A probabilistic framework for peptide and protein quantification from data-dependent and data-independent LC-MS proteomics experiments.

A probability-based quantification framework is presented for the calculation of relative peptide and protein abundance in label-free and label-dependent LC-MS proteomics data. The results are accompanied by credible intervals and regulation probabilities. The algorithm takes into account data uncertainties via Poisson statistics modified by a noise contribution that is determined automatically during an initial normalization stage.

The role of serum chromogranin A in diarrhoea predominant irritable bowel syndrome.

Background & Aims: Elevated serum chromogranin A (CgA) levels have been reported co-incidentally in a small group of irritable bowel syndrome (IBS) patients (n=19). Our aim was to ascertain the prevalence of elevated CgA in diarrhoea predominant Rome II IBS (D-IBS) patients and investigate if this could be a marker for octreotide therapy.

Methods: Patients with Rome II D-IBS were recruited prospectively and investigated as per British Society Guidelines including serial CgA levels (u/l).

ProbSeq--a fragmentation model for interpretation of electrospray tandem mass spectrometry data.

We describe a probabilistic peptide fragmentation model for use in protein databank searching and de novo sequencing of electrospray tandem mass spectrometry data. A probabilistic framework for tuning of the model using a range of well-characterized samples are introduced. We present preliminary results of our tuning efforts.

Contact line motion and dynamic wetting of nanofluid solutions.

The effect that nanoparticles play in the spreading of nanofluids dynamically wetting and dewetting solid substrates is investigated experimentally, using 'drop shape' analysis technique to analyse aluminium-ethanol contact lines advancing and receding over hydrophobic Teflon-AF coated substrates. Results obtained from the advancing/receding contact line analysis show that the nanoparticles in the vicinity of the three-phase contact line enhance the dynamic wetting behaviour of aluminium-ethanol nanofluids for concentrations up to approximately 1% concentration by weight. Two mechanisms were identified as a potential reason for the observed enhancement in spreading of nanofluids: structural disjoining pressure and friction reduction due to nanoparticle adsorption on the solid surface.