Dynamic metabolomic data analysis: a tutorial review

In metabolomics, time-resolved, dynamic or temporal data is more and more collected. The number of methods to analyze such data, however, is very limited and in most cases the dynamic nature of the data is not even taken into account. This paper reviews current methods in use for analyzing dynamic metabolomic data. Moreover, some methods from other fields of science that may be of use to analyze such dynamic metabolomics data are described in some detail. The methods are put in a general framework after providing a formal definition on what constitutes a ‘dynamic’ method. Some of the methods are illustrated with real-life metabolomics examples

The Rotterdam Study: 2012 objectives and design update

The Rotterdam Study is a prospective cohort study ongoing since 1990 in the city of Rotterdam in The Netherlands. The study targets cardiovascular, endocrine, hepatic, neurological, ophthalmic, psychiatric, dermatological, oncological, and respiratory diseases. As of 2008, 14,926 subjects aged 45 years or over comprise the Rotterdam Study cohort. The findings of the Rotterdam Study have been presented in over a 1,000 research articles and reports (see www.erasmus-epidemiology.nl/rotterdamstudy). This article gives the rationale of the study and its design. It also presents a summary of the major findings and an update of the objectives and methods

Nutrition and cancer: A review of the evidence for an anti-cancer diet

It has been estimated that 30–40 percent of all cancers can be prevented by lifestyle and dietary measures alone. Obesity, nutrient sparse foods such as concentrated sugars and refined flour products that contribute to impaired glucose metabolism (which leads to diabetes), low fiber intake, consumption of red meat, and imbalance of omega 3 and omega 6 fats all contribute to excess cancer risk. Intake of flax seed, especially its lignan fraction, and abundant portions of fruits and vegetables will lower cancer risk. Allium and cruciferous vegetables are especially beneficial, with broccoli sprouts being the densest source of sulforophane. Protective elements in a cancer prevention diet include selenium, folic acid, vitamin B-12, vitamin D, chlorophyll, and antioxidants such as the carotenoids (α-carotene, β-carotene, lycopene, lutein, cryptoxanthin). Ascorbic acid has limited benefits orally, but could be very beneficial intravenously. Supplementary use of oral digestive enzymes and probiotics also has merit as anticancer dietary measures. When a diet is compiled according to the guidelines here it is likely that there would be at least a 60–70 percent decrease in breast, colorectal, and prostate cancers, and even a 40–50 percent decrease in lung cancer, along with similar reductions in cancers at other sites. Such a diet would be conducive to preventing cancer and would favor recovery from cancer as well

Linear techniques to correct for temperature-induced spectral variation in multivariate calibration

The influence of external physical variation such as temperature fluctuations on near-infrared (NIR) spectra and their effect on the predictive power of calibration models such as PLS have been studied. Different methods to correct for the temperature effect by explicitly including the temperature in a calibration model have been tested. The results are compared to the implicit inclusion, which takes the temperature into account only through the calibration design. Two data sets are used, one well-designed data set measured in the laboratory and one industrial data set consisting of measurements for process samples. For both data sets, the explicit inclusion of the temperature in the calibration models did not result in an improvement of the prediction accuracy compared to implicit inclusion. (C) 2000 Elsevier Science B.V. All rights reserve

Effect of Synchronization on Bilinear Batch Process Modeling

There is a widespread assumption that batch synchronization is only required if the batch trajectories have different duration. This paper is devoted to demonstrate that synchronization is a critical and necessary preliminary step to bilinear batch process modeling, no matter whether batch trajectories have equal length or not. Another practical assumption is that all batches need the same synchronization method to be aligned. Two different synchronization approaches are compared in terms of synchronization quality: the Multisynchro approach that takes into account the type of asynchronism and the method based on linearly expanding and/or compressing pieces of variables trajectories (the TLEC method), implemented in commercial software. The consequences of inappropriately synchronizing batch data with multiple asynchronisms in process monitoring are investigated. For this study, the observationwise unfolding-T scores batchwise unfolding (OWU-TBWU) approach, which integrates the TLEC method for batch synchronization, is used for process modeling. Data from realistic simulations of a fermentation process of the Saccharomyces cerevisiae cultivation with five different types of asynchronism are used for illustration

Effect of synchronization on bilinear batch process modeling

There is a widespread assumption that batch synchronization is only required if the batch trajectories have different duration. This paper is devoted to demonstrate that synchronization is a critical and necessary preliminary step to bilinear batch process modeling, no matter whether batch trajectories have equal length or not. Another practical assumption is that all batches need the same synchronization method to be aligned. Two different synchronization approaches are compared in terms of synchronization quality: the Multisynchro approach that takes into account the type of asynchronism and the method based on linearly expanding and/or compressing pieces of variables trajectories (the TLEC method), implemented in commercial software. The consequences of inappropriately synchronizing batch data with multiple asynchronisms in process monitoring are investigated. For this study, the observationwise unfolding-T scores batchwise unfolding (OWU-TBWU) approach, which integrates the TLEC method for batch synchronization, is used for process modeling. Data from realistic simulations of a fermentation process of the Saccharomyces cerevisiae cultivation with five different types of asynchronism are used for illustration.This research work was partially supported by the Spanish Ministry of Economy and Competitiveness under the project DPI2011-28112-C0t4-02. Part of this research work was carried out during an internship of the corresponding author at Shell Global Solutions International B.V. (Amsterdam, The Netherlands).González Martínez, JM.; Vitale, R.; De Noord, OE.; Ferrer, A. (2014). Effect of synchronization on bilinear batch process modeling. Industrial and Engineering Chemistry Research. 53(11):4339-4351. https://doi.org/10.1021/ie402052vS43394351531