145 research outputs found

    Temperature-dependent changes to host-parasite interactions alter the thermal performance of a bacterial host.

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    This is the author accepted manuscriptThermal performance curves (TPCs) are used to predict changes in species interactions, and hence, range shifts, disease dynamics and community composition, under forecasted climate change. Species interactions might in turn affect TPCs. Here, we investigate how temperature-dependent changes in a microbial host-parasite interaction (the bacterium Pseudomonas fluorescens, and its lytic bacteriophage, SBW[Formula: see text]) changes the host TPC and the ecological and evolutionary mechanisms underlying these changes. The bacteriophage had a narrower thermal tolerance for infection, with their critical thermal maximum ~6 °C lower than those at which the bacteria still had high growth. Consequently, in the presence of phage, the host TPC changed, resulting in a lower maximum growth rate. These changes were not just driven by differences in thermal tolerance, with temperature-dependent costs of evolved resistance also playing a major role: the largest cost of resistance occurred at the temperature at which bacteria grew best in the absence of phage. Our work highlights how ecological and evolutionary mechanisms can alter the effect of a parasite on host thermal performance, even over very short timescales.NER

    Professional boundaries: crossing a line or entering the shadows?

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    This article explores the professional boundaries guidance for social workers. It presents research findings from the formal literature, from agency codes of practice, from telephone interviews with regulatory and professional bodies and from an exercise using ‘snowballing techniques’ in which informants responded to brief scenarios illustrating boundary dilemmas. The findings suggest that formal research plays little part in the guidance that individuals use to help them determine professional boundaries. Similarly, only 10–15 per cent of informants made regular reference to regulatory and professional codes of practice, with an even smaller percentage quoting specific sections from these codes. A slightly larger group (15–20 per cent) made fairly regular reference to their agency's policy documents. However, a clear majority relied on their own sense of what is appropriate or inappropriate, and made their judgements with no reference to any formal guidance. Agency guidance tended to ignore the ambiguous areas of practice and seemed to act as an insurance policy, brought out and dusted off when something goes awry. The authors caution against ever-increasing bullet points of advice and prescription, and advance a notion of ethical engagement in which professionals exercise their ethical senses through regular discussion of professional boundary dilemmas

    The 2005 Nevada Rangeland Vegetation Survey General Public Questionnaire and Survey of Responses

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    The 2005 Nevada Rangeland Vegetation Survey was conducted as a collaborative effort between the University of Nevada, Reno (UNR) Department of Resource Economics and the University of Nevada Cooperative Extension (UNCE) Natural Resources Program to fulfill two roles

    Estimation of capture probabilities using generalized estimating equations and mixed effects approaches

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    Modeling individual heterogeneity in capture probabilities has been one of the most challenging tasks in capture-recapture studies. Heterogeneity in capture probabilities can be modeled as a function of individual covariates, but correlation structure among capture occasions should be taking into account. A proposed generalized estimating equations (GEE) and generalized linear mixed modeling (GLMM) approaches can be used to estimate capture probabilities and population size for capture-recapture closed population models. An example is used for an illustrative application and for comparison with currently used methodology. A simulation study is also conducted to show the performance of the estimation procedures. Our simulation results show that the proposed quasi-likelihood based on GEE approach provides lower SE than partial likelihood based on either generalized linear models (GLM) or GLMM approaches for estimating population size in a closed capture-recapture experiment. Estimator performance is good if a large proportion of individuals are captured. For cases where only a small proportion of individuals are captured, the estimates become unstable, but the GEE approach outperforms the other methods

    Greater Phage Genotypic Diversity Constrains Arms-Race Coevolution

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    This is the final version. Available on open access from Frontiers Media via the DOI in this recordData Availability Statement: All phenotypic data and code used in the analysis is available on GitHub (https://github.com/padpadpadpad/Castledine_2022_frontiers). The raw sequencing files are archived on the European Nucelotide Archive (Experiment accession number: PRJEB50009).Antagonistic coevolution between hosts and parasites, the reciprocal evolution of host resistance and parasite infectivity, has important implications in ecology and evolution. The dynamics of coevolution-notably whether host or parasite has an evolutionary advantage-is greatly affected by the relative amount of genetic variation in host resistance and parasite infectivity traits. While studies have manipulated genetic diversity during coevolution, such as by increasing mutation rates, it is unclear how starting genetic diversity affects host-parasite coevolution. Here, we (co)evolved the bacterium Pseudomonas fluorescens SBW25 and two bacteriophage genotypes of its lytic phage SBW25ɸ2 in isolation (one phage genotype) and together (two phage genotypes). Bacterial populations rapidly evolved phage resistance, and phage reciprocally increased their infectivity in response. When phage populations were evolved with bacteria in isolation, bacterial resistance and phage infectivity increased through time, indicative of arms-race coevolution. In contrast, when both phage genotypes were together, bacteria did not increase their resistance in response to increasing phage infectivity. This was likely due to bacteria being unable to evolve resistance to both phage via the same mutations. These results suggest that increasing initial parasite genotypic diversity can give parasites an evolutionary advantage that arrests long-term coevolution. This study has important implications for the applied use of phage in phage therapy and in understanding host-parasite dynamics in broader ecological and evolutionary theory

    Will opposites attract? Similarities and differences in students' perceptions of the stereotype profiles of other health and social care professional groups

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    The extent to which health and social care (HSC) students hold stereotypical views of other HSC professional groups is of great potential importance to team working in health care. This paper explores students' perceptions of different HSC professional groups at the beginning of their university programmes. Findings are presented from an analysis of baseline data collected as part of the New Generation Project longitudinal cohort study which is assessing the impact of interprofessional education over time on a range of variables including stereotyping. Questionnaires were administered to a cohort of over 1200 students from 10 different HSC professional groups entering their first year of university. Stereotypes were measured using a tool adapted from Barnes et al. (2000) designed to elicit stereotype ratings on a range of nine characteristics. The findings confirm that students arrive at university with an established and consistent set of stereotypes about other health and social care professional groups. Stereotypical profiles were compiled for each professional group indicating the distinctive characteristics of the groups as well as the similarities and differences between groups. Midwives, social workers and nurses were rated most highly on interpersonal skills and on being a team player whilst doctors were rated most highly on academic ability. Doctors, midwives and social workers were perceived as having the strongest leadership role, whilst doctors were also rated most highly on decision making. All professions were rated highly on confidence and professional competence and, with the exception of social workers, on practical skills. A comparison of profiles for each professional group reveals that, for example, pharmacists and doctors were perceived as having very similar characteristics as were social workers, midwives and nurses. However, the profiles of nurses and doctors were perceived to be very different. The implications of these similarities and differences are discussed in terms of their potential impact on interprofessional interactions, role boundaries and team working

    Variation in centre-specific survival in patients starting renal replacement therapy in England is explained by enhanced comorbidity information from hospitalization data

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    Background Unadjusted survival on renal replacement therapy (RRT) varies widely from centre to centre in England. Until now, missing data on case mix have made it impossible to determine whether this variation reflects genuine differences in the quality of care. Data linkage has the capacity to reduce missing data. Methods Modelling of survival using Cox proportional hazards of data returned to the UK Renal Registry on patients starting RRT for established renal failure in England. Data on ethnicity, socioeconomic status and comorbidity were obtained by linkage to the Hospital Episode Statistics database, using data from hospitalizations prior to starting RRT. Results Patients with missing data were reduced from 61 to 4%. The prevalence of comorbid conditions was remarkably similar across centres. When centre-specific survival was compared after adjustment solely for age, survival was below the 95% limit for 6 of 46 centres. The addition of variables into the multivariable model altered the number of centres that appeared to be ‘outliers’ with worse than expected survival as follows: ethnic origin four outliers, socioeconomic status eight outliers and year of the start of RRT four outliers. The addition of a combination of 16 comorbid conditions present at the start of RRT reduced the number of centres with worse than expected survival to one. Conclusions Linked data between a national registry and hospital admission dramatically reduced missing data, and allowed us to show that nearly all the variation between English renal centres in 3-year survival on RRT was explained by demographic factors and by comorbidity

    New Role, New Country: introducing US physician assistants to Scotland

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    This paper draws from research commissioned by the Scottish Executive Health Department (SEHD). It provides a case study in the introduction of a new health care worker role into an already well established and "mature" workforce configuration It assesses the role of US style physician assistants (PAs), as a precursor to planned "piloting" of the PA role within the National Health Service (NHS) in Scotland
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