62 research outputs found

    Pathological and ecological host consequences of infection by an introduced fish parasite

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    The infection consequences of the introduced cestode fish parasite Bothriocephalus acheilognathi were studied in a cohort of wild, young-of-the-year common carp Cyprinus carpio that lacked co-evolution with the parasite. Within the cohort, parasite prevalence was 42% and parasite burdens were up to 12% body weight. Pathological changes within the intestinal tract of parasitized carp included distension of the gut wall, epithelial compression and degeneration, pressure necrosis and varied inflammatory changes. These were most pronounced in regions containing the largest proportion of mature proglottids. Although the body lengths of parasitized and non-parasitized fish were not significantly different, parasitized fish were of lower body condition and reduced weight compared to non-parasitized conspecifics. Stable isotope analysis (δ15N and δ13C) revealed trophic impacts associated with infection, particularly for δ15N where values for parasitized fish were significantly reduced as their parasite burden increased. In a controlled aquarium environment where the fish were fed ad libitum on an identical food source, there was no significant difference in values of δ15N and δ13C between parasitized and non-parasitized fish. The growth consequences remained, however, with parasitized fish growing significantly slower than non-parasitized fish, with their feeding rate (items s−1) also significantly lower. Thus, infection by an introduced parasite had multiple pathological, ecological and trophic impacts on a host with no experience of the parasite

    Differential expression of pathogenicity- and virulence-related genes of Xanthomonas axonopodis pv. citri under copper stress

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    In this study, we used real-time quantitative PCR (RT-qPCR) to evaluate the expression of 32 genes of Xanthomonas axonopodis pv. citri related to pathogenicity and virulence that are also involved in copper detoxification. Nearly all of the genes were up-regulated, including copA and copB. Two genes homologous to members of the type II secretion system (xcsH and xcsC) and two involved in the degradation of plant cell wall components (pglA and pel) were the most expressed in response to an elevated copper concentration. The type II secretion system (xcs operon) and a few homologues of proteins putatively secreted by this system showed enhanced expression when the bacteria were exposed to a high concentration of copper sulfate. The enhanced expression of the genes of secretion II system during copper stress suggests that this pathway may have an important role in the adaptative response of X. axonopodis pv. citri to toxic compounds. These findings highlight the potential role of these genes in attenuating the toxicity of certain metals and could represent an important means of bacterial resistance against chemicals used to control diseases

    Rhegmatogenous retinal detachment in Scotland: research design and methodology

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    <p>Abstract</p> <p>Background</p> <p>Rhegmatogenous retinal detachment (RRD) is a potentially blinding condition and a common cause of ocular morbidity. Establishing an accurate estimate of disease incidence and distribution is an important first step in assessing the healthcare burden related to this condition and in subsequent planning and provision of treatment strategies. The aim of this study is to obtain a first estimate incidence of RRD in Scotland, to estimate the incidence of familial RRD and to describe the known associations of RRD within the study population.</p> <p>Methods/Design</p> <p>We have established a national prospective observational study seeking to identify and recruit all incident cases of RRD in the Scottish population over a 2 year period. After fully informed consent, all participants will have a blood sample taken and a full medical history and clinical examination performed including visual acuity, refraction, slit-lamp examination, intra-ocular pressure measurement and detailed fundal examination. We describe the study design and protocol.</p> <p>Conclusion</p> <p>This study will provide the first estimate of the annual incidence of RRD in Scotland. The findings of this study will be important in estimating the burden of disease and in the planning of future health care policy related to this condition. This study will also establish a genetic resource for a genome wide association study to investigate if certain genetic variants predispose to RRD.</p

    Highly symmetric POVMs and their informational power

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    We discuss the dependence of the Shannon entropy of normalized finite rank-1 POVMs on the choice of the input state, looking for the states that minimize this quantity. To distinguish the class of measurements where the problem can be solved analytically, we introduce the notion of highly symmetric POVMs and classify them in dimension two (for qubits). In this case we prove that the entropy is minimal, and hence the relative entropy (informational power) is maximal, if and only if the input state is orthogonal to one of the states constituting a POVM. The method used in the proof, employing the Michel theory of critical points for group action, the Hermite interpolation and the structure of invariant polynomials for unitary-antiunitary groups, can also be applied in higher dimensions and for other entropy-like functions. The links between entropy minimization and entropic uncertainty relations, the Wehrl entropy and the quantum dynamical entropy are described.Comment: 40 pages, 3 figure

    Research utilisation and knowledge mobilisation in the commissioning and joint planning of public health interventions to reduce alcohol-related harms: a qualitative case design using a cocreation approach

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    Background: Considerable resources are spent on research to establish what works to improve the nation’s health. If the findings from this research are used, better health outcomes can follow, but we know that these findings are not always used. In public health, evidence of what works may not ‘fit’ everywhere, making it difficult to know what to do locally. Research suggests that evidence use is a social and dynamic process, not a simple application of research findings. It is unclear whether it is easier to get evidence used via a legal contracting process or within unified organisational arrangements with shared responsibilities. Objective: To work in cocreation with research participants to investigate how research is utilised and knowledge mobilised in the commissioning and planning of public health services to reduce alcohol-related harms. Design, setting and participants: Two in-depth, largely qualitative, cross-comparison case studies were undertaken to compare real-time research utilisation in commissioning across a purchaser–provider split (England) and in joint planning under unified organisational arrangements (Scotland) to reduce alcohol-related harms. Using an overarching realist approach and working in cocreation, case study partners (stakeholders in the process) picked the topic and helped to interpret the findings. In Scotland, the topic picked was licensing; in England, it was reducing maternal alcohol consumption. Methods: Sixty-nine interviews, two focus groups, 14 observations of decision-making meetings, two local feedback workshops (n = 23 and n = 15) and one national workshop (n = 10) were undertaken. A questionnaire (n = 73) using a Behaviourally Anchored Rating Scale was issued to test the transferability of the 10 main findings. Given the small numbers, care must be taken in interpreting the findings. Findings: Not all practitioners have the time, skills or interest to work in cocreation, but when there was collaboration, much was learned. Evidence included professional and tacit knowledge, and anecdotes, as well as findings from rigorous research designs. It was difficult to identify evidence in use and decisions were sometimes progressed in informal ways and in places we did not get to see. There are few formal evidence entry points. Evidence (prevalence and trends in public health issues) enters the process and is embedded in strategic documents to set priorities, but local data were collected in both sites to provide actionable messages (sometimes replicating the evidence base). Conclusions: Two mid-range theories explain the findings. If evidence has saliency (relates to ‘here and now’ as opposed to ‘there and then’) and immediacy (short, presented verbally or visually and with emotional appeal) it is more likely to be used in both settings. A second mid-range theory explains how differing tensions pull and compete as feasible and acceptable local solutions are pursued across stakeholders. Answering what works depends on answering for whom and where simultaneously to find workable (if temporary) ‘blends’. Gaining this agreement across stakeholders appeared more difficult across the purchaser–provider split, because opportunities to interact were curtailed; however, more research is needed. Funding: This study was funded by the Health Services and Delivery Research programme of the National Institute for Health Research

    Health-related quality of life in patients with type 1 diabetes mellitus in the different geographical regions of Brazil: data from the Brazilian Type 1 Diabetes Study Group

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    What makes labour and birth traumatic? A survey of intrapartum 'hotspots'

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    Evidence suggests between 1% and 6% of women develop post-traumatic stress disorder (PTSD) after childbirth. 'Hotspots' are moments of extreme distress during traumatising events that are implicated in symptoms of PTSD. This cross-sectional internet survey of hotspots examined (1) the content of intrapartum hotspots and (2) whether particular events, cognitions or emotions during hotspots are related to PTSD. Women (N = 675) who experienced a difficult or traumatic birth completed a questionnaire composed of a validated measure of PTSD, questions concerning the existence of hotspots, and a newly developed measure of emotions and cognitions during hotspots. The majority of women (67.4%) reported at least one hotspot during birth and 52.9% had re-experiencing symptoms of these hotspots. Women were more likely to have PTSD if hotspots involved fear and lack of control (odds ratio (OR) 1.30, 95% CI 1.17-1.43) or intrapartum dissociation (OR 1.12, 95% CI 1.05-1.19). Risk of PTSD was higher if hotspots concerned interpersonal difficulties (OR 4.34, 95% CI 2.15-8.77) or obstetric complications (OR 3.35, 95% CI 1.64-6.87) compared to complications with the bab
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