• 제목/요약/키워드: population concentration

검색결과 1,037건 처리시간 0.031초

Effect of condensed tannins from Leucaena leucocephala on rumen fermentation, methane production and population of rumen protozoa in heifers fed low-quality forage

  • Pineiro-Vazquez, Angel T.;Canul-Solis, Jorge R.;Jimenez-Ferrer, Guillermo O.;Alayon-Gamboa, Jose A.;Chay-Canul, Alfonso J.;Ayala-Burgos, Armin J.;Aguilar-Perez, Carlos F.;Ku-Vera, Juan C.
    • Asian-Australasian Journal of Animal Sciences
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    • 제31권11호
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    • pp.1738-1746
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    • 2018
  • Objective: The aim of the experiment was to assess the effect of increasing amounts of Leucaena leucocephala forage on dry matter intake (DMI), organic matter intake (OMI), enteric methane production, rumen fermentation pattern and protozoa population in cattle fed Pennisetum purpureum and housed in respiration chambers. Methods: Five crossbred heifers (Bos taurus${\times}$Bos indicus) (BW: $295{\pm}6kg$) were fed chopped P. purpureum grass and increasing levels of L. leucocephala (0%, 20%, 40%, 60%, and 80% of dry matter [DM]) in a $5{\times}5$ Latin square design. Results: The voluntary intake and methane production were measured for 23 h per day in respiration chambers; molar proportions of volatile fatty acids (VFAs) were determined at 6 h postprandial period. Molar concentration of VFAs in rumen liquor were similar (p>0.05) between treatments. However, methane production decreased linearly (p<0.005), recording a maximum reduction of up to ~61% with 80% of DM incorporation of L. leucocephala in the ration and no changes (p>0.05) in rumen protozoa population were found. Conclusion: Inclusion of 80% of L. leucocephala in the diet of heifers fed low-quality tropical forages has the capacity to reduce up to 61.3% enteric methane emission without affecting DMI, OMI, and protozoa population in rumen liquor.

Biomolecular Mechanism of Cadmium Toxicity

  • Park, Jung-Duck
    • 대한약학회:학술대회논문집
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    • 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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    • pp.200-200
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    • 2002
  • Cadmium (Cd) is an environmental pollutant and categorized as a human carcinogen, which has a tendency to accumulate in the human body. The level of Cd in renal cortex and liver are good indicators as an index of Cd exposure in general population. Geometric mean concentration of Cd is 27.4 and 3.1 /g wet weight in renal cortex and liver, respectively, in Korean. Cd is toxic to a number of tissues, notably the liver, kidney, testis, lung, lymphoid tissue and lung. (omitted)

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주거건축의 IAQ에 관한 연구 (A Study on Evaluation of IAQ in Dwelling House)

  • 박미진
    • 한국안전학회지
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    • 제12권1호
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    • pp.108-112
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    • 1997
  • Recently, the use of Dwelling House has been expanded due to the rapid urbainzation and congestion of population in City. Indoor Air Quality in apartment houses was investigated by measuring pollutants such as $CO_2$ gas, dust concentration. In this study, the mesurements of indoor air environment were performed in Dwelling house in Seoul area to investigate indoor air environment and the relation of air contaminative and the response level. Indoor air contamination and living environment of the occupants have been compared & analyzed with practical investigation of IAQ in Seoul, Korea and Tokyo, Japan.

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SVE 및 미생물제제를 이용한 유류 오염토양의 현장 복원

  • 박영준;염규진;김선미;이문현;박광진;이영신
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2003년도 총회 및 춘계학술발표회
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    • pp.103-106
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    • 2003
  • This study was conducted to evaluate in-situ bioremediation ability of Bioil-D, microbial material for oil degradation, at a gas station that had been treated by SVE system. TPH concentrations and total contaminated soil volume were rapidly decreased after Bioil-D treatment. The performance of Bioil-D was also estimated based on the observation of microbial population at the soil samples and $CO_2$ concentration produced at the extraction wells. The field study showed a successful work of Bioil-D.

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교통흐름에 기인하는 미세먼지 노출 도시인구에 대한 시.공간적 분석 (Spacio-temporal Analysis of Urban Population Exposure to Traffic-Related air Pollution)

  • 이금숙
    • 한국경제지리학회지
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    • 제11권1호
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    • pp.59-77
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    • 2008
  • 자동차를 중심으로 하는 도로교통량이 크게 늘면서 교통에 기인한 다양한 피해 현상들이 나타나고 있다. 특히 교통량이 집중되는 대도시에서는 교통에 기인한 도시민의 건강피해가 심각한 것으로 밝혀지고 있다. 본 연구에서는 교통에 기인한 미세먼지의 피해를 직접적으로 받는 도시인구는 미세먼지의 주 발생원인 교통흐름이 있는 도로변에 가까이에 노출되는 도시민들이라고 보고 도시 공간 내에서 교통흐름과 미세먼지, 그리고 도시 통행인구의 공간적 분포를 분석하였다. 특히 본 연구에서는 대기오염문제가 심각한 서울을 대상으로 교통에 기인한 미세먼지의 실태를 살펴보고, 서울을 둘러싸고 있는 경기도 일대에 대단위 주거지들이 밀집된 신도시들이 개발되면서 나타나는 인구분포와 통행패턴, 그리고 교통흐름 및 미세먼지 농도에 나타나는 공간적 변화와 이들 간의 공간적 관계를 종합적으로 파악하기 위하여 GIS를 적용하였다. 또한 교통카드 트랜잭션 데이터베이스에서 데이터마이닝기법으로 추출해낸 통행흐름 자료를 이용하여 통행시간별 통행인구분포도를 작성하고, 이를 바탕으로 교통에 기인한 미세먼지에 직접 노출하게 되는 도시인구를 산정하는 시 공간적 모형개발을 시도하였다.

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청간해울탕(淸肝解鬱湯)이 생취에 Immobilization-Stress 및 Cold-Stress 부하후(負荷後) 혈중(血中)Histamine과 Corticosterone 함량(含量) 및 면역능(免疫能)에 미치는 영향(影響) (Effects of Chungganhaewooltang on Serum Levels of Histamine and Corticosterone and Immune Response after Immobilization-Stress or Cold-Stress in Mice)

  • 강복환;정우석;김송백;유심근
    • 대한한방부인과학회지
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    • 제18권4호
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    • pp.85-105
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    • 2005
  • Purpose : Investigate the effects of Chungganhaewooltang(CHT) on immobilization-stress or cold-stress in C576BL/6J mice. Methods : Male C57BL/6J 30 mice of weighting 18${\pm}$2g, were divided into sixs groups including the immobilization-stress group(5heads), after immobilization-stress CHT oral administration(500mg/kg) groups(5heads), cold-stress group(5heads) and after cold-stress CHT oral administration(500mg/kg) groups(5heads). then we observed changes in the serum histamine and corticosterone level and changes immune system Results : Immobilization-stress or cold-stress increased the serum level of histamine and corticosterone. CHT decreased the serum level of histamine and corticosterone increased by cold-stress. CHT inhibited the release of histamine from mast cells at the concentration of 0.1 mg/ml. In addition, immobilization-stress or cold-stress decreased the cell viability of murine thymocytes and splenocytes. CHT increased the cell viability of thymocytes decreased by immobilization-stress or cold-stress, but did not affect the cell viability of splenocytes decreased by immobilization-stress or cold-stress. Also immobilization-stress or cold-stress increased DNA fragmentation of thymocytes and splenocytes. CHT decreased DNA fragmentation of thymocytes increased by immobilization-stress or cold-stress, but did not affect DNA fragmentation of splenocytes increased by immobilization-stress or cold-stress. Immobilization-stress increased the population of thymic $CD4^+$ cells. CHT decreased the population of thymic $CD4^+$ cells increased by immobolization-stress. Immobilization-stress or cold-stress decreased the population of $B220^+$ cells and increased the population of $thy1^+$ cells. CHT decreased the population of $thy1^+$ cells increased by immobilization-stress or cold-stress. Immobilization-stress or cold-stress increased the population of splenic $CD4^+$ cells and $CD8^+$ cells. CHT decreased the population of splenic $CD4^+$ cells increased by immobolization-stress or cold-stress. Immobilization-stress or cold-stress decreased the production of ${\gamma}-interferon$(IFN) interleukin(IL)-2 and IL-4. CHT enhanced the production of ${\gamma}-IFN$ decreased by immobilization-stress or cold-stress but did not affect the production of IL-2 and IL-4 decreased by immobilization-stress or cold-stress. Furthermore, Immobilization- stress or cold-stress decreased the phagocytic activity of peritoneal macrophages and the production of nitric oxide. CHT enhanced the phagocytic activity and nitric oxide production decreased by cold-stress. Conclusion : CHT may be useful for the prevention and treatment of stress via suppression of serum histamine and corticosterone level and enhancement of immune response.

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해산규조류(Skeletonema costatum)의 개체군 성장률을 이용한 브롬화난연제(BDE-47, BDE-209) 독성평가 (Toxic Assessment of BDE-47 and BDE-209 using the Population Growth Rates of Skeletonema costatum)

  • 허승;이주욱;박윤호;박나영;이인석;황운기;최훈
    • 환경생물
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    • 제36권3호
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    • pp.385-391
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    • 2018
  • 해산규조류 (Skeletonema. Costatum)의 개체군 성장률을 이용하여 PBDEs (BDE-47, BDE-209)의 독성평가를 실시하였다. BDE-47은 $0.31mgL^{-1}$ 이상의 농도부터 유의미하게 감소하여 농도의존성을 나타냈으나, BDE-209의 경우 시험 최고농도 $125mgL^{-1}$에서도 변화를 나타내지 않았다. 본 시험결과 $EC_{50}$값은 BDE-47과 BDE-209에서 각각 $0.55mgL^{-1}$와 >$125mgL^{-1}$이었고, NOEC값은 $0.16mgL^{-1}$와 >$125mgL^{-1}$이었으며, LOEC값은 $0.31mgL^{-1}$와 >$125mgL^{-1}$으로 나타나 BDE-47이 BDE-209에 유해성이 더 큰 것으로 나타났다. 또한, 연안환경에서의 BDE-47의 농도가 LOEC 값인 $0.31mgL^{-1}$를 초과할 경우 S. costatum과 같은 식물성플랑크톤에 악영향을 미칠 것으로 판단된다. 본 연구 결과는 PBDEs의 해양환경 기준 설정 및 타 독성물질과의 상대적 독성치를 비교하기 위한 귀중한 자료로 활용될 것으로 판단된다.

The Effects of a Raw Diet on Plasma Fasting Glucose Concentration and Immune Function in Streptozotocin-induced Diabetic Rats

  • Kim, Jeongseon;Park, Jun-Young;Kim, Sunggoo
    • Nutritional Sciences
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    • 제7권1호
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    • pp.3-7
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    • 2004
  • This study was performed to investigate the effect of a raw diet (RD) on blood glucose and immune function in non-diabetic (normal) and streptozotocin (STZ)-induced diabetic rats. Male Sprague-Dawley rats were assigned to four groups (normal control, normal RD, diabetic control and diabetic RD). The control groups and the RD groups were fed an AIN-diet and RD for four weeks, respectively. Weight gain was statistically lower in the RD groups than in the controls. Fasting plasma glucose was significantly lower in the diabetic RD group than in the diabetic control group. The $CD4^+$ T-cell population was higher along with the $CD4^+/CD8^+$ ratio of the mesenteric lymph nodes in the normal RD group compared to the other groups. It can be concluded that RD may reduce the plasma fasting glucose concentration in diabetic rats and improve mesenteric lymph node immune function in normal rats.

Optimization of Antibacterial Activity by Gold-Thread (Coptidis Rhizoma Franch) Against Streptococcus mutans Using Evolutionary Operation-Factorial Design Technique

  • Choi, Ung-Kyu;Kim, Mi-Hyang;Lee, Nan-Hee
    • Journal of Microbiology and Biotechnology
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    • 제17권11호
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    • pp.1880-1884
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    • 2007
  • This study was conducted to find the optimum extraction condition of Gold-Thread for antibacterial activity against Streptococcus mutans using The evolutionary operation-factorial design technique. Higher antibacterial activity was achieved in a higher extraction temperature ($R^2=-0.79$) and in a longer extraction time ($R^2=-0.71$). Antibacterial activity was not affected by differentiation of the ethanol concentration in the extraction solvent ($R^2=-0.12$). The maximum antibacterial activity of clove against S. mutans determined by the EVOP-factorial technique was obtained at $80^{\circ}C$ extraction temperature, 26 h extraction time, and 50% ethanol concentration. The population of S. mutans decreased from 6.110 logCFU/ml in the initial set to 4.125 logCFU/ml in the third set.

Global Carbon Budget and Ocean Buffering against Rising Atmospheric CO2 Concentration

  • Kwon, O-Yul
    • 한국환경과학회지
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    • 제11권8호
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    • pp.773-781
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    • 2002
  • The natural carbon cycle has been perturbed since the mid-19th century by anthropogenic CO$_2$emissions from fossil fuel combustion and deforestation due to population growth and industrialization. The current study simulated the global carbon cycle for the past 42 years using an eight-box carbon cycle model. The results showed that since the terrestrial biospheric carbon sink was roughly offset by the deforestation source, the fossil fuel emission source was partitioned between the atmospheric and oceanic sinks. However, the partitioning ratio between the atmosphere and the ocean exhibited a change, that is, the carbon accumulation rate was faster in the atmosphere than in the ocean, due to a decrease in the so-called ocean buffering capacity. It was found that the ocean buffering capacity to take up excess CO$_2$decreased by 50% in terms of the buffer factor over the past 42 years. Accordingly, these results indicate that if the current CO$_2$emission trend continues, the future rate of increase in the atmospheric CO$_2$concentration will accelerate.