• Title/Summary/Keyword: Primary productivity

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Primary Productivity of Phytoplankton at the Eutrophic down Reach of a Regulated River (the Han River, Korea) (부영양한 한강하류수역에서 식물플랑크톤의 1차생산)

  • Nam, Kung-Hyun;Hwang, Gil-Son;Kim, Kap-Soo;Kim, Bom-Chul
    • Korean Journal of Ecology and Environment
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    • v.34 no.4 s.96
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    • pp.267-276
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    • 2001
  • The downstream reach of the Han River adjoining Seoul in Korea was the upper boundary of an estuary where tidal effect on the flow rate could be exerted. According to the comprehensive river regulation project, the river was channelize dand impounded by two overflow dams, which provided favorable condition for algal growth in this sewage polluted eutrophic reach. In this study primary productivity of phytoplankton was measured in the down reach and the autochthonous and allochthonous organic carbon loadings were estimated. Primary production of phytoplankton measured by C-14 uptake and P-I model method ranged from 140 to $4,890\;mgC\;m^{-2}\;d^{-1}$ (median value $1,865\;mgC\;m^{-2}\;d^{-1}$) showing the level of eutrophic lakes. Phytoplankton density that varied according to water flow rate was highest in spring. Allochthonous organic carbon loading was dominated by sewage input through tributaries in most of days except flood flow period. The average proportion of autochthonous carbon generation by phytoplankton was 40.9%, which is very high proportion for a lotic habitat.

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Seasonal Nitrogen Dynamics of Zostera marina Inhabited in Dongdae Bay and Ojiri (동대만과 오지리 연안에 서식하는 해초(Zostera marina)내 질소함유율의 계절적 변화)

  • Kim, Min-Seob;Lee, Sung-Mi;Shin, Kyung-Hoon
    • Korean Journal of Environmental Biology
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    • v.24 no.2 s.62
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    • pp.186-194
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    • 2006
  • Nitrogen dynamics of Seagrass Zostera marina were investigated in both Dongdae Bay and Ojiri from March to August, 2004. All seagrass samples were separated into four fractions such as leaves (new and adult), sheath and rhizome in order to understand temporal variations of nitrogen content in different fractions of Zostera marina. There are temporal variations of shoot production rates and total nitrogen contents in their different fractions at both study areas. Leaf production were almost 4 to 5 fold higher in summer than in winter. The irradiance is the primary factor controlling the leaf production of Zostera marina in both sites although water temperature also influence its productivity. Nitrogen contents of leaves were overall low in summer than in winter, but nitrogen content of rhizome increased during the summer season. In addition, nitrogen contents of new leaves were mostly higher than adult leaves in spite of lower nitrogen content of new and adult leaves in high productivity period. This result suggests that Zostera marina seems to have significant translocation ability of nitrogen in a shoot. The nitrogen content of leaf tissue may reflect nutritional nitrogen availability.

Holocene Variations of Organic Carbon Contents in Lake Langer of King George Island, South Shetland Islands, West Antarctica

  • Khim, Boo-Keun;Yoon, Ho-Il;Kang, Cheon-Yun;Zhao, Junlin
    • Ocean and Polar Research
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    • v.26 no.3
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    • pp.507-514
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    • 2004
  • A sediment core drilled from Lake langer on King George Island was analyzed for a variety of textural md geochemical properties along with $^{14}C$ age dates. These data were combined with published records of other cores to provide a detailed history of Holocene variation of total organic carbon (TOC) contents with respect to terrestrial paleoclimate change. The lithologic contrast of the lower diamicton and upper fine-grained sediments shows the glacier activity and subsequent lake formation. Low TOC contents fluctuated during the diamicton deposition whereas the increase of TOC began with the lake formation during the postglacial period that started about 5,000 yr B.p More notable are the distinct TOC peaks that may imply enhanced primary productivity during the warm period. The uniform and low TOC contents may reflect the limited productivity during the evolution of the lake. However, the recent TOC readvance clearly indicates gradual warming on King George Island. However, the paleoclimatic signature in the terrestrial lake environment during the Holocene seems to be subtle and less distinct, compared to the marine environment.

Modeling and Forecasting Livestock Feed Resources in India Using Climate Variables

  • Suresh, K.P.;Kiran, G. Ravi;Giridhar, K.;Sampath, K.T.
    • Asian-Australasian Journal of Animal Sciences
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    • v.25 no.4
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    • pp.462-470
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    • 2012
  • The availability and efficient use of the feed resources in India are the primary drivers to maximize productivity of Indian livestock. Feed security is vital to the livestock management, extent of use, conservation and productivity enhancement. Assessment and forecasting of livestock feed resources are most important for effective planning and policy making. In the present study, 40 years of data on crop production, land use pattern, rainfall, its deviation from normal, area under crop and yield of crop were collected and modeled to forecast the likely production of feed resources for the next 20 years. The higher order auto-regressive (AR) models were used to develop efficient forecasting models. Use of climatic variables (actual rainfall and its deviation from normal) in combination with non-climatic factors like area under each crop, yield of crop, lag period etc., increased the efficiency of forecasting models. From the best fitting models, the current total dry matter (DM) availability in India was estimated to be 510.6 million tonnes (mt) comprising of 47.2 mt from concentrates, 319.6 mt from crop residues and 143.8 mt from greens. The availability of DM from dry fodder, green fodder and concentrates is forecasted at 409.4, 135.6 and 61.2 mt, respectively, for 2030.

Development of Stress-tolerant Crop Plants

  • Park, Hyung-In;Kang, Jung-Youn;Sohn, Hee-Kyung;Kim, Soo-Young
    • Journal of Plant Biotechnology
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    • v.4 no.2
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    • pp.53-58
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    • 2002
  • Adverse environmental conditions such as drought, high salt and cold/freezing are major factors that reduces crop productivity worldwide. According to a survey, 50-80% of the maximum potential yield is lost by these "environmental or abiotic stresses", which is approximately ten times higher than the loss by biotic stresses. Thus, improving stress-tolerance of crop plants is an important way to improve agricultural productivity, In order to develop such stress-tolerant crop plants, we set out to identify key stress signaling components that can be used to develop commercially viable crop varieties with enhanced stress tolerance. Our primary focus so far has been on the identification of transcription factors that regulate stress responsive gene expression, especially those involved in ABA-mediated stress response. Be sessile, plants have the unique capability to adapt themselves to the abiotic stresses. This adaptive capability is largely dependent on the plant hormone abscisic acid (ABA), whose level increases under various stress conditions, triggering adaptive response. Central to the response is ABA-regulated gene expression, which ultimately leads to physiological changes at the whole plant level. Thus, once identified, it would be possible to enhance stress tolerance of crop plants by manipulating the expression of the factors that mediate ABA-dependent stress response. Here, we present our work on the isolation and functional characterization of the transcription factors.n factors.

Comprehensive Field Measurement of Indoor Air and Thermal Quality in Naturally Ventilated Office Building with Double-Skin Façade

  • Ito, Kazuhide;Shiraishi, Yasuyuki
    • International Journal of High-Rise Buildings
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    • v.2 no.4
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    • pp.293-314
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    • 2013
  • Double-Skin Façade (DSF), which is a kind of passive indoor environmental control technique, is effective way to control environmental loads while maintaining the transparency especially in perimeter zone and hence the adoption example of DSF keep increasing recently. The objective of this study was to perform a field survey of air quality environment with natural ventilation through DSF and thermal environment within office building with six stories during a mild climate period in Japan. Moreover, to understand the comprehensive environmental performance of the target building, questionnaire survey was conducted to subjectively evaluate the productivity and satisfaction with the environmental factors in office space. In this field measurement, there was a positive correlation between the DSF internal ventilation flow and the amount of solar radiation on the DSF normal surface; the primary driving force for ventilation in the DSF was considered to be the buoyancy force caused by solar radiation. The results of questionnaire survey with regard to productivity level indicated the need for improvement in the thermal (temperature) and spatial environment (room size and furniture placement).

Comparative Analysis of Household Work Contributions and Related Factors of the Elderly between Korea and Canada (노인의 가사노동 기여도에 대한 비교문화적 연구)

  • Joung Soon-Hee
    • Journal of Families and Better Life
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    • v.23 no.3 s.75
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    • pp.53-62
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    • 2005
  • In this study, we challenge recent apocalyptic rhetoric about idle, burdensome, and dependent older people. Our primary objective is to examine and compare the productive activities of older adults in both Korea and Canada using a broader definition of productivity that included household work. Another objective is to identify and compare the factors related to the participation of household work of older adults in both countries. In order to conduct a comparative culture study two data sets were used; one was the 1999 Survey of Time Use collected by Korean Statistics Office and the other was 1998 Survey of Time Use collected by Canadian Statistics Office. Many countries have been collected a time use survey and used to study labor, welfare, and culture. Total number of 17,730 Korean and 2,729 Canadian between when and 84 were included to analyze the data. It is clear from the results that older people engage in productive behaviors, particularly when the definition of activities is broadened to include unpaid work. However, it is also clear the productive contributions in terms of household work ale lower among older Koreans than among older Canadians.

The Importance of Consultation for Employee Welfare : Qualitative Textual Analysis

  • Kyungsoo LEE
    • The Journal of Industrial Distribution & Business
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    • v.14 no.12
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    • pp.23-31
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    • 2023
  • Purpose: The primary objectives of this research are: (1) To examine the current situation of employee welfare in diverse workplace settings. (2) To explore and identify the different challenges that affect employees' overall well-being. (3) To examine and establish the importance of consultation as a strategic tool in addressing these challenges and enhancing employee welfare. Research design, data and methodology: The first step of the research design is the identification of databases, search terms, and filters. A thorough search will be conducted across respectable academic databases, journals, and pertinent sources using keywords and controlled vocabulary about consultation, employee welfare, and related concepts. The next step is full-text assessment, which verifies compliance with the research question and assesses the caliber of the methodology. Results: According to the previous evidence, the significant benefits of effective consultation for employee welfare have been highlighted: 1. positive impact on productivity in the workplace, 2. Effective consultation Improves employee's engagement, 3. Effective consultation Increases employee retention, and 4. Effective consultation facilitates trust in a corporate communication. Conclusions: The study has identified four main advantages: enhanced productivity, enhanced engagement, increased retention, and enhanced trustbuilding. These findings provide insightful information for practitioners looking to foster positive workplace cultures and improve organizational success.

Primary Production by Epiphytic Algae Attached on the Reed in Constructed Wetlands for Water Treatment (수처리용 인공습지에서 갈대부착조류의 유기물생산력)

  • Choi, Don-Hyeok;Choi, Kwang-Soon;Hwang, Gil-Son;Kim, Dong-Sup;Kim, Sea-Won;Kang, Ho
    • Journal of Korean Society of Environmental Engineers
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    • v.31 no.10
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    • pp.893-900
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    • 2009
  • To estimate the contribution of epiphytic algae attached on reed to organic matter production in constructed wetland, primary productivity by epiphytic algae was investigated in two sub-wetlands (Banweol and Donhwa wetlands) of the Sihwa Constructed Wetland (CW) with different chemistry of inflows. Chlorophyll a concentration of epiphytic algae was higher in the Banweol wetland (range:37~3,581 mgChl.a/$m^2$surface stem, average:655 mgChl.a/$m^2$surface stem) than the Donhwa wetland (range:87~2,093 mgChl.a/$m^2$surface stem, average:527 mgChl.a/$m^2$surface stem). In contrast, assimilation number (AN) representing photosynthetic activity was higher in the Donhwa wetland with low TN/TP ratio than the Banweol wetland. A negative correlation (r=0.46) was observed between TN/TP ratios of inflows and AN in two wetlands, implying that high photosynthetic activity of epiphytic algae may be related with low TN/TP ratio. The areal primary productivity ranged from 307 to 2,473 mgC/$m^2$/day in the Banweol wetland and from 756 to 2,096 mgC/$m^2$/day in the Donghwa wetland, showing high productivity in summer. Average primary production was lower in the Banweol wetland (1,166 mgC/$m^2$/day) than the Donghwa wetland (1,467 mgC/$m^2$/day), although the standing crop (as chlorophyll a concentration) was high in the Banweol wetland. This result may be due to the low photosynthetic activity of epiphytic algae in the Banweol wetland with high TN/TP ratio. The annual primary production (300 tonC/year) of epiphytic algae contributed 33% of the total production in the Sihwa CW. An excessive organic matter production in constructed wetland can negatively affect the efficiency of water treatment. Therefore, the role of epiphytic algae should be considered in management of constructed wetland for water treatment.

Family Planning and Maternal-Child Health Services that Disciplined Itself in Primary Health Care Post from 1980 to 2009 (보건진료소 가족계획 및 모자보건사업(1980년~2009년))

  • Son, Gye-Soon
    • Journal of Korean Academy of Rural Health Nursing
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    • v.3 no.2
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    • pp.104-115
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    • 2008
  • Purpose: A study of the family planning and Maternal-Child Health Services that disciplined itself in primary health care post form 1980 to 2009. Method: Investigation studies family planning in primary health care post and a change process of a Maternal-Child Health Services into case by case until 2009 from 1980. Results: Our country family planning business began at economic development dimensions in order to solve a poverty issue. This business goal were childbirth decrease of pregnancy possibility couple aged 19~49 and improve to mother and child health. For this goal, all kinds of health education included sex education and contraception education, contraception service, comprehensive maternal and child health service that management of front and back of childbirth etc. are provided. According to fail down a birthrate from 6.0(1962) to 1.25(2009), the nation reached to a dilemma called childbirth encouragement policy. Conclusions: Decrease of labor supply by low birthrate, decrease numerical an employed person by aging was brought a labor shortage and decrease of productivity of labor of industrial manpower. Deterioration phenomenon of financial income and expenditure by consumption and investment contraction caused decrease of slowdown of economic growth and potential growth rate, and a social cost burden is increased by deterioration financial old man support burden increase by this and pensions and health insurance, a sharp increase of social welfare cost etc. Now, in order to solve a low birth issue, the government establishes a whole nation forwarding system and establishes basic plan social low birth and advanced age, and to prepare for childbirth fault factors removal and advanced age society shall endeavor.