• Title/Summary/Keyword: Population heterogeneity

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Mutational Analysis of the MTHFR Gene in Breast Cancer Patients of Pakistani Population

  • Akram, Muhammad;Malik, Fa;Kayani, Mahmood Akhtar
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.4
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    • pp.1599-1603
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    • 2012
  • Objectives: Since methylenetetrahydrofolate reductase (MTHFR) maintains the balance of circulating folate and methionine and blocks the formation of homocysteine, its regulation in relation to different cancers has extensively been studied in different populations. However, information on Pakistani breast cancer patients is lacking. The MTHFR gene has two most common mutations that are single nucleotide additions which result in change of amino acids C677T to Ala222val and A1298C to Glu429Ala. Methodology: 110 sporadic breast patients with no prior family history of cancer or any other type of genetic disorders along with 110 normal individuals were screened for mutations in exons 1 to exon 9 using single strand conformational polymorphism, RFLP and sequencing analyzer. Results: The p values for the 677CC, 677CT, and 677TT genotypes were 0.223, 0.006, and 0.077, respectively. Those for the 1298AA, 1298AC, and 1298CC genotypes were 0.555, 0.009, and 0.003, respectively. Conclusions: We found an overall a significant, weak inverse association between breast cancer risk and the 677TT genotype and an inverse association with the 1298C variant. These results for MTHFR polymorphism might be population specific in sporadic breast cancer affected patients but many other factors need to be excluded before making final conclusions including folate intake, population and disease heterogeneity.

Evaluation of Genetic Heterogeniety among the Corn Landraces Collected from Farmer's Field

  • Kim, In-Jong;Min, Hwang-Kee;Park, Jong-Yeol;Choi, Ik-Young;Kim, Nam-Soo
    • Plant Resources
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    • v.1 no.1
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    • pp.26-32
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    • 1998
  • This paper describes the variations in eight agronomic traits in three unadapted local landraces and an inbred cultivar of corn. To compare the agronomic traits in field evaluation with molecular marker evaluation the genotypes of the plant introduction were also checked by 4 microsatellite-SSR loci. The variations of the eight agronomic traits were higher in the local landrades than in the inbred line. which was substantiated by the high genetic variation in the landrades with microsatellite-SSR loci. The level of genetic variation was also different between landraces. Since the genetic evaluation can be easily quantified by the analysis of microsatellite-SSR loci. the threshold level of genetic homogeneity in the population for parental lines in breeding program can be determined and the effort of maintaining the landrace population would be alleviated. As an example in our analysis. the entry from Whachon should not need the same number of selfing generations as the other two landraces to get the level of inbred state. Since this line showed lowest intra-genetic variation within the population.

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Association of Risk of Gastric Cancer and Consumption of Tobacco, Alcohol and Tea in the Chinese Population

  • Tong, Gui-Xian;Liang, Han;Chai, Jing;Cheng, Jing;Feng, Rui;Chen, Peng-Lai;Geng, Qing-Qing;Shen, Xing-Rong;Wang, De-Bin
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.20
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    • pp.8765-8774
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    • 2014
  • This study aimed at summarizing epidemiological research findings on associations between tobacco, alcohol and tea consumption and risk of gastric cancer (GC) in the Chinese population. The review searched PubMed, Embase, China National Knowledge Infrastructure (CNKI) and China Biology Medicine (CBM) databases and reference lists of review papers for all studies published in English or Chinese languages. Information extracted, via two independent researchers, from retrieved articles included first author, year of publication, study design, sample size, source of controls and adjusted odds ratio (OR) or relative risk (RR) with the corresponding 95% confidence intervals (CIs) for each category. Statistical analyses used software STATA version 12.0. The systematic search found 89 articles containing 25,821 GC cases and 135,298 non-cases. The overall random effects in terms of pooled OR and 95%CI for tobacco, alcohol and tea consumption were 1.62 (95%CI: 1.50-1.74), 1.57 (95%CI: 1.41-1.76) and 0.67 (95%CI: 0.59-0.76) respectively; while the heterogeneity among included studies ranged from 80.1% to 87.5%. The majority of subgroup analyses revealed consistent results with the overall analyses. All three behavioral factors showed statistically significant dose-dependent effects on GC (P<0.05). The study revealed that tobacco smoking and alcohol drinking were associated with over 1/2 added risk of GC, while tea drinking conferred about 1/3 lower risk of GC in the Chinese population. However, these results should be interpreted with caution given the fact that most of the included studies were based on a retrospective design and heterogeneity among studies was relatively high.

A Mode Choice Model with Market Segmentation of Beneficiary Group of New Transit Facility (신교통수단 수혜자의 시장분할을 고려한 수단선택 모형 개발)

  • Kim, Duck Nyung;Choi, A Reum;Hwang, Jae-Min;Kim, Dong-Kyu
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.2
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    • pp.667-677
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    • 2013
  • The introduction of a new transit facility affects mode share of travel alternatives. The multinomial logit model, which has been the most commonly used for estimating mode share, has difficulty in reflecting heterogeneity of travelers' choices, and it has a limitation on grasping their characteristics of mode choice. The limitation may lead to over- or under-estimation of the new transit facility and bring about significant social costs. This paper aims to find a methodology to overcome the problem of preference homogeneity. It also applies market segmentation structure of separating the whole population into direct and indirect beneficiary to consider their preference heterogeneity. A mode choice model is estimated on data from Jeju Province and statistically tested. The results show that mode transfer rate of direct beneficiaries that inhabit in downtown areas increases as the new transit facility provides more advanced services with higher costs. The results and the model suggested in this study can contribute to improving the accuracy of demand forecasting of new transit facilities by reflecting heterogeneity of mode-transfer patterns.

Community Health Practitioner's Commitment into Community : on the Aspect of Primary Health Care (보건진료원의 지역사회 몰입과정)

  • Yun, Soon-Nyoung;Kim, Young-Im;Choi, Jeong-Myung
    • Research in Community and Public Health Nursing
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    • v.6 no.2
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    • pp.173-182
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    • 1995
  • Primary health care(PHC) has been established since A Health Law for rural residents has been legislated in 1980 following the WHO declaration, 'Health for All 2000'. in 1978. PHC services are presently assumed to be provided by 2038 Community Health Practitioners(CHP) to about 28% out of rural population in Korea. Most CHPs have confronted the adaptation process to the community being practiced although a CHP's role is to evoke community participation for the improvement of their health by themselves. So the purpose of this study is to describe and explain of the commitment of CHPs into the community. Data were collected by direct interview and tape-recording under subjects' permission till theoretical saturation were occured from 6 CHPs. The subjects were 41 years old and have served in the community for 9 years in average. Main questions and concepts were explored from data according to the procedure of the grounded theory methodology. The results are as follows. 1) The number of the main concepts were twenty four that identified Motive, Desire, Personal characteristics, Unfamiliarity, Denial, Feeling of isolation, Self-sacrifice, Kindness, Patience, Assimilation, Respect for the residents, Support by the family, Support by the residents, Achievement, Acceptance of realities, Use of resources, Inducement of cooperation from the residents, Changes of the difference from time orientation between CHP and residents, Attitude as a official, Technical support, Cost management, Satisfaction level, Acknowledgement by the residents and discrepancy. 2) The twenty four concepts were categorized to seven groups such as Motivation, Feeling of Heterogeneity, Self-discipline, Social support, Induced changes in the attitudes of residents, Familarity and Persistent discrepancy. 3) The categorized groups were analyzed on the base of the Causal Conditions, Central Phenomena, Contexts, Intervening Conditions, Action / Interaction Strategies, and Consequences. Central phenomenon in this study was identified to be the feeling of heterogeneity. Community health practitioners experienced unfamiliarity and denial from the community and felt themselves isolated in the first. In time, they won the trust of residents by their efforts including self-sacrifice, kindness, patience, and assimilation. Afterward, practitioners got self-confidence and familiarity with lesser feeling of heterogeneity. Nevertheless, practitioners could not commit themselves completely because of the persistent discrepancy between CHP and residents. 4) On the commitment process, the CHPs' feeling of heterogeneity were decresed and social support increesed and newly evolved induced change of residents through the continuous interaction between CHP and them The contribution of this study would be concluded as follows. 1) It is expected that effective strategies for more rapid committment into the community can be developed based on this study. 2) More easy committment would be possible for the newly appointed CHP through understanding of the committment process identified on this study.

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Genetic Variation of Two Isolated Relict Populations of Vaccinium uliginosum L. in Korea (들쭉나무 격리잔존 2개 집단의 유전변이)

  • Han, Sang-Don;Hong, Yong-Pyo;Kwon, Hae-Yun;Yang, Byeung-Hoon;Kim, Chan-Soo
    • Journal of Korean Society of Forest Science
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    • v.94 no.4 s.161
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    • pp.209-213
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    • 2005
  • In order to provide the molecular genetic information necessary for conservation of bog whortleberry (Vaccinium uliginosum L), one of the rare species in Korea, I-SSR analysis was performed on two populations on Mt. Halla and Mt. Seorak. A total of 68 I-SSR products were observed, and higher level of genetic diversity was observed in Mt. Halla population (S.I.=0.539) than in the Mt. Seorak population (S.I,=0.401). Level of genetic diversity in this species was relatively higher than those in other rare species analysed with I-SSR marker. From the results of AMOVA, exceptionally large proportion of genetic diversity (33.5%) was resulted from genetic difference between two populations, and only 66.5% of the genetic variation was allocated in common among individuals within each population, compared with the results in other long-lived woody species. This remarkably high degree of genetic heterogeneity existed between Mt. Halla and Mt. Seorak populations might suggest that they might be originated from the independent progenitors before the post glacier ages, respectively, and/or that they undergone random genetic drift respectively due to geographical isolation resulted from dramatic changes in environmental conditions after the post glacier ages.

PCR-RFLP for Rapid Subtyping of Plasmodium vivax Korean Isolates

  • Kang, Jung-Mi;Lee, Jinyoung;Kim, Tae Im;Koh, Eun-Ha;Kim, Tong-Soo;Sohn, Woon-Mok;Na, Byoung-Kuk
    • Parasites, Hosts and Diseases
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    • v.55 no.2
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    • pp.159-165
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    • 2017
  • Vivax malaria reemerged in Korea in 1993 and the outbreak has been continued with fluctuating numbers of annual indigenous cases. Understanding the nature of the genetic population of Plasmodium vivax circulating in Korea is beneficial for the knowledge of the nationwide parasite heterogeneity and in the implementation of malaria control programs in the country. Previously, we analyzed polymorphic nature of merozoite surface protein-1 (MSP-1) and MSP-$3{\alpha}$ in Korean P. vivax population and identified the Korean P. vivax population has been diversifying rapidly, with the appearance of parasites with new genetic subtypes, despite the recent reduction of the disease incidence. In the present study, we developed simple PCR-RFLP methods for rapid subtyping of MSP-1 and MSP-$3{\alpha}$ of Korean P. vivax isolates. These PCR-RFLP methods were able to easily distinguish each subtype of Korean P. vivax MSP-1 and MSP-$3{\alpha}$ with high accuracy. The PCR-RFLP subtyping methods developed here would be easily applied to massive epidemiological studies for molecular surveillance to understand genetic population of P. vivax and to supervise the genetic variation of the parasite circulating in Korea.

A Meta-Analysis of the meets of Aromatherapy on Psychological Variables in Nursing (아로마테라피 간호중재의 정신심리적 효과 메타분석)

  • Roh, Kook-He;Park, Hyeoun-Ae
    • Research in Community and Public Health Nursing
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    • v.20 no.2
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    • pp.113-122
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    • 2009
  • Purpose: The purpose of this study is to explore the effect of aromatherapy on anxiety, depression, and stress. Methods:Medical and nursing literature databases were searched to identify studies comparing aromatherapy with a control group. Results: Thirty-one studies published till September 2008 were included in the analysis. Twenty-two studies showed that aromatherapy generally had positive effects on the anxiety level (ES: 0.61). Thirteen studies showed that aromatherapy has significantly decreased the depression level (ES: 0.91). Seven studies showed that aromatherapy had positive effect on the stress level (ES: 0.78). Further analysis found that aromatherapy was more effective for normal population than for patients group with anxiety and stress. On the contrary, aromatherapy was more effective for patients group than for general population with depression. Conclusion: Aromatherapy had positive effect on anxiety, depression and stress level. But there was no sufficient evidence to show the two different aromatherapy methods and two different period of aromatherapy had different effects due to small sample size and heterogeneity of sample. And it was needed to perform follow-up and further comparative studies.

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Application of Population Index Flood Model for Regional Frequency Analysis (지역빈도해석을 위한 모홍수지수모형의 적용)

  • Kim, Hanbeen;Joo, Kyungwon;Kim, Taereem;Heo, Jun-Haeng
    • Proceedings of the Korea Water Resources Association Conference
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    • 2018.05a
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    • pp.299-299
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    • 2018
  • 지역빈도해석은 수문관측자료의 보유기간이 짧은 지점 또는 미계측 지점에 대하여 보다 정확하며 신뢰할 수 있는 설계수문량을 산정하기 위해 널리 사용되고 있는 방법이다. 지역빈도해석에서 사용되는 가장 대표적인 모형인 홍수지수모형 (index flood model)은 각 지점의 표본평균을 홍수지수로 정의하고 이를 이용하여 설계수문량을 산정하는 방법이다. 모홍수지수모형 (population index flood model)은 표본평균을 홍수지수로 사용함으로써 발생하는 설계수문량의 왜곡과 오차를 극복하기 위해 제안된 방법으로 홍수지수를 미지의 모분포로 가정한 후 설계수문량을 산정한다. 본 연구에서는 모홍수지수모형을 국내 강우관측자료에 적용하여 지역빈도해석을 수행하고자 한다. 먼저, 이질성척도(heterogeneity)를 통해 지역동질성이 확인된 지역에 대하여 GEV 분포형을 적용한 비정상성 모홍수지수모형을 적용해 지역빈도해석을 수행하고 확률강우량을 산정하였다. 또한, 기존의 지점빈도해석 및 L-moment 기반의 지역빈도해석 결과와 비교를 통해 모홍수지수모형의 적용성을 확인하였다.

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Population Genetic Structure and Marker - Trait Associations in a Collection of Traditional Rice (Oryza sativa L.) from Northern Vietnam

  • Ngoc Ha Luong;Le-Hung Linh;Kyu-Chan Shim;Cheryl Adeva;Hyun-Sook Lee;Sang-Nag Ahn
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2022.04a
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    • pp.110-110
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    • 2022
  • Rice is the world's most important food crop and a major source of nutrition for about two thirds of populations. Northern Vietnam is one of the most important centers of genetic diversity for cultivated rice. In this study, we determined the genetic diversity and population structure of 79 rice landraces collected from northern Vietnam and 19 rice accessions collected from different countries. In total, 98 rice accessions could be differentiated into japonica and indica with moderate genetic diversity and a polymorphism information content of 0.382. We also detected subspecies-specific markers to classify rice (Oryza sativa L.) into indica and japonica. Additionally, we detected five marker-trait associations and rare alleles that can be applied in future breeding programs. Most interestingly, analysis of molecular variance (AMOVA) found genetic differentiation was related to geographical regions with an overall PhiPT (analog of fixation index FST) value of 0.130. More emphasis was given to provide signatures and infer explanations about the role of geographical isolation and environmental heterogeneity in genetic differentiation among regions in landraces from northern Vietnam. Our results suggest that rice landraces in northern Vietnam have a dynamic genetic system that can create different levels of genetic differentiation among regions, but also maintain a balanced genetic diversity between regions.

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