Effect of bioprocessing of wheat bran in wholemeal wheat breads on the colonic SCFA production in vitro and postprandial plasma concentrations in men

The health benefits of whole grain consumption can be partly attributed to the inclusion of the bran or outer-layers of the grain rich in dietary fibre. Fibre is fermented in the colon, leading to the production of beneficial metabolites, such as short-chain fatty acids (SCFA). The effect of five different types of bread on the SCFA production was studied in an in vitro model of human colon. Additionally, the postprandial effects of two selected breads on the SCFA plasma concentrations were investigated in men. A higher in vitro production of butyrate was induced by wholemeal wheat bread with bioprocessed bran than by native bran. The increase in butyrate seemed to be in exchange for propionate, whilst the total SCFA production remained similar. However, differences between the two breads in the postprandial butyrate concentrations could not be detected in peripheral blood of men, probably due to an effective utilisation by colonocytes.     

Simultaneous quantitative analysis of metabolites using ion-pair liquid chromatography-electrospray ionization mass spectrometry

We have developed an analytical method, consisting of ion-pair liquid chromatography coupled to electrospray ionization mass spectrometry (IP-LC-ESI-MS), for the simultaneous quantitative analysis of several key classes of polar metabolites, like nucleotides, coenzyme A esters, sugar nucleotides, and sugar bisphosphates. The use of the ion-pair agent hexylamine and optimization of the pH of the mobile phases were critical parameters in obtaining good retention and peak shapes of many of the above-mentioned polar and acidic metabolites that are impossible to analyze using standard reversed-phase LC/MS. Optimum conditions were found when using a gradient from 5 mM hexylamine in water (pH 6.3) to 90% methanol/10% 10 mM ammonium acetate (pH 8.5). The IP-LC-ESI-MS method was extensively validated by determining the linearity (R2 > 0.995), sensitivity (limit of detection 0.1-1 ng), repeatability, and reproducibility (relative standard deviation <10%). The IP-LC-ESI-MS method was shown to be a useful tool for microbial metabolomics, i.e., the comprehensive quantitative analysis of metabolites in extracts of microorganisms, and for the determination of the energy charge, i.e., the cellular energy status, as an overall quality measure for the sample workup and analytical protocols.     

Application of hierarchical matrices to boundary element methods for elastodynamics based on Green's functions for a horizontally layered halfspace

This paper presents the application of hierarchical matrices to boundary element methods for elastodynamics based on Green's functions for a horizontally layered halfspace. These Green's functions are computed by means of the direct stiffness method; their application avoids meshing of the free surface and the layer interfaces. The effectiveness of the methodology is demonstrated through numerical examples, indicating that a significant reduction of memory and CPU time can be achieved with respect to the classical boundary element method. This allows increasing the problem size by one order of magnitude. The proposed methodology therefore offers perspectives to study large scale problems involving three-dimensional elastodynamic wave propagation in a layered halfspace, with possible applications in seismology and dynamic soil–structure interaction.     

Chromosomal mapping of two novel human FGF genes, FGF11 and FGF12

The fibroblast growth factor (FGF) family comprises to date 12 members, which are involved in various physiological processes throughout embryogenesis and adult life. Two novel members of the family have been identified recently (FGF11 and FGF12). Using in situ hybridization on metaphasic chromosomes, we have been able to assign FGF11 to band p12-p13 of human chromosome 17 and FGF12 to band q28 of human chromosome 3.     

Coupled finite element – hierarchical boundary element methods for dynamic soil–structure interaction in the frequency domain

This paper discusses the coupling of finite element and fast boundary element methods for the solution of dynamic soil–structure interaction problems in the frequency domain. The application of hierarchical matrices in the boundary element formulation allows considering much larger problems compared to classical methods. Three coupling methodologies are presented and their computational performance is assessed through numerical examples. It is demonstrated that the use of hierarchical matrices renders a direct coupling approach the least efficient, as it requires the assembly of a dynamic soil stiffness matrix. Iterative solution procedures are presented as well, and it is shown that the application of such schemes to dynamic soil–structure interaction problems in the frequency domain is not trivial, as convergence can hardly be achieved if no relaxation procedure is incorporated. Aitken's Δ²‐method is therefore employed in sequential iterative schemes for the calculation of an optimized interface relaxation parameter, while a novel relaxation technique is proposed for parallel iterative algorithms. It is demonstrated that the efficiency of these algorithms strongly depends on the boundary conditions applied to each subdomain; the fastest convergence is observed if Neumann boundary conditions are imposed on the stiffest subdomain. The use of a dedicated solver for each subdomain hence results in a reduced computational effort. A monolithic coupling strategy, often used for the solution of fluid–structure interaction problems, is also introduced. The governing equations are simultaneously solved in this approach, while the assembly of a dynamic soil stiffness matrix is avoided. Copyright © 2013 John Wiley & Sons, Ltd.     

New figures of merit for comprehensive functional genomics data: the metabolomics case

In the field of metabolomics, hundreds of metabolites are measured simultaneously by analytical platforms such as gas chromatography/mass spectrometry (GC/MS), liquid chromatography/mass spectrometry (LC/MS) and NMR to obtain their concentration levels in a reliable way. Analytical repeatability (intrabatch precision) is a common figure of merit for the measurement error of metabolites repeatedly measured in one batch on one platform. This measurement error, however, is not constant as its value may depend on the concentration level of the metabolite. Moreover, measurement errors may be correlated between metabolites. In this work, we introduce new figures of merit for comprehensive measurements that can detect these nonconstant correlated errors. Furthermore, for the metabolomics case we identified that these nonconstant correlated errors can result from sample instability between repeated analyses, instrumental noise generated by the analytical platform, or bias that results from data pretreatment.     

Ancient large-scale genome duplications: phylogenetic and linkage analyses shed light on chordate genome evolution

Paralogous genes from several families were found in four human chromosome regions (4p16, 5q33-35, 8p12-21, and 10q24-26), suggesting that their common ancestral region underwent several rounds of large-scale duplication. Searches in the EMBL databases, followed by phylogenetic analyses, showed that cognates (orthologs) of human duplicated genes can be found in other vertebrates, including bony fishes. In contrast, within each family, only one gene showing the same high degree of similarity with all the duplicated mammalian genes was found in nonvertebrates (echinoderms, insects, nematodes). This indicates that large-scale duplications occurred after the echinoderms/chordates split and before the bony vertebrate radiation. It has been suggested that two rounds of gene duplication occurred in the vertebrate lineage after the separation of Amphioxus and craniate (vertebrates + Myxini) ancestors. Before these duplications, the genes that have led to the families of paralogous genes in vertebrates must have been physically linked in the craniate ancestor. Linkage of some of these genes can be found in the Drosophila melanogaster and Caenorhabditis elegans genomes, suggesting that they were linked in the triploblast Metazoa ancestor.     

Intrinsic Thiophene Hydrodesulfurization Kinetics of a Sulfided NiMo/SiO2 Model Catalyst: Volcano-Type Behavior

A realistic planar model of a silica-supported NiMo sulfide hydrotreating catalyst was used to study the intrinsic kinetics of thiophene hydrodesulfurization over a broad temperature range at atmospheric pressure. The specific nonporous nature of the model catalysts excludes possible diffusion limitations, which are commonly encountered in kinetic studies of their industrial porous analogues. The unique possibility to measure the intrinsic chemical kinetics over a large temperature range allowed us to observe a Volcano-type behavior for thiophene hydrodesulfurization. The specific kinetic parameters are discussed in terms of possible mechanisms.     

FGF6 modulates the expression of fibroblast growth factor receptors and myogenic genes in muscle cells

A recent policy change by the University of California (UC) provides a unique natural experiment for investigating how consumers respond to financial incentives when choosing health plans. In 1994 UC went from a premium contribution policy that subsidized more costly plans to a policy of contributing a constant dollar amount. As a result, employee premium contributions increased for roughly one-third of university employees. The response to this change in relative prices was strong. Whereas only 5 percent of employees facing constant premium contributions switched plans, roughly one-quarter of those facing premium contribution increases of less than $10 per month switched to lower-cost plans. Higher price increases led to even greater rates of plan switching.     

TiO2-Supported Mo Model Catalysts: Ti as Promoter for Thiophene HDS?

The combination of thiophene hydrodesulfurization (HDS) activity measurements and X-ray photoelectron spectroscopy on flat model systems of sulfided HDS Mo catalysts showed that sulfided Ti-species can act as a promoter in the same way as Co and Ni, although less effectively. This explains the higher thiophene HDS activity and hydrogenation selectivity of Mo/TiO₂ compared with Mo/Al₂O₃, while for Ni-promoted Mo catalysts the difference between the two supports is negligible.