Charmonium spectral functions in Nf=2 QCD

We report on a study of charmonium at high temperature in 2-flavour QCD. This is the first such study with dynamical fermions. Using an improved anisotropic lattice action, spectral functions are extracted from correlators in the vector and pseudoscalar channels. No signs of medium-induced suppression of the ground states are seen for temperatures up to 1.5T_c, while at T~2T_c there are clear signs of modifications. The current systematic and statistical uncertainties in our data, in particular the relatively coarse lattice and small volume, do not allow us to draw a firm conclusion at this stage.Comment: 6 pages, talk by JIS at Lattice 2005 (Non-zero temperature and density

The development of a self-regulated isometric handgrip training protocol and its effects on blood pressure (resting and ambulatory), markers of autonomic function and adherence in pre-hypertensive and stage 1 hypertensive adults (≥55years).

Isometric exercise training is gaining recognition for its blood pressure (BP) lowering effects. The current thesis had four primary purposes, to: i) assess the reproducibility of various BP and heart rate variability (HRV) measures (ii) validate the CR-10 scale as a novel method for self-regulating the intensity of isometric handgrip (IHG) exercise and iii) determine the effects of self-regulated IHG exercise on resting and 24-hour ambulatory BP iv) investigate levels of participant adherence to self-regulated IHG training. Secondary to these purposes, indirect measures of autonomic function were recorded to provide insight into a possible mechanistic pathway for BP reductions. Study 1 (Chapter 4) assessed the reproducibility of 24-hour ambulatory BP, 24-hour HRV, resting HRV and resting systolic blood pressure variability (BPV). It was shown that i) the typical error in ambulatory systolic BP recordings reduced over consecutive pairs of measurements (3.8-2.8mmHg) and would therefore benefit from familiarisation periods ii) 24-hour HRV provided superior reproducibility to resting measurements and iii) resting systolic BPV displayed poor reproducibility (coefficient of variation, 27-60%) . Study 2 (Chapter 5) determined the validity of self-regulating IHG exercise as an alternative to the commonly-prescribed 30% maximal voluntary contraction (MVC). Findings showed that exercising at “Level-6” on the category-ratio scale (CR-10) enabled participants to produce an appropriate IHG exercise intensity (mean 33% MVC). Thus, the CR-10 scale provides a valid means for participants to self-regulate the intensity of IHG exercise. Study 3 (Chapter 6) implemented an IHG training programme in a 2-phase training study design. Phase 1 showed that 10-weeks of self-regulated IHG training (at CR-10 “Level 6”) induced clinically-relevant reductions in resting systolic BP (-6mmHg). However, no changes were observed in 24-hour ambulatory BP. The data also displayed trending changes in autonomic modulation of both heart (HRV) and systolic BP (BPV), these findings could offer some explanation for the reductions in resting BP. Phase 2 revealed excellent adherence (average, 95%) during both shorter-term (14 weeks) and longer-term (24 weeks) self-regulated, home-based, unsupervised IHG training. However, despite excellent adherence, the longer-term exercise group did not maintain their reduced resting BP upon completion of 24-weeks of isometric exercise training. Taken together, these findings demonstrate the appropriateness of self-regulated IHG training as a non-pharmacological intervention for lowering resting BP. However, it seems that the reductions in resting BP may be lost with prolonged training and further investigation into the long-term effects of isometric exercise training on resting and ambulatory BP is required

A Short Form Of The Maximization Scale: Factor Structure, Reliability And Validity Studies

We conducted an analysis of the 13-item Maximization Scale (Schwartz et al., 2002) with the goal of establishing its factor structure, reliability and validity. We also investigated the psychometric properties of several proposed refined versions of the scale. Four sets of analyses are reported. The first analysis confirms the 3-part factor structure of the scale and assesses its reliability. The second analysis identifies those items that do not perform well on the basis of internal, external, and judgmental criteria, and develops three shorter versions of the scale. In the third analysis, the three refined versions of the scale are cross-validated to confirm dimensionality, reliability, and validity. The fourth analysis uses an experiment in an investment decision making context to assess the reliability and nomological validity of the refined scales. These analyses lead us to conclude that a shorter, 6-item Maximization Scale performs best and should be used by future researchers. It is hoped that clarification of the conceptual underpinnings of the maximization construct and development of a refined scale will enhance its use among researchers across severa

Static-light matrix elements on a dynamical anisotropic lattice

The static-light matrix element needed to determine $f_B$ is studied on an anisotropic lattice with $N_f=2$. The improvement in precision due to stout links and all-to-all propagators is investigated.Comment: Lattice2004(heavy), Fermilab, June 21-26, 2004. 3 page

Characterisation of horseradish peroxidase immobilisation on an electrochemical biosensor by colorimetric and amperometric techniques

This study presents the use of complementary colorimetric and amperometric techniques to measure the quantity of protein or enzyme immobilised onto a carbon paste electrode modified with a layer of electrodeposited polyaniline. By applying a solution of bovine serum albumin at 0.75 mg/ml, efficient blocking of the electrode from electroactive species in the bulk solution could be achieved. When the horseradish peroxidase was immobilised on the electrode, optimal amperometric responses from hydrogen peroxide reduction were achieved at approximately the same concentration. The mass of enzyme immobilised at this solution concentration was determined by a colorimetric enzyme assay to be equivalent to the formation of a protein monolayer. Under these conditions, amperometric responses from the immobilised layer are maximised and non-specific bulk solution interactions are minimised. At higher immobilised protein concentrations, diminished amperometric responses may be due to inhibited diffusion of hydrogen peroxide to enzyme which is in electronic communication with the electrode surface, or impeded electron transfer

Electrocatalytic sensor devices: (I) cyclopentadienylnickel(II) thiolato Schiff base monolayer self-assembled on gold

The fabrication of a self-assembled monolayer (SAM) of a cyclopentadienylnickel(II) thiolato Schiff base compound, [Ni(SC6H4NC(H)C6H4OCH2CH2SMe)(η5-C5H5)]2 on a gold electrode is described. Effective electronic communication between the Ni(II) centres and the gold surface was established by electrochemically cycling the Schiff base-doped Au electrode in 0.1 M NaOH from −200 mV to +600 mV. The SAM-modified electrode exhibited quasi-reversible electrochemistry. The integrity of this electrocatalytic SAM, with respect to its ability to block and electro-catalyse certain Faradaic processes, was interrogated using cyclic voltammetric experiments. The formal potential, E°′, varied with pH to give a slope of about −30 mV pH−1. The surface concentration, G, of the nickel redox centres was found to be 1.548×10−11 mol cm−2. By electrostatically doping the SAM using an applied potential of +700 mV versus Ag/AgCl, in the presence of horseradish peroxidase (HRP), it was fine-tuned for amperometric determination of H2O2. The electrocatalytic-type biosensor displayed typical Michaelis–Menten kinetics and the limit of detection was found to be 6.25 mM

Immunoglobulin G from bovine milk primes intestinal epithelial cells for increased colonization of bifidobacteria

peer-reviewedAbstract A bovine colostrum fraction (BCF) was recently shown to enhance the adherence of several commensal organisms to intestinal epithelial cells through modulating the epithelial cell surface. In this study, the main components of the BCF were examined to investigate the active component/s responsible for driving the changes in the intestinal cells. The adherence of various bifidobacteria to HT-29 cells was increased when the intestinal cells were pre-incubated with immunoglobulin G (IgG). Modulation of the intestinal cells by IgG was concentration dependent with 16 mg/mL IgG resulting in a 43-fold increase in the adhesion of Bifidobacterium longum NCIMB 8809 to HT-29 cells. Periodate treatment of colostral IgG prior to performing the colonization studies resulted in a reduction in the adhesion of the strain to the intestinal cells demonstrating that the glycans of IgG may be important in modulating the intestinal cells for enhanced commensal adhesion. IgG isolated from mature milk also resulted in significant increases in adhesion of the Bifidobacterium strains tested albeit at reduced levels (3.9-fold). The impact of IgG on the HT-29 cells was also visualised via scanning electron microscopy. This study builds a strong case for the inclusion of IgG ingredients sourced from cow’s milk in functional foods aimed at increasing numbers of health promoting bacteria in the human gut