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Introduction: During prostate radiotherapy treatment, it is important to ensure the position of the bladder and prostate is consistent between treatments. The aim of this study was to provide a quantitative basis for incorporating ultrasound bladder volume estimates into local practice for prostate radiotherapy. Methods: Agreement between bladder volume estimates obtained using computed tomography (CT) and ultrasound was assessed. Analysis of bladder volumes between planning and treatment scans was used to quantify expected variations in bladder volume over the course of radiotherapy. Dose–volume statistics were estimated and compared to planned dose constraints to propose a target bladder volume and tolerance. Results: Bladder volume measurements were obtained from 19 radiotherapy patients using ultrasound and CT. Ultrasound underestimated bladder volume compared to CT with a mean bias of –28 ± 30 ml. Pre-treatment (planning) bladder volumes varied from 71 to 383 ml with a mean of 200 ml. Treatment bladder volumes reduced by more than half in 9% of patients during the course of their treatment, potentially leading to a 30% increase in mean bladder dose. Patients with pre-treatment bladder volumes < 200 ml were most likely to exhibit differences in bladder volume, resulting in 'out of tolerance' increases in dose. Conclusions: A pragmatic individualised drinking protocol, aimed at achieving a minimum ultrasound bladder volume of 200 ml at planning CT, may be beneficial to reproducibility in radiotherapy treatment. Ultrasound measurements prior to treatment should ideally confirm that bladder volume is at least half the volume measured at planning. [ABSTRACT FROM AUTHOR]

A forwards induction policy is a type of greedy algorithm for Markov decision processes. It is straightforward to implement and is optimal for a large class of models, especially in stochastic resource allocation. In this paper we consider a model for the optimal allocation of resources in pre-clinical pharmaceutical research. We show that although they are not always strictly optimal, forwards induction policies perform well. [ABSTRACT FROM AUTHOR]

To test the efficacy of enhanced biosecurity measures on poultry farms for reducing environmental contamination with Campylobacter during partial depopulation of broiler flocks prior to normal slaughter age. The study has also evaluated the risk of infection from live-bird transport crates that are routinely cleaned at the slaughterhouse, but may remain contaminated. On-farm sampling and Campylobacter isolation was undertaken to compare the prevalence of contamination on vehicles, equipment and catching personnel during farm visits that took place under normal or enhanced biosecurity. Campylobacters were found in almost all types of sample examined and enhanced biosecurity reduced the prevalence. However, the additional measures failed to prevent colonisation of the flocks. For transport crates, challenge trials involved exposure of broilers to commercially cleaned crates and genotyping of any campylobacters isolated. The birds were rapidly colonised with the same genotypes as those isolated from the cleaned crates. The enhanced biosecurity measures were insufficient to prevent flock colonisation, and the problem was exacerbated by inadequate cleaning of transport crates at the slaughterhouse. Current commercial practices in the United Kingdom facilitate the spread of campylobacters among broiler chicken flocks. Prevention of flock infection appears to require more stringent biosecurity than that studied here. [ABSTRACT FROM AUTHOR]

Pharmaceutical companies have to face huge risks and enormous costs of production before they can produce a drug. Efficient allocation of resources is essential to help in maximizing profits. Yu and Gittins (2007) described a model and associated software for determining efficient allocations for a preclinical research project. This is the starting point for this paper. We provide explicit optimal policies for the selection of successive candidate drugs for two restricted versions of the Yu and Gittins (2007) model. To some extent these policies are likely to be applicable to the unrestricted model. [ABSTRACT FROM AUTHOR]

Planning, especially with the increasing prominence given to community involvement, is a key vehicle for delivering sustainable development. Between 2003 and 2005 two community groups in Cheshire wrote parish landscape character assessments. The completed assessments were combined with an appropriate village design statement and subsequently approved as Supplementary Planning Guidance by Chester City and Vale Royal District Councils respectively. The experiences of these groups are critically appraised against the project aims, tangible and not-tangible costs and criteria relating to the enhancement of community engagement in sustainable development practice. The evaluation highlights the importance of the process as well as the product, the financial costs involved, the volunteer time commitment required, the skills required in the community, the issues associated with data acquisition and the importance of building a strong, open partnership between local authorities and the local community. These findings have relevance to others involved in community-led initiatives. [ABSTRACT FROM AUTHOR]

The microbiological implications of using a small-scale bucket-style washer are reported forchicken eggs. On average, the bucket washerreduced the total bacterial numbers on the surface of eggs under manufacturer-recommended conditions from 5.36 log CFU egg-1 to 2.82 log CFU egg-1. No evidence of enhanced bacterial contamination of the egg contents was found when microbiological examination was undertaken a few hours afterwashing. When washing visibly soiled free-range eggs, there was a tendency forthe wash-waterto become dirty afteronly a few batches of eggs had been washed. Washing in dirty water could increase the numbers of bacteria on the surfaces of those shells which were visibly clean before washing. These additional shell-surface bacteria however, were not detected in the egg contents (n=1032), when analyses were undertaken 1–2 hours after washing. In contrast, when washed eggs were stored for2 weeks at 15°C, we found that bacterial numbers in the egg contents were elevated when compared with unwashed controls. To determine if cool washing temperatures could cause water to taken up by egg contents, eggs were warmed to 37°C, 30°C, 25°C or 20°C and were submerged in aqueous protein stain at 15°C forup to 7 minutes. We did not observe take up of the stain solution unless its temperature was 15°C cooler than the egg contents and the eggs were immersed forat least 3 minutes. [ABSTRACT FROM PUBLISHER]

The potential benefits of washing eggs is offset by a historical perception in the European Union that wetted eggs are prone to spoilage and water loss. This study describes the effects of spray jet washing under various processing conditions to shell surface counts of Salmonella and the presence of bacteria in egg contents. Experiments used eggs that were contaminated with Salmonella Enteritidis PT4 or Salmonella Typhimurium DT104 before cuticle hardening. Washing of contaminated eggs under optimum conditions resulted in a more than 5-log reduction of Salmonella counts from the shell surface. Salmonella was not isolated from the yolk or albumen of any egg washed by the optimal protocol, suggesting that when properly controlled, egg washing did not cause Salmonella to enter the contents. However, contamination did arise if strict control was not maintained over the wash and rinse water temperatures. Both Salmonella Enteritidis and Salmonella Typhimurium were shown to enter the egg contents when water temperatures were lowered, indicating that strict temperature control must be maintained in order to prevent the ingress of Salmonella into egg contents. Other washing machine parameters that were investigated did not significantly affect Salmonella entry into the egg contents but influenced shell surface kill levels to varying degrees. [ABSTRACT FROM AUTHOR]

Current European Union legislation prohibits the washing of Class A eggs. This is in stark contrast to countries such as the United States of America and, more recently Japan, which have embraced egg-washing technology. The emergence in the UK of egg associated Salmonella enteritidis as a significant cause of food poisoning has, combined with the increase in non-cage egg production systems, increased interest in technologies that might improve the microbial quality of the egg. This paper reviews the history of egg washing in the European Union and more specifically its restricted use in the UK and contrasts this with its uptake in the United States among other countries. Similarly the technological advances in egg washing are reviewed, in the context of the underpinning science. [ABSTRACT FROM PUBLISHER]

A bound on the performance of the greedy algorithm for finding the maximum of a submodular set function subject to a cardinality constraint is shown to apply to the problem of selecting a fixed number of events so that the probability that at least one of the selected events occurs is maximized. The bound is improved under an additional assumption which is plausible when the aim is to find a biologically active compound in pharmaceutical research.

Some results of Sidney (1975) concerning order-constrained deterministic scheduling with linear costs are extended to the more complex discounted costs case. Further, certain order-constrained stochastic scheduling problems are shown to have optimal strategies which are nonpreemptive. When this is so, results for the deterministic case may be utilized to obtain these optimal strategies. The models discussed are of interest in computer and job-shop scheduling and research planning. [ABSTRACT FROM AUTHOR]

There is much debate about whether carbonatite magmas are derived in ‘secondary’ fashion through the advent of liquid immiscibility operating in the crust on evolved nephelinitic magma, or whether they are derived in the mantle by direct partial melting of a carbonated peridotite. This paper briefly summarizes the εSr–εNd data fo carbonatites in general and evaluates the isotopic relationships between carbonatites and alkaline silicate rocks in several well-studied complexes from Africa. Available data for carbonatites younger than 200 Ma have a range in εSr–εNd that is less than that found in oceanic basalts despite the fact that carbonatites traverse lithospheres that ar much more complex than those in the oceans. By contrast, for the Napak, Kerimasi, Shombole, Dorowa, Shawa and Spitskop complexes the alkaline silicate rocks show greater variability and have more enriched εSr–εNd (higher εSr, lower εNd) values than their associated carbonatites. In general, the carbonatites hav isotopic compositions that are closer to the more primitive silicate rocks, such as melilitites a olivine nephelinites, than to more evolved nephelinites and phonolites. In the case of the Napak Complex the enriched component was introduced from the lower crust whereas for the Dorowa and Shawa complexes of SE Zimbabwe, the component was derived from the sub-continental lithospheric mantle. These relationships indicate that the carbonatites must have existed as discrete magmas i themantle and argue against a derivation by liquid immiscibility in the crust. Although a contrast i isotopic composition does not rule out an immiscibility relationship at mantle depths and early in the evolutionary history of a melilititic or nephelinitic magma, there is little experimental support for it. Existing experimental data indicate that immiscibility between carbonate an silicate liquids is favoured at low, crustal, pressures but that immiscibility is unlikely to occur in realistic mantle melts or their derivatives at mantle pressures. Many experimental data exist to show that magnesian carbonatite liquids form as the near-solidus melts of carbonated mantl peridotite at depths in excess of 75 km. We conclude that the calcitic and dolomitic carbonatite magma discussed in this paper are best considered as being derived from primary carbonatite magmas generated in the mantle by partial melting of carbonated peridotite. [ABSTRACT FROM AUTHOR]

Presents experimental results that show that fluorine is an efficient agent for lowering the minimum melting temperatures of carbonate systems and is an important constituent of most carbonatite magmas. Methods; Results; Discussion.