The influence of different sources of polyphenols on submaximal cycling and time trial performance

The primary purpose of the study was to establish the effects of commercially available polyphenol-rich antioxidant supplements, Pycnogenol® with added bioflavonoids (PYC-B) and CherryActive (CHA), on 20 km cycling performance. Using a double-blind counterbalanced, repeated-measures design, nine male cyclists or triathletes (32.1 ± 11.2 years; maximal aerobic capacity 4.2 ± 0.7 L•min-1; maximal power output 391.7 ± 39.5 watts) consumed 200 mg of CHA, 120 mg of PYC-B, or 200 mg of placebo (PLA) capsules, 2 days before and on the day of each experimental trial. The experimental trials consisted of four 5 minute stages at 40%, 50%, 60%, and 70% maximal power output (Wmax), followed by a 20 km time trial (TT). Statistical analysis revealed no significant differences between trials for heart rate, respiratory exchange ratio, gross mechanical efficiency, oxygen consumption, or blood lactate, at any of the intensities completed during the initial 20 minute phase of the trial (p>0.05). Final 20 km TT times were not significantly different between trials (p=0.115), but, compared to PLA, PYC-B did significantly increase power output by 6.2% over the final 5 km of the TT (p=0.022). The study suggests that the PYC-B supplement could be beneficial towards the end of an intense bout of cycling exercise. However, as total 20 km time was not significantly different between trials the doses used are unlikely to benefit 20 km cycling time trial performance

Orthotropic cyclic stress-softening model for pure shear during repeated loading and unloading

We derive an orthotropic model to describe the cyclic stress softening of a carbon-filled rubber vulcanizate through multiple stress-strain cycles with increasing values of the maximum strain. We specialize the deformation to pure shear loading. As a result of strain-induced anisotropy following on from initial primary loading, the material may subsequently be described as orthotropic because in pure shear there are three different principal stretches so that the strain-induced anisotropy of the stress response is different in each of these three directions. We derive non-linear orthotropic models for the elastic response, stress relaxation and residual strain to model accurately the inelastic features associated with cyclic stress softening. We then develop an orthotropic version of the Arruda-Boyce eight-chain model of elasticity and then combine it with the ideas previously developed in this paper to produce an orthotropic constitutive relation for the cyclic stress softening of a carbon-filled rubber vulcanizate. The model developed here includes the widely occurring effects of hysteresis, stress-relaxation and residual strain. The model is found to compare well with experimental data

An Application of Armitage Trend Test to Genome-wide Association Studies

Genome-wide Association (GWA) studies have become a widely used method for analyzing genetic data. It is useful in detecting associations that may exist between particular alleles and diseases of interest. This thesis investigates the dataset provided from problem 1 of the Genetic Analysis Workshop 16 (GAW 16). The dataset consists of GWA data from the North American Rheumatoid Arthritis Consortium (NARAC). The thesis attempts to determine a set of single nucleotide polymorphisms (SNP) that are associated significantly with rheumatoid arthritis. Moreover, this thesis also attempts to address the question of whether the one-sided alternative hypothesis that the minor allele is positively associated with the disease or the two-sided alternative hypothesis that the genotypes at a locus are associated with the disease is appropriate, or put another way, the question of whether examining both alternative hypotheses yield more information

The ion exchange behaviour of some trivalent cations in aqueous monoethanolamine

Includes bibliography.This investigation of the behaviour of cation exchange resins in aqueous monoethanolamine has led to some interesting conclusions regarding the influence of the solvent onion exchange resins. The main results and conclusions, which have been discussed in detail in the preceding chapters, will now be summarised. The observed decrease in weight-swelling of the three resins in the various trivalent ionic states with a decrease in the dielectric constant of the ambient medium, by virtue of an increase in the monoethanolamine content of the external phase, may be attributed to :1) a decrease in the solvation tendency of the fixed ionic groups and counter-ions ; 2) an increase in ion-pair formation, resulting in a decrease in the number of osmotically active ions in the resin phase, and tin accompanying reduction in the osmotic pressure difference between resin and solution phases;3) an increase in association between resin anions and counter-ions, giving rise to a lower electrostatic potential of the polymer chains

A Study of Caffeine and Its Metabolites in Human Body Fluids.

This study describes the development and application of sensitive and specific, reverse-phase high performance liquid chromatography procedures for the measurement of caffeine and its metabolites in biological fluids. Satisfactory resolution of these compounds was achieved using Hypersil octadecylsilane columns with elution solvents consisting of buffered aceto-nitrile solutions containing tetrahydrofuran as an ion-pairing reagent. Eluted compounds were detected by monitoring their UV absorption at a wavelength of 280 nm. Conditions for processing body fluids for analysis were optimised using organic extraction techniques with proxyphylline incorporated as an internal standard. Maximum recovery of urine metabolites required the formation of ion-pair complex with tetrabutyl-ammonium. hydrogen sulphate. Serum caffeine levels determined by HPLC and a radioimmunoassay procedure showed good agreement. Furthermore, caffeine concentrations in saliva, following oral ingestion of caffeine, correlated well with corresponding values found in serum. An assessment of the consumption of caffeinated beverages in a local population indicated that the dietary intake of caffeine in the U.K. is significantly higher than that previously reported for American and Canadian populations. Measurement of serum caffeine levels in non-pregnant subjects showed a mean value of 2.42 mg/l; 6% of the values were in excess of 5 mg/l which is comparable to the average peak level found following a 250 mg oral dose of caffeine. Reference ranges are established for serum and salivary pharmacokinetic data and recoveries of metabolites from urine of normal volunteers who received oral doses of caffeine. In addition the electrophysiological and psychopharmacological responses to oral doses of caffeine are reported following a collaborative study with the Institute of Psychiatry, London. Evidence for alterations in the biotransformation of caffeine during pregnancy was obtained by comparing urine metabolite concentrations in pregnant women, receiving a known dietary intake of caffeine, with values obtained for a non-pregnant control group. It is suggested that hormonal influences on the hepatic drug metabolising enzymes may be implicated. Whilst pharmacologically significant concentrations of caffeine and its metabolites were detected in samples of maternal serum, cord blood and breast milk, no evidence was found to relate caffeine levels in the newborn infant with the onset of attacks of jitteriness or neonatal apnoea. In a study of caffeine elimination in chronic liver disease, the clearance of caffeine in compensated cirrhotic patients was similar to that of normal controls. However for patients with decompensated liver disease, significant levels of impairement were found in both serum and salivary caffeine clearance. This change in the disposition of caffeine was also reflected in the profiles of it metabolites excreted in the urine. Since the biotransformation pattern of caffeine in these patients was shown to be normal, this impairement of caffeine clearance could be attributed to a reduction in intrinsic clearance resulting from a reduced mass of viable hepatocytes. Preliminary findings indicated that salivary caffeine clearance measurements might provide an accurate means of assessing the extent of hepato-cellular dysfunction

Lyophilisation of lentiviral pseudotypes for the development and distribution of virus neutralisation assay kits for rabies, Marburg and influenza viruses

Purpose: Some conventional serological assays can accurately quantify neutralising antibody responses raised against epitopes on virus glycoproteins, enabling mass vaccine evaluation and serosurveillance studies to take place. However, these assays often necessitate the handling of wild-type virus in expensive high biosafety laboratories, which restricts the scope of their application, particularly in resource-deprived areas. A solution to this issue is the use of lentiviral pseudotype viruses (PVs)—chimeric, replication-deficient virions that imitate the binding and entry mechanisms of their wild-type equivalents. Pseudotype virus neutralisation assays (PVNAs) bypass high biosafety requirements and yield comparable results to established assays. This study explores the potential for using lyophilisation of pseudotypes as a cost-effective, alternative means for production, distribution and storage of a PVNAbased diagnostic kit. Methods & Materials: Rabies, Marburg and H5 subtype Influenza virus pseudotypes were each suspended in cryoprotectant solutions of various molarities and subjected to freeze-drying before incubation at a variety of temperatures, humidities and time periods. Samples were then employed in antibody neutralisation assays using specific sera. Results: High levels of PV titre were retained post-lyophilisation, with acceptable levels of virus activity maintained even after medium-term storage in tropical conditions. Also, the performance of PVs in neutralisation assays was not affected by the lyophilisation process. Conclusion: These results confirm the viability of a freeze-dried PVNA-based diagnostic kit, which could considerably facilitate in-field serology for a number of clinically important viruses

The Individual Recovery Outcomes Counter:preliminary validation of a personal recovery measure

Aims and methodThe Individual Recovery Outcomes Counter (I.ROC) is to date the only recovery outcomes instrument developed in Scotland. This paper describes the steps taken to initially assess its validity and reliability, including factorial analysis, internal consistency and a correlation benchmarking analysis.ResultsThe I.ROC tool showed high internal consistency. Exploratory factor analysis indicated a two-factor structure comprising intrapersonal recovery (factor 1) and interpersonal recovery (factor 2), explaining between them over 50% of the variance in I.ROC scores. There were no redundant items and all loaded on at least one of the factors. The I.ROC significantly correlated with widely used existing instruments assessing both personal recovery and clinical outcomes.Clinical implicationsI.ROC is a valid and reliable measure of recovery in mental health, preferred by service users when compared with well-established instruments. It could be used in clinical settings to map individual recovery, providing feedback for service users and helping to assess service outcomes.</p

AFM imaging and plasmonic detection of organic thin-films deposited on nanoantenna arrays

In this study, atomic force microscopy (AFM) imaging has been used to reveal the preferential deposition of organic thin-films on patterned nanoantenna array surfaces - identifying the localised formation of both monolayer and multilayer films of octadecanethiol (ODT) molecules, depending on the concentration of the solutions used. Reliable identification of this selective deposition process has been demonstrated for the first time, to our knowledge. Organic thin-films, in particular films of ODT molecules, were deposited on plasmonic resonator surfaces through a chemi-sorption process - using different solution concentrations and immersion times. The nanoantennas based on gold asymmetric-split ring resonator (A-SRR) geometries were fabricated on zinc selenide (ZnSe) substrates using electron-beam lithography and the lift-off technique. Use of the plasmonic resonant-coupling technique has enabled the detection of ODT molecules deposited from a dilute, micromolar (1 M) solution concentration - with attomole sensitivity of deposited material per A-SRR – a value that is three orders of magnitude lower in concentration than previously reported. Additionally, on resonance, the amplitude of the molecular vibrational resonance peaks is typically an order of magnitude larger than that for the non-resonant coupling. Fourier-transform infrared (FTIR) spectroscopy shows molecule specific spectral responses – with magnitudes corresponding to the different film thicknesses deposited on the resonator surfaces. The experimental results are supported by numerical simulation

The use of equine influenza pseudotypes for serological screening

Standard assays used for influenza serology present certain practical issues, such as inter-laboratory variability, complex protocols and the necessity for handling certain virus strains in high biological containment facilities. In an attempt to address this, avian and human influenza HA pseudotyped retroviruses have been successfully employed in antibody neutralization assays. In this study we generated an equine influenza pseudotyped lentivirus for serological screening. This was achieved by co-transfection of HEK293T cells with plasmids expressing the haemagglutinin (HA) protein of an H3N8 subtype equine influenza virus strain, HIV gag-pol and firefly luciferase reporter genes and harvesting virus from supernatant. In order to produce infective pseudotype particles it was necessary to additionally co-transfect a plasmid encoding the TMPRSS2 endoprotease to cleave the HA. High titre pseudotype virus (PV) was then used in PV antibody neutralization assays (PVNAs) to successfully distinguish between vaccinated and non-vaccinated equines. The sera were also screened by single radial haemolysis (SRH) assay. There was a 65% correlation between the results of the two assays, with the PVNA assay appearing slightly more sensitive. Future work will extend the testing of the PVNA with a larger number of serum samples to assess sensitivity/specificity, inter/intra-laboratory variability and to define a protective titre

Deposition of Organic Molecules on Gold Nanoantennas for Sensing

The deposition of organic molecules on gold nanoantennas is reported through chemisorption for sensing in the midinfrared (mid-IR) spectral range. The specific nanostructures are gold asymmetric-split ring resonators (A-SRRs) based on circular-geometry with two different ‘arc’ lengths. The plasmonic resonant coupling technique was used to match the vibrational responses of the targeted molecules for their enhanced detection. Gold nanostructures are functionalised through chemisorption of octadecanethiol (ODT) in ethanol solution. The molecular vibrational responses were measured using a microscope coupled Fourier Transform Infrared (FTIR) spectroscopy. The experimental findings are closely supported using FDTD simulation. The modified nanoantennas surfaces are capable of supporting wide range of organic-sensing applications