1,084 research outputs found

    Ecosystem-Based Fishery Management: A Critical Review of Concepts and Ecological Economic Models

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    An ecosystem approach means different things to different people. As a result the concept of ecosystem-based fishery management is evolving and it has no universal definition or consistent application. As regards ecosystem modeling, most economic models of fishery ignore the linkages to lower trophic levels. In particular, environmental data and other bottom-up information is widely disregarded. The objective of this paper is to provide a critical review of concepts and ecological economic models relating to ecosystem-based fishery management especially to the environmental issues. The paper started by reviewing basic concepts related to ecosystem-based fishery management and the economic value of ecosystems. Then it aimed to review the development of ecosystem modeling with emphasis on economic aspects of ecology. This was followed by a presentation of the applications of ecosystem-based fishery management in practice. The paper concluded with some critical discussions and brought together conclusions derived from previous literature reviews. We found that although the concept of ecosystem-based fishery management has no universal definition, there is a widespread agreement about the need to implement the ecosystem approach for fisheries in practice. We also revealed that nutrient flow plays a crucial role in an ecosystem. In addition, it has many properties such as recycling and exchanging between consumers and producers, which are similar to monetary flows in an economy. Therefore, nutrients should be chosen as the currency in ecological economic models.Ecosystem approach, fisheries management, ecological economic models

    Total synthesis of cofacial chlorin dimers of two different symmetries - Models of photosynthetic reaction centers

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    In photosynthetic reaction center, the special pair (SP) functions as the primary and significant part of the electron transfer. The function of SP is resulted from the particular structure with two nearly two-folded bacterio(chlorophyll). In this account, we focus on the basic principles underlying the design of artificial special pair. Toward this goal, two molecules were designed of having different symmetries and arranged in a cofacial fashion mimicking the special pair chlorophyll of naturally occurring photosynthetic reaction center. We employed chlorins as building blocks and they were connected at different positions to the diethynylbiphenylen spacer affording cis or trans orientations. The two chlorins with iodine substituents were successfully synthesized based on the condensation of 4 heterocyclic building blocks. The diethynylbiphenylen spacer linked two chlorin subunits via Shonogashira coupling affording the cofacial chlorin dimer. This construced model in trans symmetry mimicking the special pair of photosynthetic reaction center. The total synthesis of the cofacial chlorin dimmer in cis orientation is still in progress

    R PEAK DETERMINATION USING A WDFR ALGORITHM AND ADAPTIVE THRESHOLD

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    The determination of the R peak position in the ECG signal helps physicians not only to know the heart rate per minute, but also to monitor the patient’s health related to heart disease. This paper proposes a system to accurately determine the R peak position in the ECG signal. The system consists of a pre-processing block for filtering out noise using a WDFR algorithm and highlighting the amplitude of the R peak and a threshold value is calculated for determining the R peak. In this research, the MIT-BIH ECG dataset with 48 records are used for evaluation of the system. The results of the SEN, +P, DER and ACC parameters related to the system quality are 99.70%, 99.59%, 0.70% and 99.31%, respectively. The obtained performance of the proposed R peak position determination system is very high and can be applied to determine the R peak of the ECG signal measuring devices in practice

    A case study: Institutional Factors Affecting Lecturers’ Research Engagement in A University in Mekong Delta region, Vietnam

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    This case study investigated institutional factors affecting university lecturers’ research engagement in a multidisciplinary higher education institution in the Mekong Delta region, Vietnam. The study employed the interpretive qualitative case study approach with the use of three data collection tools (document analysis, surveys, and recorded semi-structured interviews). In this paper, the authors presented the findings of document analysis and the recorded semi-structured interviews. The findings indicated that institutional factors affecting lecturers’ research engagement in this studied university included governmental policies, funding and structure, resources, teaching loads, leadership and research environment. The paper suggested some recommendations to foster the lecturers’ research engagement in this university

    THE VARIATION OF QUALITY AND CURRENT SITUATION OF ARSENIC IN THE PLEISTOCENE AQUIFER- MEKONG DELTA

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    Joint Research on Environmental Science and Technology for the Eart

    Factors Affecting the Competitiveness of Logistics Service Enterprises: A Case Study of Dong Nai Province

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    Competitiveness of enterprises can maintain and improve competitive advantage in consuming products or services. Besides, enterprises expanded their consumption network through surveying experiences in the logistics service sector. Therefore, the authors surveyed 30 logistics service enterprises with 500 customers. The results showed five factors that affected the competitiveness of logistics service enterprises of Dong Nai Province with 1% significance. Finally, the article draws some recommendations to help enterprises improve the competitiveness of logistics service

    Ecosystem-based fishery management: A critical review of concepts and ecological economic models

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    An ecosystem approach means different things to different people. As a result the concept of ecosystem-based fishery management is evolving and it has no universal definition or consistent application. As regards ecosystem modeling, most economic models of fishery ignore the linkages to lower trophic levels. In particular, environmental data and other bottom-up information is widely disregarded. The objective of this paper is to provide a critical review of concepts and ecological economic models relating to ecosystem-based fishery management especially to the environmental issues. The paper started by reviewing basic concepts related to ecosystem-based fishery management and the economic value of ecosystems. Then it aimed to review the development of ecosystem modeling with emphasis on economic aspects of ecology. This was followed by a presentation of the applications of ecosystem-based fishery management in practice. The paper concluded with some critical discussions and brought together conclusions derived from previous literature reviews. We found that although the concept of ecosystem-based fishery management has no universal definition, there is a widespread agreement about the need to implement the ecosystem approach for fisheries in practice. We also revealed that nutrient flow plays a crucial role in an ecosystem. In addition, it has many properties such as recycling and exchanging between consumers and producers, which are similar to monetary flows in an economy. Therefore, nutrients should be chosen as the currency in ecological economic models
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