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The Birmingham Solar Oscillations Network (BiSON) observes acoustic oscillations of the Sun. The dominant noise source is caused by fluctuations of Earth’s atmosphere, and BiSON seeks to mitigate this effect by combining multiple rapid observations in alternating polarization states. Current instrumentation uses bespoke Pockels-effect cells to select the polarization state. Here, we investigate an alternative off-the-shelf solution, a liquid crystal (LC) retarder, and discuss the potential impact of differences in performance. We show through electrical simulation of the photodiode-based detectors, and assessment of both types of polarization device, that although the switching rate is slower the off-the-shelf LC retarder is a viable replacement for a bespoke Pockels-effect cell. The simplifications arising from the use of off-the-shelf components allow easier and quicker instrumentation deployment.

Mars is one of the prime candidates in the search for extraterrestrial life. At the most comparable terrestrial Martian analogue sites, life often occurs in endolithic form; i.e. hiding below the surface. To detect biomarkers of endolithic life, the two most promising options are drilling or measuring through the surface, the latter being less invasive and preferable. Raman spectroscopy is an established chemical identification method, and advanced Raman modes have been developed for sub-surface analysis. Time-resolved Raman spectroscopy (TRRS), based on picosecond pulsed excitation and a gated intensified charge-coupled device (ICCD) detector, adds the capability of fluorescence suppression and depth selection. This paper focuses on the separation of layers with time differences that are much smaller than the 200 ps full width at half-maximum gating time of the detector. As an analogue for endolithic life on Mars, Deinococcus radiodurans bacteria were measured through a 2.5 mm and 7.5 mm top layer of translucent calcite. TRRS spectra were recorded in a backscattering geometry, while stepwise increasing the detector delay in 25 ps steps. Through both of these layers, the Raman spectrum of the bacteria’s carotenoids could be detected. Global analysis was used to model a complete time-resolved spectrum of the sample. Using this analysis, the signals could be separated into three components: mineral Raman, bacterial Raman and bacterial fluorescence. The model also corrects for gating differences across the horizontal axis of the ICCD camera. With this approach well-separated Raman spectra were obtained even for the 2.5 mm calcite layer despite the temporal separation of approximately 20 ps , which is much shorter than the 200 ps detector gating time. TRRS could be a suitable approach for non-invasive detection of extraterrestrial subsurface biomarkers.

We describe a new spectrophotometer for the Birmingham Solar Oscillations Network (BiSON), based on a next generation observation platform, BiSON:NG, a significantly miniaturised system making use of inexpensive consumer-grade hardware and off-the-shelf components, where possible. We show through system modelling and simulation, along with a summer observing campaign, that the prototype instrument produces data on the Sun's low-degree acoustic (p-mode) oscillations that are of equal quality and can be seamlessly integrated into the existing network. Refreshing the existing ageing hardware, and the extended observational network potential of BiSON:NG, will secure our ongoing programme of high-quality synoptic observations of the Sun's low-degree oscillations (e.g., for seismic monitoring of the solar cycle at a "whole Sun" level)., 8 pages, 8 figures, 1 table. Accepted by RAS Techniques and Instruments: 2022 September 26

Context. Increasing the number of detected exoplanets is far from anecdotal, especially for long-period planets that require a long duration of observation. More detections imply a better understanding of the statistical properties of exoplanet populations, and detailed modelling of their host stars also enables thorough discussions of star–planet interactions and orbital evolution of planetary systems. Aims. In the context of the discovery of a new planetary system, we aim to perform a complete study of HD 29399 and its companion by means of radial-velocity measurements, seismic characterisation of the host-star, and modelling of the orbital evolution of the system. Methods. High-resolution spectra of HD 29399 were acquired with the CORALIE spectrograph mounted on the 1.2-m Swiss telescope located at La Silla Observatory (Chile) as part of the CASCADES survey. We used the moments of the cross-correlation function profile as well as the photometric variability of the star as diagnostics to distinguish between stellar and planetary-induced signals. To model the host star we combined forward modelling with global and local minimisation approaches and inversion techniques. We also studied the orbital history of the system under the effects of both dynamical and equilibrium tides. Results. We present the detection of a long-period giant planet. Combining these measurements with photometric observations by TESS, we are able to thoroughly model the host star and study the orbital evolution of the system. We derive stellar and planetary masses of 1.17 ± 0.10 M⊙ and 1.59 ± 0.08 MJup, respectively, and an age for the system of 6.2 Gyr. We show that neither dynamical nor equilibrium tides have been able to affect the orbital evolution of the planet. Moreover, no engulfment is predicted for the future evolution of the system.

After a century of semi-restricted floodplain development, Southern Alberta, Canada, was struck by the devastating 2013 Flood. Aging infrastructure and limited property-level floodproofing likely contributed to the $4–6 billion (CAD) losses. Following this catastrophe, Alberta has seen a revival in flood management, largely focused on structural protections. However, concurrent with the recent structural work was a 100,000+ increase in Calgary's population in the 5 years following the flood, leading to further densification of high-hazard areas. This study implements the novel Stochastic Object-based Flood damage Dynamic Assessment (SOFDA) model framework to quantify the progression of the direct-damage flood risk in a mature urban neighborhood after the 2013 Flood. Five years of remote-sensing data, property assessment records, and inundation simulations following the flood are used to construct the model. Results show that in these 5 years, vulnerability trends (like densification) have increased flood risk by 4%; however, recent structural mitigation projects have reduced overall flood risk by 47% for this case study. These results demonstrate that the flood management revival in Southern Alberta has largely been successful at reducing flood risk; however, the gains are under threat from continued development and densification absent additional floodproofing regulations.

The COVID-19 pandemic has increased the worldwide production and use of disposable plastic face masks (DPFMs). The release of micro- and nanopollutants into the environment is one of the impacts derived from regulated and unregulated disposal of DPFMs. This study focuses on the emission of pollutants from medical-grade DPFMs when submerged in deionized water, simulating regulated and unregulated disposal of these masks. Three brands of FFP2 and three brands of Type IIR medical masks, produced in various countries (UK, EU, and non-EU), were investigated. Field emission gun scanning electron microscopy (FEG-SEM) was used to obtain high-resolution images of the micro- and nanoparticles, and 0.02 μm pore size inorganic membranes were used to retain and subsequently analyze smaller particle size nanoparticles (20 nm) released from the DPFMs. Particles and fibers in the micro- and nanoscale were found in all six DPFM brands. SEM with energy-dispersive spectroscopy analysis revealed the presence of particles containing different heavy metals like lead, mercury, and arsenic. Inductively coupled plasma mass spectrometry analysis confirmed the leaching of trace heavy metals to water (antimony up to 2.41 μg/L and copper up to 4.68 μg/L). Liquid chromatography-mass spectrometry analysis identified polar organic species related to plastic additives and contaminants such as polyamide-66 monomers and oligomers.

Context. Current and future space-based observatories such as the Transiting Exoplanet Survey Satellite (TESS) and PLATO are set to provide an enormous amount of new data on oscillating stars, and in particular stars that oscillate similar to the Sun. Solar-like oscillators constitute the majority of known oscillating stars and so automated analysis methods are becoming an ever increasing necessity to make as much use of these data as possible. Aims. Here we aim to construct an algorithm that can automatically determine if a given time series of photometric measurements shows evidence of solar-like oscillations. The algorithm is aimed at analyzing data from the TESS mission and the future PLATO mission, and in particular stars in the main-sequence and subgiant evolutionary stages. Methods. The algorithm first tests the range of observable frequencies in the power spectrum of a TESS light curve for an excess that is consistent with that expected from solar-like oscillations. In addition, the algorithm tests if a repeating pattern of oscillation frequencies is present in the time series, and whether it is consistent with the large separation seen in solar-like oscillators. Both methods use scaling relations and observations which were established and obtained during the CoRoT, Kepler, and K2 missions. Results. Using a set of test data consisting of visually confirmed solar-like oscillators and nonoscillators observed by TESS, we find that the proposed algorithm can attain a 94.7% true positive (TP) rate and a 8.2% false positive (FP) rate at peak accuracy. However, by applying stricter selection criteria, the FP rate can be reduced to ≈ 2%, while retaining an 80% TP rate.

Asteroseismology is an exceptional tool for studying stars by using the properties of observed modes of oscillation. So far the process of performing an asteroseismic analysis of a star has remained somewhat esoteric and inaccessible to non-experts. In this software paper we describe PBjam, an open-source Python package for analyzing the frequency spectra of solar-like oscillators in a simple but principled and automated way. The aim of PBjam is to provide a set of easy-to-use tools to extract information about the radial and quadrupole oscillations in stars that oscillate like the Sun, which may then be used to infer bulk properties such as stellar mass, radius and age or even structure. Asteroseismology and its data analysis methods are becoming increasingly important as space-based photometric observatories are producing a wealth of new data, allowing asteroseismology to be applied in a wide range of contexts such as exoplanet, stellar structure and evolution, and Galactic population studies., 12 Pages, 4 figures. Accepted for publication in AJ. Associated software available at https://doi.org/10.5281/zenodo.4300079

The Birmingham Solar Oscillations Network (BiSON) is a collection of ground-based automated telescopes observing oscillations of the Sun. The network has been operating since the early 1990s. We present development work on a prototype next generation observation platform, BiSON:NG, based almost entirely on inexpensive off-the-shelf components, and where the footprint is reduced to a size that can be inexpensively installed on the roof of an existing building. Continuous development is essential in ensuring that automated networks such as BiSON are well placed to observe the next solar cycle and beyond., Comment: 12 pages, 6 figures. Accepted by SPIE Software and Cyberinfrastructure for Astronomy VI: 2020 December 13

Resonance scattering techniques are often used to study the properties of atoms and molecules. The Birmingham Solar Oscillations Network (BiSON) makes use of Resonance Scattering Spectroscopy by applying the known properties of potassium vapour to achieve ultra-precise Doppler velocity observations of oscillations of the Sun. We present a model of the resonance scattering properties of potassium vapour which can be used to determine the ideal operating vapour temperature and detector parameters within a spectrophotometer. The model is validated against a typical BiSON vapour cell using a tunable diode laser, where the model is fitted to observed absorption profiles at a range of temperatures. Finally we demonstrate using the model to determine the effects of varying scattering detector aperture size, and vapour temperature, and again validate against observed scattering profiles. Such information is essential when designing the next generation of BiSON spectrophotometers (BiSON:NG), where the aim is to make use of off-the-shelf components to simplify and miniaturise the instrumentation as much as practical., 18 pages, 11 figures. Accepted by Journal of Physics B: 2020 February 11

The properties of the acoustic modes are sensitive to magnetic activity. The unprecedented long-term Kepler photometry, thus, allows stellar magnetic cycles to be studied through asteroseismology. We search for signatures of magnetic cycles in the seismic data of Kepler solar-type stars. We find evidence for periodic variations in the acoustic properties of about half of the 87 analysed stars. In these proceedings, we highlight the results obtained for two such stars, namely KIC 8006161 and KIC 5184732., Comment: 4 pages, 1 figure, to appear in the Proceedings of the IAUS340

[ABRIDGED] The purpose of this work is to evaluate how several elements produced by different nucleosynthesis processes behave with stellar age and provide empirical relations to derive stellar ages from chemical abundances. We derive different sets of ages using Gaia parallaxes for a sample of more than 1000 FGK dwarf stars for which he have spectra from the HARPS-GTO program. We analyze the temporal evolution of different abundance ratios to find the best chemical clocks. We find that [$\alpha$/Fe] ratio (average of Mg, Si and Ti), [O/Fe] and [Zn/Fe] are good age proxies with a lower dispersion than the age-metallicity dispersion. Several abundance ratios present a significant correlation with age for chemically separated thin disk stars (i.e. low-$\alpha$) but in the case of the chemically defined thick disk stars (i.e. high-$\alpha$) only the elements Mg, Si, Ca and TiII show a clear correlation with age. We find that the thick disk stars are more enriched in light-s elements than thin disk stars of similar age. The maximum enrichment of s-process elements in the thin disk occurs in the youngest stars which in turn have solar metallicity. The slopes of the [X/Fe]-age relations are quite constant for O, Mg, Si, Ti, Zn, Sr and Eu regardless of the metallicity. However, this is not the case for Al, Ca, Cu and most of the s-process elements, which display very different trends depending on the metallicity. This demonstrates the limitations of using simple linear relations based on certain abundance ratios to obtain ages for stars of different metallicities. Finally, we show that by using 3D relations with a chemical clock and two stellar parameters (either Teff, [Fe/H] or stellar mass) we can explain up to 89% of age variance in a star. A similar result is obtained when using 2D relations with a chemical clock and one stellar parameter, being up to a 87% of the variance explained., Comment: accepted for publication in A&A, version after language revision

Asteroseismology provides global stellar parameters such as masses, radii or surface gravities using the mean global seismic parameters as well as the effective temperature for thousands of low-mass stars $(0.8 M_\odot, Comment: 9 pages, 4 figures

The pattern of migrating zonal flow bands associated with the solar cycle, known as the torsional oscillation, has been monitored with continuous global helioseismic observations by the Global Oscillations Network Group, together with those made by the Michelson Doppler Imager onboard the Solar and Heliosepheric Observatory and its successor the Helioseismic and Magnetic Imager onboard the Solar Dynamics Observatory, since 1995, giving us nearly two full solar cycles of observations. We report that the flows now show traces of the mid-latitude acceleration that is expected to become the main equatorward-moving branch of the zonal flow pattern for Cycle 25. Based on the current position of this branch, we speculate that the onset of widespread activity for Cycle 25 is unlikely to be earlier than the middle of 2019., Comment: 8 pages, 5 figures, accepted by ApJL 5 July 2018

The study was supported by a Wellcome Trust (London, UK) Clinical PhD Fellowship awarded to DS (086757/Z/08/A) and the Malawi Liverpool Wellcome Trust (MLW) Core grant from the Wellcome Trust. SETTING: Vitamin D deficiency is common in African adults with tuberculosis (TB), and may be exacerbated by the metabolic effects of anti-tuberculosis drugs and antiretroviral therapy (ART). It is unclear whether vitamin D deficiency influences response to antituberculosis treatment. OBJECTIVES : To describe risk factors for baseline vitamin D deficiency in Malawian adults with pulmonary TB, assess the relationship between serum 25-hydroxy vitamin D (25[OH]D) concentration and treatment response, and evaluate whether the administration of anti-tuberculosis drugs and ART is deleterious to vitamin D status during treatment. DESIGN: A prospective longitudinal cohort study. RESULTS : The median baseline 25(OH)D concentration of the 169 patients (58% human immunodeficiency virus [HIV] infected) recruited was 57 nmol/l; 47 (28%) had vitamin D deficiency (

We present a set of 87 RAVE stars with detected solar like oscillations, observed during Campaign 1 of the K2 mission (RAVE K2-C1 sample). This dataset provides a useful benchmark for testing the gravities provided in RAVE Data Release 4 (DR4), and is key for the calibration of the RAVE Data Release 5 (DR5). In the present work, we use two different pipelines, GAUFRE (Valentini et al. 2013) and Sp_Ace (Boeche & Grebel 2016), to determine atmospheric parameters and abundances by fixing log(g) to the seismic one. Our strategy ensures highly consistent values among all stellar parameters, leading to more accurate chemical abundances. A comparison of the chemical abundances obtained here with and without the use of seismic log(g) information has shown that an underestimated (overestimated) gravity leads to an underestimated (overestimated) elemental abundance (e.g. [Mg/H] is underestimated by ~0.25 dex when the gravity is underestimated by 0.5 dex). We then perform a comparison between the seismic gravities and the spectroscopic gravities presented in the RAVE DR4 catalogue, extracting a calibration for log(g) of RAVE giants in the colour interval 0.50, Comment: 20 pages, 27 figures, accepted

We report here on our search for excess power in photometry of Neptune collected by the K2 mission that may be due to intrinsic global oscillations of the planet Neptune. To conduct this search, we developed new methods to correct for instrumental effects such as intrapixel variability and gain variations. We then extracted and analyzed the time-series photometry of Neptune from 49 days of nearly continuous broadband photometry of the planet. We find no evidence of global oscillations and place an upper limit of $\sim$5 ppm at 1000 \uhz\ for the detection of a coherent signal. With an observed cadence of 1-minute and point-to-point scatter less than 0.01\%, the photometric signal is dominated by reflected light from the Sun, which is in turn modulated by atmospheric variability of Neptune at the 2\% level. A change in flux is also observed due to the increasing distance between Neptune and the K2 spacecraft, and solar variability with convection-driven solar p modes present., Comment: 31 pages, 6 figure, accepted for publication in AJ

SUMMARY To test the hypothesis that administration of a non-steroidal anti-inflammatory drug formulated as a pro-drug, inactive as a cyclooxygenase inhibitor until after absorption, might cause less intestinal damage than conventional non-steroidal anti-inflammatory drugs, intestinal permeation to 51Cr-EDTA and mannitol was assessed in healthy volunteers before and after oral treatment for 1 week with either the pro-drug sulindac or the conventional non-steroidal anti-inflammatory drug indomethacin. Indomethacin, but not sulindac, significantly increased intestinal permeation to 51Cr-EDTA and reduced haemoglobin and haematocrit; neither affected mannitol permeation.

Sustainable reservoir management is essential to ensure the productivity of agriculture and to adapt to a changing climate. Despite progress in reservoir modelling and management with the improvement of computer capabilities and the development of optimization methods, managers and decision-makers still face the challenge of applying the output of more-theoretical optimization models to real-world reservoir operations. This research analyzes reservoir managers’ perspectives in Alberta’s heavily-allocated South Saskatchewan River basin, in order to improve understanding of the behaviour of reservoir operators under different climatic and hydrological conditions. The method involves in-person interviews with twelve water managers of Southern Alberta’s irrigation districts. The data collected suggest that seniority-based allocation priorities are generally not strictly applied. Instead, cooperation between districts and between irrigators within a district indicates that water allocations are driven principally by the infrastructure capacity on a river-basin-scale basis. Of additional importance is recognition of the “day-by-day” approach adopted by all water managers interviewed who will “never sacrifice today for tomorrow”. Moreover, water managers do not apply annual or multi-year water deficit-distribution strategies, but instead impose variable water rationing for all irrigators at the beginning of a growing season. The contribution of this research is to provide real-world data and a better understanding of water managers’ perspectives that may lead to more valuable outcomes from modelling studies, and results that may be more readily adopted by water managers.

Small-angle X-ray scattering profiles of ethylene and styrene ionomers were studied to clarify the structure of ionic aggregates as a function of humidity or temperature. The intensity and position of ionic cluster peaks were observed for ionomers with a certain degree of neutralization. The intensity of the ionic cluster peak for the ethylene ionomer increased with increasing relative humidity, but it decreased for the styrene ionomer. With increasing humidity, the position of the ionic cluster peak shifted to smaller angles for both ionomers. The size of the ionic aggregates and the closest approach distance between the aggregates were analyzed, and the results varied with humidity for both ionomers. The size did not vary markedly with a change in temperature, whereas the closest approach distance and number of ionic aggregates changed slightly with the melting temperature of the ethylene ionomer and the glass-transition temperature of the styrene ionomer. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 831–839, 2002

This article considers the electrostrictive response of an ideal polar rubber in which each random link carries a dipole which is constrained to remain perpendicular to the link but is free to rotate about it. It thus mimics typical polar polymers with dipoles essentially perpendicular to the chain backbone and which rotate preferentially about the local chain axis (Stockmayer type B). In such materials, there is a genuine interplay between mechanical deformation and the electrical permittivity since an applied strain can produce preferential segmental orientation, align dipole rotation axes, and thus cause a change in permittivity. Though this is a plausible mechanism of electrostriction in polar rubbers, the quantitative analysis presented in this article suggests that the effect makes only a small contribution to the observed deformation of actuators based on typical polar rubber films with compliant electrodes.

Molecular dynamics simulations were performed for a series of AB2 dendrimer models, in explicit-solvent solutions where the ratio Rg/L (Rg is the radius of gyration and L the size of the simulation box) is kept between 0.15⩽Rg/L⩽0.2. Results on static properties (size, shape, density profiles) are in good agreement with recent theoretical and experimental studies. Dynamic properties are systematically investigated on the local and entire molecule length scale. The dynamic characteristics of the examined models capture the qualitative behavior observed experimentally in dendrimer molecules. The systematic and comparative nature of this study affords detailed insight into the origin and the relative contribution of different relaxational mechanisms in the observed dynamic spectra.

comparable with those of alkali basalts. Rb–Sr mica ages, >72 Ma, demonstrate that kimberlite volcanism occurred between 5 and 10 my after the inferred passage of the Discovery plume beneath the Gibeon region. Sr–Nd–Pb isotope relationships of the kimberlite and megacrysts are distinct from that of the inferred INTRODUCTION plume and hence it is argued that the plume contributed little mass Kimberlites have been subdivided into Group I (basaltic) to the volcanism. The megacryst suite has a strong DUPAL Pb and Group II (micacous) on the basis of their petisotope signature. Two hypotheses can explain the genesis of the rography and geochemistry (Smith, 1983). Low Crkimberlite and megacryst suites. The first is that the DUPAL Pb megacrysts are a characteristic of the majority of Group isotope signature is derived from the lower mantle. The megacryst I kimberlites. These megacrysts, also termed discrete suite therefore represents the high-pressure crystallization product of nodules, comprise large (>1 cm), rounded, fractured deep plume-related magmatism. This magmatism interacts with the single crystals. Mutual inclusions and lamella intersub-continental lithospheric mantle (SCLM) to produce the kim- growths define a suite that consists predominantly of berlite magmatism. Alternatively, fluid-rich melts derived from pyrope garnet, magnesian ilmenite (picro-ilmenite), the Discovery plume migrated under the lithosphere and become clinopyroxene (sub-calcic to varying degrees), orthoconcentrated in areas that were recently thermally perturbed as- pyroxene, zircon and possibly olivine. These minerals thenosphere, causing small degrees of melting and kimberlite mag- are compositionally distinct from those found in asmatism. In this scenario the megacrysts represent polybaric sociated peridotite xenoliths, which coupled with differfractionation products from ‘basaltic’ asthenospheric-derived melts ent deformation rules out derivation from peridotites that ponded at the base of, but underwent interaction with, the sub- or eclogites (e.g. Mitchell, 1987). The association with continental lithosphere. Storage of the megacrysts for an extended kimberlite, plus the homogeneity of single crystals, which can be up to 40 cm across, led workers to period (>10 and

A quantitative study was undertaken of the anisotropy of low-strain mechanical behavior for specially oriented polyethylene with controlled crystalline and lamellar orientation. The samples were prepared by the die drawing of injection-molded rods of polyethylene and annealing. This produced a parallel lamellar structure for which a simple, three-dimensional composite laminate model could be used to calculate the expected anisotropy. Experimental data, including X-ray strain measurements of the lateral crystalline elastic constants, showed good quantitative agreement with the model prediction. The X-ray strain measurements confirmed that the amorphous regions exert large constraints on the crystalline phase in the lateral directions, where an order of magnitude difference was found between the measured apparent lateral crystalline compliances in the lamellar-stack sample and the expected values for a perfect crystal. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 755–764, 2000

Abstract Ice loads on buried pipelines through ice-soil-pipeline interaction is a field with limited industry experience. As exploration in Arctic and cold climate regions increases it is of great importance to understand and to design for the challenges offshore pipelines must be able to withstand in these harsh areas with a suitable level of confidence. Together with thirteen industry partners, DNV has carried out a joint industry project in order to better define and therefore understand the Arctic specific challenges to pipelines. This project has developed initial industry guidelines for offshore pipelines in cold climate regions, in general and for ice scour in particular. A major design issue for Arctic offshore pipelines in shallow water is ice keels gouging the seabed and imposing loads on the pipeline through ice-soil-pipeline interaction. The industry has somewhat limited experience with deep ice gouges and ice keels interacting with buried pipelines. A common practice has been to bury the pipeline well below the deepest registered gouge mark in the relevant geographical area with the objective to limit the pipeline response. In order to render future projects in regions with severe ice gouges economically feasible whilst still being sufficiently safe there is a need to utilise modern design principles based upon statistical methods, advanced FE models calibrated to ice gouging tests, limit state design principles and strain based design. The ICE PIPE JIP provided the introduction of a more systematic approach for the identification, quantification and ranking of design uncertainties, and how this could be adopted to existing pipeline design methodologies and criteria. This paper presents some pertinent results and recommendations from the ICEPIPE JIP. The paper presents a sample case study for how the assessment of some elements of statistical uncertainty can be used in the definition of the 100 year return period ice gouge depth. This paper highlights one methodology for approaching this and it is emphasised that not all the steps that would be required in design are included in this brief paper. A discussion on the use of advanced FE tools in the ICE PIPE JIP is also presented.

Different genomic DNA samples and primer sequences were evaluated in urease ( ure ) gene-based PCR assays for rapid identification of Helicobacter pylori . Purified DNA and heated (boiled) cell lysates of bacterial cultures from gastric biopsies were tested with three primer sets for unique internal ure A, ure A + B and ure C sequences. The heated-lysates of H. pylori were quick to prepare but more frequently gave unexpected variable or negative PCR results than assays performed on purified DNA, which were highly specific and reproducible for all three primer sets. Results indicated that sensitivity of the assay was linked to the size of the amplified target region rather than any particular strain feature, with the small 294 bp ure C product providing more accurate assays with heated-lysates of H. pylori . We strongly recommend that negative results in any PCR assay should be checked on purified DNA to exclude the possibility of a false-negative result.

Biopsy of a suspected oral squamous cell carcinoma (SCC) is important for diagnosis. Concerns have been raised about the potential for tumour spread by incisional biopsy techniques. This study aimed to investigate the five-year survival and recurrence of oral SCC after incisional and excisional biopsy in total population data available from the Western Australian Cancer Registry (WACR).Total population data from the WACR, comprising all primary oral SCC cases diagnosed between 1990 and 1999, were examined. Information extracted included date of birth, gender, biopsy date, biopsy type, disease stage (TNM classification), disease site, date of recurrence and date of death. Records were excluded if the diagnosis was fine needle aspiration based, was not that of oral SCC and if a history was noted of another malignant neoplasm. Incisional and excisional biopsy cases were compared for five-year survival, adjusting for disease stage.No association was found between biopsy type and five-year survival or recurrence amongst individuals with Stage I or II disease.In this study, biopsy type was not associated with survival of oral SCC patients with Stage I or II disease, adding to the evidence that incisional biopsy of oral SCC can be a safe procedure.

A previously described method for mannitol in urine has been modified and improved. End product inhibition by fructose in the mannitol dehydrogenase method for mannitol has been minimized; the assay is linear over a sample mannitol concentration range of 0–12 mmol/L; no significant interference from other sugars or sugar alcohols could be demonstrated. The method is precise (within-batch CV < 1%), rapid and shows excellent recovery of mannitol in spiked samples. Comparison with gas liquid chromatography shows excellent correlation ( r = 0 · 994) between the two methods.

Current treatment for pulmonary tuberculosis (TB) might be shortened by the incorporation of fluoroquinolones (FQs).A Phase II study aimed to assess the sterilising activities of three novel regimens containing FQs before a Phase III trial of a 4-month regimen containing gatifloxacin (GFX).A total of 217 newly diagnosed smear-positive patients were randomly allocated to one of four regimens: isoniazid (INH), pyrazinamide and rifampicin (RMP) with either ethambutol, GFX, moxifloxacin (MFX) or ofloxacin (OFX) for 2 months. At the end of the study, RMP and INH were given for 4 months. The rates of elimination of Mycobacterium tuberculosis were compared in the regimens using non-linear mixed effects modelling of the serial sputum colony counts (SSCC) during the first 8 weeks.After adjustment for covariates, MFX substitution appeared superior during the early phase of a bi-exponential fall in colony counts, but significant and similar acceleration of bacillary elimination during the late phase occurred with both GFX and MFX (P = 0.002). Substitution of OFX had no effect. These findings were supported by estimates of time to conversion, using Cox regression, but there were no significant differences in proportions culture-negative at 8 weeks.GFX and MFX improve the sterilising activity of regimens and might shorten treatment; their progression into Phase III trials therefore seems warranted.

Various methods have been used to estimate the prevalence of Mycobacterium tuberculosis infection from tuberculin survey data. All are complicated by prior sensitisation to environmental mycobacteria and bacille Calmette-Guérin (BCG) vaccination. Mixture analysis has recently been proposed as a means of overcoming misclassification and improving infection prevalence estimates.To compare conventional and mixture model estimates of M. tuberculosis infection prevalence.Mixture models with two or three univariate normal components were fitted to the results of 53 909 tuberculin tests conducted in northern Malawi during 1980-1984. Data were stratified by BCG status, sex and age and corrected for digit preference. Prevalence estimates derived from mixture models were compared with those of conventional methods.The optimal model was age-dependent, with three- and one-component solutions preferred in younger and older age groups, respectively. In contrast with findings from elsewhere, a component corresponding to BCG vaccination was indistinguishable from that attributable to environmental mycobacterial exposure, and infection prevalence estimates in younger individuals with a BCG scar were inflated, irrespective of the method used.The validity of infection prevalence and incidence estimates based on mixture modelling is probably locale-dependent, and the assumptions underlying mixture models may not realistically reflect underlying immunological processes.

We have carried out molecular dynamics simulations of methyl group torsional librations in glassy polyisoprene at 150 K using the Insight and Discover codes from MSI Inc. with the Polymer Consortium Force Field. The model system was built using the MSI Amorphous Cell construction protocol with periodic boundary conditions. During the NVT molecular dynamics runs, the dihedral angle of each of the methyl groups and the positions of all of the atoms were recorded at 10 fs intervals. The results obtained support the generally assumed threefold approximation for the single particle methyl group potential. The density of states for methyl group torsional librations, as calculated from the time evolution of the dihedral angles, agrees quite well with previous inelastic neutron scattering results and shows a broad feature reflecting a distribution of potential barriers. This distribution is quantified in the framework of the threefold approximation. Performing similar simulations under different conditions for the nonbond interactions considered in the used force field, we conclude that the width of this distribution is mainly controlled by the nonbond interactions. Moreover, it turns out that these nonbond interactions also contribute significantly to the value of the average barrier for methyl group reorientation., F.A., A.A., and J.C. acknowledge the support given by the Spanish Ministry of Education (Project No. PB97-0638), the Government of the Basque Country (Projects No. PI-1998-20 and EX-1998-23), the University of the Basque Country (Project No UPV206.215-G20/98), Donostia International Physics Center, Gipuzkoako Foru Aldundia, and Iberdrola S.A.