| 1. |
- Johansson, Daniel, et al.
(författare)
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A multivariate approach applied to microarray data for identification of genes with cell cycle-coupled transcription
- 2003
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Ingår i: Bioinformatics. - : Oxford University Press (OUP). - 1367-4811 .- 1367-4803. ; 19:4, s. 467-73
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Tidskriftsartikel (refereegranskat)abstract
- We have analyzed microarray data using a modeling approach based on the multivariate statistical method partial least squares (PLS) regression to identify genes with periodic fluctuations in expression levels coupled to the cell cycle in the budding yeast, Saccharomyces cerevisiae. PLS has major advantages for analyzing microarray data since it can model data sets with large numbers of variables and with few observations.A response model was derived describing the expression profile over time expected for periodically transcribed genes, and was used to identify budding yeast transcripts with similar profiles. PLS was then used to interpret the importance of the variables (genes) for the model, yielding a ranking list of how well the genes fitted the generated model. Application of an appropriate cutoff value, calculated from randomized data, allows the identification of genes whose expression appears to be synchronized with cell cycling. Our approach also provides information about the stage in the cell cycle where their transcription peaks.Three synchronized yeast cell microarray data sets were analyzed, both separately and combined. Cell cycle-coupled periodicity was suggested for 455 of the 6,178 transcripts monitored in the combined data set, at a significance level of 0.5%. Among the candidates, 85% of the known periodic transcripts were included. Analysis of the three data sets separately yielded similar ranking lists, showing that the method is robust.
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| 2. |
- Lundborg, Petter, et al.
(författare)
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Do they know what they are doing? Risk perceptions and smoking behaviour among Swedish teenagers
- 2004
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Ingår i: Journal of Risk and Uncertainty. - 1573-0476. ; 28:3, s. 261-286
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Tidskriftsartikel (refereegranskat)abstract
- Cross-sectional survey data on Swedish adolescents aged 12 - 18 was used to analyse perceived risks of smoking-related lung cancer, the determinants of these risk perceptions, and how these perceptions related to smoking behaviour. Three major conclusions were drawn: ( 1) that both smokers and non-smokers overestimated the risks of lung cancer, ( 2) that these risk perceptions fell substantially with age, but nevertheless implied risk overestimation, and ( 3) that individuals with higher perceived risks were less likely to be smokers but that risk beliefs had no effect on the number of cigarettes smoked.
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| 3. |
- Lundborg, Petter, et al.
(författare)
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Risk perceptions and alcohol consumption among young people
- 2002
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Ingår i: Journal of Risk and Uncertainty. - 1573-0476. ; 25:2, s. 165-183
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Tidskriftsartikel (refereegranskat)abstract
- Swedish cross-sectional survey data on young individuals was used to analyse the determinants of perceived risks of alcohol use and how these perceptions relate to drinking behaviour. Three major conclusions were drawn: (1) that people overestimate the risks of alcoholism, (2) that these risk perceptions fall substantially with age, but nevertheless imply risk overestimation, and (3) that education about alcohol, narcotics and tobacco leads individuals to perceive risks more correctly and to have lower risk beliefs. An additional finding was that individuals with higher perceived risks were less likely to consume alcohol. Equations were estimated both separately and simultaneously.
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