• 제목/요약/키워드: population variability

검색결과 271건 처리시간 0.023초

Near-ground wind and its characterization for engineering applications

  • Crandell, Jay H.;Farkas, William;Lyons, James M.;Freeborne, William
    • Wind and Structures
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    • 제3권3호
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    • pp.143-158
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    • 2000
  • This report presents the findings of a one-year monitoring effort to empirically characterize and evaluate the nature of near-ground winds for structural engineering purposes. The current wind engineering practice in the United States does not explicitly consider certain important near-ground wind characteristics in typical rough terrain conditions and the possible effect on efficient design of low-rise structures, such as homes and other light-frame buildings that comprise most of the building population. Therefore, near ground wind data was collected for the purpose of comparing actual near-ground wind characteristics to the current U.S. wind engineering practice. The study provides data depicting variability of wind speeds, wind velocity profiles for a major thunderstorm event and a northeaster, and the influence of thunderstorms on annual extreme wind speeds at various heights above ground in a typical rough environment. Data showing the decrease in the power law exponent with increasing wind speed is also presented. It is demonstrated that near-ground wind speeds (i.e., less than 10 m above ground) are likely to be over-estimated in the current design practice by as much as 20 percent which may result in wind load over-estimate of about 50% for low-rise buildings in typical rough terrain. The importance of thunderstorm wind profiles on determination of design wind speeds and building loads (particularly for buildings substantially taller than 10 m) is also discussed. Recommendations are given for possible improvements to the current design practice in the United States with respect to low-rise buildings in rough terrain and for the need to study the impact of thunderstorm gust profile shapes on extreme value wind speed estimates and building loads.

High Genetic Variability of Schistosoma haematobium in Mali and Nigeria

  • Ezeh, Charles;Yin, Mingbo;Li, Hongyan;Zhang, Ting;Xu, Bin;Sacko, Moussa;Feng, Zheng;Hu, Wei
    • Parasites, Hosts and Diseases
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    • 제53권1호
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    • pp.129-134
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    • 2015
  • Schistosoma haematobium is one of the most prevalent parasitic flatworms, infecting over 112 million people in Africa. However, little is known about the genetic diversity of natural S. haematobium populations from the human host because of the inaccessible location of adult worms in the host. We used 4 microsatellite loci to genotype individually pooled S. haematobium eggs directly from each patient sampled at 4 endemic locations in Africa. We found that the average allele number of individuals from Mali was significantly higher than that from Nigeria. In addition, no significant difference in allelic composition was detected among the populations within Nigeria; however, the allelic composition was significantly different between Mali and Nigeria populations. This study demonstrated a high level of genetic variability of S. haematobium in the populations from Mali and Nigeria, the 2 major African endemic countries, suggesting that geographical population differentiation may occur in the regions.

Effect of Butyrophilin Gene Polymorphism on Milk Quality Traits in Crossbred Cattle

  • Bhattacharya, T.K.;Misra, S.S.;Sheikh, Feroz D.;Sukla, Soumi;Kumar, Pushpendra;Sharma, Arjava
    • Asian-Australasian Journal of Animal Sciences
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    • 제19권7호
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    • pp.922-926
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    • 2006
  • A genetic polymorphism study on butyrophilin gene was carried out to explore variability of this gene and to estimate effects of such variability on milk quality traits in crossbred cattle. Polymorphism was unraveled by conducting Hae III PCR-RFLP of this gene. Three genotypes such as AA, BB and AB and two alleles namely A and B were observed in crossbred population. The frequencies of genotypes and alleles were 0.78, 0.17 and 0.04 for AA, AB and BB genotypes, respectively, and 0.87 and 0.13 for A and B alleles, respectively. The nucleotides, which have been substituted from allele A to B, were observed as C to G ($71^{st}$ nucleotide), C to T ($86^{th}$ nucleotide), A to T ($217^{th}$ nucleotide), G to A ($258^{th}$ nucleotide), A to C ($371^{st}$ nucleotide) and C to T ($377^{th}$ nucleotide). The nucleotide substitutions at $71^{st}$, $86^{th}$ and $377^{th}$ position of the fragment were found as silent mutations whereas nucleotide changes at $217^{th}$, $258^{th}$ and $371^{st}$ positions were detected as substitution of amino acid lysine with arginine, valine with isoleucine, and leucine with proline from allele A to B. The genotypes had significant effects ($p{\leq}0.05$) on total milk solid%, fat%, SNF%, while showing nonsignificant impact on total protein%. AA genotype produced highest average yield for all the traits.

A new species of Parastenocaris from Korea, with a redescription of the closely related P. biwae from Japan (Copepoda: Harpacticoida: Parastenocarididae)

  • Karanovic, Tomislav;Lee, Wonchoel
    • Journal of Species Research
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    • 제1권1호
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    • pp.4-34
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    • 2012
  • Parastenocaris koreana sp. nov. is described based on examination of numerous adult specimens of both sexes from several localities in Korea. Scanning electron micrographs are used to examine intra- and interpopulation variability of micro-characters, in addition to light microscopy. The new species is most closely related to the Japanese P. biwae Miura, 1969, which we redescribe based on newly collected material from the Lake Biwa drainage area. The two species differ in size, relative length of the caudal rami, shape of the anal operculum, shape of the genital double somite, relative length of the inner distal process on the female fifth leg, as well as relative length of the apical setae on the second, third, and fourth legs exopods in both sexes. Detailed examinations of three disjunct populations of P. koreana reveal also some geographical variation, especially in the surface ornamentation of somites, which may indicate some population structuring or even cryptic speciation. Lack of intraspecific variability in the number and position of sensilla on somites, as well as their potential phylogenetic significance, is a novel discovery. Both species examined here belong to the brevipes group, which we redefine to include 20 species from India (including Sri Lanka), Australia, East Asia, Northern Europe, and North America. A key to species of this group is also provided. In order to test the monophyly of the redefined brevipes group with highly disjunct distribution, as well as relationship between different species, a cladistics analysis is performed based on 39 morphological characters and with help of three outgroup taxa. Six equally parsimonious cladograms are generated, all of which show that the ingroup is well defined by at least three synapomorphies. Reconstructed phylogeny questions the previously suggested hypothesis about the origin of this group in South East Asia, with one Australian species showing the most basal position. We speculate that the present distribution of this group may be a combination of ancient vicariance and subsequent dispersal, with a possible origin in the Gondwanaland, in the rift valley between Australia and India.

우리나라 오염총량관리제도의 적용 및 개선: 2. 안전율 산정 및 삭감부하량 할당 (Improvement and Application of Total Maximum Daily Load Management System of Korea: 2. Determination of Margin of Safety and Allocation of Pollutant Loads)

  • 김경태;정은성;김상욱;이길성
    • 한국물환경학회지
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    • 제26권1호
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    • pp.168-176
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    • 2010
  • This study proposes the improvement of the present Total Maximum Daily Load (TMDL) management system of MOE (Ministry of Environment). The margin of safety (MOS) is calculated by a method using standard error and a method using variability and uncertainty. The allocation of pollutant loads are calculated using three methods, equal load reduction method, equal percent removal method and method using equity standards. This study applied the improved TMDL management system to the Anyangcheon watershed. Since MOS varies from 12% to 44% due to the high variability of measured and simulated data, it must not be ignored in the TMDL. The method using equity standards is the most proper in this application since the others produced unrealistic allocations. Area, runoff, water use quantity, population and budget are considered for equity standards. This study shows that this allocation method can be also applicable for the administrative units as well as the sub-watersheds. Finally, Hydrologic Simulation Program-FORTRAN (HSPF) with the allocated pollutant load was used to confirm whether it satisfy the water quality standard or not. This study will be helpful to improve the MOS and allocation system TMDL in the future.

Complete Genomic Characterization of Two Beet Soil-Borne Virus Isolates from Turkey: Implications of Comparative Analysis of Genome Sequences

  • Moradi, Zohreh;Maghdoori, Hossein;Nazifi, Ehsan;Mehrvar, Mohsen
    • The Plant Pathology Journal
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    • 제37권2호
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    • pp.152-161
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    • 2021
  • Sugar beet (Beta vulgaris L.) is known as a key product for agriculture in several countries across the world. Beet soil-borne virus (BSBV) triggers substantial economic damages to sugar beet by reducing the quantity of the yield and quality of the beet sugars. We conducted the present study to report the complete genome sequences of two BSBV isolates in Turkey for the first time. The genome organization was identical to those previously established BSBV isolates. The tripartite genome of BSBV-TR1 and -TR3 comprised a 5,835-nucleotide (nt) RNA1, a 3,454-nt RNA2, and a 3,005-nt RNA3 segment. According to sequence identity analyses, Turkish isolates were most closely related to the BSBV isolate reported from Iran (97.83-98.77% nt identity). The BSBV isolates worldwide (n = 9) were phylogenetically classified into five (RNA-coat protein read through gene [CPRT], TGB1, and TGB2 segments), four (RNA-rep), or three (TGB3) lineages. In genetic analysis, the TGB3 revealed more genetic variability (Pi = 0.034) compared with other regions. Population selection analysis revealed that most of the codons were generally under negative selection or neutral evolution in the BSBV isolates studied. However, positive selection was detected at codon 135 in the TGB1, which could be an adaptation in order to facilitate the movement and overcome the host plant resistance genes. We expect that the information on genome properties and genetic variability of BSBV, particularly in TGB3, TGB1, and CPRT genes, assist in developing effective control measures in order to prevent severe losses and make amendments in management strategies.

초.중.고등학교 확률과 통계 단원에 나타난 표본개념에 대한 분석 (Features of sample concepts in the probability and statistics chapters of Korean mathematics textbooks of grades 1-12)

  • 이영하;신수영
    • 대한수학교육학회지:수학교육학연구
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    • 제21권4호
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    • pp.327-344
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    • 2011
  • 본 연구는 고등학교 수학교과에서 배우는 모평균의 신뢰구간 구하기와 같은 통계적 추론 능력을 기르기 위한 방안의 첫 단계연구이다. 통계적 추론과정을 비판적으로 분석하여 신뢰할만한 추론방법으로 이를 인정할 수 있는 표본개념의 형성을 위해, 연구자들은 우연과 필연, 귀납과 연역, 가능성원리, 통계량의 변이성, 통계적 모형 등의 하위 개념들이 형성되어야 한다고 보았다. 그리고 초중등 통계단원의 전 과정에서 이들 개념의 체계적인 발달을 도모해야 한다는 전제 아래, 초 중 고등학교 통계단원을 분석해 본 결과는 아래와 같았다. 첫째, 문제해결 방법 선택의 지도와 관련하여, 통계적 방법을 선택할 문제 상황으로서, 우연적 상황을 필연적 상황과 구분하기위한 설명이 있는 교과서가 초등학교에는 없고, 중등 수준에서도 매우 드물었다. 둘째 표본의 모집단 관련 의미를 이해시키려는 단계적 준비가 미흡하다고 할 수 있다. 전체와 부분의 모집단과 표본 구분이 고등학교에서 비로소 공식화되고 있으며, 초 중학교에서 사용되는 표본자료는 그것으로부터 얻어지는 계산적 결과에만 초점이 맞추어짐으로서, 학년이 올라감에 따라 모집단을 향한 귀납적 추론의 신뢰성에 대한 비판적 사고의 깊이가 더해지는 모습을 찾아보기 어려웠다. 셋째, 무작위 추출이 갖는 대표성의 의미에 대한 설명보다는 무작위 활동 자체에 대한 설명이 중심이 됨으로서 무작위 추출의 확률적 의미, 즉 무작위 표본을 통해 구해질 통계량의 표집분포에서의 (상속된) 무작위성을 위한 담보로서의 목적에 대한 설명이 없다는 점이다. 넷째 통계적 추론을 수학(연역)적 추론과 구분해 주는 설명이 없을 뿐 아니라, 학습자의 논리성 발달 수준에 맞게 변화하는 가능성원리에 대한 설명, 적용 등을 전혀 찾기 어렵다는 점이다. 다섯째 통계량의 우연변이성과 그에 따른 표집분포의 존재에 대한 이해를 추구하는 설명을 찾기 어렵다는 점이다. 표집분포를 수학적으로 구하는 것은 매우 어려운 과정이지만, 그것의 존재를 인식하느냐 못하느냐는 통계적 추론 자체의 이해 가능성을 달리하는 중요한 문제이기 때문이다.

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RAPD를 이용한 겨자의 유전적 다양성과 집단구조 (Genetic Diversity and Population Structure of Brassica juncea by Random Amplified Polymorphic DNA (RAPD))

  • 오영희;문성기;채양희;홍화진;조철민;박소혜;허만규
    • 생명과학회지
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    • 제20권10호
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    • pp.1538-1543
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    • 2010
  • 본 연구는 우리나라 겨자 17집단에 대한 유전적 다양도와 집단구조를 조사하였다. 60개의 다형성 좌위와 18개 단형성 좌위가 발견되었다. 다형성 밴드의 비율은 전남 진도 집단이 가장 높았으며 재배종이 가장 낮았다. 대립유전자좌위의 수는 1.221이였으며 유효한 대립유전자좌위의 수는 1.167이였다. 이 종의 전형적인 집단은 작고 격리되어 낮은 유전적 다양도를 가지고 있었다. 전체 다양도는 0.347이였으며 집단 내 다양도는 0.141이였다. 집단간분화를 나타내는 척도는 0.589였다. 아는 58.9%의 다양도가 집단간에 있음을 시사한다. 세대 간 이주하는 개체수는 0.617로 낮았다. RAPD는 겨자 집단을 구분하는데 유익하였다.

Genetic characterisation of PPARG, CEBPA and RXRA, and their influence on meat quality traits in cattle

  • Goszczynski, Daniel Estanislao;Mazzucco, Juliana Papaleo;Ripoli, Maria Veronica;Villarreal, Edgardo Leopoldo;Rogberg-Munoz, Andres;Mezzadra, Carlos Alberto;Melucci, Lilia Magdalena;Giovambattista, Guillermo
    • Journal of Animal Science and Technology
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    • 제58권4호
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    • pp.14.1-14.9
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    • 2016
  • Background: Peroxisome proliferator-activated receptor gamma (PPARG), CCAAT/enhancer binding protein alpha (CEBPA) and retinoid X receptor alpha (RXRA) are nuclear transcription factors that play important roles in regulation of adipogenesis and fat deposition. The objectives of this study were to characterise the variability of these three candidate genes in a mixed sample panel composed of several cattle breeds with different meat quality, validate single nucleotide polymorphisms (SNPs) in a local crossbred population (Angus - Hereford - Limousin) and evaluate their effects on meat quality traits (backfat thickness, intramuscular fat content and fatty acid composition), supporting the association tests with bioinformatic predictive studies. Results: Globally, nine SNPs were detected in the PPARG and CEBPA genes within our mixed panel, including a novel SNP in the latter. Three of these nine, along with seven other SNPs selected from the Single Nucleotide Polymorphism database (SNPdb), including SNPs in the RXRA gene, were validated in the crossbred population (N = 260). After validation, five of these SNPs were evaluated for genotype effects on fatty acid content and composition. Significant effects were observed on backfat thickness and different fatty acid contents (P < 0.05). Some of these SNPs caused slight differences in mRNA structure stability and/or putative binding sites for proteins. Conclusions: PPARG and CEBPA showed low to moderate variability in our sample panel. Variations in these genes, along with RXRA, may explain part of the genetic variation in fat content and composition. Our results may contribute to knowledge about genetic variation in meat quality traits in cattle and should be evaluated in larger independent populations.

Rett 증후군 환자에서의 자율신경 활성도 및 심박수 변이도 측정 (Heart Rate Variability and Autonomic Activity in Patients Affected with Rett Syndrome)

  • 최덕영;장진하;정희정
    • Clinical and Experimental Pediatrics
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    • 제46권10호
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    • pp.996-1002
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    • 2003
  • 목 적 : Rett 증후군 환자에서는 일반인에서 보다 돌연사의 확률이 높은 것으로 알려져 있으며, 그 원인으로 자율신경계 기능 부전에 의한 치명적인 부정맥 같은 심장의 전기 생리적 불안정성이 가장 의심되고 있다. 본 연구는 Rett 증후군 환자에서 심박수 변이도와 교정 QT 간격을 측정하여 실제로 자율신경 활성도에 문제가 있는지의 여부를 확인하기 위하여 실시하였다. 방 법 : 분자유전학적 염색체검사나 임상적 진단기준에 의하여 진단된 Rett 증후군 환자 12례를 대상군으로, 나이가 비슷한 정상아 30례를 대조군으로 하여 이들에서의 자율신경 활성도인 심박수 변이도와 교정 QT 간격을 측정하여 비교하였다. 심박수 변이도는 24시간 보행 심전도를 기록한 후 디지털화 된 심전도를 자동적으로 분석하여 power spectrum을 만들고 그 중 주파수영역(고주파 성분, 저주파 성분, 극소저주파 성분, LF/HF 비율)과 시간 영역(평균 RR 간격, SDNN, rMSSD, pNN50), 교정 QT 간격을 측정하여 비교하였다. 비교는 세 그룹으로 나누어서 전체 Rett 증후군과 정상 대조군 사이, 전형적인 Rett 증후군과 정상 대조군 사이, 비전형적 Rett 증후군과 정상 대조군 사이에서 실시하였다. 결 과 : 1) Rett 증후군 환자에서는 대조군에서 보다 시간영역의 rMSSD이 통계적으로 의미있게 낮았고(P<0.005), LF/HF 비율이 의미있게 높았으며(P<0.005), 교정 QT 간격도 의미있게 연장되어(P<0.005) 있었다. 2) 전형적인 Rett 증후군 환자에서도 대조군에서 보다 rMSSD이 통계적으로 의미있게 낮았고(P<0.005), LF/HF 비율도 의미있게 높았으며(P<0.05), 교정 QT 간격도 의미있게 연장되어 있었다(P<0.001). 3) 비전형적 Rett 증후군에서도 마찬가지로 rMSSD이 통계적으로 의미있게 낮았고(P<0.05), LF/HF 비율도 의미있게 높았으며(P<0.001), 교정 QT간격도 의미있게 연장되어 있었다(P<0.05). 4) 이상의 결과에서 Rett 증후군에서는 전형적인 환자나 비전형적인 환자 모두 미주신경긴장의 변화와 호흡에 의해 민감한 영향을 받는 rMSSD의 저하가 있었고, 교감-부교감신경 균형성을 나타내는 LF/HF 비율의 증가가 있었으며, 자율신경계에 영향을 받는 교정 QT 간격이 연장되었던 것으로 보아, 교감-부교감신경의 균형성에 이상이 있는 것으로 사료된다. 결 론 : Rett 증후군 환자에서 자율신경 활성도의 지표인 심박수 변이도의 의미있는 저하와 교정 QT 간격의 의미있는 연장이 나타나는 것으로 미루어 보아, 이 질환에서 자주 동반되는 돌연사가 일어나는 원인 중의 하나로 이러한 교감-부교감신경의 불균형을 의심할 수 있겠다.