Lipidomic Profiling of Chylomicron Triacylglycerols in Response to High Fat Meals

Using lipidomic methodologies the impact that meal lipid composition and metabolic syndrome (MetS) exerts on the postprandial chylomicron triacylglycerol (TAG) response was examined. Males (9 control; 11 MetS) participated in a randomised crossover trial ingesting two high fat breakfast meals composed of either dairy-based foods or vegetable oil-based foods. The postprandial lipidomic molecular composition of the TAG in the chylomicron-rich (CM) fraction was analysed with tandem mass spectrometry coupled with liquid chromatography to profile CM TAG species and targeted TAG regioisomers. Postprandial CM TAG concentrations were significantly lower after the dairy-based foods compared with the vegetable oil-based foods for both control and MetS subjects. The CM TAG response to the ingested meals involved both significant and differential depletion of TAG species containing shorter- and medium-chain fatty acids (FA) and enrichment of TAG molecular species containing C16 and C18 saturated, monounsaturated and diunsaturated FA. Furthermore, there were significant changes in the TAG species between the food TAG and CM TAG and between the 3- and 5-h postprandial samples for the CM TAG regioisomers. Unexpectedly, the postprandial CM TAG concentration and CM TAG lipidomic responses did not differ between the control and MetS subjects. Lipidomic analysing of CM TAG molecular species revealed dynamic changes in the molecular species of CM TAG during the postprandial phase suggesting either preferential CM TAG species formation and/or clearance.     

Derivation of concurrent programs by stepwise scheduling of Event-B models

Concurrent programs are often complex and they are not straightforward to develop and prove correct. Formal development methods based on refinement make it possible not only to derive programs gradually, but also to prove their correctness in a stepwise fashion. Event-B is a formal framework that has been shown useful for developing concurrent and distributed programs. In order to scale to large systems, models can be decomposed into sub-models that can be refined semi-independently and executed in parallel. In this paper, we show how to introduce explicit control flow for the concurrent sub-models in the form of event schedules. The purpose of these schedules is both to provide process-oriented specifications of the programs to complement the state-based approach in Event-B, as well as to facilitate more efficient implementation of the models. The schedules are introduced in a stepwise manner and should be designed to result in a correctness-preserving refinement step. In order to reduce the verification burden on the developers, we provide patterns for schedule introduction, together with their associated proof obligations. We demonstrate our method by applying it on the dining philosophers problem.     

Application of a Bayesian model for the quantification of the European methodology for qualification of non-destructive testing

The European methodology for qualification of non-destructive testing is a well-established approach adopted by nuclear utilities in many European countries. According to this methodology, qualification is based on a combination of technical justification and practical trials. The methodology is qualitative in nature, and it does not give explicit guidance on how the evidence from the technical justification and results from trials should be weighted. A Bayesian model for the quantification process was presented in a previous paper, proposing a way to combine the “soft” evidence contained in a technical justification with the “hard” evidence obtained from practical trials.This paper describes the results of a pilot study in which such a Bayesian model was applied to two realistic Qualification Dossiers by experienced NDT qualification specialists. At the end of the study, recommendations were made and a set of guidelines was developed for the application of the Bayesian model.     

Use of enzymes to elucidate the factors contributing to bitterness in rye flavour

In spite of the health-beneficial character of whole grain rye its use may be limited because of bitter taste. The impact of non-volatile chemical compounds on the bitter taste of rye was analysed by the aid of enzymatic hydrolysis, releasing potentially flavour-active compounds from the rye matrix. Whole grain rye flour–water suspension was treated with hydrolytic enzymes, whereafter portions of the rye suspensions were baked into crackers, assessed for their sensory profile as well as solubilised hydrolysis products. Heat treatment reduced the perceived bitterness. The treatment with enzyme preparation with high protease activity increased the bitterness of rye and also wheat flour both as suspension and as crackers. Other enzymes tested (with high polygalacturonase, endo-glucanase, xylanase or amyloglucosidase activity) had no significant impact on the perceived bitterness. Thus, small molecular weight peptides were considered to be a significant contributor to the bitter note of rye.