451 research outputs found

    Public Choice for Flood Defence

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    Why do we want to value the environment? Environmental assets provide a flow of goods and services over time which benefit mankind. Valuing these services contributes towards their protection and enhancement, however many of these benefits cannot be valued in traditional markets and as such rely on non-market valuation techniques. One of these is contingent valuation (CV) which directly asks respondents whether they are willing to pay for an improvement in the good or service. This thesis seeks to explore methodological issues associated with this method by undertaking a CV survey to elicit willingness to pay (WTP) for a new type of flood defence (managed realignment) on the Tay Estuary, Scotland. One challenge for survey designers is to provide high quality, readily understandable information to mitigate bias in WTP estimates. This thesis contributes to the information provision literature by examining whether prior knowledge or new information has a greater effect on the WTP estimate when controlling for respondent experience and familiarity with the good. A field experiment was designed to test for respondent’s prior knowledge; allow for varying levels of information to be presented to respondents and identify information acquisition for each respondent. Specifically tested was the notion that respondents who learn the most about the good during the survey process will have a more robust WTP estimate. Results were mixed: a causal relationship between information provision and learning was established with respondents in the higher treatment groups scoring higher in the second quiz. However, there was no relationship identified between prior knowledge, information provision and WTP. Personal motivations were the strongest predictors of WTP: those who were most concerned about flood risk and who lived closest to the proposed flood defence were willing to pay the most. A second issue in CV is consequentiality. Carson and Groves (2007) argue that for a survey to produce meaningful information about respondent’s preferences the respondent must view their responses as potentially influencing the supply of the public good. This thesis seeks add to this relatively new literature by exploring the observable factors which may influence respondents perceived consequentiality; specifically the effects of familiarity and information. Respondents were asked to state how confident they were that the results of the survey would be used by policy makers on a Likert scale ranging from “very unconfident” through to “very confident”. Results conformed to the Carson and Groves knife edge result: consequential respondents had significantly different WTP distributions compared to inconsequential and unsure respondents and were willing to pay significantly more towards the scheme. Consequential respondents also conformed the theoretical considerations of construct validity whilst inconsequential respondents did not. Respondents with more prior knowledge also appeared to be more likely to perceive the survey as consequential, although this was not consistent across all treatment groups. There is a concern that WTP and consequentiality are endogenous: respondents who want the policy to go ahead may be more likely to state the survey is consequential and state a high WTP in the hope these responses combined contribute to the policy maker’s decision. From a policy perspective the high level of support for the new scheme was encouraging and in contrast to previous findings on preferences for managed realignment. From a flood risk management perspective a “miss-match” between actual and perceived flood risk was highlighted, with many respondents stating they were not at risk from flooding when they in fact were. This is potentially concerning as respondents may not be taking adequate steps to protect their home from future flood risks. Overall it is recognised that values derived from the CV survey form one small part of the planning process and while informative, the decision for a scheme to take place should not be based on these values alone

    Feline primary erythrocytosis: a multicentre case series of 18 cats

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    A retrospective multicentre case series of feline primary erythrocytosis (PE) was evaluated. The aim was to gain better understanding of disease presentation and progression to guide management and prognostication. Case records were assessed for evidence of increased packed cell volume (PCV; >48%), sufficient investigation to rule out relative and secondary erythrocytosis, and follow-up data for at least 12 months or until death. Eighteen cats were included in the case series. No significant trends in signalment were noted. Seizures and mentation changes were the most common presenting signs (both n = 10). Median PCV was 70% (median total protein concentration of 76 g/l) with no other consistent haematological changes. Sixteen cats survived to discharge. Phlebotomy was performed initially in 15/16 surviving animals and performed after discharge in 10/16. Hydroxyurea was the most common adjunctive therapy, used in 10/16 cats. Of the 16 patients surviving to discharge, 14 patients were still alive at the conclusion of the study (survival time >17 months post-discharge), with the two non-survivors having lived for 5 years or more after diagnosis. PCV, when stabilised, did not correlate with resolution of clinical signs

    Expanding the diversity of mycobacteriophages: insights into genome architecture and evolution.

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    Mycobacteriophages are viruses that infect mycobacterial hosts such as Mycobacterium smegmatis and Mycobacterium tuberculosis. All mycobacteriophages characterized to date are dsDNA tailed phages, and have either siphoviral or myoviral morphotypes. However, their genetic diversity is considerable, and although sixty-two genomes have been sequenced and comparatively analyzed, these likely represent only a small portion of the diversity of the mycobacteriophage population at large. Here we report the isolation, sequencing and comparative genomic analysis of 18 new mycobacteriophages isolated from geographically distinct locations within the United States. Although no clear correlation between location and genome type can be discerned, these genomes expand our knowledge of mycobacteriophage diversity and enhance our understanding of the roles of mobile elements in viral evolution. Expansion of the number of mycobacteriophages grouped within Cluster A provides insights into the basis of immune specificity in these temperate phages, and we also describe a novel example of apparent immunity theft. The isolation and genomic analysis of bacteriophages by freshman college students provides an example of an authentic research experience for novice scientists

    Children must be protected from the tobacco industry's marketing tactics.

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    Evaluating the Effects of SARS-CoV-2 Spike Mutation D614G on Transmissibility and Pathogenicity.

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    Global dispersal and increasing frequency of the SARS-CoV-2 spike protein variant D614G are suggestive of a selective advantage but may also be due to a random founder effect. We investigate the hypothesis for positive selection of spike D614G in the United Kingdom using more than 25,000 whole genome SARS-CoV-2 sequences. Despite the availability of a large dataset, well represented by both spike 614 variants, not all approaches showed a conclusive signal of positive selection. Population genetic analysis indicates that 614G increases in frequency relative to 614D in a manner consistent with a selective advantage. We do not find any indication that patients infected with the spike 614G variant have higher COVID-19 mortality or clinical severity, but 614G is associated with higher viral load and younger age of patients. Significant differences in growth and size of 614G phylogenetic clusters indicate a need for continued study of this variant

    International genome-wide meta-analysis identifies new primary biliary cirrhosis risk loci and targetable pathogenic pathways.

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    Primary biliary cirrhosis (PBC) is a classical autoimmune liver disease for which effective immunomodulatory therapy is lacking. Here we perform meta-analyses of discovery data sets from genome-wide association studies of European subjects (n=2,764 cases and 10,475 controls) followed by validation genotyping in an independent cohort (n=3,716 cases and 4,261 controls). We discover and validate six previously unknown risk loci for PBC (Pcombined<5 × 10(-8)) and used pathway analysis to identify JAK-STAT/IL12/IL27 signalling and cytokine-cytokine pathways, for which relevant therapies exist

    IMPACT-Global Hip Fracture Audit: Nosocomial infection, risk prediction and prognostication, minimum reporting standards and global collaborative audit. Lessons from an international multicentre study of 7,090 patients conducted in 14 nations during the COVID-19 pandemic

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    The development and validation of a scoring tool to predict the operative duration of elective laparoscopic cholecystectomy

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    Background: The ability to accurately predict operative duration has the potential to optimise theatre efficiency and utilisation, thus reducing costs and increasing staff and patient satisfaction. With laparoscopic cholecystectomy being one of the most commonly performed procedures worldwide, a tool to predict operative duration could be extremely beneficial to healthcare organisations. Methods: Data collected from the CholeS study on patients undergoing cholecystectomy in UK and Irish hospitals between 04/2014 and 05/2014 were used to study operative duration. A multivariable binary logistic regression model was produced in order to identify significant independent predictors of long (> 90 min) operations. The resulting model was converted to a risk score, which was subsequently validated on second cohort of patients using ROC curves. Results: After exclusions, data were available for 7227 patients in the derivation (CholeS) cohort. The median operative duration was 60 min (interquartile range 45–85), with 17.7% of operations lasting longer than 90 min. Ten factors were found to be significant independent predictors of operative durations > 90 min, including ASA, age, previous surgical admissions, BMI, gallbladder wall thickness and CBD diameter. A risk score was then produced from these factors, and applied to a cohort of 2405 patients from a tertiary centre for external validation. This returned an area under the ROC curve of 0.708 (SE = 0.013, p  90 min increasing more than eightfold from 5.1 to 41.8% in the extremes of the score. Conclusion: The scoring tool produced in this study was found to be significantly predictive of long operative durations on validation in an external cohort. As such, the tool may have the potential to enable organisations to better organise theatre lists and deliver greater efficiencies in care
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