216 research outputs found

    Epiparasitic plants specialized on arbuscular mycorrhizal fungi

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    Over 400 non-photosynthetic species from 10 families of vascular plants obtain their carbon from fungi and are thus defined as myco-heterotrophs. Many of these plants are epiparasitic on green plants from which they obtain carbon by 'cheating' shared mycorrhizal fungi. Epiparasitic plants examined to date depend on ectomycorrhizal fungi for carbon transfer and exhibit exceptional specificity for these fungi, but for most myco-heterotrophs neither the identity of the fungi nor the sources of their carbon are known. Because many myco-heterotrophs grow in forests dominated by plants associated with arbuscular mycorrhizal fungi (AMF; phylum Glomeromycota), we proposed that epiparasitism would occur also between plants linked by AMF. On a global scale AMF form the most widespread mycorrhizae, thus the ability of plants to cheat this symbiosis would be highly significant. We analysed mycorrhizae from three populations of Arachnitis uniflora (Corsiaceae, Monocotyledonae), five Voyria species and one Voyriella species (Gentianaceae, Dicotyledonae), and neighbouring green plants. Here we show that non-photosynthetic plants associate with AMF and can display the characteristic specificity of epiparasites. This suggests that AMF mediate significant inter-plant carbon transfer in nature

    Pharmacoeconomic analysis of adjuvant oral capecitabine vs intravenous 5-FU/LV in Dukes' C colon cancer: the X-ACT trial

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    Oral capecitabine (Xeloda<sup>®</sup>) is an effective drug with favourable safety in adjuvant and metastatic colorectal cancer. Oxaliplatin-based therapy is becoming standard for Dukes' C colon cancer in patients suitable for combination therapy, but is not yet approved by the UK National Institute for Health and Clinical Excellence (NICE) in the adjuvant setting. Adjuvant capecitabine is at least as effective as 5-fluorouracil/leucovorin (5-FU/LV), with significant superiority in relapse-free survival and a trend towards improved disease-free and overall survival. We assessed the cost-effectiveness of adjuvant capecitabine from payer (UK National Health Service (NHS)) and societal perspectives. We used clinical trial data and published sources to estimate incremental direct and societal costs and gains in quality-adjusted life months (QALMs). Acquisition costs were higher for capecitabine than 5-FU/LV, but higher 5-FU/LV administration costs resulted in 57% lower chemotherapy costs for capecitabine. Capecitabine vs 5-FU/LV-associated adverse events required fewer medications and hospitalisations (cost savings £3653). Societal costs, including patient travel/time costs, were reduced by >75% with capecitabine vs 5-FU/LV (cost savings £1318), with lifetime gain in QALMs of 9 months. Medical resource utilisation is significantly decreased with capecitabine vs 5-FU/LV, with cost savings to the NHS and society. Capecitabine is also projected to increase life expectancy vs 5-FU/LV. Cost savings and better outcomes make capecitabine a preferred adjuvant therapy for Dukes' C colon cancer. This pharmacoeconomic analysis strongly supports replacing 5-FU/LV with capecitabine in the adjuvant treatment of colon cancer in the UK

    Ross, Macdonald, and a Theory for the Dynamics and Control of Mosquito-Transmitted Pathogens

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    Ronald Ross and George Macdonald are credited with developing a mathematical model of mosquito-borne pathogen transmission. A systematic historical review suggests that several mathematicians and scientists contributed to development of the Ross-Macdonald model over a period of 70 years. Ross developed two different mathematical models, Macdonald a third, and various “Ross-Macdonald” mathematical models exist. Ross-Macdonald models are best defined by a consensus set of assumptions. The mathematical model is just one part of a theory for the dynamics and control of mosquito-transmitted pathogens that also includes epidemiological and entomological concepts and metrics for measuring transmission. All the basic elements of the theory had fallen into place by the end of the Global Malaria Eradication Programme (GMEP, 1955–1969) with the concept of vectorial capacity, methods for measuring key components of transmission by mosquitoes, and a quantitative theory of vector control. The Ross-Macdonald theory has since played a central role in development of research on mosquito-borne pathogen transmission and the development of strategies for mosquito-borne disease prevention

    Res Medica, Autumn 1959, Volume 2, Number 1

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    TABLE OF CONTENTSSYLLABUS FOR THE 223RD SESSIONHYPOTENSIVE DRUGS: G. E. Mawer, B.ScAN OCULIST LOOKS ATENDOCRINE EXOPHTHALMOS: C. R. S. Jackson.M.A., M.D., D.O.M .S., F.R.C.S.E.RES MEDICA THE TREATMENT OF CANCER: John McKendrick,M.B., Ch.B.DOCTORS AND ARTISTS: Professor W. I. C.Morris, F.R.C.S.E.SOME ASPECTS OFRHEUMATIC FEVER: David J. ClarkABDOMINAL PAIN: Geoffrey T. Millar,M.B., Ch.B.TWO HUNDRED YEARS AGO: James A. Gray, M.B..Ch.B

    Paratuberculosis infection of nonruminant wildlife in Scotland

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    Recent reports of natural paratuberculosis (or Johne's disease) in rabbits, foxes, and stoats has focused debate on the presence and importance of wildlife reservoirs in the epidemiology of this disease. This paper describes an extensive study investigating 18 nonruminant wildlife species for evidence of paratuberculosis. Using both culture and histopathological analysis, fox, stoat, weasel, crow, rook, jackdaw, rat, wood mouse, hare, and badger were found to harbor Mycobacterium avium subsp. paratuberculosis, the causative organism of paratuberculosis, suggesting that the epidemiology of this disease is more complex than previously realized

    How Malthusian Ideology crept into the Newsroom: British tabloids and the coverage of the ‘underclass’

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    This article argues that Malthusianism as a series of discursive regimes, developed in the Victorian-era, serves in times of austerity to reproduce an elite understanding of social exclusion in which those in a state of poverty are to blame for their own situation. It highlights that Malthusianism is present in the public discourse, becoming an underlining feature in news coverage of the so-called ‘underclass’. Our findings broadly contradict the normative claim that journalism ‘speaks truth to power’, and suggest instead that overall as a political practice, journalism tends to reproduce and reinforce hegemonic discourses of power. The piece is based on critical discourse analysis (CDA), which has been applied to a significant sample of news articles published by tabloid newspapers in Britain which focussed on the concept of the ‘underclass’. By looking at the evidence, the authors argue that the ‘underclass’ is a concept used by some journalists to cast people living in poverty as ‘undeserving’ of public and state support. In so doing, these journalists help create a narrative which supports cuts in welfare provisions and additional punitive measures against some of the most vulnerable members of society

    Severity of Giardia infection associated with post-infectious fatigue and abdominal symptoms two years after

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    <p>Abstract</p> <p>Background</p> <p>A high rate of post-infectious fatigue and abdominal symptoms two years after a waterborne outbreak of giardiasis in Bergen, Norway in 2004 has previously been reported. The aim of this report was to identify risk factors associated with such manifestations.</p> <p>Methods</p> <p>All laboratory confirmed cases of giardiasis (n = 1262) during the outbreak in Bergen in 2004 received a postal questionnaire two years after. Degree of post-infectious abdominal symptoms and fatigue, as well as previous abdominal problems, was recorded. In the statistical analyses number of treatment courses, treatment refractory infection, delayed education and sick leave were used as indices of protracted and severe <it>Giardia </it>infection. Age, gender, previous abdominal problems and symptoms during infection were also analysed as possible risk factors. Simple and multiple ordinal logistic regression models were used for the analyses.</p> <p>Results</p> <p>The response rate was 81% (1017/1262), 64% were women and median age was 31 years (range 3-93), compared to 61% women and 30 years (range 2-93) among all 1262 cases. Factors in multiple regression analysis significantly associated with abdominal symptoms two years after infection were: More than one treatment course, treatment refractory infection, delayed education, bloating and female gender. Abdominal problems prior to <it>Giardia </it>infection were not associated with post-infectious abdominal symptoms. More than one treatment course, delayed education, sick leave more than 2 weeks, and malaise at the time of infection, were significantly associated with fatigue in the multiple regression analysis, as were increasing age and previous abdominal problems.</p> <p>Conclusion</p> <p>Protracted and severe <it>giardiasis </it>seemed to be a risk factor for post-infectious fatigue and abdominal symptoms two years after clearing the <it>Giardia </it>infection.</p

    British Escherichia coli O157 in Cattle Study (BECS) to determine the prevalence of E. coli O157 in herds with cattle destined for the food chain

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    Escherichia coli O157 are zoonotic bacteria for which cattle are an important reservoir. Prevalence estimates for E. coli O157 in British cattle for human consumption are over 10 years old. A new baseline is needed to inform current human health risk. The British E. coli O157 in Cattle Study (BECS) ran between September 2014 and November 2015 on 270 farms across Scotland and England & Wales. This is the first study to be conducted contemporaneously across Great Britain, thus enabling comparison between Scotland and England & Wales. Herd-level prevalence estimates for E. coli O157 did not differ significantly for Scotland (0·236, 95% CI 0·166–0·325) and England & Wales (0·213, 95% CI 0·156–0·283) (P = 0·65). The majority of isolates were verocytotoxin positive. A higher proportion of samples from Scotland were in the super-shedder category, though there was no difference between the surveys in the likelihood of a positive farm having at least one super-shedder sample. E. coli O157 continues to be common in British beef cattle, reaffirming public health policy that contact with cattle and their environments is a potential infection source
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