• Title/Summary/Keyword: Continent

검색결과 375건 처리시간 0.037초

Evaluation of Genetic Differentiation of Albizia lucida Populations from Eastern Region of the Indian Sub-continent by ISSR Markers

  • Aparajita, Subhashree;Rout, G.R.
    • Journal of Forest and Environmental Science
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    • 제24권1호
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    • pp.27-34
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    • 2008
  • Level and distribution of genetic diversity in seven populations of Albizia lucida Benth. in eastern region of the Indian sub-continent were estimated using ISSR markers. Relatively higher level of genetic diversity within populations was observed in seven populations of A. lucida (mean of 0.38). From the result of AMOVA, majority of genetic diversity was allocated within populations (96.2%) resulting in a moderate degree of population differentiation. The observed distribution pattern of I-SSR variant among the populations was coincided with the typical pattern of long-lived woody tree species. Genetic relationships among the populations, reconstructed by UPGMA method, revealed two genetic groups. The population of Anugul and Bargarh turned out to be the most closely related despite a distance location between them. These formations will be of great value in the development of conservation plans for species exhibiting high levels of genetic differentiation due to fragmentation, such as indication of conservation unit size, which populations should be chosen as priority in conservation plans and which samples should be introduced in areas with a low number of individuals of A. lucida.

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원격상관을 이용한 동아시아 6월 강수의 예측 (A Prediction of Precipitation Over East Asia for June Using Simultaneous and Lagged Teleconnection)

  • 이강진;권민호
    • 대기
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    • 제26권4호
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    • pp.711-716
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    • 2016
  • The dynamical model forecasts using state-of-art general circulation models (GCMs) have some limitations to simulate the real climate system since they do not depend on the past history. One of the alternative methods to correct model errors is to use the canonical correlation analysis (CCA) correction method. CCA forecasts at the present time show better skill than dynamical model forecasts especially over the midlatitudes. Model outputs are adjusted based on the CCA modes between the model forecasts and the observations. This study builds a canonical correlation prediction model for subseasonal (June) precipitation. The predictors are circulation fields over western North Pacific from the Global Seasonal Forecasting System version 5 (GloSea5) and observed snow cover extent over Eurasia continent from Climate Data Record (CDR). The former is based on simultaneous teleconnection between the western North Pacific and the East Asia, and the latter on lagged teleconnection between the Eurasia continent and the East Asia. In addition, we suggest a technique for improving forecast skill by applying the ensemble canonical correlation (ECC) to individual canonical correlation predictions.

African Indigenous Cattle: Unique Genetic Resources in a Rapidly Changing World

  • Mwai, Okeyo;Hanotte, Olivier;Kwon, Young-Jun;Cho, Seoae
    • Asian-Australasian Journal of Animal Sciences
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    • 제28권7호
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    • pp.911-921
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    • 2015
  • At least 150 indigenous African cattle breeds have been named, but the majority of African cattle populations remain largely uncharacterized. As cattle breeds and populations in Africa adapted to various local environmental conditions, they acquired unique features. We know now that the history of African cattle was particularly complex and while several of its episodes remain debated, there is no doubt that African cattle population evolved dramatically over time. Today, we find a mosaic of genetically diverse population from the purest Bos taurus to the nearly pure Bos indicus. African cattle are now found all across the continent, with the exception of the Sahara and the river Congo basin. They are found on the rift valley highlands as well as below sea level in the Afar depression. These unique livestock genetic resources are in danger to disappear rapidly following uncontrolled crossbreeding and breed replacements with exotic breeds. Breeding improvement programs of African indigenous livestock remain too few while paradoxically the demand of livestock products is continually increasing. Many African indigenous breeds are endangered now, and their unique adaptive traits may be lost forever. This paper reviews the unique known characteristics of indigenous African cattle populations while describing the opportunities, the necessity and urgency to understand and utilize these resources to respond to the needs of the people of the continent and to the benefit of African farmers.

백악기 동아시아 신지구조 모델: 맨틀 플룸의 역할 (A New Tectonic Model of Cretaceous East Asia: Role of Mantle Plume)

  • 이창열
    • 자원환경지질
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    • 제52권5호
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    • pp.337-345
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    • 2019
  • 중국, 한국 그리고 일본을 포함한 동아시아 지역의 백악기 시기 화성 활동을 설명하기 위하여 해령 섭입 가설이 제안되어 널리 받아들여 졌다. 특히, 해령 섭입 가설은 남서일본에서 발견되는 아다카이트의 북동 방향으로의 분출 시기의 감소를 잘 설명하였다. 그러나, 해령 섭입 가설은 이후 밝혀진 지구화학 연구 결과 및 판재구성 모델과 배치되기 때문에 여러 문제점을 지닌다. 따라서, 해령 섭입 가설의 문제점을 극복하고 이 시기 화성 활동을 설명하기 위한 플룸-대륙 및 플룸-슬랩 상호 작용 가설이 제안되었고 이 가설은 해령 섭입 가설이 내포한 문제점을 극복할 뿐만 아니라 동아시아 지역의 백악기 화성 활동을 설명할 수 있다. 이 고찰에서는 해령 섭입 가설과 그 대안인 플룸-대륙 및 플룸-슬랩 상호 작용 가설에 대해 요약하여 소개하고 이 대안 가설을 증명하기 위한 추가 연구에 대해 제언한다.

Development and Characterization of 14 Microsatellite Markers for the Antarctic Midge Parochlus steinenii (Diptera, Chironomidae) in Maritime Antarctic

  • Kim, Hanna;Kang, Seunghyun;Kim, Hanul;Kim, Sanghee;Jung, Jongwoo
    • Animal Systematics, Evolution and Diversity
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    • 제33권2호
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    • pp.140-143
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    • 2017
  • A winged midge species, Parochlus steinenii is one of the most abundant species in Antarctica, which is distributed over a wide area from the South American continent to the South Shetland Islands in Antarctica. It was dispersed into islands in the South Shetland Islands from the South American continent, and it adapted to a variety of environments and settled. This species, therefore, is a good model organism to explain the evolutionary process of Antarctic terrestrial fauna. Nevertheless, there are few genetic studies on this species, which are necessary for understanding the genetic diversity, population structure, etc. Here, we developed and characterized 14 polymorphic microsatellite markers. The number of alleles per locus ranged from 2 to 5. The observed and expected heterozygosities were in the range of 0.024 to 0.561 and 0.024 to 0.535, respectively. Identifying genetic differences between populations, they are suitable markers for researches investigating genetic diversity and population structure of P. steinenii, which provide us with clues to dispersion, evolution and ecology of this species.

Malaria Epidemic Prediction Model by Using Twitter Data and Precipitation Volume in Nigeria

  • Nduwayezu, Maurice;Satyabrata, Aicha;Han, Suk Young;Kim, Jung Eon;Kim, Hoon;Park, Junseok;Hwang, Won-Joo
    • 한국멀티미디어학회논문지
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    • 제22권5호
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    • pp.588-600
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    • 2019
  • Each year Malaria affects over 200 million people worldwide. Particularly, African continent is highly hit by this disease. According to many researches, this continent is ideal for Anopheles mosquitoes which transmit Malaria parasites to thrive. Rainfall volume is one of the major factor favoring the development of these Anopheles in the tropical Sub-Sahara Africa (SSA). However, the surveillance, monitoring and reporting of this epidemic is still poor and bureaucratic only. In our paper, we proposed a method to fast monitor and report Malaria instances by using Social Network Systems (SNS) and precipitation volume in Nigeria. We used Twitter search Application Programming Interface (API) to live-stream Twitter messages mentioning Malaria, preprocessed those Tweets and classified them into Malaria cases in Nigeria by using Support Vector Machine (SVM) classification algorithm and compared those Malaria cases with average precipitation volume. The comparison yielded a correlation of 0.75 between Malaria cases recorded by using Twitter and average precipitations in Nigeria. To ensure the certainty of our classification algorithm, we used an oversampling technique and eliminated the imbalance in our training Tweets.

A Review of the Phylogenetic Studies on the Kentish & Snowy Plovers

  • Woo-Yuel Kim;Dong-Yun Lee;Gun-hwa Kang;Ha-Cheol Sung
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • 제4권2호
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    • pp.63-68
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    • 2023
  • The Kentish Plover (Charadrius alexandrinus ; family Charadriidae; genus Charadrius) is a small bird that moves from continent to continent depending on the season. On the Kentish Plovers, phylogenetic studies have been widely conducted to classify different species or subspecies and to determine the time of speciation. However, the perspectives on the interspecific or intraspecific relationships in the phylogenetic analysis of Kentish Plovers remain debatable. Here, we reviewed the differences between the Kentish and Snowy Plovers (C. nivosus ) in terms of their morphology, ecology, and genetic information. Particularly, their differences in genetic information can be well demonstrated; however, the intraspecies differences in the populations that live in different environments can relatively be poorly explained. We suggest that not only genetic features but also morphological, ecological, and behavioral traits are important when comparing the Kentish Plovers with other species, such as the Snowy Plovers, in phylogenetic studies. Furthermore, we suggest that phylogenetic studies on the subspecies of the Kentish and Snowy Plovers should be conducted for their better identification.

아시아 대륙, 동아시아, 대한민국을 대상으로 다른 공간적 규모의 기후변화시나리오 예측 비교 (Comparing climate projections for Asia, East Asia and South Korea)

  • 최혜영;;이동근
    • 환경영향평가
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    • 제26권2호
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    • pp.114-126
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    • 2017
  • 우리나라의 많은 기후변화 관련 영향 평가 연구들이 기상청에서 제공하는 기후변화 시나리오를 이용하고 있지만, 하나의 기후 시나리오로 기후변화의 잠정적인 영향을 정확히 예측하기에는 한계가 있다. 본 연구는 세 가지의 지역적 스케일 - 아시아 대륙, 동아시아 6개국, 대한민국- 을 대상으로 두 가지 대표농도경로 시나리오에서 17개의 지역기후모델을 이용하여 현재와 2070년의 연간 최저 온도와 연간 강수량의 차이를 확인하였다. 대한민국의 경우 최저온도 증가량의 범위는 아시아 규모보다 작았으며 강수량 차이에 대한 편차는 아시아 규모보다 컸다. 최저온도 증가범위는 $1.3^{\circ}C$에서 $5.2^{\circ}C$이며, 연간 강수량 차이는 -42.4 mm (-3.2%) 에서 +389.8 mm (+ 29.6%) 로 기상청의 기후변화 시나리오는 긍정적 기후 시나리오의 예측값에 가까운 것으로 나타났다. 따라서 기후변화 및 관련 영향 평가 연구들은 다양한 기후변화 시나리오를 이용하여 그 예측 범위에 대비할 필요가 있으며, 본 연구 결과에 따라 GFDL-CM3와 INMCM4의 두 가지 기후모델을 이용하여 우리나라의 지구 온난화에 대한 잠정적인 영향을 평가하기를 권한다.

Economic Integration and the Changes in Logistics Circumstances in Northeast Asia -Emphasizing the Strengthening of Competitive Power of Hub Ports-

  • Park, Byung-Hong
    • 한국항만경제학회지
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    • 제20권1호
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    • pp.95-122
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    • 2004
  • This study focuses on analyzing the potentiality of economic integration and the changes in logistics circumstances in Northeast Asia. So far as the changes in logistics circumstances in it, it is emphasized a complex transport system by sea and by land, according to the connection with the Railroad of South-North in Korean Peninsula and the Railroad of the Continent of Siberia. It first considers the propriety of economic integration among Korea, China and Japan in Northeast Asia. The first stage of the economic integration in Northeast Asia means it is started from contracting of FTA(Free Trade Agreement) which just agreed at the Summit Conference among Korea, China and Japan in ASEAN+3(Korea China. Japan). At that time, the Summit Conference between the three countries have agreed to study on the propriety of FTA charging by own country's research organization. At first China has been hesitated to join with FTA in spite of high growth in his economy, because the time is not yet for it. After all, China also decided himself to participate to FTA together with Korea and Japan by reacted to the stimulus at the conference atmosphere between every country of ASEAN. The discussion on the changes in logistics circumstances also is needed to deal simultaneously with a situation in the economic integration in Northeast Asia. It is worthy to be paid our attention to the restoration of the Railroad of South-North in Korean Peninsula, which was disconnected for a long time from the dispute between South Korea and North Korea. Therefore, it needs to be investigated together with the movement of economic integration in Northeast Asia. The reaction on the restoration of the Railroad of South-North in Korean Peninsula is not only limited to the transport of trade cargo between South Korea and North Korea, but also it is reached to all of Northeast Asia, so far as to all of the area of Russia, Europe, and the other neighbor countries. Because this railroad is connected with the Railroad of the Continent of Siberia. The transport of trade cargo in Northeast Asia have been mostly depended upon the transport by sea until now. However, it would be divided into the transport by sea as well as by land from now. As its economic effect, the restoration of the Railroad of South-North in Korean Peninsula could be not only contributed to reduce the cost of logistics within South Korea and North Korea, but also within or without in Northeast Asia, Russia, and Europe. Consequently, it could be improved the power of international competitiveness of goods in Northeast Asia, according to the formation of a complex transport system together with the transport by sea and by land.

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지반조건과 지진파를 고려한 해저철도 터널의 동적 수치 모델링 (Dynamic Numerical Modeling of Subsea Railway Tunnel Based on Geotechnical Conditions and Seismic Waves)

  • 곽창원;유민택
    • 한국지반공학회논문집
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    • 제38권11호
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    • pp.69-86
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    • 2022
  • 철도는 정시성과 수송능력을 갖춘 여객 및 물류 운송 수단으로서 널리 사용되고 있다. 근래의 급격한 건설기술의 발전으로 철도는 대륙과 대륙, 대륙과 섬을 잇는 다양한 해저철도의 건설이 계획되고 있으며 국내에는 보령 해저터널(2021), 가덕 해저터널(2010) 등 유사 설계 및 시공 경험이 축적되고 있다. 그러나 최근 국내외적으로 다양한 규모의 지진이 빈번하게 발생함에 따라 지진위험에 대한 인식이 증대되고 있으며, 국내 지진의 발생빈도 또한 증가하고 있다. 해저터널에 대한 지진의 영향은 매우 복잡하나 주로 지반조건, 지진하중 등에 의하여 큰 차이를 보일 수 있다. 본 연구에서는 외부수압이 작용하는 가상의 해저철도 쉴드터널에 대하여 지반구성과 지진파 의한 영향을 파악하기 위하여 토사, 암반, 복합지반 및 파쇄대로 구성된 4 가지 지반조건을 반영한 3차원 수치해석 모델을 구축하였다. 각 해석 모델에 대하여 장주기, 단주기, 그리고 장단주기 특성을 모두 가지는 인공지진파를 각각 적용하여 유한차분해석법에 의한 동적해석을 수행하여 변위 및 터널 부재력 응답을 검토하였다. 그 결과 터널 변위는 토사지반에서 터널 진행방향에 연직방향 지진하중이 작용 시 장주기파의 영향이 우세하고 암반지반에서는 단주기파의 영향이 우세한 결과를 얻었다. 또한 국부적 취약구간인 파쇄대에서는 인공지진파의 영향이 우세하였다. 터널 세그먼트의 부재력 검토 결과 지반 및 세그먼트의 구속효과로 인하여 지진하중이 변위보다 부재력에 미치는 영향이 크게 나타남을 확인하였다.