Biochemical diagnosis of ventricular dysfunction in elderly patients in general practice: observational study

Objective: To investigate the usefulness of measuring plasma concentrations of B type natriuretic peptide in the diagnosis of left ventricular systolic dysfunction in an unselected group of elderly people. Design: Observational study. Setting: General practice with four centres in Poole, Dorset. Participants: 155 elderly patients aged 70 to 84 years. Main outcome measures: Diagnostic characteristics of plasma B type natriuretic peptide measured by radioimmunoassay as a test for left ventricular systolic dysfunction assessed by echocardiography. Results: The median plasma concentration of B type natriuretic peptide was 39.3 pmol/l in patients with left ventricular systolic dysfunction and 15.8 pmol/l in those with normal function. The proportional area under the receiver operator curve was 0.85. At a cut-off point of 18.7 pmol/l the test sensitivity was 92% and the predictive value 18%. Conclusions: Plasma concentration of B type natriuretic peptide could be used effectively as an initial test in a community screening programme and, possibly, using a low cut-off point, as a means of ruling out left ventricular systolic dysfunction. It is, however, not a good test to “rule in” the diagnosis, and access to echocardiography remains essential for general practitioners to diagnose heart failure early

A Four-Factor User Interaction Model for Content-Based Image Retrieval

In order to bridge the “Semantic gap”, a number of relevance feedback (RF) mechanisms have been applied to content-based image retrieval (CBIR). However current RF techniques in most existing CBIR systems still lack satisfactory user interaction although some work has been done to improve the interaction as well as the search accuracy. In this paper, we propose a four-factor user interaction model and investigate its effects on CBIR by an empirical evaluation. Whilst the model was developed for our research purposes, we believe the model could be adapted to any content-based search system

Prevalence and clinical characteristics of left ventricular dysfunction among elderly patients in general practice setting: cross sectional survey

Objective: To assess the prevalence and clinical characteristics of left ventricular dysfunction among elderly patients in the general practice setting by echocardiographic assessment of ventricular function. Design: Cross sectional survey. Setting: Four centre general practice in Poole, Dorset. Subjects: 817 elderly patients aged 70-84 years. Main outcomes: Echocardiographic assessment of left ventricular systolic function including measurement of ejection fraction by biplane summation method where possible, clinical symptoms, and signs of left ventricular dysfunction. Results: The overall prevalence of left ventricular systolic dysfunction was 7.5% (95% confidence interval 5.8% to 9.5%); mild dysfunction (5.0%) was considerably more prevalent than moderate (1.6%) or severe dysfunction (0.7%). Measurement of ejection fraction was possible in 82% of patients (n=667): in patients categorised as having mild, moderate, or severe dysfunction, the mean ejection fraction was 48% (SD 12.0), 38% (8.1), and 26% (7.9) respectively. At all ages the prevalence was much higher in men than in women (odds ratio 5.1, 95% confidence interval 2.6 to 10.1). No clinical symptom or sign was both sensitive and specific. In around half the patients with ventricular dysfunction (52%, 32/61) heart failure had not been previously diagnosed. Conclusions: Unrecognised left ventricular dysfunction is a common problem in elderly patients in the general practice setting. Appropriate treatment with angiotensin converting enzyme inhibitors has the potential to reduce hospitalisation and mortality in these patients, but diagnosis should not be based on clinical history and examination alone. Screening is feasible in general practice, but it should not be implemented until the optimum method of identifying left ventricular dysfunction is clarified, and the cost effectiveness of screening has been shown

Renormalisation Invariance and the Soft β\beta-Functions

We demonstrate that the soft supersymmetry-breaking terms in a N=1 theory can be linked by simple renormalisation group invariant relations which are valid to all orders of perturbation theory. In the special case of finite N=1 theories, the soft terms preserve finiteness to all orders.Comment: 9 pages, tex, Uses harvmac (big

Novel Approach to the Energy Analysis of Mine Cooling Strategies

The extraction of minerals and coal at increasing depth, employing higher-powered, mechanized machinery to increase production levels imposes an increased burden on the ability to maintain an acceptable mine climate. Any deterioration in the mine climate within working zones may adversely affect the health and safety of the workforce. The combination of the optimal design of the mine system layout, together with the selective application of suitable ventilation and cooling systems, may be used to control the climate within working zones. The adoption of mechanical cooling within mines is an expensive process in terms of both capital and operating costs. Therefore, as mechanized mining takes place at increased depth, the need to maintain or improve the mine climate becomes more expensive. Consequently, to decrease overhead costs, reduce energy consumption and meet current and future environmental obligations, it is essential to provide the mine operator with a method with which to determine the most cost effective and efficient mine cooling system. To perform this analysis it is necessary to have a good understanding of the energy balances governing both the operation and utilization of a cooling system. This paper introduces the application of a novel approach to energy analysis of mine cooling systems, with a combination of the concepts of exergy and composite curves. These methods are used extensively throughout chemical and process industries to increase energy efficiency and reduce capital and operating costs. An outline of the methods employed in the application of these techniques to the energy analysis of a mining cooling system is presented

Examination of inequivalent wetting on the crystal habit surfaces of RS-ibuprofen using grid-based molecular modelling

Synthonic engineering tools, including grid-based searching molecular modelling, are applied to investigate the wetting interactions of the solute and four crystallisation solvents (ethanol, ethyl acetate, acetonitrile and toluene) with the {100}, {001} and {011} forms of RS-ibuprofen. The grid-based methods, in particular the construction of a crystal slab parallel to a given plane in a coordinate system with one axis perpendicular to the surface, are defined in detail. The interaction strengths and nature (dispersive, hydrogen bonding (H-bonding) or coulombic forces) are related to the crystal growth rates and morphologies. The solute is found to interact strongest with the capping {011}, then the side {001} and weakest with the top {100} habit surfaces. The solute interactions with the {100} and {001} surfaces are found to be almost solely dominated by dispersive force contributions, whilst the same with the {011} surfaces are found to have a greater contribution from H-bonding and coulombic forces. The increased surface rugosity, at the molecular level of the {011} surfaces, results in a favourable docking site in a surface 'valley', not present in the {100} and {001} surfaces. The H-bonding solvents ethanol, acetonitrile and ethyl acetate are found to strongly interact with the {011} surfaces and weakly with the {001} surfaces, with the {011} interactions having a much greater contribution from H-bonding and coulombic forces. The interaction energies of the apolar and aprotic solvent toluene, with the {011} and {001} surfaces, are found to be very close. Toluene is found having slightly stronger interactions with the {001} than the {011} surfaces, which are all dominated by dispersive interactions. The ratio of the average energy of the top 100 solvent interactions with the {001} surface divided by the average energy of the top 100 interactions with the {011} surface is compared to the ratio of the experimentally measured growth rates of the same forms. In general, the interaction energy ratio is found to have an inverse ratio with the growth rates, implying that the solvents which are calculated to interact strongly with a particular surface are impeding the growth of that surface and reducing the growth rate, in turn impacting upon the final morphology of the material

Sustainable biomass production in agroforestry systems

Non-Peer ReviewedResearch conducted in 2007 through 2009 on the occasional biomass harvest from willow rings could provide balanced co-existence between agriculture and wetlands. This would provide biomass feedstock while preserving the wetland for future generations. The focus of the research will be on the sustainable production of biomass in agroforestry systems. The goals of this research project are to determine the impact of biomass harvest on re-growth of willow rings; evaluate the feasibility of mechanical harvest using a bio-baler; determine the biomass yield and production costs; and quantify fuel characteristics of harvested willow. Results have shown that the bio-baler tested can efficiently harvest biomass from willow rings at a rate of 6.5 tonnes/hour. The re-growth of the willows was rapid and was not impacted by the harvest. There are thousands of hectares of wetlands and surrounding willow rings available on the Canadian landscape for harvesting at a reasonable cost of production. The willow ring biomass harvested is suitable for small scale heating systems. Additional research will be conducted on the utilization of the biomass harvested from willow rings as a bioenergy source to supply a biomass boiler for heating purposes at the Agriculture and Agri-Food Canada (AAFC) Agroforestry Development Centre (ADC) in Indian Head, Saskatchewan. This research will include the economics and environmental aspects and will consider the life cycle analysis

Mode identification in the high-amplitude {\delta} Scuti star V2367 Cyg

We report on a multi-site photometric campaign on the high-amplitude $\delta$ Scuti star V2367 Cyg in order to determine the pulsation modes. We also used high-dispersion spectroscopy to estimate the stellar parameters and projected rotational velocity. Time series multicolour photometry was obtained during a 98-d interval from five different sites. These data were used together with model atmospheres and non-adiabatic pulsation models to identify the spherical harmonic degree of the three independent frequencies of highest amplitude as well as the first two harmonics of the dominant mode. This was accomplished by matching the observed relative light amplitudes and phases in different wavebands with those computed by the models. In general, our results support the assumed mode identifications in a previous analysis of Kepler data.Comment: 9 pages, 5 figures, 4 tables. Accepted for publication in MNRA

The influence of Harmonia axyridis morbidity on 2-Isopropyl-3-methoxypyrazine in 'Cabernet Sauvignon' wine

Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae; the Multicolored Asian Lady Beetle; MALB) is a vineyard pest in many winemaking regions of the world due to its ability to taint juice and wine (‘ladybug taint’) through excretion or extraction of 2-isopropyl-3-methoxypyrazine (IPMP) when the beetles are incorporated with the grapes at harvest. A common vineyard intervention is the use of insecticidal sprays and the resulting dead beetles are often incorporated in with the harvested fruit. The main objective of this study was to quantify the impact of dead MALB on IPMP concentrations in red wine. Duplicate 'Cabernet Sauvignon' wines were produced with the addition of 10 beetles·l-1 juice, added either live or at 1, 3, 7, or 60-days postmortem. A control wine with no added beetles was included. IPMP concentration was substantially higher in live-beetle wines, and decreased to base-line levels at approximately 6.5 days post-mortem. These results should assist in decisions on viticultural interventions, such as timing of insecticidal sprays, as well as the establishment of grape quality parameters.