531 research outputs found

    Takiff superalgebras and Conformal Field Theory

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    A class of non-semisimple extensions of Lie superalgebras is studied. They are obtained by adjoining to the superalgebra its adjoint representation as an abelian ideal. When the superalgebra is of affine Kac-Moody type, a generalisation of Sugawara's construction is shown to give rise to a copy of the Virasoro algebra and so, presumably, to a conformal field theory. Evidence for this is detailed for the extension of the affinisation of the superalgebra gl(1|1): Its highest weight irreducible modules are classified using spectral flow, the irreducible supercharacters are computed and a continuum version of the Verlinde formula is verified to give non-negative integer structure coefficients. Interpreting these coefficients as those of the Grothendieck ring of fusion, partial results on the true fusion ring and its indecomposable structures are deduced.Comment: 25 page

    Water butts as sustainable (urban) drainage systems (SuDS) devices

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    Heightened levels of urban development and population rise, combined with increased precipitation resulting from climatic variations, have escalated runoff rates within urban areas, causing urban flooding and polluting of watercourses. Implementing effective drainage solutions to manage these effects is essential to promote sustainable economic, environmental and social development. Larger-scale SuDS implementation has seen a rise in recent years. However, according to current literature, small-scale property-specific SuDS solutions require further research before implementation is possible, to develop guidance on optimum setups and assess performance levels. This gap in literature directed the aim of this project to determine if, and how, domestic water butts can perform as SuDS devices, to provide storage and attenuation, with the aim of reducing surface runoff and urban flooding. This project utilised physical modelling to explore different outlet options and generate original data related to the outlets, and numerical modelling (Excel) to quantify the benefits achieved by using a water butt with restricted flow outlets as a SuDS device. The main conclusion is that under the storm conditions used within the model, water butts can perform as SuDS devices by providing temporary storage and reducing runoff volumes conveyed to sewer systems during a storm event. Conclusions related to water butt setups suggested that larger capacity water butts, outlets that provide significant restriction, and drawdown levels at half the capacity or below, provide better SuDS performance. Finally, the project identified that simple outlets should be the primary outlet solution to provide consistent operation and SuDS performance, whereas siphon outlets should be used where storm events consistently guarantee adequate runoff to fill the water butt above the upper bend of the siphon

    A randomized study of autologous bone marrow–derived stem cells in pediatric cardiomyopathy

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    Background: Bone marrow mononuclear cell fraction has been used as therapy for dilated cardiomyopathy in adults. Although case series are reported, there are no randomized controlled studies in children. / Methods: We designed a randomized, crossover, controlled pilot study to determine safety and feasibility of intracoronary stem cell therapy in children. The primary safety end-point was freedom from death and transplantation or any complication that could be considered related to bone marrow injection or anesthesia (e.g., infection, malignancy, anaphylaxis, renal deterioration). Other end-points were magnetic resonance imaging measurements and N-terminal prohormone brain natriuretic peptide. Participants included 10 children (mean age 7.2 years; range, 2.2–14.1 years; 6 boys) with cardiomyopathy (New York Heart Association/Ross Classification II–IV). Patients were crossed over at 6 months. / Results: The original protocol was completed by 9 patients. The safety end-point was achieved in all. Ratio of the geometric means for treatment effect adjusting for baseline was assessed for end-diastolic and end-systolic volumes (EDV, ESV): 0.93 for EDV (95% confidence interval 0.88–0.99, p = 0.01), indicating EDV was on average 7% lower in patients after stem cell treatment, and 0.90 for ESV (95% confidence interval 0.82–1.00, p = 0.05), indicating ESV was on average 10% lower after stem cell treatment compared with placebo. The primary efficacy end-point ejection fraction was not met. / Conclusions: Bone marrow mononuclear cell therapy for cardiomyopathy is feasible and safe in children. Left ventricular volumes were significantly reduced 6 months after stem cell injection compared with placebo, which may reflect reverse remodeling

    P02.123. The anti-diabetic and cholesterol-lowering effects of common and cassia cinnamon (Cinnamomum verum and C. aromaticum): a randomized controlled trial

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    This paper accompanies a poster presentation on the anti-diabetic and cholesterol-lowering effects of common and cassia cinnamon (Cinnamomum verum and C. aromaticum)

    A change in temperature modulates defence to yellow (stripe) rust in wheat line UC1041 independently of resistance gene Yr36

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    Background Rust diseases are of major importance in wheat production worldwide. With the constant evolution of new rust strains and their adaptation to higher temperatures, consistent and durable disease resistance is a key challenge. Environmental conditions affect resistance gene performance, but the basis for this is poorly understood. Results Here we show that a change in day temperature affects wheat resistance to Puccinia striiformis f. sp tritici (Pst), the causal agent of yellow (or stripe) rust. Using adult plants of near-isogenic lines UC1041 +/- Yr36, there was no significant difference between Pst percentage uredia coverage in plants grown at day temperatures of 18°C or 25°C in adult UC1041 + Yr36 plants. However, when plants were transferred to the lower day temperature at the time of Pst inoculation, infection increased up to two fold. Interestingly, this response was independent of Yr36, which has previously been reported as a temperature-responsive resistance gene as Pst development in adult UC1041 -Yr36 plants was similarly affected by the plants experiencing a temperature reduction. In addition, UC1041 -Yr36 plants grown at the lower temperature then transferred to the higher temperature were effectively resistant and a temperature change in either direction was shown to affect Pst development up to 8 days prior to inoculation. Results for seedlings were similar, but more variable compared to adult plants. Enhanced resistance to Pst was observed in seedlings of UC1041 and the cultivar Shamrock when transferred to the higher temperature. Resistance was not affected in seedlings of cultivar Solstice by a temperature change in either direction. Conclusions Yr36 is effective at 18°C, refining the lower range of temperature at which resistance against Pst is conferred compared to previous studies. Results reveal previously uncharacterised defence temperature sensitivity in the UC1041 background which is caused by a change in temperature and independently of Yr36. This novel phenotype is present in some cultivars but absent in others, suggesting that Pst defence may be more stable in some cultivars than others when plants are exposed to varying temperatures

    A critical reflection on the development of the Participatory Autism Research Collective (PARC)

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    Purpose The Participatory Autism Research Collective (PARC) was initially set up with the purpose of bringing autistic people, including scholars and activists (but not exclusively), together with early career researchers and practitioners who work with autistic people, with the aim being to build a community where those who wished to see more significant involvement of autistic people in autism research could share knowledge and expertise. Approach This article explores the development of the PARC network, reflecting upon its activities and ethos within current Higher Education (HE) practices and structures. Findings In supporting autistic individuals in their attempts to establish themselves within academic systems that may not always be considerate or accommodating, the existence of PARC creates a structure with which autistic people can influence social change. PARC serves as a network of support, strengthening the presence of autistic scholars in academia. It also provides a structure through which autistic people are able to demonstrate helpful practices with which to engage more broadly. Value The PARC network is the first autistic-led venture of its kind in the UK to have a sustained impact. PARC is growing to become an important element in the field of autism studies both by supporting the emerging autistic academics and by promoting ethical and participatory research methods and practices

    Combining qualitative and quantitative operational research methods to inform quality improvement in pathways that span multiple settings

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    BACKGROUND: Improving integration and continuity of care across sectors within resource constraints is a priority in many health systems. Qualitative operational research methods of problem structuring have been used to address quality improvement in services involving multiple sectors but not in combination with quantitative operational research methods that enable targeting of interventions according to patient risk. We aimed to combine these methods to augment and inform an improvement initiative concerning infants with congenital heart disease (CHD) whose complex care pathway spans multiple sectors. METHODS: Soft systems methodology was used to consider systematically changes to services from the perspectives of community, primary, secondary and tertiary care professionals and a patient group, incorporating relevant evidence. Classification and regression tree (CART) analysis of national audit datasets was conducted along with data visualisation designed to inform service improvement within the context of limited resources. RESULTS: A 'Rich Picture' was developed capturing the main features of services for infants with CHD pertinent to service improvement. This was used, along with a graphical summary of the CART analysis, to guide discussions about targeting interventions at specific patient risk groups. Agreement was reached across representatives of relevant health professions and patients on a coherent set of targeted recommendations for quality improvement. These fed into national decisions about service provision and commissioning. CONCLUSIONS: When tackling complex problems in service provision across multiple settings, it is important to acknowledge and work with multiple perspectives systematically and to consider targeting service improvements in response to confined resources. Our research demonstrates that applying a combination of qualitative and quantitative operational research methods is one approach to doing so that warrants further consideration

    Assimilation of sea ice thickness derived from CryoSat-2 along-track freeboard measurements into the Met Office's Forecast Ocean Assimilation Model (FOAM)

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    The feasibility of assimilating sea ice thickness (SIT) observations derived from CryoSat-2 along-track measurements of sea ice freeboard is successfully demonstrated using a 3D-Var assimilation scheme, NEMOVAR, within the Met Office's global, coupled ocean–sea-ice model, Forecast Ocean Assimilation Model (FOAM). The CryoSat-2 Arctic freeboard measurements are produced by the Centre for Polar Observation and Modelling (CPOM) and are converted to SIT within FOAM using modelled snow depth. This is the first time along-track observations of SIT have been used in this way, with other centres assimilating gridded and temporally averaged observations. The assimilation leads to improvements in the SIT analysis and forecast fields generated by FOAM, particularly in the Canadian Arctic. Arctic-wide observation-minus-background assimilation statistics for 2015–2017 show improvements of 0.75 m mean difference and 0.41 m root-mean-square difference (RMSD) in the freeze-up period and 0.46 m mean difference and 0.33 m RMSD in the ice break-up period. Validation of the SIT analysis against independent springtime in situ SIT observations from NASA Operation IceBridge (OIB) shows improvement in the SIT analysis of 0.61 m mean difference (0.42 m RMSD) compared to a control without SIT assimilation. Similar improvements are seen in the FOAM 5 d SIT forecast. Validation of the SIT assimilation with independent Beaufort Gyre Exploration Project (BGEP) sea ice draft observations does not show an improvement, since the assimilated CryoSat-2 observations compare similarly to the model without assimilation in this region. Comparison with airborne electromagnetic induction (Air-EM) combined measurements of SIT and snow depth shows poorer results for the assimilation compared to the control, despite covering similar locations to the OIB and BGEP datasets. This may be evidence of sampling uncertainty in the matchups with the Air-EM validation dataset, owing to the limited number of observations available over the time period of interest. This may also be evidence of noise in the SIT analysis or uncertainties in the modelled snow depth, in the assimilated SIT observations, or in the data used for validation. The SIT analysis could be improved by upgrading the observation uncertainties used in the assimilation. Despite the lack of CryoSat-2 SIT observations available for assimilation over the summer due to the detrimental effect of melt ponds on retrievals, it is shown that the model is able to retain improvements to the SIT field throughout the summer months due to prior, wintertime SIT assimilation. This also results in regional improvements to the July modelled sea ice concentration (SIC) of 5 % RMSD in the European sector, due to slower melt of the thicker sea ice

    A Note on the Equality of Algebraic and Geometric D-Brane Charges in WZW Models

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    The algebraic definition of charges for symmetry-preserving D-branes in Wess-Zumino-Witten models is shown to coincide with the geometric definition, for all simple Lie groups. The charge group for such branes is computed from the ambiguities inherent in the geometric definition.Comment: 12 pages, fixed typos, added references and a couple of remark

    Assessing the effectiveness of front of pack labels: Findings from an online randomised-controlled experiment in a representative British sample

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    Front of pack food labels (FOPLs) provide accessible nutritional information to guide consumer choice. Using an online experiment with a large representative British sample, we aimed to examine whether FOPLs improve participants’ ability to identify the healthiness of foods and drinks. The primary aim was to compare ability to rank between FOPL groups and a no label control. Adults (≥18 years), recruited from the NatCen panel, were randomised to one of five experimental groups (Multiple Traffic Light, MTL; Nutri-Score, N-S; Warning Label, WL; Positive Choice tick, PC; no label control). Stratification variables were year of recruitment to panel, sex, age, government office region, and household income. Packaging images were created for three versions, varying in healthiness, of six food and drink products (pizza, drinks, cakes, crisps, yoghurts, breakfast cereals). Participants were asked to rank the three product images in order of healthiness. Ranking was completed on a single occasion and comprised a baseline measure (with no FOPL), and a follow-up measure including the FOPL as per each participant’s experimental group. The primary outcome was the ability to accurately rank product healthiness (all products ranked correctly vs. any incorrect). In 2020, 4504 participants had complete data and were included in the analysis. The probability of correct ranking at follow-up, and improving between baseline and follow-up, was significantly greater across all products for the N-S, MTL and WL groups, compared to control. This was seen for only some of the products for the PC group. The largest effects were seen for N-S, followed by MTL. These analyses were adjusted for stratification variables, ethnicity, education, household composition, food shopping responsibility, and current FOPL use. Exploratory analyses showed a tendency for participants with higher compared to lower education to rank products more accurately. Conclusions: All FOPLs were effective at improving participants’ ability to correctly rank products according to healthiness in this large representative British sample, with the largest effects seen for N-S, followed by MTL
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