• 제목/요약/키워드: diversity methods

검색결과 1,261건 처리시간 0.027초

Use of Terminal Restriction Length Polymorphism (T-RFLP) Analysis to Evaluate Uncultivable Microbial Community Structure of Soil

  • Chauhan, Puneet Singh;Shagol, Charlotte C.;Yim, Woo-Jong;Tipayno, Sherlyn C.;Kim, Chang-Gi;Sa, Tong-Min
    • 한국토양비료학회지
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    • 제44권1호
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    • pp.127-145
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    • 2011
  • Various environmental ecosystems are valuable sources for microbial ecology studies, and their analyses using recently developed molecular ecological approaches have drawn significant attention within the scientific community. Changes in the microbial community structures due to various anthropogenic activities can be evaluated by various culture-independent methods e.g. ARISA, DGGE, SSCP, T-RFLP, clone library, pyrosequencing, etc. Direct amplification of total community DNA and amplification of most conserved region (16S rRNA) are common initial steps, followed by either fingerprinting or sequencing analysis. Fingerprinting methods are relatively quicker than sequencing analysis in evaluating the changes in the microbial community. Being an efficient, sensitive and time- and cost effective method, T-RFLP is regularly used by many researchers to access the microbial diversity. Among various fingerprinting methods T-RFLP became an important tool in studying the microbial community structure because of its sensitivity and reproducibility. In this present review, we will discuss the important developments in T-RFLP methodology to distinguish the total microbial diversity and community composition in the various ecosystems.

Effects of cutting and sowing seeds of native species on giant ragweed invasion and plant diversity in a field experiment

  • Byun, Chaeho;Choi, Ho;Kang, Hojeong
    • Journal of Ecology and Environment
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    • 제44권4호
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    • pp.256-263
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    • 2020
  • Background: Ambrosia trifida is a highly invasive annual plant, but effective control methods have not been proposed. Among various eradication methods, cutting is a simple measure to control invasive plants, and sowing seeds of native plants may effectively increase biotic resistance to invasion. In this study, we conducted a field experiment with two treatments: cutting and sowing seeds of six native or naturalized plants. Results: We found a significantly lower A. trifida abundance after cutting than in the control (77% decrease). Sowing seeds of native species did not provide any additional benefit for the control of A. trifida, but increased the importance values and diversity of other native vegetation. The abundance of A. trifida was negatively correlated with that of other plant taxa based on plant cover, biomass, and density. However, biotic resistance of sown plants was not effective to control invasion because A. trifida was so competitive. Conclusions: We concluded that cutting is an effective measure to control Ambrosia trifida while sowing seeds of native plants can increase native plant diversity.

A Study on Diverse Designs of Furniture Presented as Graduation Projects by Graduates of Local Universities - Focusing on painting methods for wooden surface -

  • Choi, Ki;Lee, Jae-Young
    • 한국가구학회지
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    • 제19권4호
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    • pp.252-259
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    • 2008
  • High glossy painting and UV lithographic painting as painting methods for wooden furniture have played a positive role in enhancing the diversity of furniture design, which has been proved by the analysis on the relationship between the change in the diversity of design and painting methods of graduation projects (wooden furniture) presented by graduates of local universities, as a focus of this article. Since the development of new painting methods has the potential to develop aesthetic characteristics of wooden furniture, many design experiments are needed to improve decorative features of furniture, such as the application of high glossy painting and UV lithographic painting.

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다양성관리가 조직인력구성과 재무성과에 미치는 영향 (The Impact of the Diversity Management on the Workforce Composition and Financial Performance)

  • 성상현;김대룡
    • 한국산학기술학회논문지
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    • 제12권1호
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    • pp.110-124
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    • 2011
  • 단일민족으로 오랫동안 지내왔던 한국사회의 구성원들이 급속하게 다양화되면서 앞으로 한국 조직 내 인적자원관리에서 다양성이 차지하는 비중은 늘어날 것이다. 본 연구에서는 한국노동연구원 사업체패널자료를 활용하여 다양성 친화적인 인적자원관리가 조직의 인력구성에 미치는 영향을 분석하였다. 실증분석에 따른 주요결과들로는 여성인력에 대한 훈련비중이 높으면 여성인력 구성비율이 증가되며, 임금에서 이익분배와 집단성과급제도가 차지하는 비중이 높은 기업은 장애인 비율이 높고, 다수의 모집제도를 활용하는 기업에서는 외국인 근로자 비율이 증가하는 것으로 나타났다. 하지만 인력다양성 확대를 억제할 가능성이 있는 인적자원관리제도(핵심인력관리제, 연봉제, 인사고과제)에 비하여 다양성 친화형 인적자원관리제도는 기업의 재무성과에 유의한 영향을 미치지 못하는 것으로 나타났다. 따라서 기업은 처해진 경영상황과 조직문화에 따라 인력구조의 다양성과 경쟁력을 효과적으로 관리하는 인적자원관리제도를 구상하여야 할 것이다. 본 연구는 다양성 친화형 인적자원관리제도를 형성하는데 있어서 경영성과에 근거하여 주요 세부제도들이 어떻게 효과적으로 형성되어야 할 것인지에 대한 시사점을 주는데 의의가 있다.

Y-Single Nucleotide Polymorphisms Diversity in Chinese Indigenous Horse

  • Han, Haoyuan;Zhang, Qin;Gao, Kexin;Yue, Xiangpeng;Zhang, Tao;Dang, Ruihua;Lan, Xianyong;Chen, Hong;Lei, Chuzhao
    • Asian-Australasian Journal of Animal Sciences
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    • 제28권8호
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    • pp.1066-1074
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    • 2015
  • In contrast to high genetic diversity of mitochondrial DNA (mtDNA), equine Y chromosome shows extremely low variability, implying limited patrilines in the domesticated horse. In this study, we applied direct sequencing and restriction fragment length polymorphism (RFLP) methods to investigate the polymorphisms of 33 Y chromosome specific loci in 304 Chinese indigenous horses from 13 breeds. Consequently, two Y-single nucleotide polymorphisms (SNPs) (Y-45701/997 and Y-50869) and one Y-indel (Y-45288) were identified. Of those, the Y-50869 (T>A) revealed the highest variation frequency (24.67%), whereas it was only 3.29% and 1.97% in Y-45288 (T/-) and Y-45701/997 (G>T) locus, respectively. These three mutations accounted for 27.96% of the total samples and identified five Y-SNP haplotypes, demonstrating genetic diversity of Y chromosome in Chinese horses. In addition, all the five YSNP haplotypes were shared by different breeds. Among 13 horse breeds analyzed, Balikun horse displayed the highest nucleotide diversity (${\pi}=5.6{\times}10^{-4}$) and haplotype diversity (h = 0.527), while Ningqiang horse showed the lowest nucleotide diversity (${\pi}=0.00000$) and haplotype diversity (h = 0.000). The results also revealed that Chinese horses had a different polymorphic pattern of Y chromosome from European and American horses. In conclusion, Chinese horses revealed genetic diversity of Y chromosome, however more efforts should be made to better understand the domestication and paternal origin of Chinese indigenous horses.

An Overview of Different Techniques on the Microbial Community Structure, and Functional Diversity of Plant Growth Promoting Bacteria

  • Kim, Kiyoon;Islam, Rashedul;Benson, Abitha;Joe, Manoharan Melvin;Denver, Walitang;Chanratan, Mak;Chatterjee, Poulami;Kang, Yeongyeong;Sa, Tongmin
    • 한국토양비료학회지
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    • 제49권2호
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    • pp.144-156
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    • 2016
  • Soil is a dynamic biological system, in which it is difficult to determine the composition of microbial communities. Knowledge of microbial diversity and function in soils are limited because of the taxonomic and methodological limitations associated with studying the organisms. In this review, approaches to measure microbial diversity in soil were discussed. Research on soil microbes can be categorized as structural diversity, functional diversity and genetic diversity studies, and these include cultivation based and cultivation independent methods. Cultivation independent technique to evaluate soil structural diversity include different techniques such as Phospholipid Fatty Acids (PLFA) and Fatty Acid Methyl Ester (FAME) analysis. Carbon source utilization pattern of soil microorganisms by Community Level Physiological Profiling (CLPP), catabolic responses by Substrate Induced Respiration technique (SIR) and soil microbial enzyme activities are discussed. Genetic diversity of soil microorganisms using molecular techniques such as 16S rDNA analysis Denaturing Gradient Gel Electrophoresis (DGGE) / Temperature Gradient Gel Electrophoresis (TGGE), Terminal Restriction Fragment Length Polymorphism (T-RFLP), Single Strand Conformation Polymorphism (SSCP), Restriction Fragment Length Polymorphism (RFLP) / Amplified Ribosomal DNA Restriction Analysis (ARDRA) and Ribosomal Intergenic Spacer Analysis (RISA) are also discussed. The chapter ends with a final conclusion on the advantages and disadvantages of different techniques and advances in molecular techniques to study the soil microbial diversity.

MIMO Ad Hoc Networks: Medium Access Control, Saturation Throughput, and Optimal Hop Distance

  • Hu, Ming;Zhang, Junshan
    • Journal of Communications and Networks
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    • 제6권4호
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    • pp.317-330
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    • 2004
  • In this paper, we explore the utility of recently discovered multiple-antenna techniques (namely MIMO techniques) for medium access control (MAC) design and routing in mobile ad hoc networks. Specifically, we focus on ad hoc networks where the spatial diversity technique is used to combat fading and achieve robustness in the presence of user mobility. We first examine the impact of spatial diversity on the MAC design, and devise a MIMO MAC protocol accordingly. We then develop analytical methods to characterize the corresponding saturation throughput for MIMO multi-hop networks. Building on the throughout analysis, we study the impact of MIMO MAC on routing. We characterize the optimal hop distance that minimizes the end-to-end delay in a large network. For completeness, we also study MAC design using directional antennas for the case where the channel has a strong line of sight (LOS) component. Our results show that the spatial diversity technique and the directional antenna technique can enhance the performance of mobile ad hoc networks significantly.

한국 해산어류의 종다양성 및 보전 (Diversity and Conservation of Korean Marine Fishes)

  • 김진구
    • 한국어류학회지
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    • 제21권sup1호
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    • pp.52-62
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    • 2009
  • 한반도 주변 3개 해역은 서로 다른 지형과 다양한 해류의 교차로 종다양성의 근간이 된다. 또한, 복잡한 해류가 만나는 전선 주변으로는 좋은 어장이 형성된다. 그러나, 남획에 의한 자원의 감소 및 EEZ 발효에 의한 어장의 축소는 새로운 수산자원 관리법을 필요로 하게 되었다. 수산자원의 효율적 관리를 위해 우선 다양한 해양환경에 적응한 지역개체군의 실체를 파악하는 것이 필요하다. 지역개체군의 형태 및 유전에 관한 연구는 자원의 관리단위 및 구역을 명확히 하는 데 기여할 것이다. 최종적으로 해역별 수산자원의 관리방안 제시가 가능할 것으로 기대된다.

도플러 확산 환경에서의 안테나 다이버시티 효과에 관한 연구 (A Study on Effects of Antenna Diversity in Doppler Spread Environments)

  • 이종길
    • 한국정보통신학회논문지
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    • 제9권3호
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    • pp.510-515
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    • 2005
  • 도플러 확산은 송수신단의 이동에 따라 발생하며 송수신단의 상대적인 위치 및 이동속도에 따라 도플러 주파수 변이 정도가 다르게 나타난다 본 논문에서는 앞으로 폭 넓게 활용될 것으로 예상되는 OFDM(Orthogonal Frequency Division Multiplexing) 통신방식을 적용했을 경우를 가정하여 다양한 무선채널에서의 도플러 확산에 의한 성능 열화 현상을 안테나 다이버시티(diversity) 효과를 활용하여 어느 정도까지 개선할 수 있는지를 분석하였다. 이를 위하여 다양한 무선채널 모델을 설정하고 도플러 확산에 따른 SIR(Signal to interference) 값 및 SIR을 고려한 effective SNR을 계산하였다. 이러한 결과들을 바탕으로 도플러 확산 정도에 따른 다이버시티 효과를 구체적으로 분석하기 위하여 수신단에서의 BER 개선 정도를 고찰하였다.

Bacterial Diversity in a Korean Traditional Soybean Fermented Foods (Doenjang and Ganjang) by 16S rRNA Gene Sequence Analysis

  • Cho, Kye-Man;Seo, Weon-Taek
    • Food Science and Biotechnology
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    • 제16권2호
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    • pp.320-324
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    • 2007
  • The bacterial diversity in Korean soybean-fermented foods was investigated using a PCR-based approach. 16S rRNA sequences were amplified and cloned from two different soybean-fermented foods such as doenjang (soybean paste), and ganjang (soybean sauce). Staphylococcus equorum (60.6%), Tetragenococcus halophila (21.2%), Leuconostoc mesenteroides (9.1%), Lactobacillus sakei (6.1%), and Bacillus subtilis (3.0%) were detected among clones isolated from soybean paste samples and Halanaerobium sp. (37.5%), Halanaerobium fermentans (37.5%), T. halophila (12.5%), Staphylococcus sp. (6.3%), S. equorum (3.1%), and B. subtilis (3.1%) were detected among clones isolated from soybean sauce. Our approach revealed different bacterial distributions and diversity from those previously obtained using culture-dependent methods.