| 1. |
- Rowley, M., et al.
(författare)
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A latent class model for competing risks
- 2017
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Ingår i: Statistics in Medicine. - : Wiley. - 0277-6715 .- 1097-0258. ; 36:13, s. 2100-2119
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Tidskriftsartikel (refereegranskat)abstract
- Survival data analysis becomes complex when the proportional hazards assumption is violated at population level or when crude hazard rates are no longer estimators of marginal ones. We develop a Bayesian survival analysis method to deal with these situations, on the basis of assuming that the complexities are induced by latent cohort or disease heterogeneity that is not captured by covariates and that proportional hazards hold at the level of individuals. This leads to a description from which risk-specific marginal hazard rates and survival functions are fully accessible, 'decontaminated' of the effects of informative censoring, and which includes Cox, random effects and latent classmodels as special cases. Simulated data confirm that our approach can map a cohort's substructure and remove heterogeneity-induced informative censoring effects. Application to data from the Uppsala Longitudinal Study of Adult Men cohort leads to plausible alternative explanations for previous counter-intuitive inferences on prostate cancer. The importance of managing cardiovascular disease as a comorbidity in women diagnosed with breast cancer is suggested on application to data from the Swedish Apolipoprotein Mortality Risk Study.
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| 2. |
- Bui, Tuyet T. A., et al.
(författare)
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Botrytis cinerea differentially induces postharvest antioxidant responses in 'Braeburn' and 'Golden Delicious' apple fruit
- 2019
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Ingår i: Journal of the Science of Food and Agriculture. - : John Wiley & Sons. - 0022-5142 .- 1097-0010. ; 99:13, s. 5662-5670
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The fruit of two apple cultivars - 'Braeburn', which is susceptible to inoculation with Botrytis cinerea, and the less susceptible cv. 'Golden Delicious' - were investigated with respect to their response to inoculation with B. cinerea. Successful infection by B. cinerea leads to an oxidative burst and perturbation of plant redox homeostasis. To investigate the interaction between apple fruit and B. cinerea, antioxidant metabolism in fruit samples from sun-exposed and shaded sides of different tissue types was measured over time.RESULTS: The sun-exposed tissue of 'Braeburn' had higher initial levels of total vitamin C in the peel and phenolic compounds in the flesh than 'Golden Delicious', despite its greater susceptibility to gray mold. A substantial antioxidant response was recorded in diseased 'Braeburn' fruit 14 days after inoculation, which involved an elevated superoxide dismutase activity and ascorbate peroxidase activity, a progressive oxidation of total vitamin C, and a decrease in peroxidase activity and phenolic content. Disease development was slower on the sun-exposed sides than on the shaded sides.CONCLUSION: The two cultivars appeared to utilize different strategies to defend themselves against B. cinerea. 'Golden Delicious' almost entirely escaped infection. Preharvest exposure of apple fruit to high light / temperature stress appears to prepare them to better resist subsequent postharvest attack and disease.
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