is the limiting point in which the comparative analysis of non-drinkers and non-smokers is unable to be performed in this study, further wide research is needed on that matter.

인천 지역 여대생의 체질량 지수와 체형 인식에 따른 식행동 및 영양소 섭취 상태 분석 (A Study on Food Behaviors and Nutrient Intakes according to Body Mass Index and Body Image Recognition in Female University Students from Incheon)

  • 홍명선;박희옥;손춘영
    • 한국식품영양학회지
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    • 제24권3호
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    • pp.386-395
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    • 2011
  • The purpose of this research was to study food behaviors and nutrient intakes according to body mass index(BMI) and body image recognition in 211 female university students in Incheon. The majority of the surveyed subjects were in the normal range for BMI. Most of these female university students preferred a thin body type and were not satisfied with their body shapes. Most also controlled their body weight for appearance by exercising and limiting food intake. The obese group often ate processed foods(p<0.01) and ate out(p<0.05). The underweight group and normal-weight group took vitamins and supplements more frequently(p<0.001). Those students who recognized their body image as a 'fat shape' had good appetites(p<0.05) and those who recognized themselves as 'normal shape' considered food formulations ate every meal (p<0.05) and consumed vitamins and other supplements frequently(p<0.01). The mean calorie intake of all students was about 80% of the recommend amount, so there was a risk of lack of various nutrients. The 'fat' students by body image recognition had lower calorie intakes in order to reduce body weight. In all the groups, there was a lack of vitamins $B_1$ and $B_2$, as well as the minerals Ca and Fe. Therefore, education on correct body image recognition and training on proper weight control are deemed necessary. In addition, education and counseling on nutrition that are tailored to individual status are needed.

Effects of Feeding Dried Food Waste on Growth and Nutrient Digestibility in Growing-Finishing Pigs

  • Chae, B.J.;Choi, S.C.;Kim, Y.G.;Kim, C.H.;Sohn, K.S.
    • Asian-Australasian Journal of Animal Sciences
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    • 제13권9호
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    • pp.1304-1308
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    • 2000
  • A total of thirty-six gilts $(24.78{\pm}1.39kg)$ were employed for 38 days (Exp. 1), and twenty-four gilts $(46.50{\pm}1.90kg)$ for 43 days (Exp. 2) to determine growth performance and carcass characteristics in pigs fed dried food waste (DFW). Pigs were allocated by dietary treatments: 0%, 20% and 40% DFW. For nutrient digestibility, twelve female pigs $(50.20{\pm}0.52kg)$ were used in individual pens to collect feces. Food wastes were collected from restaurants and apartment complex areas and dried in a drum-type dryer at $115{\pm}2{^{\circ}C}$. Experimental diets for feeding trials were formulated to contain 3,400 kcal DE/kg and 17% crude protein. The tested DFW contained 2,858 kcal DE/kg, 25.0% crude protein, 17.3% crude fat, 1.37% Ca, 1.28% P, and 3.28% NaCl. As compared to crude protein content, the limiting amino acids (i.e., 0.90% lysine and 0.52% methionine) were low. The digestibilities of energy, ash, calcium and phosphorus in the DFW were generally lower than those in the grower diets, but the digestibilities of crude protein and crude fat were higher in DFW than the grower diet. Feeding DFW in pigs had a linear (p<0.01) effect on ADG and feed/gain as the inclusion levels of DFW were increased (Exp. 1). The ADG of pigs fed 40% DFW was also poorer (p<0.05) than that fed the control diet (Exp. 2). Carcass characteristics in terms of backfat and dressing percentage were not affected by dietary treatments. In conclusion, it seems that the optimal dietary inclusion level of the DFW is about 20% in the diet for growing-finishing pigs.

광양만에서 춘계와 하계 영양염류 첨가가 식물플랑크톤군집의 성장에 미치는 영향 (The Influence of Nutrients Addition on Phytoplankton Communities Between Spring and Summer Season in Gwangyang Bay, Korea)

  • 배시우;김동선;최현우;김영옥;문창호;백승호
    • 한국해양학회지:바다
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    • 제19권1호
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    • pp.53-65
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    • 2014
  • 춘계와 하계 광양만에서 식물플랑크톤 군집구조와 그들의 성장에 영향을 미치는 영양염제한 특성을 파악하기 위해서 만내외측의 20개 정점에서 생물학적 요인과 무생물학적 요인을 조사했다. 또한 식물플랑크톤 군집에 대한 영양염 첨가 효과를 알아보기 위해서 실험실에서 현장 20개 정점의 표층수를 이용하여 생물검정실험을 수행하였다. 전체 식물플랑크톤 군집의 90%이상을 규조류가 차지하였다. 이들 규조류중 Eucampia zodiacus와 Skeletonema costatum-like 종이 춘계와 하계에 각각 우점하였다. E. zodiacus와 S. costatum-like 규조류의 개체군 밀도가 춘계와 하계에 높은 밀도를 유지하게 된 이유를 간단히 설명하면, E. zodiacus 의 성장은 춘계 투명도가 높게 나타나 유광층내 광량의 증가가 원인으로 생각된다. 즉 유광층내 광량의 증가는 E. zodiacus의 개체수를 폭발적으로 증가시킬 수 있는 방아쇠 역할을 한 것으로 판단된다. 하계에 S. costatum-like이 전해역에서 우점한 이유는, 섬진강 담수 유입에 의한 낮은 염분과 함께 공급된 다량의 영양염은 그들 생물의 증식에 중요한 bottom-up 효과를 보였다고 판단된다. 실험실의 생물검정실험에서는 비록 내만(정점 8)과 외해(정점 20)에서 식물플랑크톤 군집의 최대 성장율은 유사하였지만, 인산염에 대한 반포화계수($K_s$)는 내만정점보다 약간 낮았다. 상대적으로 낮은 영양염농도에 적응한 세포는 낮은 인산염농도에서 충분히 성장할 수 있고, 다른 미세조류에 비하여 낮은 영양염농도의 조건에서 경쟁의 우위를 차지 할 것이다. 특히, 하계의 N영양염 첨가군의 효율은 대조군과 P영양염 첨가군에 비해서 높았다. 이는 광양만에서 하계에 N영양염의 공급이 섬진강을 통하여 계속적으로 유입되지만, 빠른 식물플랑크톤의 증식으로 인하여 N영양염 제한이 일어날 수 있다는 것을 시사할 수 있다. 반면, 규산염은 식물플랑크톤의 성장에 영향을 미치는 제한인자로 나타나지 않았고, 규조류의 분해로 인하여 Si의 재순환과 담수로부터 공급된 높은 규산염농도는 광양만에서 규조류 생태계를 유지할수 있는 유리한 조건이라 생각된다.

FEED RESOURCE AVAILABILITY AND UTILIZATION IN SMALLHOLDER PIG FARMS IN SRI LANKA

  • Ravindran, V.;Cyril, H.W.;Nadesalingam, P.;Gunawardene, D.D.
    • Asian-Australasian Journal of Animal Sciences
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    • 제8권4호
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    • pp.311-316
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    • 1995
  • Data on available feed resources, feeding practices and nutrient adequacy of rations under small farm conditions in Sri Lanka were obtained in a baseline survey involving 104 pig farms. The results showed that a wide range of non-conventional feedstuffs are used for pig feeding under typical small farm conditions and that dietary protein quality is a major factor limiting productivity. Following the survey, two on-farm trials were conducted to evaluate cheaper, alternative feeding strategies. In trial 1, a test diet was formulated using several non-conventional feedstuffs and compared with a commercial feed that is normally fed in the farms. In trial 2, the possibility of improving growth rates by amino acid supplementation was evaluated. The results demonstrated that feed costs can be considerably lowered through these packages. Some problems inherent to on-farm livestock trials are highlighted.

농축배지에서 Glucose와 Glutamine 농도가 하이브리도마 증식과 간염표면항원에 대한 단일클론항체 생산에 미치는 영향 (Effects of Glucose and Glutamine Concentrations on Hybridoma Growth ann Anti-HBsAg MAb Production in Enriched Medium)

  • 전복환;조의철김동일
    • KSBB Journal
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    • 제5권4호
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    • pp.365-371
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    • 1990
  • To improve the growth of mouse hybridoma 2c3.1 secreting anti-Hepatitis B surface antigen monoclonal antibody (anti-HBsAg MAb), we had constructed an enriched medium and observed the effects of fetal bovine serum and serum-free supplements including human serum albumin, 'insulin and transferrin', and monoethanolamine. For further enhancement of growth, the concentrations of two major energy sources, glucose and glutamine, were strengthened with various ratios in the enriched medium. Maximum cell growth and monoclonal antibody production obtained in various ratios of glucose/glutamine with an inoculation concentration of 2$\times$105 cells/ml were 0.73$\times$106-4.62$\times$106 cells/ml and 65.1-422.6 $\mu\textrm{g}$/ml, respectively. Glutamine was round to be a major energy source and a limiting nutrient in comparison to glucose for 2c3.1 cell cultivation in enriched media with low serum.

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