• 제목/요약/키워드: Continents

검색결과 125건 처리시간 0.022초

Identification and Characterization of a New Strain of the Unicellular Green Alga Dunaliella salina (Teod.) from Korea

  • Polle, Jurgen E.W.;Struwe, Lena;Jin, Eon-Seon
    • Journal of Microbiology and Biotechnology
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    • 제18권5호
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    • pp.821-827
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    • 2008
  • The unicellular green alga Dunaliella salina is a halotolerant eukaryotic organism. Its halophytic properties provide an important advantage for open pond mass cultivation, since D. salina can be grown selectively. D. salina was originally described by E. C. Teodoresco in 1905. Since that time, numerous isolates of D. salina have been identified from hypersaline environments on different continents. The new Dunaliella strain used for this study was isolated from the salt farm area of the west coastal side of South Korea. Cells of the new strain were approximately oval- or pear-shaped (approximately $16-24\;{\mu}m$ long and $10-15\;{\mu}m$ wide), and contained one pyrenoid, cytoplasmatic granules, and no visible eyespot. Although levels of $\beta$-carotene per cell were relatively low in cells grown at salinities between 0.5 to 2.5 M NaCl, cells grown at 4.5 M NaCl contained about a ten-fold increase in cellular levels of $\beta$-carotene, which demonstrated that cells of the new Korean strain of Dunaliella can overaccumulate $\beta$-carotene in response to salt stress. Analysis of the ITS1 and ITS2 regions of the new Korean isolate showed that it is in the same clade as D. salina. Consequently, based on comparative cell morphology, biochemistry, and molecular phylogeny, the new Dunaliella isolate from South Korea was classified as D. salina KCTC10654BP.

Allelic Diversity and Geographical Distribution of the Gene Encoding Plasmodium falciparum Merozoite Surface Protein-3 in Thailand

  • Sawaswong, Vorthon;Simpalipan, Phumin;Siripoon, Napaporn;Harnyuttanakorn, Pongchai;Pattaradilokrat, Sittiporn
    • Parasites, Hosts and Diseases
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    • 제53권2호
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    • pp.177-187
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    • 2015
  • Merozoite surface proteins (MSPs) of malaria parasites play critical roles during the erythrocyte invasion and so are potential candidates for malaria vaccine development. However, because MSPs are often under strong immune selection, they can exhibit extensive genetic diversity. The gene encoding the merozoite surface protein-3 (MSP-3) of Plasmodium falciparum displays 2 allelic types, K1 and 3D7. In Thailand, the allelic frequency of the P. falciparum msp-3 gene was evaluated in a single P. falciparum population in Tak at the Thailand and Myanmar border. However, no study has yet looked at the extent of genetic diversity of the msp-3 gene in P. falciparum populations in other localities. Here, we genotyped the msp-3 alleles of 63 P. falciparum samples collected from 5 geographical populations along the borders of Thailand with 3 neighboring countries (Myanmar, Laos, and Cambodia). Our study indicated that the K1 and 3D7 alleles co-existed, but at different proportions in different Thai P. falciparum populations. K1 was more prevalent in populations at the Thailand-Myanmar and Thailand-Cambodia borders, whilst 3D7 was more prevalent at the Thailand-Laos border. Global analysis of the msp-3 allele frequencies revealed that proportions of K1 and 3D7 alleles of msp-3 also varied in different continents, suggesting the divergence of malaria parasite populations. In conclusion, the variation in the msp-3 allelic patterns of P. falciparum in Thailand provides fundamental knowledge for inferring the P. falciparum population structure and for the best design of msp-3 based malaria vaccines.

Genetic Diversity of Taenia asiatica from Thailand and Other Geographical Locations as Revealed by Cytochrome c Oxidase Subunit 1 Sequences

  • Anantaphruti, Malinee Thairungroj;Thaenkham, Urusa;Watthanakulpanich, Dorn;Phuphisut, Orawan;Maipanich, Wanna;Yoonuan, Tippayarat;Nuamtanong, Supaporn;Pubampen, Somjit;Sanguankiat, Surapol
    • Parasites, Hosts and Diseases
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    • 제51권1호
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    • pp.55-59
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    • 2013
  • Twelve 924 bp cytochrome c oxidase subunit 1 (cox1) mitochondrial DNA sequences from Taenia asiatica isolates from Thailand were aligned and compared with multiple sequence isolates from Thailand and 6 other countries from the GenBank database. The genetic divergence of T. asiatica was also compared with Taenia saginata database sequences from 6 different countries in Asia, including Thailand, and 3 countries from other continents. The results showed that there were minor genetic variations within T. asiatica species, while high intraspecies variation was found in T. saginata. There were only 2 haplotypes and 1 polymorphic site found in T. asiatica, but 8 haplotypes and 9 polymorphic sites in T.saginata. Haplotype diversity was very low, 0.067, in T. asiatica and high, 0.700, in T. saginata. The very low genetic diversity suggested that T. asiatica may be at a risk due to the loss of potential adaptive alleles, resulting in reduced viability and decreased responses to environmental changes, which may endanger the species.

Sulzbacheromyces sinensis, an Unexpected Basidiolichen, was Newly Discovered from Korean Peninsula and Philippines, with a Phylogenetic Reconstruction of Genus Sulzbacheromyces

  • Liu, Dong;Wang, Xin Yu;Wang, Li Song;Maekawa, Nitaro;Hur, Jae-Seoun
    • Mycobiology
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    • 제47권2호
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    • pp.191-199
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    • 2019
  • Most of lichens are formed by Ascomycota, less than 1% are lichenized Basidiomycota. The flora investigation of lichenized Ascomycota of South Korea has been well studied in the past three decades; however, prior to this study, none of basidiolichens was discovered. During the recent excursion, an unexpected clavarioid basidiolichen, Sulzbacheromyces sinensis was collected. Morphology and ecology has been recorded in detail. DNA was extracted, and ITS, 18S, 28S nuclear rDNA were generated. In order to further confirm the systematic position of the Korean specimens, maximum likelihood and Bayesian inference analysis including all the species of the order Lepidostromatales were conducted based on the ITS. As a result, the phylogenetic tree of the order Lepidostromatales was reconstructed, which differed from the previous studies. The inferred phylogenetic tree showed that species of Sulzbacheromyces in three different continents (Asia, South Africa and South America) were separated into three clades with support. In this study, the species worldwide distribution map of Lepidostromatales was illustrated, and S. sinensis had a widest distribution range (paleotropical extend to the Sino-Japanese) than other species (paleotropical or neotropical). Prior to this study, the range of distribution, southernmost and northernmost points and the fruiting time of S. sinensis were recorded, and the genus Sulzbacheromyces was firstly reported from Korean peninsula and Philippines.

Prevalence and extension of the anterior loop of the mental nerve in different populations and CBCT imaging settings: A systematic review and meta-analysis

  • Hadilou, Mahdi;Gholami, Leila;Ghojazadeh, Morteza;Emadi, Naghmeh
    • Imaging Science in Dentistry
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    • 제52권2호
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    • pp.141-153
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    • 2022
  • Purpose: This study aimed to identify the prevalence and extension of the anterior loop (AL) of the mental nerve in different populations and according to different cone-beam computed tomography (CBCT) imaging settings. Materials and Methods: Medline/PubMed, Embase, Scopus, Web of Science, and ProQuest were searched. The main inclusion criterion was ALs evaluated in CBCT images. The quality of studies was assessed with the Joanna Briggs Institute risk of bias checklist. Subgroup analyses were conducted for sex, side, continent, voxel size, field of view, and type of CBCT-reconstruction images with a random-effects model. Results: Sixty-three studies with 13,743 participants (27,075 hemimandibles) were included. An AL was found in 40.6% (95% CI: 32.8%-48.9%, P<0.05) of participants and 36.0% (95% CI: 27.5%-45.5%, P<0.05) of hemimandibles, in 34.9% (95% CI: 25.1%-46.2%, P<0.05) of males and 34.5% (95% CI: 23.5%-47.4%, P<0.05) of females. The average length of ALs was 2.39 mm (95% CI: 2.07-2.70 mm, P<0.05). Their extension was 2.13 mm (95% CI: 1.54-2.73 mm, P<0.05) in males and 1.85 mm (95% CI: 1.35-2.36 mm, P<0.05) in females. Significant differences were observed regarding the prevalence and length of ALs among continents and for its measured length on different CBCT-reconstruction images, but not between other subgroups. Conclusion: AL was a relatively common finding. The voxel size and fields of view of CBCT devices were adequate for assessing AL; however, a 2-mm safety margin from anatomical structures(such as the AL) could be recommended to be considered when using CBCT imaging.

African swine fever: Etiology, epidemiological status in Korea, and perspective on control

  • Yoo, Dongwan;Kim, Hyunil;Lee, Joo Young;Yoo, Han Sang
    • Journal of Veterinary Science
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    • 제21권2호
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    • pp.38.1-38.24
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    • 2020
  • African swine fever (ASF), caused by the ASF virus, a member of the Asfarviridae family, is one of the most important diseases in the swine industry due to its clinical and economic impacts. Since the first report of ASF a century ago, ample information has become available, but prevention and treatment measures are still inadequate. Two waves of epizootic outbreaks have occurred worldwide. While the first wave of the epizootic outbreak was controlled in most of the infected areas, the second wave is currently active in the European and Asian continents, causing severe economic losses to the pig industry. There are different patterns of spreading in the outbreaks between those in European and Asian countries. Prevention and control of ASF are very difficult due to the lack of available vaccines and effective therapeutic measures. However, recent outbreaks in South Korea have been successfully controlled on swine farms, although feral pigs are periodically being found to be positive for the ASF virus. Therefore, we would like to share our story regarding the preparation and application of control measures. The success in controlling ASF on farms in South Korea is largely due to the awareness and education of swine farmers and practitioners, the early detection of infected animals, the implementation of strict control policies by the government, and widespread sharing of information among stakeholders. Based on the experience gained from the outbreaks in South Korea, this review describes the current understanding of the ASF virus and its pathogenic mechanisms, epidemiology, and control.

소셜 네트워크 사이트의 사용자 행동 분석을 통한 사용성 결점 식별 및 효과적인 사용자 경험을 위한 상호작용성 프레임워크 (Interactivity Framework for Analysis of Social Network Sites User's Behavior for Identification of Usability Flaws and Effective User's Experience)

  • 새미 압둘자릴;윤석진;강대기
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2011년도 춘계학술발표대회
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    • pp.544-546
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    • 2011
  • Due to the explosive growth of online social network users, large numbers of users discover these social network sites are a place where they can be able to spend their spare time, share feelings, ideas freely, and to search for new friends or partners. These web sites give an opportunity for its users to socialize with new people and to keep in touch or reconnect with current or old friends and families across disperse continents via these web sites, which traditionally replace the traditional methods. These social network web sites need careful investigations and findings on the usability for effective interactivity and more usability. However, little research might have previously invested on the usability of these on social network web sites. Therefore, we propose a new framework to study the usability of these social network sites. We namely call our framework "Interactivity". This framework will enable us to assess the usability of the social network sites. It will provide an overview of the user's behavior while interacting in these social network web sites. Measurement of the interactivity will be measured using Camtasia software. This software will entirely capture the interactivity of users including the screen and the movements, which the screen and the motion of the user action will undergo to analysis at the end of our research.

Marketing Feng Shui to Asia: A Case Study

  • Bela Florenthal;Noriko Yagi;Hongjiang Xu
    • Asia Marketing Journal
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    • 제11권2호
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    • pp.1-20
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    • 2009
  • Feng Shui practice is very popular in East Asia and has been rapidly adopted by the population of the West. As Feng Shui involves knowledge of object placement, it opens opportunities to market Feng Shui knowledge and products. This paper presents an analysis of a successful Feng Shui enterprise, World of Feng Shui (WOFS), that has been established by a well-known Feng Shui expert Lillian Too and her daughter Jennifer Too. The enterprise's marketing strategies and tactics are tied to the theoretical concept of social influence, widely researched in the consumer behavior literature. The three types of social influence (informational, utilitarian, and value-expressive) are examined in relation to WOFS' marketing strategies using secondary data material. The main results indicate that the strategies of WOFS enterprise address all three types of social influence. The articles generated on-and off-line can be mostly associated with the informational influence. The off- line activities such as events, courses/workshops, and TV shows are also informational in nature. The Q & A sections/postings can be considered as representative of the utilitarian influence. They give experts (e.g., Lillian Too) the opportunity to provide individuals with problem-specific recommendations. Mega-mall website provides the value-expressive influence as purchase and consumption of the Feng Shui products is most susceptible to this type of influence. In terms of implications, WOFS enterprise strategies are suitable not only for consumes but also for business executives in Asia and in the West as architects, designers, and homeowners across continents use Feng Shui practices for building placements and decoration of dwellings and workplaces. Feng Shui practice has some limitations such as conflicting opinions of experts and increased complexity when the dimension of time is taken into consideration. Still, Feng Shui as a practice is growing globally adjusting itself to regional and cultural challenges.

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한반도 동남부 신생대 지각변형의 주요 특징과 지구조적 의의 (Characteristics of the Cenozoic crustal deformation in SE Korea and their tectonic implications)

  • 손문;김종선;정혜윤;이융희;김인수
    • 한국석유지질학회지
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    • 제13권1호
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    • pp.1-16
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    • 2007
  • 한반도 동남부는 신생대 동안 지구조 환경의 변화에 따라 다중 지각변형을 겪었다. 신생대 동안의 주요 지구조 사건과 이에 따른 한반도 동남부에서 발생한 지각변형의 주요 특징들을 정리하면 다음과 같다. (1) 인도-아시아의 충돌과 태평양판의 이동방향 변화기(약 50${\sim}$43 Ma): 인도판의 충돌에 인해 동아시아 대륙이 동쪽의 태평양판쪽으로 밀려가면서 해구의 퇴각이 발생하였으며, 태평양판의 이동방향이 북북서에서 서북서방향으로 회전되었다. 그 결과 한반도 동남부에는 동서 내지 서북서-동남동방향의 인장력이 발생하였고 이로 인해 남${\sim}$북북동방향의 염기성 암맥군이 관입하였다.(48 Ma 전후). (2) 동해 화장기(약 25${\sim}$16 Ma): 남북 내지 북북서-남남동방향으로 동해가 활발히 확장됨에 따라 한반도 동쪽 해안선을 따라 우수향 전단력이 발생하였다. 이로 인해 한반도 동남부에는 북북서-남남동방향의 우수향 주향이동단층운동이 발생하였으며 단층의 우향 굴곡부 혹은 오버스텝 부분에는 당겨열림형 퇴적분지가 형성되었다. 기하 및 운동학적 특징에 따라 퇴적분지들은 평행사변형과 쐐기형 확장 분지로 나누어진다. 또한 이 시기에는 지괴가 시계방향으로 수평 회전되고 북서향으로 경동되었으며 일부 퇴적분지들은 확장 축이 동에서 서쪽으로 이동되는 전파열개 과정을 겪었다. 또한 약 17Ma경에는 이러한 지각변형을 가장 서쪽에서 규제하는 연일구조선이 우수향 주향이동단층으로 운동하기 시작하였다. (3) 일본 남서부 시계방향 회전기(약 15Ma): 필리핀해판의 북상으로 이즈-보닌 아크와 일본 남서부가 충돌해 일본 남서부의 시계방향 회전운동이 발생하였다. 이로 인해 대한해협에는 북서향 압축력이 가해졌으며 한반도 동남부에서는 응력반전으로 인해 퇴적분지의 확장이 종결되고 지괴의 융기와 국지적인 지괴의 반시계방향 수평회전운동이 발생하였다. (4) 동서방향 압축응력기(약 5Ma 이후): 태평양판의 섭입각도가 얕아지고 아무르판이 동진함으로써 한반도 동남부 특히, 울산단층 동부에 상반서향의 충상단층들이 형성되어 지괴가 융기되었으며, 최근 한반도 지진 발생의 주요 원인이 되고 있다.

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$1920{\sim}1930$년대(年代) 독일(獨逸) 지지학(地誌學)의 연구(硏究) 동향(動向) (The Trend of Regional Geography in Germany in the 1920s and 1930s)

  • 김재완
    • 한국지역지리학회지
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    • 제6권1호
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    • pp.69-89
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    • 2000
  • 20세기 전반기는 리터, 홈볼트로부터 시작된 근대 지리학이 꽃 피던 전성기였다. 19세기말 답보 상태였던 지리학이 20세기 들어서면서 지지학(地誌學)을 중심으로 유럽 각국에서 눈부신 발달을 보였다. 특히 독일의 헤트너와 쉬뤼터, 프랑스의 비달 드 라 블라쉬, 영국의 허버트슨 등을 지도자로 하여 각기 독특한 지지학(地誌學) 방법론(方法論)이 발전하였고, 경험적 연구도 많이 쏟아졌다. 그리하여 1920년대와 30년대에는 지지학(地誌學)의 전성기를 이루었다. 본고는 1920년대와 1930년대 독일에서 논의된 지리학자들의 지역 개념과 지지 방법론을 고찰하는데 연구 목적을 두었다. 1920년대와 1930년대 독일(獨逸)의 지지학(地誌學) 동향(動向)은 일본 지리학자들에게 직접적인 영향을 주었다. 그 영향으로 당시 일본의 대표적인 지지자(地誌學者)인 전중계이(田中啓爾) 지형, 기후, 식물대, 인문을 종합적으로 고려하여 일본의 지역구분을 시도하였다. 그는 당시 일본 지리학자들과 일본에서 공부하던 한국의 지리학자들에게 많은 영향을 미쳤다.

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