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  • 11
    Keywords: Germany ; MODELS ; ALGORITHM ; DISEASE ; POPULATION ; RISK ; MARKER ; ASSOCIATION ; LINKAGE ; DESIGN ; genetics ; MARKERS ; LINKAGE DISEQUILIBRIUM ; gene-environment interaction ; case-control studies ; case control study ; case-control study ; REGRESSION ; VARIANT ; interaction ; TESTS ; GENOTYPE DATA ; POWER ; prospective ; LINKAGE PHASE ; UNIT ; INFERENCE ; LOGISTIC-REGRESSION ; indirect association ; Genetic ; EM ALGORITHM ; Expectation maximization algorithm ; Hardy Weinberg equilibrium ; Logistic regression ; MAXIMUM-LIKELIHOOD-ESTIMATION ; Retrospective and prospective likelihood
    Abstract: Objective: We compared four haplotype-based approaches for the analysis of gene-environment interactions when haplotype-phase is ambiguous. The methods employ different versions of the expectation maximization algorithm and differ in the choice of the reference group and in the way the risk of disease is modeled (retrospective versus prospective). Furthermore, the methods are based on distinct assumptions (such as Hardy Weinberg equilibrium). The haplotype-based methods were also compared to single-marker logistic regression (LR). Methods: We simulated case-control scenarios where the risk variant was directly genotyped (direct scenario) or in linkage disequilibrium with the genotyped markers (indirect scenario). Results: The retrospective methods tended to be more powerful for detecting interactions than the prospective methods. In the indirect scenarios, the power of all methods was decreased. However, the power of the retrospectives methods was high in some scenarios and the interactions may only be detectable when using these approaches. Furthermore, we observed that the precision of one prospective method was clearly lower than the precision of the retrospective methods. Conclusion: For the analysis of gene-environment (GxE) interactions in case-control data, the investigated retrospective methods can be an attractive alternative to haplotype-based methods which do not account for the retrospective sampling design. Copyright (C) 2009 S. Karger AG, Basel
    Type of Publication: Journal article published
    PubMed ID: 19622892
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  • 12
    Publication Date: 2014-05-09
    Description: Electromagnetic noise is emitted everywhere humans use electronic devices. For decades, it has been hotly debated whether man-made electric and magnetic fields affect biological processes, including human health. So far, no putative effect of anthropogenic electromagnetic noise at intensities below the guidelines adopted by the World Health Organization has withstood the test of independent replication under truly blinded experimental conditions. No effect has therefore been widely accepted as scientifically proven. Here we show that migratory birds are unable to use their magnetic compass in the presence of urban electromagnetic noise. When European robins, Erithacus rubecula, were exposed to the background electromagnetic noise present in unscreened wooden huts at the University of Oldenburg campus, they could not orient using their magnetic compass. Their magnetic orientation capabilities reappeared in electrically grounded, aluminium-screened huts, which attenuated electromagnetic noise in the frequency range from 50 kHz to 5 MHz by approximately two orders of magnitude. When the grounding was removed or when broadband electromagnetic noise was deliberately generated inside the screened and grounded huts, the birds again lost their magnetic orientation capabilities. The disruptive effect of radiofrequency electromagnetic fields is not confined to a narrow frequency band and birds tested far from sources of electromagnetic noise required no screening to orient with their magnetic compass. These fully double-blinded tests document a reproducible effect of anthropogenic electromagnetic noise on the behaviour of an intact vertebrate.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Engels, Svenja -- Schneider, Nils-Lasse -- Lefeldt, Nele -- Hein, Christine Maira -- Zapka, Manuela -- Michalik, Andreas -- Elbers, Dana -- Kittel, Achim -- Hore, P J -- Mouritsen, Henrik -- England -- Nature. 2014 May 15;509(7500):353-6. doi: 10.1038/nature13290. Epub 2014 May 7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉1] Institut fur Biologie und Umweltwissenschaften, Universitat Oldenburg, D-26111 Oldenburg, Germany [2] Research Centre for Neurosensory Sciences, University of Oldenburg, D-26111 Oldenburg, Germany [3]. ; 1] Institut fur Biologie und Umweltwissenschaften, Universitat Oldenburg, D-26111 Oldenburg, Germany [2] Research Centre for Neurosensory Sciences, University of Oldenburg, D-26111 Oldenburg, Germany. ; Institute of Physics, University of Oldenburg, D-26111 Oldenburg, Germany. ; Department of Chemistry, University of Oxford, Physical and Theoretical Chemistry Laboratory, Oxford OX1 3QZ, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24805233" target="_blank"〉PubMed〈/a〉
    Keywords: Aluminum ; Animal Migration/*physiology ; Animals ; Cities ; Conservation of Natural Resources ; Double-Blind Method ; Electricity/adverse effects ; Electromagnetic Fields/*adverse effects ; Electronics/instrumentation ; Germany ; Housing ; *Magnetic Fields ; Orientation/*physiology ; Radio Waves/adverse effects ; Reproducibility of Results ; Seasons ; Songbirds/*physiology ; Universities
    Print ISSN: 0028-0836
    Electronic ISSN: 1476-4687
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
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