• Title/Summary/Keyword: CROSSOVER

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Application of Crossover Analysis-logistic Regression in the Assessment of Gene- environmental Interactions for Colorectal Cancer

  • Wu, Ya-Zhou;Yang, Huan;Zhang, Ling;Zhang, Yan-Qi;Liu, Ling;Yi, Dong;Cao, Jia
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.5
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    • pp.2031-2037
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    • 2012
  • Background: Analysis of gene-gene and gene-environment interactions for complex multifactorial human disease faces challenges regarding statistical methodology. One major difficulty is partly due to the limitations of parametric-statistical methods for detection of gene effects that are dependent solely or partially on interactions with other genes or environmental exposures. Based on our previous case-control study in Chongqing of China, we have found increased risk of colorectal cancer exists in individuals carrying a novel homozygous TT at locus rs1329149 and known homozygous AA at locus rs671. Methods: In this study, we proposed statistical method-crossover analysis in combination with logistic regression model, to further analyze our data and focus on assessing gene-environmental interactions for colorectal cancer. Results: The results of the crossover analysis showed that there are possible multiplicative interactions between loci rs671 and rs1329149 with alcohol consumption. Multifactorial logistic regression analysis also validated that loci rs671 and rs1329149 both exhibited a multiplicative interaction with alcohol consumption. Moreover, we also found additive interactions between any pair of two factors (among the four risk factors: gene loci rs671, rs1329149, age and alcohol consumption) through the crossover analysis, which was not evident on logistic regression. Conclusions: In conclusion, the method based on crossover analysis-logistic regression is successful in assessing additive and multiplicative gene-environment interactions, and in revealing synergistic effects of gene loci rs671 and rs1329149 with alcohol consumption in the pathogenesis and development of colorectal cancer.

Investigation of Factors Influencing Methanol Crossover in Direct Methanol Fuel Cell (직접메탄올연료전지에서 메탄올 크로스오버에 미치는 인자 연구)

  • Hyun, Min-Soo;Kim, Sang-Kyung;Lim, Seong-Yop;Lee, Byung-Rock;Peck, Dong-Hyun;Jung, Doo-Hwan
    • Journal of the Korean Electrochemical Society
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    • v.11 no.1
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    • pp.6-10
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    • 2008
  • The amount of methanol crossover was measured with changing the operating condition by using a liquid methanol concentration sensor. Appropriate operating condition was discussed in terms of methanol crossover. Mechanism of methanol crossover was classified into three items which are diffusion, convection and electro-osmosis. Contribution of each mechanism to methanol crossover and the effect of operating condition were analyzed with varying methanol concentration, pressure difference between anode and cathode, current, temperature, and stoichiometry of anode fuel. Among the three mechanisms diffusion affected mostly and electro-osmosis effect was observed only under high methanol concentration.

Identification of Meiotic Recombination Intermediates in Saccharomyces cerevisiae (효모 감수분열과정에서의 유전자 재조합 기전 특이적 DNA 중간체의 구조 변화)

  • Sung, Young Jin;Yoon, Sang Wook;Kim, Keun Pil
    • Korean Journal of Microbiology
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    • v.49 no.1
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    • pp.1-7
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    • 2013
  • During meiosis, genetic recombinants are formed by homologous recombination accompanying with the programmed double-strand breaks (DSBs) and strand exchanges between homologous chromosomes. The mechanism is generated by recombination intermediates such as single-end invasions (SEIs) and double-Holliday junctions (dHJs), and followed by crossover (CO) or non-crossover (NCO) products. Our study was focused on the analysis of meiotic recombination intermediates (DSBs, SEIs, and dHJs) and final recombination products (CO and NCO). We identified these meiotic recombination intermediates using DNA physical analysis under HIS4LEU2 "hot spot" system in budding yeast, Saccharomyces cerevisiae. For DNA physical analysis, when the hot spot locus is recognized by restriction enzyme from synchronous meiotic cells, the fragmented DNA that are forming recombination intermediates can be detected and quantified through Southern hybridization analysis. Our study suggests that this system can analyze the structural change of recombination intermediates during DSB-SEI transition, double-Holiday junctions and crossover/non-crossover products in meiosis.

Some Statistical Considerations on 2×k Crossover Designs for Bioequivalence Trial (생물학적 동등성 시험을 위한 2×k 교차설계법의 통계적 고려)

  • Noh, So-Young;Park, Sang-Gue
    • The Korean Journal of Applied Statistics
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    • v.26 no.4
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    • pp.675-686
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    • 2013
  • The Korea Food and Drug Administration(KFDA) recommends the use of a $2{\times}2$ crossover design to assess the bioequivalence of generic drugs. However, a standard $2{\times}2$ crossover design for bioequivalence trials is often considered problematic due to ethical and economic issues as highly variable drugs are usually required by large numbers of subjects when designing the trial. To overcome this problem a $2{\times}4$ crossover design has been a recommended option as per US regulations; in addition, a $2{\times}3$ crossover design has also recently drawn special attention as an efficient alternative. The current KFDA regulation requires an ANOVA table for every bioequivalence study; however, ANOVA tables of $2{\times}4$ and $2{\times}3$ crossover designs have never been published in the literature. This study shows the derivation of tables of analysis of variance for a $2{\times}4$ cross-over design and a $2{\times}3$ cross-over design. We also suggest a sample size formulas for $2{\times}2$, $2{\times}4$ and $2{\times}3$ crossover designs to provide information on the selection of efficient designs for highly variable drugs.

Crossover and Spillover of Emotions from Work to Family among Working Couples in their Daily Lives (직장에서 경험한 강한 감정의 전이(spillover)와 교차전이(crossover): 시카고 지역 맞벌이 부부를 중심으로)

  • Kim, Yo-Jin
    • Korean Journal of Social Welfare
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    • v.60 no.3
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    • pp.253-274
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    • 2008
  • The link between work life and family life is an essential subject matter in understanding the lives of dual-earner couples. Concepts of spillover and crossover explain the link between work and family. The present study examines both the positive and negative aspects in these processes. The data come from the Sloan Working Families Study conducted by the Alfred P. Sloan Center on Parents, Children, and Work and NORC at the University of Chicago. The Experience Sampling Method employed explores directly the daily life experiences of the participants. The data were analysed using t-test. Both spillover and crossover were found in the lives of dual-earner couples in this study. Men and women brought happy emotions at work to home, but the data provide limited support for spillover of negative emotions. Gender differences were more apparent in examining the process of crossover. Men appear responsive to the positive and negative emotional experiences their spouse brought home while women were found not to be responsive to their spouses' positive emotional experiences at work. Furthermore, the analysis revealed an interesting trend concerning the emotions of working couples in that they generally seem to recover to their average level of emotions once home. This suggests that home can be a respite from strong emotions, a comforting place. By looking closely into the emotions experienced by working parents in their daily lives, this study adds contextual understanding concerning the link between work and family life. The findings on the effects of positive experiences at work invite social work practitioners and researchers to further investigate the phenomena of spillover and crossover processed in greater detail, taking into account this contextual aspect of family life as well as the work life of dual-earner couples.

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A Crossover Node Discovery and Local Repair Mechanism for Reducing the Signaling Delay of Resource Reservation on HMIPv6 Networks (HMIPv6 네트워크에서 자원예약 시그널링 지연을 줄이기 위한 크로스오버 노드 발견 및 지역적 자원 갱신 방안)

  • Byun, Hae-Sun;Lee, Mee-Jeong
    • The KIPS Transactions:PartC
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    • v.15C no.1
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    • pp.37-44
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    • 2008
  • In order to minimize the signaling delay for a resource reservation on the new routing path after the handover of Mobile Node(MN) is completed, it is important to discover the crossover node where the old and new routing paths meet. With the 크로스오버 노드 being found, the signaling messages only need to be transferred on the changed part of the end-to-end path. The crossover node is generally discovered using the end-to-end Session ID(SID) of the established session between MN and Correspondent Node(CN). However, in the Hierarchical Mobile IPv6(HMIPv6) network, if the Mobile Anchor Point (MAP) reserves the resource by aggregate with the Home Agent(HA), the crossover node discovery cannot be performed in the general way since the aggregate SID that has established between the previous MAP and HA is different from the that of the current MAP and HA after MN's handover. In this paper, we propose a mechanism to discover the crossover node within the tunnel between the MAP and the HA in an HMIPv6 network, assuming that the Next Steps in Signaling(NSIS) is deployed for the resource reservation and the aggregate reservation is applied over the MAP and HA tunnel. The local repair required for the change of path is performed upon the crossover node discovery. The simulation results show that the proposed scheme reduces the signaling delay for the reservation and outperforms the existing scheme with respect to throughput during the handover.