• 제목/요약/키워드: Primary productivity

검색결과 387건 처리시간 0.023초

Effects of Asian Dust (KOSA) Deposition Event on Bacterial and Microalgal Communities in the Pacific Ocean

  • Maki, Teruya;Ishikawa, Akira;Kobayashi, Fumihisa;Kakikawa, Makiko;Aoki, Kazuma;Mastunaga, Tomoki;Hasegawa, Hiroshi;Iwasaka, Yasunobu
    • Asian Journal of Atmospheric Environment
    • /
    • 제5권3호
    • /
    • pp.157-163
    • /
    • 2011
  • Atmospheric aerosol deposition caused by Asian dust (KOSA) events provide nutrients, trace metals, and organic compounds over the Pacific Ocean that enhance ocean productivity and carbon sequestration and, thus, influence the atmospheric carbon dioxide concentrations and climate. Using dust particles obtained from the snow layers on Mt. Tateyama and the surface sand of Loess Plateau in incubation experiments with natural seawater samples on a shipboard, we demonstrate that dust-particle additions enhanced the bacterial growth on the first day of incubation. Gram-positive bacterial group and alpha-proteobacteria were specifically detected form seawater samples including the mineral particles. Although the remarkable dynamics of trace elements and nutrients depend on dust-particle additions, it is possible that organic compounds present in the mineral particles or transported microbial cells could also contribute to an increase in the quantities of bacteria. The chlorophyll concentrations at fractions of every size indicated a similar pattern of change between the seawater samples with and without the dust-particle additions. In contrast, the chlorophyll measurement using submersible fluorometer revealed that the dynamics of phytoplankton composition were influenced by the dust-particles treatments. We conclude that the phytoplankton that uses the bacterial products would increase their biomass. We show that KOSA deposition can potentially alter the structures of bacterial communities and indirectly influence the patterns of marine primary production in the Pacific Ocean.

안정 동위원소를 이용한 육상 생태계의 물과 탄소의 순환 연구: 재검토 (Stable Isotope Studies for Constraining Water and Carbon Cycles in Terrestrial Ecosystems: A Review)

  • 이동호
    • 한국농림기상학회지
    • /
    • 제7권1호
    • /
    • pp.15-27
    • /
    • 2005
  • 육상생태계의 물/탄소 순환은 기후변화의 원인과 진행 과정 그리고 결과를 예측하는데 필수적인 기초 자료이다. CarboKorea와 HydroKorea 연구에서는 한반도의 대표적인 지형과 식생 유형에 적합한 물/탄소 순환 해석과 실황예보를 위한 기술개발을 목표로, 안정동위원소를 이용해 물/탄소 순환의 구성요소를 성인적으로 세분하는 연구를 수행하고 있다. 본 논문에서는 이러한 안정 동위원소 연구가 국내 생태계의 물과 탄소 순환연구에 적극적으로 활용될 수 있도록 하기 위해 그 이론적 배경과 광릉 소유역의 연구 사례를 소개하였다. 시간과 공간 규모의 확장을 가능케 하는 안정 동위원소 연구는 다양한 관련분야의 연구와 함께 한반도 육상생태계의 물/탄소 순환과정에 대한 보다 정량적인 해석을 가능하게 함으로써 기후변화와 관련하여 제기되고 있는 당면한 과학적, 사회경제적 요구에 부흥할 수 있는 과학적 기반을 구축하는데 기여할 것으로 기대된다.

북동 태평양 심해저에 서식하는 중형저서동물 군집의 위도별 분포 특성 (Distribution of Meiobenthic Communities in the Deep-sen Floor of Northeastern Pacific Seafloor along a Latitudinal Transect)

  • 민원기;김동성;김웅서
    • Ocean and Polar Research
    • /
    • 제26권2호
    • /
    • pp.255-263
    • /
    • 2004
  • This study was conducted to investigate the community structure and distributional pattern of meiobenthos in the deep-sea bottom of the Clarion-Clipperton Fracture Zone of the northeastern Pacific during July 2003. The samples were collected using the multiple corer at 13 stations along the transects fiom $5^{\circ}N\;to\;17^{\circ}N$. The most abundant meiobenthos was nematodes and followed by sarcomastigophorans; these two taxa comprised more than 70% of the total abundance at all stations. For size distribution analyses showed that animals which fit into the sieve mesh size of 0.063mm were abundant. The maximum density of meiobenthos was $147inds./10cm^2$ at station located in $7^{\circ}N$, and the minimum density was $6 inds./10cm^2$ at station located in $14^{\circ}N$. More than 60% of meiobenthos were distributed at surface sediment layer within 1.0cm, and the peak abundance was found at $0{\sim}0.25cm$ layer. The latitudinal distribution pattern of meiobenthos in the study area seemed to be related with the primary productivity of the surface water that is also connected to the water circulation pattern of the Pacific Ocean near the Equator, diverging at latitude of $8^{\circ}N$ and conversing at $5^{\circ}N$.

Conservation potential of North American large rivers: the Wabash River compared with the Ohio and Illinois rivers

  • Pyron, Mark;Muenich, Rebecca Logsdon;Casper, Andrew F.
    • Fisheries and Aquatic Sciences
    • /
    • 제23권6호
    • /
    • pp.15.1-15.14
    • /
    • 2020
  • Background: Large rivers are ecological treasures with high human value, but most have experienced decades of degradation from industrial and municipal sewage, row-crop agricultural practices, and hydrologic alteration. We reviewed published analyses of long-term fish diversity publications from three intensively managed large river ecosystems to demonstrate the conservation potential of large river ecosystems. Results: We show how the incorporation of recent advances in river concepts will allow a better understanding of river ecosystem functioning and conservation. Lastly, we focus on the Wabash River ecosystem based on high conservation value and provide a list of actions to maintain and support the ecosystem. In the Wabash River, there were originally 66 species of freshwater mussels, but now only 30 species with reproducing populations remain. Although there were multiple stressors over the last century, the largest change in Wabash River fish biodiversity was associated with rapid increases in municipal nutrient loading and invasive bigheaded carps. Conclusions: Like similarly neglected large river systems worldwide, the Wabash River has a surprising amount of ecological resilience and recovery. For instance, of the 151 native fish species found in the 1800s, only three species have experienced local extinctions, making the modern assemblage more intact than many comparable rivers in the Mississippi River basin. However, not all the changes are positive or support the idea of recovery. Primary production underpins the productivity of these ecosystems, and the Wabash River phytoplankton assemblages shifted from high-quality green algae in the 1970s to lower less nutritional blue-green algae as nutrient and invasive species have recently increased. Our recommendations for the Wabash River and other altered rivers include the restoration of natural hydrology for the mainstem and tributaries, nutrient reductions, mechanisms to restore historical hydrologic patterns, additional sediment controls, and improved local hydraulics.

PHC 파일 두부정리 자동화 장비의 말단장치 개발 (Development of the End-effector for Developing a PHC Pile Cutting and Crushing Machine)

  • 이정호;김영석;조문영;김성근;성낙원
    • 한국건설관리학회:학술대회논문집
    • /
    • 한국건설관리학회 2004년도 제5회 정기학술발표대회 논문집
    • /
    • pp.531-534
    • /
    • 2004
  • 재래식 두부정리 작업은 노동 집약적이며 노무자간의 숙련도 차이에 의해 품질 및 작업 생산성이 크게 영향을 받고 있다. 국내 $\cdot$ 외에서는 두부정리 작업의 생산성 및 안전성, 품질을 향상시키기 위해 자동화 장비를 개발 중에 있으나 기존에 개발된 두부정리 자동화 장비는 파일 파쇄 작업만을 자동화 대상으로 하고 있고, PHC 파일에 종방향 균열을 발생시켜 두부정리 작업의 품질을 크게 저하시키고 있는 실정이었다. 기존 두부정리 자동화 장비가 PHC 파일에 종방향 균열을 발생시키는 원인은 PHC 파일의 물리적 특성을 고려한 자동화 장비 말단장치의 설계 및 제작, 배치가 제대로 이루어지지 못한 것으로 분석되었다. 따라서, 본 연구에서는 기존에 개발된 두부정리 자동화 장비 및 본 연구를 통해 현재까지 개발된 두부정리 자동화 장비 파일롯타입의 실험결과를 토대로 PHC 파일을 종방향 균열 없이 효과적으로 파쇄할 수 있는 두부정리 자동화 장비 프로토타입의 말단장치를 개발하고자 한다.

  • PDF

용승을 고려한 인공해중산 최적배치 수치실험 (Numerical Upwelling Experiment for Optimum Arrangement of Artificial Seamount)

  • 김성현;김동선
    • 한국환경과학회지
    • /
    • 제20권8호
    • /
    • pp.997-1009
    • /
    • 2011
  • In order to estimate volume transport by upwelling for single artificial seamount, same shape and size of artificial seamount already deployed was applied to numerical experiment. The result showed that strong upwelling appeared at front while took place downwelling at rear. The strongest upwelling existed at the top of the artificial seamount. Volume transport by upwelling was computed as 785 m3/s. Column arrangement was applied to two artificial seamount in three cases; case 1) no clearance, case 2) sixty-five meters of clearance as half of artificial seamount's length, and case 3) hundred-thirty meters of clearance as an artificial seamount's length. All cases of column arrangements showed more upwelling volume transport than that of single seamount. Particularly, the case of no clearance calculated as 106% and appeared the most upwelling effect comparing to two other cases. Row arrangement was also applied to two artificial seamount in three cases; case 4) no clearance, case 5) forty meters of clearance as an artificial seamount's width, and case 6) eighty meters of clearance as twice of artificial seamount's width. Upwelling volume transport in case 4 increased 48% than the case of single seamount. Other two cases of 5 and 6 were estimated as 97% increased and more effective than case 4. According to the case experiments, column arrangements show more upwelling volume transport than that of row arrangements. In cases of column arrangements, with decreasing clearance between two seamount, the effect increases while showing maximum value at clearance zero. In cases of row arrangements, on the contrary, with decreasing clearance between two seamount, the effect decreases while showing minimum value at clearance zero. Since simple barotropic condition was considered for this study, further study is necessary by considering baroclinic condition to get close to reality. In conclusion, in deploying artificial seamount, optimal arrangement should be well designed to enhance primary and secondary productivity and to increase the diversity of species as well as reducing time and space.

성상신경절차단술로 제어되지 않은 대상포진후 신경통환자 치험 1예 (A Case Report of Post-herpetic neuralgia uncontroled after Stellate Ganglion Block)

  • 이정은;배한호;한영주;임도희;채은영;조철준;박양춘
    • 대한한방내과학회지
    • /
    • 제25권3호
    • /
    • pp.669-676
    • /
    • 2004
  • Post-herpetic neuralgia(PHN) is a chronic pain syndrome associated with the reactivation of a primary infection with varicella zoster virus(chinken pox), which leads to a chronic infection of dorsal root ganglia. The most common risk factor for shingles and its potential sequela, PHN, is advanced age. For a significant number of patients, the pain following healing of shingles can persist for months to years. If this pain, classified as PHN, persists longer than one month. PHN often leads to depression, disrupted sleep, decreased productivity, and utilization of health care. We treated a 60 year-old female patient who suffered pain and headache after Stellate Ganglion Blocks(SGB). In identifying points for differentiation of syndrom(辨證), this subject was diagnosed as Yangmyeong Merdian wind-heat syndrom(陽明經風熱證) and was administered Seungmagalgeuntanggamibang(revised Shengmagalgen-tang, 升麻葛根湯加味方). To ease pain, Western medication was administered as well. After fourteen days of treatment, pain and other symptoms improved.

  • PDF

물리치료사의 보수교육 실태분석 : 2014~2015년도 (The Analysis on Continuing Education in Physical Therapy : In 2014~2015)

  • 문소라;김명철;이준철
    • 대한통합의학회지
    • /
    • 제4권3호
    • /
    • pp.101-108
    • /
    • 2016
  • Purpose : The primary objective of this study was to examine the status of continuing education, and to identify the current state and employment status of these physical therapists. Moreover, the study also aimed to provide basic data for establishing improvement measures in various continuing education programs to enhance the quality of physical therapists, thereby providing high quality service to patients and contributing to the increasing productivity of hospitals. Method : The present study analyzed the basic data obtained from KPTA regarding the 671 physical therapists throughout Korea. Questionnaires were sent by mail to from direct visits were used in the final data analysis. The questionnaire consisted of 45 questions in 3 categories: general characteristics, continuing education. Collected data were analyzed using frequencies, percentages, means, and standard deviations. Result : Subjects 88 (87.1%) indicated that they continuing education, showing that most had taken continuing education courses. The importance and necessity of continuing education was much higher for those with doctoral degrees than for those who graduated from college, or who possessed bachelors or master's degrees. Conclusion : A necessary follow-up study using these findings would contribute to providing a high quality medical service and to enhancing the quality of physical therapists. Moreover, systematic management of continuing education is necessary to devise comprehensive and effective measures for the development and acquisition of updated skills by health care professionals.

가막만의 환경용량 산정 ( II ) -굴양식장 환경용량 산정- (Estimation of Carrying Capacity in Kamak Bay ( II ) - Estimation of carrying capacity of oyster culture ground -)

  • 조은일;박청길;이석모
    • 한국수산과학회지
    • /
    • 제29권5호
    • /
    • pp.709-715
    • /
    • 1996
  • 가막만의 굴양식장 환경용량을 산정하기 위해 생태계 모델을 이용하여 월별 기초생산력을 산정하고 년간 식물플랑크톤의 생산량을 구하여 얼굴로서의 전환계수를 사용하여 굴의 최대 생산 가능량 즉 환경용량을 산정 하였다. 1994년 6월부터 1995년 3월까지 굴양식기간 동안의 가막만 전체에서의 식물플랑크톤 생산량은 181,594 tonC이였고 최대 알굴 생산가능량은 287,033 ton이었고 단위용적당 생산가능량은 $0.29kg/m^3/year$였다. 가막만내에서 굴양식시설이 되어 있는 공간에서의 년간 최대 알굴생산 가능량은 15,443 ton이고 1994년도 실제 알굴생산량은 4,532 ton이므로 굴양식장 환경용량의 약 $29\%$에 해당되었고 1987년도 생산량은 14,592 ton이므로 환경용량의 $95\%$에 해당되었다. 따라서 다른 굴양식장 관리조건만 허용된다면 가막만에는 굴양식시설대수를 증가시키면 생산량이 더 증가할 수 있는 해역으로 평가되었다.

  • PDF

Nutrient dynamics in montane wetlands, emphasizing the relationship between cellulose decomposition and water chemistry

  • Kim, Jae Geun
    • 한국습지학회지
    • /
    • 제7권4호
    • /
    • pp.33-42
    • /
    • 2005
  • Wetlands often function as a nutrient sink. It is well known that increased input of nutrient increases the primary productivity but it is not well understood what is the fate of produced biomass in wetland ecosystem. Water and sediment quality, decomposition rate of cellulose, and sediment accumulation rate in 11 montane marshes in northern Sierra Nevada, California were analyzed to trace the effect of nitrogen and phosphorus content in water on nutrient dynamics. Concentrations of ammonium, nitrate, soluble reactive phosphorus (SRP) in water were in the range of 27 to 607, 8 to 73, and 6 to 109 ppb, respectively. Concentrations of ammonium, calcium, magnesium, sodium, and potassium in water were the highest in Markleeville, which has been impacted by animal farming. Nitrate and SRP concentrations in water were the highest in Snow Creek, which has been impacted by human residence and a golf course. Cellulose decomposition rates ranged from 4 to 75 % per 90 days and the highest values were measured in Snow Creek. Concentrations of total carbon, nitrogen, and phosphorus in sediment ranged from 8.0 to 42.8, 0.5 to 3.0, and 0.076 to 0.162 %, respectively. Accumulation rates of carbon, nitrogen, and phosphorus fluctuated between 32.7 to 97.1, 2.4 to 9.0, and 0.08 to $1.14gm^{-2}yr{-1}$, respectively. Accumulation rates of carbon and nitrogen were highest in Markleeville and that of phosphorus was highest in Lake Van Norden. Correlation analysis showed that decay rate is correlated with ammonium, nitrate, and SRP in water. There was no correlation between element content in sediment and water quality. Nitrogen accumulation rate was correlated with ammonium in water. These results showed that element accumulation rates in montane wetland ecosystems are determined by decomposition rate rather than nutrient input. This study stresses a need for eco-physiological researches on the response of microbial community to increased nutrient input and environmental change because the microbial community is responsible for the decomposition process.

  • PDF