Evaluation of a modified food frequency questionnaire to measure lignans in Australian men and women

Phytoestrogens are plant compounds that possess estrogenic and biological properties that have been postulated to protect against chronic diseases. Isoflavonoids and lignans are two main classes of phytoestrogen that have been investigated for their estrogenic efficacy and occurrence in the human diet. Isoflavonoids are found in soy and related products, whereas lignans are found in a wider range of plant-based foods, such as cereals, vegetables, fruits, legumes, nuts and seeds; and in beverages such as tea, coffee and wine. In Western populations with low dietary intake of soy products, compared to the Asian counterparts, lignans could be a more important and consistent source of phytoestrogens from the diet. Data for the phytoestrogen content in foods are now available, as more recent research has been conducted to quantify content in commonly consumed food choices in Western populations. The collation of these published values has led to the desire to adequately assess lignan intake. The aims of the research were to evaluate the validity and reliability of a phytoestrogen food frequency questionnaire (FFQ) tool, with a reference method, the weighed food record (WFR), and urinary biomarkers, to measure phytoestrogen intake in the Australian context. The phytoestrogen FFQ was updated and refined to align with food groups and dietary patterns in the current Australian Dietary Guidelines, in particular to optimise measurement of lignans from the FFQ, and utilise current databases of lignan content available from direct measurement of lignans in foods. Intake level and contributing food sources of each class of phytoestrogen, and the associations between social and lifestyle characteristics and phytoestrogen intake and urinary biomarker were also explored. This was a cross-sectional study that recruited 59 Australian men and women aged 18 to 67 years at Joondalup campus, Edith Cowan University. Intake of lignans, isoflavonoids and enterolignans from foods was assessed using the 277-item phytoestrogen FFQ and 3-day WFR, and excretion was assessed with urinary biomarkers. Published values of phytoestrogen content in foods were utilised to measure the intakes. Subjects collected three 24-hour urine samples and phytoestrogen concentration was analysed using a liquid chromatography-mass spectrometry (LC-MS) technique for four lignan subclasses, five isoflavonoids and two enterolignans. Statistical analyses were conducted using IBM SPSS for Windows (SPSS Inc., Version 22 Chicago, IL). Median intake comparisons were assessed with the Wilcoxon signed rank test. Associations between the intake and excretion measurements of two dietary assessment methods were assessed using Spearman’s Rho correlations. Level of agreement between methods was assessed with cross-classification analysis and Bland Altman plots. A triangular comparison between the three methods was conducted with the Method of Triads (MOT) using the software R. The Mann-Whitney U test and Kruskal-Wallis one-way ANOVA were used to compare the median intakes and excretion across categories of social and lifestyle factors. The FFQ had acceptable convergent validity for intake of total lignans and enterolignans when compared to a WFR, in terms of median intakes (lignans: 3914 versus 4302 μg/day, p=0.09; enterolignans: 54 versus 65 μg/day, p=0.81, respectively); and associations between the two methods (lignans ρ=0.42, p Top contributing food sources of lignans were from the nuts and seeds group (30%), nonalcoholic beverages (19%), and breads and cereals (19%); for enterolignans, from dairy products (86%) followed by nonalcoholic beverages (11%). Soy and related food products were the major contributors (78%) to total isoflavones, followed by breads and cereal products (17%). Female subjects who were Caucasian, were at, or had achieved university education level and took regular commercial dietary supplements, were more likely to have a higher lignan and enterolignan intake and excretion level than subjects with different characteristics. Based on these findings, we conclude that the modified phytoestrogen FFQ is highly reliable. It would be a useful assessment tool for example to rank usual intake of phytoestrogen classes for individuals within a group, or quantify mean intakes between different population groups. It is not acceptably valid or accurate for estimation of individual phytoestrogen status, for example for use in experimental studies or to investigate associations with chronic diseases. The lack of associations between measurement of the FFQ and biomarkers could partly be due to limitations of the FFQ tool, such as recall bias or inaccuracies in the estimation of frequency of intake or portion sizes. They also suggest that urinary biomarkers alone are not sufficient for estimation of phytoestrogen status and that additional biomarkers obtained from faecal and plasma samples should be considered for a more complete picture of phytoestrogen status

Theory of variational quantum simulation

The variational method is a versatile tool for classical simulation of a variety of quantum systems. Great efforts have recently been devoted to its extension to quantum computing for efficiently solving static many-body problems and simulating real and imaginary time dynamics. In this work, we first review the conventional variational principles, including the Rayleigh-Ritz method for solving static problems, and the Dirac and Frenkel variational principle, the McLachlan's variational principle, and the time-dependent variational principle, for simulating real time dynamics. We focus on the simulation of dynamics and discuss the connections of the three variational principles. Previous works mainly focus on the unitary evolution of pure states. In this work, we introduce variational quantum simulation of mixed states under general stochastic evolution. We show how the results can be reduced to the pure state case with a correction term that takes accounts of global phase alignment. For variational simulation of imaginary time evolution, we also extend it to the mixed state scenario and discuss variational Gibbs state preparation. We further elaborate on the design of ansatz that is compatible with post-selection measurement and the implementation of the generalised variational algorithms with quantum circuits. Our work completes the theory of variational quantum simulation of general real and imaginary time evolution and it is applicable to near-term quantum hardware.Comment: 41 pages, accepted by Quantu

Charmless B(s)→VVB_{(s)}\to VV Decays in Factorization-Assisted Topological-Amplitude Approach

Within the factorization-assisted topological-amplitude approach, we studied the 33 charmless $B_{(s)} \to VV$ decays, where $V$ stands for a light vector meson. According to the flavor flows, the amplitude of each process can be decomposed into 8 different topologies. In contrast to the conventional flavor diagrammatic approach, we further factorize each topological amplitude into decay constant, form factors and unknown universal parameters. By $\chi^2$ fitting 46 experimental observables, we extracted 10 theoretical parameters with $\chi^2$ per degree of freedom around 2. Using the fitted parameters, we calculated the branching fractions, polarization fractions, CP asymmetries and relative phases between polarization amplitudes of each decay mode. The decay channels dominated by tree diagram have large branching fractions and large longitudinal polarization fraction. The branching fractions and longitudinal polarization fractions of color-suppressed decays become smaller. Current experimental data of large transverse polarization fractions in the penguin dominant decay channels can be explained by only one transverse amplitude of penguin annihilation diagram. Our predictions of those not yet measured channels can be tested in the ongoing LHCb experiment and the Belle-II experiment in future.Comment: 22 pages, 2 figure

Design Method for Cold-Formed Thin-Walled Steel Beams with Built-up Box Section

Built-up sections has been extensively used in cold-formed thin-walled steel structures. The structural behaviour and moment capacity of built-up box beams, which is consisted of nested C and U-sections, are the major concerns in this paper. A finite element model for built-up box beams was firstly developed and validated by existing test results. The effects of screw configuration and the global buckling behaviour of built-up box beams were investigated by parametric analysis. Then, the simple superposition method and equivalent cross-section method were introduced and adopted to estimate the moment capacity of built-up box beams bending about major or minor axis. Finally, a comparison was made between the predicted capacity and the numerical analysis results and the reasonability of these methods was assessed

A Note on Symplectic, Multisymplectic Scheme in Finite Element Method

We find that with uniform mesh, the numerical schemes derived from finite element method can keep a preserved symplectic structure in one-dimensional case and a preserved multisymplectic structure in two-dimentional case in certain discrete version respectively. These results are in fact the intrinsic reason that the numerical experiments indicate that such finite element algorithms are accurate in practice.Comment: 7 pages, 3 figure