• 제목/요약/키워드: population biology

검색결과 1,554건 처리시간 0.027초

Ocean Color Monitoring of Coastal Environments in the Asian Waters

  • Tang, Danling;Kawamura, Hiroshi
    • Journal of the korean society of oceanography
    • /
    • 제37권3호
    • /
    • pp.154-159
    • /
    • 2002
  • Satellite remote sensing technology for ocean observation has evolved considerably in these last twenty years. Ocean color is one of the most important parameters of ocean satellite measurements. This paper describes a remote sensing of ocean color data project - Asian I-Lac Project; it also introduces several case studies using satellite images in the Asian waters. The Asian waters are related to about 30 Asian countries, representing about 60% of the world population. The project aims at generating long-term time series images (planned for 10 years from 1996 to 2006) by combining several ocean color satellite data, i.e., ADEOS-I OCTS and SeaWiFS, and some other sensors. Some typical parameters that could be measured include Chlorophyll- a (Chl-a), Colored Dissolved Organic Matter (CDOM), and Suspended Material (SSM). Reprocessed OCTS images display spatial variation of Chl-a, CDOM, and SSM in the Asian waters; a short term variability of phytoplankton blooms was observed in the Gulf of Oman in November 1996 by analyzing OCTS and NOAA sea surface temperature (SST); Chl-a concentrations derived from OCTS and SeaWiFS have also been evaluated in coastal areas of the Taiwan Strait, the Gulf of Thailand, the northeast Arabian Sea, and the Japan Sea. The data system provides scientists with capability of testing or developing ocean color algorithms, and transferring images for their research. We have also analyzed availability of OCTS images. The results demonstrate the potential of long-term time series of satellite ocean color data for research in marine biology, and ocean studies. The case studies show multiple applications of satellite images on monitoring of coastal environments in the Asian Waters.

Population Dynamics and Fitness Comparison of Sensitive and Resistant Phenotypes of Botrytis cinerea to Benzimidazole, Dicarboximide, and N-phenylar-bamate Fungicides

  • Kim, Byung-Sup;Park, Eun-Woo;Cho, Kwang-Yun
    • The Plant Pathology Journal
    • /
    • 제17권3호
    • /
    • pp.149-153
    • /
    • 2001
  • A total of 2109 isolates of Botrytis cinerea were collected from infected plants fo strawberry, tomato, and cucumber in Korea from 1994 to 1996. Based on in virtotests for mycelial growth on potato-dextrose agar containing fungicides, the esolates were classified into six phenotypic groups : SSR, SRR, RSS, RRS, RSR, and RRR, representing sensitivity (S) or resistance (R) to carbendazim, procymidone, and diethofencarb. In that order the isolation frequencies of the SSR, SRR, RSS, RRS, RSR, and RRR phenotypes were 28.7, 1.1, 28.8, 39.4, 1.0, and 0.9%, respectively. Three isolates from each SSR, SRR, RSS, RRS, and RSR and an isolate of RRR phenotype were selected and evaluated for their fitness-related characteristics such as pathogenic aggressiveness, mycelial growth rate, sporulation, and sclerotial formation. Competitive abilities of the SSR, SRR, RSS, RRS, and RSR phenotypes were also compared by inculating mixtures of conidial suspensions of two phenotypes to cucumber plant, and then determining re-isolation frequencies from lesions. In general, significant differences in fitness-related characteristics, except pathogenic aggressiveness, were found not only between but also within phenotype groups. In the competitiveness tests, carbendazim-sinsitive phenotypes (SSR and SRR) were found to be more competitive than the resistant ones (RSS and RSR), whereas, the procymidone-resistant phenotypes (SRR and RRS) appeared to be more competitive than the sensitive ones (SSR, RSS, and RSR). There was no consistent dominance in competitiveness between the diethofencarb-resistant and sensitive phenotypes. The RSR phenotype was the least competitive among the five phenotypes.

  • PDF

De Novo Transcriptome Analysis of Cucumis melo L. var. makuwa

  • Kim, Hyun A;Shin, Ah-Young;Lee, Min-Seon;Lee, Hee-Jeong;Lee, Heung-Ryul;Ahn, Jongmoon;Nahm, Seokhyeon;Jo, Sung-Hwan;Park, Jeong Mee;Kwon, Suk-Yoon
    • Molecules and Cells
    • /
    • 제39권2호
    • /
    • pp.141-148
    • /
    • 2016
  • Oriental melon (Cucumis melo L. var. makuwa) is one of six subspecies of melon and is cultivated widely in East Asia, including China, Japan, and Korea. Although oriental melon is economically valuable in Asia and is genetically distinct from other subspecies, few reports of genome-scale research on oriental melon have been published. We generated 30.5 and 36.8 Gb of raw RNA sequence data from the female and male flowers, leaves, roots, and fruit of two oriental melon varieties, Korean landrace (KM) and Breeding line of NongWoo Bio Co. (NW), respectively. From the raw reads, 64,998 transcripts from KM and 100,234 transcripts from NW were de novo assembled. The assembled transcripts were used to identify molecular markers (e.g., single-nucleotide polymorphisms and simple sequence repeats), detect tissue-specific expressed genes, and construct a genetic linkage map. In total, 234 single-nucleotide polymorphisms and 25 simple sequence repeats were screened from 7,871 and 8,052 candidates, respectively, between the KM and NW varieties and used for construction of a genetic map with 94 F2 population specimens. The genetic linkage map consisted of 12 linkage groups, and 248 markers were assigned. These transcriptome and molecular marker data provide information useful for molecular breeding of oriental melon and further comparative studies of the Cucurbitaceae family.

ISSR을 이용한 음나무속 분류군의 유전적 다양성과 관련성 비교 (Comparison of Genetic Diversity and Relationships of Genus Kalopanax Using ISSR Markers)

  • 허만규
    • 생명과학회지
    • /
    • 제16권5호
    • /
    • pp.740-745
    • /
    • 2006
  • ISSR 마크로 한국내 자생하는 음나무속 4분류군(음나무, 가시없는 음나무, 털음나무, 가는잎음나무)에 대해 유전적 다양성과 계통관계를 조사하였다. 64개의 재현성 높은 ISSR 밴드가 생성되었다. 음나무속의 각 개체별 분석에서 41개 밴드(64.1%)가 다형성을 나타내었다. 네 분류군을 통합하였을 때 그룹내 다양도는 0.115였고 그룹간 다양도는 0.467이였다. 종내 유전자 흐름(Nm)의 측정결과 음나무의 Nm값은 털음나무, 가는잎음나무에 비해 낮았다. 이는 지리적 거리에 따른 생식적 격리가 이 종의 집단구조를 형성하고 있다고 판단된다. 계통도 분석에서 ISSR 마크로 속수준의 네 분류군뿐만 아니라 집단까지도 잘 분리되어 본 연구에 사용한 마크가 분류에 효과적임이 규명되었다.

Diversity in Betasatellites Associated with Cotton Leaf Curl Disease During Source-To-Sink Movement Through a Resistant Host

  • Khan, Iftikhar Ali;Akhtar, Khalid Pervaiz;Akbar, Fazal;Hassan, Ishtiaq;Amin, Imran;Saeed, Muhammad;Mansoor, Shahid
    • The Plant Pathology Journal
    • /
    • 제32권1호
    • /
    • pp.47-52
    • /
    • 2016
  • Cotton leaf curl is devastating disease of cotton characterized by leaf curling, vein darkening and enations. The disease symptoms are induced by DNA satellite known as Cotton leaf curl Multan betasatellite (CLCuMuB), dominant betasatellite in cotton but another betasatellite known as Chili leaf curl betasatellite (ChLCB) is also found associated with the disease. Grafting experiment was performed to determine if host plant resistance is determinant of dominant population of betasatellite in cotton (several distinct strains of CLCuMuB are associated with the disease). Infected scion of Gossypium hirsutum collected from field (the source) was grafted on G. arboreum, a diploid cotton species, resistant to the disease. A healthy scion of G. hirsutum (sink) was grafted at the top of G. arboreum to determine the movement of virus/betasatellite to upper susceptible scion of G. hirsutum. Symptoms of disease appeared in the upper scion and presence of virus/betasatellite in the upper scion was confirmed via molecular techniques, showing that virus/betasatellite was able to move to upper scion through resistant G. arboreum. However, no symptoms appeared on G. arboreum. Betasatelites were cloned and sequenced from lower scion, upper scion and G. arboreum which show that the lower scion contained both CLCuMuB and ChLCB, however only ChLCB was found in G. arboreum. The upper scion contained CLCuMuB with a deletion of 78 nucleotides (nt) in the non-coding region between Arich sequence and ${\beta}C1$ gene and insertion of 27 nt in the middle of ${\beta}C1$ ORF. This study may help in investigating molecular basis of resistance in G. arboreum.

Geographic Genetic Contour of A Leaf Beetle, Chrysolina aurichalcea (Coleoptera: Chysomelidae), on the Basis of Mitochondrial COI Gene and Nuclear ITS2 Sequences

  • Park, Joong-Won;Park, Sun-Young;Wang, Ah-Rha;Kim, Min-Jee;Park, Hae-Chul;Kim, Ik-Soo
    • International Journal of Industrial Entomology and Biomaterials
    • /
    • 제23권1호
    • /
    • pp.155-166
    • /
    • 2011
  • The leaf beetle, $Chrysolina$ $aurichalcea$ (Coleoptera: Chysomelidae), is a pest damaging plants of Compositae. In order to understand the genetic diversity and geographic variation we sequenced a portion of mitochondrial COI gene (658 bp) and complete nuclear internal transcribed spacer 2 (ITS2) of the species collected from seven Korean localities. A total of 17 haplotypes (CACOI01~CACOI17), with the maximum sequence divergence of 3.04% (20 bp) were obtained from COI gene sequence, whereas 16 sequence types (ITS2CA01~ITS2CA16), with the maximum sequence divergence of 2.013% (9 bp) were obtained from ITS2, indicating substantially larger sequence divergence in COI gene sequence. Phylogenetically, the COI gene provided two haplotype groups with a high nodal support (${\geq}87%$), whereas ITS2 provided only one sequence type group with a high nodal support (${\geq}92%$). The result of COI gene sequence may suggest the presence of historical biogeographic barriers that bolstered genetic subdivision in the species. Different grouping pattern between COI gene and ITS2 sequences were interpreted in terms of recent dispersal, reflected in the ITS2 sequence. Finding of unique haplotypes and sequence types only from Beakryeng-Islet population was interpreted as an intact remnant of ancient polymorphism. As more samples are analyzed using further hyper-variable marker, further fruitful inference on the geographic contour of the species might be available.

Generation of transposon insertion mutants from type A Pasteurella multocida

  • Choi, Keum-hwa;Maheswaran, Samuel K.
    • 대한수의학회지
    • /
    • 제39권2호
    • /
    • pp.327-337
    • /
    • 1999
  • The transposon TnphoA was used to generate avirulent mutants from a type A Pasteurella multocida. A suicide vector plasmid pRT733 carrying TnphoA, having the kanamycin resistant gene and harbored in Escherichia coli K-12 strain SM10(${\lambda}pir$), was mated with streptomycin resistant P. multocida P-1059 strain as recipient. This resulted in the generation of two TnphoA insertion mutants (transconjugants, tc95-a and tc95-b) which were resistant both to kanamycin ($Km^{R}$) and streptomycin ($Sm^{R}$), secreted alkaline phosphatase, and were avirulent to turkeys. Southern blot hybridization using two probes derived from internal fragments of TnphoA, confirmed the insertion of TnphoA into 12.9kb or 13.7kb DNA fragment from the EcoRV digested genomic fragments of transconjugants. The two transconjugants, tc95-a and tc95-b, were distinguishable from their parent strains by differences in ribotypes, and outer membrane protein profiles. TnphoA insertion in both transconjugants also resulted in constitutive expression of a 33Kd iron regulated outer membrane protein (IROMP). The gene encoding $Sm^{R}$ was also located within the same 12.9kb EcoRV genomic fragment from both transconjugants. Furthermore, our finding that the recipient P. multocida P-1059 $Sm^{R}$ strain and both transconjugants were avirulent to turkeys suggest that the either 12.9kb or 13.7kb genomic DNA contains the virulence gene and speculate that the presence of $Sm^{R}$ gene or TnphoA insertion may be responsible for regulating and inactivating the gene(s) encoding virulence in P. multocida.

  • PDF

Nutrient Supplementation in the Elderly

  • Meydani, Mohsen
    • Journal of Community Nutrition
    • /
    • 제2권1호
    • /
    • pp.5-11
    • /
    • 2000
  • Populations both in the US and worldwide are aging. It is projected that by the year 2030 the population of Americans over 65 will increase to 70 million, more than twice their number in 1998. About one-third of elderly over the age of 65 have debilitating chronic health conditions that greatly impede their activities. Age-associated chronic diseases are believed to be associated with free radicals and the imbalance in antioxidant and oxidative stress contributes to development of several chronic health conditions. Diet and nutrients can have great impact in the health status of elderly. Several factors may contributor to the inadequate consumption of nutrients in elderly, including an inability to chew food adequately, polypharmacy, living along and limited income. Low intake of energy and several micronutrients are common among the elderly. Although overt deficiency of nutrients among the elderly is not common. a recent study showed that while elderly consume more fat, the total energy intake is low among the elderly. Inadequate intake of antioxidant nutrients such as vitamin E in elderly may contribute to the development of chronic health problems. Intake of higher than normal RDA levels of vitamin E for long periods of time has been shown to reduce the risk of many degenerative diseases, such as cardiovascular diseases(CVD) and cancer, and improve immune response in elderly. High intake of other antioxidants is also associated with reduced risk chronic diseases. Dietary antioxidants are abundant in fruits and vegetables. However, due to variety of factors, the elderly may not be able to receive these and other micronutrients through diet. Therefore, supplemental intake of micronutrients in the form of multi vitamins/minerals and/or specific micronutrients is a more practical approach to the maintenance of health status in the elderly.

  • PDF

Effect of Extrinsic Factors on Differentiated Cardiomyocyte-like Cells from Human Embryonic Stem Cells

  • Gil, Chang-Hyun;Jang, Jae-Woo;Lee, Won-Young;Park, Ze-Won;Lee, Jae-Ho;Chung, Sun-Hwa;Chae, Jung-Il;Chung, Hyung-Min
    • Reproductive and Developmental Biology
    • /
    • 제33권4호
    • /
    • pp.263-271
    • /
    • 2009
  • Cardiovascular diseases (CVDs) are one of the most cause of death around the world and fields of interest for cardiac stem cells. Also, current use of terminally differentiated adult cardiomyocytes for CVDs has limited regenerative capacity therefore any significant cell loss may result in the development of progressive heart failure. Human embryonic stem cells (hESCs) derived from blastocyst-stage embryos spontaneously have ability to differentiate via embryo-like aggregates (endoderm, ectoderm and mesoderm) in vitro into various cell types including cardiomyocyte. However, most effective molecule or optimized condition which can induce cardiac differentiation of hESCs is rarely studied. In this study, we developed both spontaneous and inductive cardiomyocyte-like cells differentiation from hESCs by treatment of induced-factors, 5-azacytidine, BMP-4 and cardiogenol C. On the one hand, spontaneous and inductive cardiomyocyte-like cells showed that cardiac markers are expressed for further analysis by RT-PCR and immunocytochemistry. Interestingly, BMP-4 greatly improved homogeneous population of the cardiomyocyte-like cells from hESCs CHA15 and H09. In conclusion, we verified that spontaneously differentiated cells showed cardiac specific markers which characterize cardiac cells, treated extrinsic factors can manage cellular signals and found that hESCs can undergo differentiation into cardiomyocytes better than spontaneous group. This finding offers an insight into the inductive factor of differentiated cardiomyocytes and provides some helpful information that may offer the potential of cardiomyocytes derived from hESCs using extrinsic factors.

꽁치의 어업생물학적 연구 2. 회유 (STUDIES ON THE FISHERY BIOLOGY OF THE PACIFIC SAURY, COLOLABIS SAIRA OF THE EAST COAST OF KOREA 2. Migration)

  • 김기주
    • 한국수산과학회지
    • /
    • 제6권1_2호
    • /
    • pp.49-57
    • /
    • 1973
  • 우리나라 동안의 꽁치에 대해서 1968년, 1970년 및 1971년 $1\~7$월의 어획통계 자료와 1968년의 체장측정자료를 이용하여 꽁치의 체형군에 따른 회유를 고찰한 결과는 다음과 같다. 1. 어장내의 전어군의 분포중심의 이동은 북상 회유에서나 남하 회유에서나 대체로 $130^{\circ}\~130^{\circ}30'$의 범위를 중심으로 이루어지고 있으며, 각월의 동서 방향으로의 편배의 정도는 해에 따라 대단히 심하다. 이 중심의 이동은 해황외에 해에 따른 체형군별의 자원량의 크기와도 깊은 관계를 가질 것이라 추측된다. 2. 체형군을 분류하는 기준체장의 주년에 걸친 변화곡선을 구한 결과는 다음과 같다. 5, 6월에 있어서 중형군을 구분하는 체장의 변화곡선은 $Y=24.807X^{0.0885}$이며, 중형군과 소형군을 구분하는 체장의 변화곡선은 $Y=21.532X^{0.1177}$이다. 단 Y는 체장, X는 역상의 월을 표시함. 3. 회유에 있어서 북상기에는 체형이 작은 것이 먼저 북상하고 남하기에는 체형이 큰 것이 먼저 남하하는 경향을 보인다. 4. 회유경로는 어장내의 분포중심의 이동방향으로서 추적될수 있는 것이 아니며, 1968년의 각 체형군의 회유경로는 Fig. 6과 같이 추정된다.

  • PDF