622 research outputs found
Comparative biology of different plant pathogens to estimate effects of climate change on crop diseases in Europe
This review describes environmental factors that influence severity of crop disease epidemics, especially in the UK and north-west Europe, in order to assess the effects of climate change on crop growth and yield and severity of disease epidemics. While work on some diseases, such as phoma stem canker of oilseed rape and fusarium ear blight of wheat, that combine crop growth, disease development and climate change models is described in detail, climate-change projections and predictions of the resulting biotic responses to them are complex to predict and detailed models linking climate, crop growth and disease development are not available for many crop-pathogen systems. This review uses a novel approach of comparing pathogen biology according to 'ecotype' (a categorization based on aspects such as epidemic type, dissemination method and infection biology), guided by detailed disease progress models where available to identify potential future research priorities for disease control. Consequences of projected climate change are assessed for factors driving elements of disease cycles of fungal pathogens (nine important pathogens are assessed in detail), viruses, bacteria and phytoplasmas. Other diseases classified according to 'ecotypes' were reviewed and likely changes in their severity used to guide comparable diseases about which less information is available. Both direct and indirect effects of climate change are discussed, with an emphasis on examples from the UK, and considered in the context of other factors that influence diseases and particularly emergence of new diseases, such as changes to farm practices and introductions of exotic material and effects of other environment changes such as elevated CO 2. Good crop disease control will contribute to climate change mitigation by decreasing greenhouse gas emissions from agriculture while sustaining production. Strategies for adaptation to climate change are needed to maintain disease control and crop yields in north-west Europe.Peer reviewe
Characterisation of the effects of salicylidene acylhydrazide compounds on type three secretion in Escherichia coli O157:H7
Recent work has highlighted a number of compounds that target bacterial virulence by affecting gene regulation. In this work, we show that small-molecule inhibitors affect the expression of the type III secretion system (T3SS) of <i>Escherichia coli</i> O157:H7 in liquid culture and when the bacteria are attached to bovine epithelial cells. The inhibition of T3SS expression resulted in a reduction in the capacity of the bacteria to form attaching and effacing lesions. Our results show a marked variation in the ability of four structurally-related compounds to inhibit the T3SS of a panel of isolates. Using transcriptomics, we provide a comprehensive analysis of the conserved- and inhibitor-specific transcriptional responses to the four compounds. These analyses of gene expression show that numerous virulence genes, located on horizontally-acquired DNA elements, are affected by the compounds but the number of genes significantly affected varied markedly between the compounds. Overall, we highlight the importance of assessing the effect of such "anti-virulence" agents on a range of isolates and discuss the possible mechanisms which may lead to the co-ordinate down-regulation of horizontally acquired virulence genes
Search for the hero: an investigation into the sports heroes of British sports fans
This is an initial study into British sports fans’ heroes. A questionnaire was sent to 95 students (average age ¼ 19.75) to identify their sporting hero, the hero’s sport and nationality and the reasons for this choice. Football was the most common source of sports heroes, identified by 49% of participants with a sporting hero. The majority (60%, N ¼ 48) of heroes chosen by participants were British, with David Beckham the most popular choice. Differences were observed between the gender of participants, gender of hero chosen and the reasons for choosing the hero. The most common reason for selecting a hero was a personal trait rather than skill, while in the questionnaire a category of Local Affiliation was added to those suggested by previous work. It was concluded that to become a hero athletes should combine skill with devotion to family, charity work and a place in popular culture
Estimating an exchange rate between the EQ-5D-3L and ASCOT
Background The aim was to estimate an exchange ratebetween EQ-5D-3L and the Adult Social Care OutcomeTool (ASCOT) using preference-based mapping via com-mon time trade-off (TTO) valuations. EQ-5D and ASCOTare useful for examining cost-effectiveness within thehealth and social care sectors, respective ly, but there is apolicy need to understand overall benefits and compareacross sectors to assess relative value for money. Standardstatistical mapping is unsuitable since it relies on concep-tual overlap of the measures but EQ-5D and ASCOT havedifferent conceptualisations of quality of life.Methods We use a preference-based mapping approach toestimate the exchange rate using common TTO valuationsfor both measures. A sample of health states from eachmeasure was valued using TTO by 200 members of the UKadult general population. Regression analyses are used togenerate separate equations between EQ-5D-3L andASCOT values using their original value set and TTOvalues elicited here . These are solved as simultaneousequations to estimat e the relationship between EQ-5D- 3Land ASCOT.Results The relationship for moving from ASCOT to EQ-5D-3L is a linear transformation with an intercept of-0.0488 and gradient of 0.978. This enables QALY gainsgenerated by ASCOT and EQ-5D to be compared acrossdifferent interventions.Conclusions This paper estimated an exchange ratebetween ASCOT and EQ-5D-3L usin g a preference-basedmapping approach that does not compromise the descrip-tive systems of the two measures. This contributes to thedevelopment of preference-based mapping through the useof TTO as the common metric used to estimate theexchange rate between measures
Can we avoid high coupling?
It is considered good software design practice to organize source code into modules and to favour within-module connections (cohesion) over between-module connections (coupling), leading to the oft-repeated maxim "low coupling/high cohesion". Prior research into network theory and its application to software systems has found evidence that many important properties in real software systems exhibit approximately scale-free structure, including coupling; researchers have claimed that such scale-free structures are ubiquitous. This implies that high coupling must be unavoidable, statistically speaking, apparently contradicting standard ideas about software structure. We present a model that leads to the simple predictions that approximately scale-free structures ought to arise both for between-module connectivity and overall connectivity, and not as the result of poor design or optimization shortcuts. These predictions are borne out by our large-scale empirical study. Hence we conclude that high coupling is not avoidable--and that this is in fact quite reasonable
Using a discrete choice experiment involving cost to value a classification system measuring the quality of life impact of self-management for diabetes
Objective: This paper describes the use of a novel approach in health valuation of a discrete choice
experiment (DCE) including a cost attribute to value a recently developed classification system for
measuring the quality of life impact (both health and treatment experience) of self-management for
diabetes.
Methods: A large online survey was conducted using DCE with cost on UK respondents from the
general population (n=1,497) and individuals with diabetes (n=405). The data was modelled using a
conditional logit model with robust standard errors. The marginal rate of substitution (MRS) was used
to generate willingness to pay estimates for every state defined by the classification system.
Robustness of results was assessed by including interaction effects for household income.
Results: There were some logical inconsistencies and insignificant coefficients for the milder levels of
some attributes. There were some differences in the rank ordering of different attributes for the
general population and diabetes patients. The willingness to pay to avoid the most severe state was
£1,118.53 per month for the general population and £2,356.02 per month for the diabetes patient
population. The results were largely robust.
Conclusion: Health and self-management can be valued in a single classification system using DCE
with cost. The MRS for key attributes can be used to inform cost-benefit analysis of self-management
interventions in diabetes using results from clinical studies where this new classification system has
been applied. The method shows promise, but found large willingness to pay estimates exceeding
the cost levels used in the survey
Ontologies for Intelligent e-Theraoy: Application to Obesity
[EN] In this paper we propose a new approach for mental e-health
treatments named intelligent e-therapy (e-it) with capabilities for ambient intelligence
and ubiquitous computing. The proposed e-it system supposes an evolution
of cybertherapy and telepsychology tools used up to now. The e-it system
is based in a knowledge base that includes all the knowledge related to the disorder
and its treatment. We introduce the use of ontologies as the best option for
the design of this knowledge base. We also present a fist e-it system for obesity
treatment called etiobeZaragozá Álvarez, I.; Guixeres Provinciale, J.; Alcañiz Raya, ML. (2009). Ontologies for Intelligent e-Theraoy: Application to Obesity. Lecture Notes in Computer Science. 5518:894-901. doi:10.1007/978-3-642-02481-8_136S8949015518Baños, R.M., Botella, C., Perpiñá, C., Alcañiz, M., Lozano, J.A., Osma, J., Gallardo, M.: Virtual reality treatment of flying phobia. IEEE Transactions on Information Technology in Biomedicine 6(3), 206–212 (2002)Botella, C., Baños, R.M., Perpiña, C., et al.: Virtual reality treatment of claustrophobia: a case report. Behaviour Research & Therapy 36, 239–246 (1998)Hu, B., Dasmahapatra, S., Dupplaw, D., Lewis, P., Shadbolt, N.: Reflections on a medical ontology. International Journal of Human- Computer Studies 65(2007), 569–582 (2007)Rubin, D.L., Shah, N.H., Noy, N.F.: Biomedical ontologies: a functional perspective. Briefings in bioinformatics 9(1), 75–90 (2007)Stevens, R., Egaña Aranguren, M., Wolstencroft, K., Sattler, U., Drummond, N., Horridge, M., Rector, A.: Using OWL to model biological knowledge. International Journal of Human-Computer Studies 65(2007), 583–594 (2007)Park, S., Lee, J.K.: Rule identification using ontology while acquiring rules from Web pages. International Journal of Human-Computer Studies 65(2007), 644–658 (2007)Clark, K.L., McCabe, F.G.: Ontology schema for an agent belief store. International Journal of Human-Computer Studies 65(2007), 625–643 (2007)Gruber, T.R.: A Translation Approach to Portable Ontology Specifications. Knowledge Acquisition 5(2), 199–220 (1993)Franco, C., Bengtsson, B., Johannsson, G.: The GH/IGF-1 Axis in Obesity: Physiological and Pathological aspects. Metabolic syndrome and Related Disorders 4, 51–56 (2006
Space Vehicle Terrestrial Environment Design Requirements Guidelines
The terrestrial environment is an important driver of space vehicle structural, control, and thermal system design. NASA is currently in the process of producing an update to an earlier Terrestrial Environment Guidelines for Aerospace Vehicle Design and Development Handbook. This paper addresses the contents of this updated handbook, with special emphasis on new material being included in the areas of atmospheric thermodynamic models, wind dynamics, atmospheric composition, atmospheric electricity, cloud phenomena, atmospheric extremes, and sea state. In addition, the respective engineering design elements are discussed relative to terrestrial environment inputs that require consideration. Specific lessons learned that have contributed to the advancements made in the application and awareness of terrestrial environment inputs for aerospace engineering applications are presented
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Microstructure and kinetics of hot corrosion for a nickel alloy in molten salt
Metallography, analytical SEM, and XRD were used to measure kinetics and characterize the microstructure of hot corrosion of the Ni-Cr-Fe alloy INCONEL 600 after 500 h immersion in molten Na{sub 2}CO{sub 3}- NaCl salt at 900-950 C in an oxidizing atmosphere. This was done to assess the alloy as a reaction vessel material for a waste treatment process known as Molten Salt Oxidation. The alloy was found to hot corrode by surface oxidation and intergranular attack. Combined rate for loss of load-bearing cross-section metal was comparable to corrosion rates for analogous salts. About 5% of the oxide scale was a continuous, dense, protective layer of Cr{sub 2}O{sub 3} at the metal/oxide interface. A middle portion comprised about 55% of the scale and was a porous, mixed oxide of NiO>Cr{sub 2}O{sub 3}>Fe{sub 2}O{sub 3}. The outer 40% was nearly all NiO with dense grains and cavitated grain boundaries. Overall, the NiO was dominant and the lesser amounts of Cr{sub 2}O{sub 3} and Fe{sub 2}O{sub 3} were roughly equivalent. No direct invasion of salt through the oxide to the metal was observed
Certolizumab Pegol for Treating Rheumatoid Arthritis Following Inadequate Response to a TNF-α Inhibitor: An Evidence Review Group Perspective of a NICE Single Technology Appraisal.
As part of its single technology appraisal (STA) process, the National Institute for Health and Care Excellence (NICE) invited the manufacturer (UCB Pharma) of certolizumab pegol (CZP; Cimzia(®)) to submit evidence of its clinical and cost effectiveness for the treatment of rheumatoid arthritis (RA) following inadequate response to a tumour necrosis factor-α inhibitor (TNFi). The School of Health and Related Research Technology Appraisal Group at the University of Sheffield was commissioned to act as the independent Evidence Review Group (ERG). The ERG produced a detailed review of the evidence for the clinical and cost effectiveness of the technology, based upon the company's submission to NICE. The clinical effectiveness evidence in the company's submission for CZP was based predominantly on six randomised controlled trials (RCTs) comparing the efficacy of CZP against placebo. The clinical effectiveness review identified no head-to-head evidence on the efficacy of CZP against the comparators within the scope; therefore, the company performed a network meta-analysis (NMA). The company's NMA concluded that CZP had a similar efficacy to that of its comparators. The company submitted a Markov model that assessed the incremental cost effectiveness of CZP versus comparator biologic disease-modifying antirheumatic drugs (bDMARDs) for the treatment of RA from the perspective of the National Health Service for three decision problems, each of which followed an inadequate response to a TNFi. These were (1) a comparison against rituximab (RTX) in combination with methotrexate (MTX); (2) a comparison against bDMARDs when RTX was contraindicated or withdrawn due to an adverse event; and (3) a comparison against bDMARDs when MTX was contraindicated or withdrawn due to an adverse event. Results from the company's economic evaluation showed that CZP resulted in a similar number of quality-adjusted life years (QALYs) produced at similar or lower costs compared with comparator bDMARDs. The commercial-in-confidence patient access schemes for abatacept and tocilizumab could not be incorporated by the company, but were incorporated by the ERG in a confidential appendix for the NICE Appraisal Committee (AC). The company estimated that the addition of CZP before RTX in a sequence for patients who could receive MTX produced more QALYs at an increased cost, with a cost per QALY of £33,222. Following a critique of the model, the ERG undertook exploratory analyses that did not change the conclusions reached based on the company's economic evaluation in relation to the comparison with bDMARDs. The ERG estimated that where CZP replaced RTX, CZP was dominated, as it produced fewer QALYs at an increased cost. The AC concluded that there was little difference in effectiveness between CZP and comparator bDMARDs and that equivalence among bDMARDs could be accepted. The AC consequently recommended CZP plus MTX for people for whom RTX is contraindicated or not tolerated and CZP monotherapy for people for whom MTX is contraindicated or not tolerated. The AC concluded that CZP plus MTX could not be considered a cost-effective use of National Health Service resources when RTX plus MTX is a treatment option
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