• 제목/요약/키워드: Geographic differentiation

검색결과 62건 처리시간 0.028초

Contrasting TiO$_2$/MgO ratios in the Namwon granitic complex

  • Kwon, S.T.;Hong, S.S.
    • 암석학회지
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    • 제2권1호
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    • pp.41-52
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    • 1993
  • We report adventages of employing MgO as a differentiation index for the Namwon granitic complex. It is shown to be much more sensitive than the usual Harker index. The complex can be divided into two groups on the basis of $TiO_2$/MgO ratio. The low $TiO_2$/MgO group consists of hornblende biotite tonalite-granodiorite, porphyritic hornblende biotite granodiorite (PHBGd) and part of biotite granite (loBG). PHBGd shows its own distinct variation in the low group. This group is characterized in most cases by the presence of hornblende, even if it occurs as a trace amount. The high $TiO_2$/MgO group consists of part of biotite granite (hiBG) and two mica granite. The major element differences between rock types are also apparent in biotite chemistry. These chemical data indicate that at least two distinct origins of magma are rquired for the complex. Two kinds of biotite granite revealed in this study show distinct geographic distribution, suggesting that a new geologic map should be made.

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감귤 잿빛곰팡이병균의 살균제에 대한 저항성 및 유전적 다양성 (Fungicide Resistance and Genetic Diversity of Botrytis cinerea of Citrus)

  • 고영진;이재군;서정규;문두길;한해룡
    • 한국식물병리학회지
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    • 제14권6호
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    • pp.682-688
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    • 1998
  • Fungicide resistance of 48 isolates of Botrytis cinerea collected from citrus in Cheju was investigated and genetic diversity was analyzed with random amplified polymorphic DNA(RAPD). High levels of resistance to benzimidazole fungicides benomyl and thiophanate-methyl and N-phenylcarbamate fungicide diethofencarb were observed. Negative cross resistance was clear between benzimidazole and N-phenylcarbamate fungicides, and multiple resistance to the fungicides was also observed. There was cross resistance among the dicarboximide fungicides procymidione, vinclozolin and iprodione as it was observed between the benzimidazole fungicides benomyl and thiophanate-methyl. The lowest levels of resistance were to the dicarboximide fungicides, but no sensitive isolate to polyoxin B was observed. The isolates showed genetically diverse RAPD profiles according to the geographic origin collected, but there was no significant correaltion between RAPD profiles of genomic DNA and the levels of fungicide resistance of the isolates. The isolates showed genetically diverse RAPD profiles, indicating that genetic differentiation had already occurred in the populations of B. cinerea distributed in Cheju.

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Reproductive aspects of the Amazon giant paiche (Arapaima gigas): a review

  • Marie Anne Galvez Escudero;Anthony Jesus Mendoza De La Vega
    • Fisheries and Aquatic Sciences
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    • 제27권2호
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    • pp.57-65
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    • 2024
  • Paiche (Arapaima gigas), is a colossal freshwater fish native to the Amazon basin. Its geographic distribution spans various regions, including Brazil, Peru, Colombia, and Guyana, making it a significant component of the aquatic ecosystems in this area. Beyond its ecological role, the paiche holds substantial importance as a valuable fish resource for local communities, providing sustenance and economic opportunities. This review provides a comprehensive analysis of the reproductive aspects of the paiche, based on information published from January 2000 to January 2022. It encompasses a wide range of reproductive characteristics, including sexual differentiation, age at first maturity, and identification techniques. Additionally, it offers an evaluation of various mating behaviors, highlighting their respective advantages and disadvantages. The review also explores genetic and behavioral traits observed in both wild and captive specimens, offering valuable insights for the effective management of breeding programs.

미토콘드리아 16S rRNA 염기서열에 의한 한국, 중국 낙지의 유전자 집단 분석 (Population Genetic Structure of Octopus minor Sasaki from Korea and China Based on a Partial Sequencing of Mitochondrial 16S rRNA)

  • 김주일;오택윤;서영일;조은섭
    • 생명과학회지
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    • 제19권6호
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    • pp.711-719
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    • 2009
  • 본 연구는 2006년 8월부터 2007년 9월까지 여수, 남해, 진도, 무안, 거문도, 서산 및 중국의 산동에서 포획한 낙지 유전자 집단을 분석하기 위하여 미토콘드리아 16S rRNA 염기서열로 조사했다. 유전자 분석은 총 28 개체로부터 11개의 haplotype이 발견되었다. 유전자 분화율은 0.2-1.2% 범위로 나타났다. Haplotype에 대한 PHYLIP 및 network 조사에 따르면 낙지는 두개의 clade (clade AIclade B)로 나뉘어지며, clade 사이의 분화율은 0.4%로 나타났다. 지역적 거리에 따라 haplotype이 다음과 같이 분화되었다. 하나는 여수, 남해, 무안, 진도 haplotype과 다른 하나는 서산, 거문도, 산동 haplotype으로 나뉘어졌다. 계충구조 분석에서도 한국 낙지집단 및 중국과의 유전적 차이를 볼 수 있으나, 현저한 지역적 차이는 나타나지 않았다. 따라서 한국연안에 서식하고 있는 일부 낙지집단은 gene flow에 의해서 유전적 동질성을 나타낼 수 있지만, 한국집단 간 뿐만 아니라 중국집단과의 유전적 분화는 지역적 거리 및 장벽으로 인하여 제한적인 gene flow로 설명될 수 있다.

적설의 동질지역 구분과 지역 차등화 (Homogeneous Regions Classification and Regional Differentiation of Snowfall)

  • 김현욱;심재관;최병철
    • 한국지리정보학회지
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    • 제20권3호
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    • pp.42-51
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    • 2017
  • 대설은 우리나라의 법적 자연재해 중 하나이다. 최근 기상현상에 의한 사회경제적 영향력을 함께 예보하는 영향예보가 부각되고 있으며, 이를 위해서는 먼저 각 지역의 기후적 특징을 분석할 필요가 있다. 본 연구에서는 영향예보의 기반마련을 위해 자기조직화지도를 활용하여 적설동질지역을 구분하여 지역별 적설 특징을 분석했다. 연구결과 적설동질지역은 7개 군집으로 나타났으며, 강설량 및 관측일수, 최대강설량을 이용하여 각 그룹의 특징을 구분했다. 대관령, 강릉시, 정읍시는 강설량이 많은 지역으로, 경상도는 강설량이 적은 지역으로 구분되었다. 선행연구와 비교결과 대표적인 지역이 잘 구분되었으나 강설의 특징은 차이가 있는 것으로 나타났다. 본 연구의 결과는 각 지역의 영향예보를 위한 정책결정에 기초자료로 활용될 수 있다.

Genetic Diversify and Population Structure of Two Korean Pond Frog Species, Rana nigromaculata and R. plancyi (Anura, Ranidae), with a Survey of Temporal Genetic Variation in R. nigromaculata

  • Suh-Yung Yang;Jong-Bum Kim;Mi-Sook Min;Jae-Hwa Suh
    • Animal cells and systems
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    • 제3권3호
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    • pp.275-283
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    • 1999
  • Korean R. plancyi occupies a restricted area in western South Korea and shows a relatively low level of genic variability (%P=15.2, Ho=0.052, He=0.048). In contrast, R. nigromaculata is broadly distributed in South Korea. The observed low level of variability of R. nigromaculata (%P=14.3, Ho=0.042, He=0.043) is probably due to its recent colonization. Populations of R. nigromaculata exhibited considerable genetic differentiation (F$_{sT}$=0.149) and low level of gene flow (Nm=1.427) among populations, compared to those of R. Plancyi (F$_{sTF$_{sT}$}$=0.096, Nm=2.354), which occupies a restricted area. The observed levels of gene flow among populations of R. nigromaculata (Nm=1.427) over a broad geographic range is relatively higher than other amphibian species. The high level of gene flow is probably the result of the high dispersal abilities of R. nigromaculata. A survey of temporal genic variation of R. nigromaculata showed that there was no significant change on the overall average genetic diversity from 1978 (average He=0.044) to 1997 (average He=0.040). Wright's F-statistics also indicated no significant genetic differentiation from 1978 (F$_{sT}$=0.118) to 1997 (F$_{sT}$=0.108). This suggests that the environmental change appears to have had little influence on the genetic composition of R. nigromaculata in the study areas during the past 20 years. The low level of temporal variation might be due to the result of high dispersal abilities and wide migration range of this species.

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학력자본 재생산의 차별화와 빗장도시의 형성 (The Differentiation of Reproductions of Educational Capitals and the Formation of the Gated City)

  • 최은영
    • 대한지리학회지
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    • 제39권3호
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    • pp.374-390
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    • 2004
  • 본 연구에서는 부모세대의 사회 경제적 지위에 따라 결정된 거주지에 따라 자녀세대의 학력자본이 차별적으로 재생산되고 있는지를 살펴보고자 하였다. 연구결과 고학력으로 대표되는 사회ㆍ경제적 지위가 높은 집단의 거주 비율이 높은 분리된 거주지에서 재생산되는 학력자본은 양적인 면에서나 질적인 면에서 모두 매우 차별적으로 나타나고 있다. 특정 지역에 거주하는 것 자체가 자녀 미래의 많은 부분을 결정하게 되어 사회집단들 간의 경계가 부와 빈곤의 지리적 집중에 의해 확대ㆍ강화되고 있다. 다른 지역과 구분되는 차별화된 학력자본의 재생산이 이루어지는 강남구는 고학력집단의 지속적 집중과 아파트 가격의 급격한 상승으로 비가시적이지만 견고한 사회 경제적 장벽을 갖는 빗장도시의 성격이 강화되고 있다. 높은 주택 가격에 의한 타 계급에 대한 배제를 통해 이 지역의 교육환경은 장벽안에 거주하는 사람들에 의해 배타적으로 전유되는 사회적 결과가 나타나고 있다.

Assessment of genetic diversity of Prangos fedtschenkoi (Apiaceae) and its conservation status based on ISSR markers

  • Mustafina, Feruza U.;Kim, Eun Hye;Son, Sung-Won;Turginov, Orzimat T.;Chang, Kae Sun;Choi, Kyung
    • 식물분류학회지
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    • 제47권1호
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    • pp.11-22
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    • 2017
  • Prangos fedtschenkoi (Regel et Schmalh.) Korovin (Apiaceae) is an endemic species for mountainous Middle Asia, which is both a rare and useful plant. Organic extractions from this species are being used in pharmaceutics and cosmetology. In recent years, P. fedtschenkoi distribution area has considerably decreased, presumably, resulting from human activities such as agriculture, construction works, overgrazing and collection from wild for pharmaceutic purposes. Six populations were found in Uzbekistan and their genetic divergence and differentiation were studied with 10 inter-simple sequence repeat (ISSR) markers, selected out of 101. Totally 166 amplified ISSR fragments (loci) were revealed, of which 164 were polymorphic. Relatively moderate level of polymorphism was found at population level with polymorphic bands ranging from 27.71% to 47.59%. Mean P = 39.05%, $N_a=1.40$, $N_e=1.25$, S.I. = 0.21, and $H_e=0.14$ were revealed for all loci across six populations. AMOVA showed higher variation among populations (62%) than within them (38%). The Bayesian model determined 5 clusters, or genetic groups. The posteriori distribution of the Theta II estimator detected full model identifying high inbreeding, intensified by low gene flow (Nm = 0.3954). Mantel test confined population 6 as distinct cluster corresponding to geographic remoteness (R = 0.5137, $p{\leq}0.005$). Results were used as the bases for developing conserve measures to restore populations.

Isolation and characterization of micro satellite loci in the Korean crayfish, Cambaroides similis and application to natural population analysis

  • Ahn, Dong-Ha;Park, Mi-Hyun;Jung, Jae-Ho;Oh, Mi-Jin;Kim, Sang-Hee;Jung, Jong-Woo;Min, Gi-Sik
    • Animal cells and systems
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    • 제15권1호
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    • pp.37-43
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    • 2011
  • The Korean freshwater crayfish, Cambaroides similis, has recently suffered from range reduction and habitat degradation caused by environmental changes and water pollution. For the conservation and restoration of this species, it is necessary to understand the current population structures of Korean C. similis using estimation of their genetic variation. In this study, eight micro satellite loci were developed and characterized from 49 individuals collected from four locations: one population from Mt. Bukhan (BH) and three populations from Mt. Gwanak (GA) in Seoul, Korea. As a result, the number of alleles per locus ranged from 2 to 12. The observed heterozygosities and expected heterozygosities ranged from 0.000 to 0.833 and from 0.125 to 0.943, respectively, and the former values were significantly lower than the latter ones expected under the Hardy-Weinberg equilibrium. No significant linkage disequilibrium was revealed between any of the locus pairs after Bonferroni correction. From the pairwise Fst results over all samples, higher differentiation between GA-BH population pairs (mean 0.1789) was observed than between GA population pairs (mean 0.0454). This was also supported by Mantel's test showing that the genetic distances of these crayfish populations were significantly correlated with geographic distances. This result may show the regional differentiation caused by restricted gene flow between northern (BH) and southern (GA) populations within Seoul. These micro satellite markers have the potential for use in analyses of the genetic diversity and population structure of C. similis species, with implications for its conservation and management plans.

밀어속(genus Rhinogobius, Gobiidae) 어류의 계통분류학적 연구II. 한국산 밀어(R. brunneus complex) 3型의 분포 및 분류학적 고찰 (Systematic studies on the freshwater goby, Rhinogobius species (Percifromes, Gobiidae). II. BEographic distribution and taxonomic status of three color types in the Rhinogobius brunneus complex from South Korea.)

  • 김종범;양서영
    • Animal Systematics, Evolution and Diversity
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    • 제12권4호
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    • pp.331-347
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    • 1996
  • 한국산 밀어(R. brunneus complex)에 대한 지리적 변이 및 분포를 조사한 결과 반 문 및 체색 등에 뚜렷한 차이가 있는 3type이 채집되었다. 이들은 유전적으로도 typerks에 총 genome의 26-30%(A-B type : 30%, A-C type : 30%, B-C type : 26%) 차이가 있어 유전적 근연치(Rogers' S)가 S=0.628-0.661(A-B type : 0.631, A-C type : 0.628, B-C type : 0.661)로 뚜렷한 유전적 차이를 나타냈다. 각 type의 유전적 변이 정도를 비교한 결과 A-type은 평균 P=25.90%, Ho=0.081, He=0.092로 B-type(P=12.33%, Ho=0.037, He=0.044)과 C-type(P=11.10%, Ho=0.032, He=0.048)에 비하여 약 2배 이상 높은 특징을 보였다. 이들 3 type의 분류학적 위치를 명확히 구명하고자 3type이 모두 서식하는 고성의 북천에서 유전적 표식인자를 이용하여 각 typerks의 생식적 격리 수준을 분석하였다. 이들 3 type은 동서(同 棲)하천에서 하구로부터의 거리에 따라 parapatric 하게 서식하면서 각 typerks에 유전자 교 환이 전혀없었다. 이러한 결과로부터 3type은 이미 생식적 격리가 완성되고 미세분포역에 차이가 있는 별종으로 판단되었다.

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