417 research outputs found

    Development of Strategies for the Control and Eradication of Japanese Knotweed

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    This work has investigated a range of aspects of the physiology and management of Fallopia japonica (Ronse Decraene) and closely related invasive introduced plant species, colloquially referred to as Japanese knotweed. Prior to this work very little detailed scientific research had been done into the nature of the plant and its related species or into the effectiveness of control methods over the long term. This work has highlighted the need for education of the public to prevent further spread by inappropriate disposal, and advice on suitable and practical methods of control in a wide range of environments. The creation of an online GIS database has led to an increase in reporting of sites on private land by the public and this has in turn strengthened the Cornwall database which is the most comprehensive of its type ever created. This database has enabled detailed analysis of distribution, identification of likely areas of colonisation and indicated mechanisms of spread. It has also provided a basis for targeting of resources and prioritisation of treatment. Initial field observations also prompted research on physiological aspects of the plant which have particular implication for determining methods for its control. The work has shown that much smaller fragments of rhizome than those previously tested are capable of regeneration (down to 0.01g) and that there is a significant likelihood of fragments of 0.06g regenerating in suitable conditions which has implications for separation techniques. It has demonstrated that typical rhizome material is capable of survival for at least three months under saline conditions thus highlighting a risk of marine spread along coasts. Extension rates of above ground material of up to 13.8 cm over a 24 hour period have been recorded. Cutting of above ground material caused a stimulation of new above ground stems – thus any proposed treatment should continue consistently over a number of years. A temperature of 40C maintained over a period of 7 days removed rhizome viability in chopped fragments of up to 10cm thus suggesting that temperature controlled in-vessel composting may be a possible disposal route for chopped rhizome. Main underground extension growth has been shown to occur in the Autumn with no particular orientation to the growth. Up to 50kg (wet weight) of underground material has been discovered in a cubic metre of excavated material. Rhizome disturbance has been shown to promote underground extension. The way in which rhizome desiccates, leaving viable buds separated by necrotic material, means that underground connections within an area cannot be assumed. This has implications for the effectiveness of chemical treatment. The suggested regeneration from leaf material has not been demonstrated, nor has a reliable chemical method of testing the viability of rhizome material. The implications of these physiological aspects on a wide range of treatment methodologies have been considered and control methods have been tested. Excavation and separation of material can be effective in appropriate soil conditions. The need to use glyphosate based herbicides primarily in the Autumn has been demonstrated. This work has called into question the current methods of assessment of effectiveness of control and the use of viability assessments on sites. It has highlighted that monitoring of treated sites needs to be continued over a number of years in order to determine whether eradication has been achieved. In view of the legal proscriptions about the plant, it is considered that some control measures currently deployed could have the potential to breach current legislation by being likely to cause the plant to spread

    The mouth, stomach and intestines

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    Food is chewed into digestible portions in the mouth and swallowed – a complex reflex process involving several cranial nerves. The stomach homogenizes food, begins digestion and regulates the rate at which food enters the duodenum. Pancreatic juices containing powerful digesting enzymes are added and digestion is completed in the small intestine. The large bowel dehydrates the gastrointestinal contents

    Modular electric automatic guided vehicle suspension-drive unit

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    This report discusses the design, development, elevation and creation of a modular omni-directional suspension-drive train unit for use on 1000 kg automatic guided vehicle. The system included a semi-active suspension oleo strut system that can vary its dampening and ride height. The drive train system is capable of omni-directional motion through the use of separately driven mechanum wheels power by a 48 volt DC system

    Parametric search and optimisation of fast displacement hull forms using rans simulations of full-scale flow

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    Abstract. A methodology to derive parametric hull design candidates with a specified displacement and initial stability is introduced. A gradient-free search and optimisation algorithm coupled to a RANS CFD solver is then used to identify efficient pure-displacement hull shapes with minimal hydrodynamic resistance operating in the transition speed region without relying on dynamic lift

    RNA-dependent RNA polymerase 1 in potato (Solanum tuberosum) and its relationship to other plant RNA-dependent RNA polymerases

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    Cellular RNA-dependent RNA polymerases (RDR) catalyze synthesis of double stranded RNAs that can serve to initiate or amplify RNA silencing. Arabidopsis thaliana has six RDR genes; RDRs 1, 2 and 6 have roles in anti-viral RNA silencing. RDR6 is constitutively expressed but RDR1 expression is elevated following plant treatment with defensive phytohormones. RDR1 also contributes to basal virus resistance. RDR1 has been studied in several species including A. thaliana, tobacco (Nicotiana tabacum), N. benthamiana, N. attenuata and tomato (Solanum lycopersicum) but not to our knowledge in potato (S. tuberosum). StRDR1 was identified and shown to be salicylic acid-responsive. StRDR1 transcript accumulation decreased in transgenic potato plants constitutively expressing a hairpin construct and these plants were challenged with three viruses: potato virus Y, potato virus X, and tobacco mosaic virus. Suppression of StRDR1 gene expression did not increase the susceptibility of potato to these viruses. Phylogenetic analysis of RDR genes present in potato and in a range of other plant species identified a new RDR gene family, not present in potato and found only in Rosids (but apparently lost in the Rosid A. thaliana) for which we propose the name RDR7.LJRH was supported by a studentship co-funded by the James Hutton Institute (formerly Scottish Crop Research Institute) and the UK Biotechnological and Biological Sciences Research Council (BBSRC). Work in the JPC lab is funded by The Leverhulme Trust (RPG-2012-667), BBSRC (BB/D014376/1, BB/J011762/1) and the Cambridge University Newton Trust. SFB was funded by Leverhulme grant F/09-741/G to Professor Beverley Glover. KG was funded by an EMBO Short Term Fellowship. Work in the PP lab is funded by grant number NRF-2013R1A2A2A01016282 from the Korean National Research Foundation.This is the author accepted manuscript. The final version is available from Nature Publishing Group via https://doi.org/10.1038/srep2308

    RNA-dependent RNA polymerase 1 in potato (Solanum tuberosum) and its relationship to other plant RNA-dependent RNA polymerases.

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    Cellular RNA-dependent RNA polymerases (RDRs) catalyze synthesis of double-stranded RNAs that can serve to initiate or amplify RNA silencing. Arabidopsis thaliana has six RDR genes; RDRs 1, 2 and 6 have roles in anti-viral RNA silencing. RDR6 is constitutively expressed but RDR1 expression is elevated following plant treatment with defensive phytohormones. RDR1 also contributes to basal virus resistance. RDR1 has been studied in several species including A. thaliana, tobacco (Nicotiana tabacum), N. benthamiana, N. attenuata and tomato (Solanum lycopersicum) but not to our knowledge in potato (S. tuberosum). StRDR1 was identified and shown to be salicylic acid-responsive. StRDR1 transcript accumulation decreased in transgenic potato plants constitutively expressing a hairpin construct and these plants were challenged with three viruses: potato virus Y, potato virus X, and tobacco mosaic virus. Suppression of StRDR1 gene expression did not increase the susceptibility of potato to these viruses. Phylogenetic analysis of RDR genes present in potato and in a range of other plant species identified a new RDR gene family, not present in potato and found only in Rosids (but apparently lost in the Rosid A. thaliana) for which we propose the name RDR7.LJRH was supported by a studentship co-funded by the James Hutton Institute (formerly Scottish Crop Research Institute) and the UK Biotechnological and Biological Sciences Research Council (BBSRC). Work in the JPC lab is funded by The Leverhulme Trust (RPG-2012-667), BBSRC (BB/D014376/1, BB/J011762/1) and the Cambridge University Newton Trust. SFB was funded by Leverhulme grant F/09-741/G to Professor Beverley Glover. KG was funded by an EMBO Short Term Fellowship. Work in the PP lab is funded by grant number NRF-2013R1A2A2A01016282 from the Korean National Research Foundation.This is the author accepted manuscript. The final version is available from Nature Publishing Group via https://doi.org/10.1038/srep2308

    Natural resistance to Potato virus Y in <i>Solanum tuberosum</i> Group Phureja

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    This work was supported by funding from the Scottish Government’s Rural and Environmental Science and Analytical Services (RESAS) Division.A new source of genetic resistance derived from Solanum tuberosum Group Phureja against Potato virus Y (PVY) was identified and genetically characterised in three diploid biparental potato populations. Segregation data for two populations (05H1 and 08H1) suggested the presence of a single dominant gene for resistance to PVY which, following DaRT analysis of the 08H1 cross, was mapped to chromosome 9. More detailed genetic analysis of resistance utilised a well-characterised SNP-linkage map for the 06H1 population, together with newly generated marker data. In these plants, which have both S. tuberosum Group Phureja and S. tuberosum Group Tuberosum in their pedigree, the resistance was shown to map to chromosome 9 at a locus not previously associated with PVY resistance, although there is evidence for at least one other genetic factor controlling PVY infection. The resistance factor location on chromosome 9 (named as Ry(o)phu) suggests a potential role of NB-LRR genes in this resistance. Phenotypic analysis using a GUS-tagged virus revealed that a small amount of PVY replication occurred in occasional groups of epidermal cells in inoculated leaves of resistant plants, without inducing any visible hypersensitive response. However, the virus did not enter the vascular system and systemic spread was completely prevented.Publisher PDFPeer reviewe

    Antibiotics for acute bronchitis.

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    BACKGROUND: The benefits and risks of antibiotics for acute bronchitis remain unclear despite it being one of the most common illnesses seen in primary care. OBJECTIVES: To assess the effects of antibiotics in improving outcomes and assess adverse effects of antibiotic therapy for patients with a clinical diagnosis of acute bronchitis. SEARCH METHODS: We searched CENTRAL 2013, Issue 12, MEDLINE (1966 to January week 1, 2014), EMBASE (1974 to January 2014) and LILACS (1982 to January 2014). SELECTION CRITERIA: Randomised controlled trials (RCTs) comparing any antibiotic therapy with placebo or no treatment in acute bronchitis or acute productive cough, in patients without underlying pulmonary disease. DATA COLLECTION AND ANALYSIS: At least two review authors extracted data and assessed trial quality. MAIN RESULTS: Seventeen trials with 3936 participants were included in the primary analysis. The quality of trials was generally good. There was limited evidence to support the use of antibiotics in acute bronchitis. At follow-up, there was no difference in participants described as being clinically improved between antibiotic and placebo groups (11 studies with 3841 participants, risk ratio (RR) 1.07, 95% confidence interval (CI) 0.99 to 1.15; number needed to treat for an additional beneficial outcome (NNTB) 22. Participants given antibiotics were less likely to have a cough (four studies with 275 participants, RR 0.64, 95% CI 0.49 to 0.85; NNTB 6); have a night cough (four studies with 538 participants, RR 0.67, 95% CI 0.54 to 0.83; NNTB 7) and a shorter mean cough duration (seven studies with 2776 participants, mean difference (MD) -0.46 days, 95% CI -0.87 to -0.04). The differences in presence of a productive cough at follow-up and MD of productive cough did not reach statistical significance.Antibiotic-treated patients were more likely to be unimproved according to clinician\u27s global assessment (six studies with 891 participants, RR 0.61, 95% CI 0.48 to 0.79; NNTB 25); have an abnormal lung exam (five studies with 613 participants, RR 0.54, 95% CI 0.41 to 0.70; NNTB 6); have a reduction in days feeling ill (five studies with 809 participants, MD -0.64 days, 95% CI -1.16 to -0.13) and a reduction in days with limited activity (six studies with 767 participants MD -0.49 days, 95% CI -0.94 to -0.04). The differences in proportions with activity limitations at follow-up did not reach statistical significance. There was a significant trend towards an increase in adverse effects in the antibiotic group (12 studies with 3496 participants) (RR 1.20, 95% CI 1.05 to 1.36; NNT for an additional adverse effect 5). AUTHORS\u27 CONCLUSIONS: There is limited evidence to support the use of antibiotics in acute bronchitis. Antibiotics may have a modest beneficial effect in some patients such as frail, elderly people with multimorbidity who may not have been included in trials to date. However, the magnitude of this benefit needs to be considered in the broader context of potential side effects, medicalisation for a self-limiting condition, increased resistance to respiratory pathogens and cost of antibiotic treatment
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