1,165 research outputs found
Symmetries of Abelian Orbifolds
Using the Polya Enumeration Theorem, we count with particular attention to
C^3/Gamma up to C^6/Gamma, abelian orbifolds in various dimensions which are
invariant under cycles of the permutation group S_D. This produces a collection
of multiplicative sequences, one for each cycle in the Cycle Index of the
permutation group. A multiplicative sequence is controlled by its values on
prime numbers and their pure powers. Therefore, we pay particular attention to
orbifolds of the form C^D/Gamma where the order of Gamma is p^alpha. We propose
a generalization of these sequences for any D and any p.Comment: 75 pages, 13 figures, 30 table
Frequent use of paracetamol and risk of allergic disease among women in an Ethiopian population
Introduction
The hypothesis that paracetamol might increase the risk of asthma and other allergic diseases have gained support from a range of independent studies. However, in studies based in developed countries, the possibility that paracetamol and asthma are associated through aspirin avoidance is difficult to exclude.
Objectives
To explore this hypothesis among women in a developing country, where we have previously reported aspirin avoidance to be rare.
Methods
In 2005/6 a population based cohort of 1065 pregnant women was established in Butajira, Ethiopia and baseline demographic data collected. At 3 years post birth, an interview-based questionnaire administered to 945 (94%) of these women collected data on asthma, eczema, and hay fever in the past 12 month, frequency of paracetamol use and potential confounders. Allergen skin tests to Dermatophagoides pteronyssinus and cockroach were also performed. The independent effects of paracetamol use on allergic outcomes were determined using multiple logistic regression analysis.
Findings
The prevalence of asthma, eczema and hay fever was 1.7%, 0.9% and 3.8% respectively; of any one of these conditions 5.5%, and of allergen sensitization 7.8%. Paracetamol use in the past month was reported by 29%, and associations of borderline significance were seen for eczema (adjusted OR (95% CI) = 8.51 (1.68 to 43.19) for 1–3 tablets and 2.19 (0.36 to 13.38) for ≥4 tablets, compared to no tablets in the past month; overall p = 0.055) and for ‘any allergic condition’ (adjusted OR (95% CI) = 2.73 (1.22 to 6.11) for 1–3 tablets and 1.35 (0.67 to 2.70) for ≥4 tablets compared to 0 in the past month; overall p = 0.071).
Conclusions
This study provides further cross-sectional evidence that paracetamol use increases the risk of allergic disease
Contribution of main causes of death to social inequalities in mortality in the whole population of Scania, Sweden
BACKGROUND: To more efficiently reduce social inequalities in mortality, it is important to establish which causes of death contribute the most to socioeconomic mortality differentials. Few studies have investigated which diseases contribute to existing socioeconomic mortality differences in specific age groups and none were in samples of the whole population, where selection bias is minimized. The aim of the present study was to determine which causes of death contribute the most to social inequalities in mortality in each age group in the whole population of Scania, Sweden. METHODS: Data from LOMAS (Longitudinal Multilevel Analysis in Skåne) were used to estimate 12-year follow-up mortality rates across levels of socioeconomic position (SEP) and workforce participation in 975,938 men and women aged 0 to 80 years, during 1991–2002. RESULTS: The results generally showed increasing absolute mortality differences between those holding manual and non-manual occupations with increasing age, while there were inverted u-shaped associations when using relative inequality measures. Cardiovascular diseases (CVD) contributed to 52% of the male socioeconomic difference in overall mortality, cancer to 18%, external causes to 4% and psychiatric disorders to 3%. The corresponding contributions in women were 55%, 21%, 2% and 3%. Additionally, those outside the workforce (i.e., students, housewives, disability pensioners, and the unemployed) showed a strongly increased risk of future mortality in all age groups compared to those inside the workforce. Even though coronary heart disease (CHD) played a major contributing role to the mortality differences seen, stroke and other types of cardiovascular diseases also made substantial contributions. Furthermore, while the most common types of cancers made substantial contributions to the socioeconomic mortality differences, in some age groups more than half of the differences in cancer mortality could be attributed to rarer cancers. CONCLUSION: CHD made a major contribution to the socioeconomic differences in overall mortality. However, there were also important contributions from diseases with less well understood mechanistic links with SEP such as stroke and less-common cancers. Thus, an increased understanding of the mechanisms connecting SEP with more rare causes of disease might be important to be able to more successfully intervene on socioeconomic differences in health
Cross-sectional analysis of educational inequalities in primary prevention statin use in UK Biobank.
OBJECTIVE: Identify whether participants with lower education are less likely to report taking statins for primary cardiovascular prevention than those with higher education, but an equivalent increase in underlying cardiovascular risk. METHODS: Using data from a large prospective cohort study, UK Biobank, we calculated a QRISK3 cardiovascular risk score for 472 097 eligible participants with complete data on self-reported educational attainment and statin use (55% female participants; mean age 56 years). We used logistic regression to explore the association between (i) QRISK3 score and (ii) educational attainment on self-reported statin use. We then stratified the association between QRISK3 score and statin use, by educational attainment to test for interactions. RESULTS: There was evidence of an interaction between QRISK3 score and educational attainment. Per unit increase in QRISK3 score, more educated individuals were more likely to report taking statins. In women with ≤7 years of schooling, a one unit increase in QRISK3 score was associated with a 7% higher odds of statin use (OR 1.07, 95% CI 1.07 to 1.07). In women with ≥20 years of schooling, a one unit increase in QRISK3 score was associated with an 14% higher odds of statin use (OR 1.14, 95% CI 1.14 to 1.15). Comparable ORs in men were 1.04 (95% CI 1.04 to 1.05) for ≤7 years of schooling and 1.08 (95% CI 1.08, 1.08) for ≥20 years of schooling. CONCLUSION: Per unit increase in QRISK3 score, individuals with lower educational attainment were less likely to report using statins, likely contributing to health inequalities
The Beta Ansatz: A Tale of Two Complex Structures
Brane tilings, sometimes called dimer models, are a class of bipartite graphs on a torus which encode the gauge theory data of four-dimensional SCFTs dual to D3-branes probing toric Calabi-Yau threefolds. An efficient way of encoding this information exploits the theory of dessin d’enfants, expressing the structure in terms of a permutation triple, which is in turn related to a Belyi pair, namely a holomorphic map from a torus to a P1 with three marked points. The procedure of a-maximization, in the context of isoradial embeddings of the dimer, also associates a complex structure to the torus, determined by the R-charges in the SCFT, which can be compared with the Belyi complex structure. Algorithms for the explicit construction of the Belyi pairs are described in detail. In the case of orbifolds, these algorithms are related to the construction of covers of elliptic curves, which exploits the properties of Weierstraß elliptic functions. We present a counter example to a previous conjecture identifying the complex structure of the Belyi curve to the complex structure associated with R-charges
Trial Protocol: Randomised controlled trial of the effects of very low calorie diet, modest dietary restriction, and sequential behavioural programme on hunger, urges to smoke, abstinence and weight gain in overweight smokers stopping smoking
Background\ud
Weight gain accompanies smoking cessation, but dieting during quitting is controversial as hunger may increase urges to smoke. This is a feasibility trial for the investigation of a very low calorie diet (VLCD), individual modest energy restriction, and usual advice on hunger, ketosis, urges to smoke, abstinence and weight gain in overweight smokers trying to quit. \ud
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Methods\ud
This is a 3 armed, unblinded, randomized controlled trial in overweight (BMI > 25 kg/), daily smokers (CO > 10 ppm); with at least 30 participants in each group. Each group receives identical behavioural support and NRT patches (25 mg(8 weeks),15 mg(2 weeks),10 mg(2 weeks)). The VLCD group receive a 429-559 kcal/day liquid formula beginning 1 week before quitting and continuing for 4 weeks afterwards. The modest energy restricted group (termed individual dietary and activity planning(IDAP)) engage in goal-setting and receive an energy prescription based on individual basal metabolic rate(BMR) aiming for daily reduction of 600 kcal. The control group receive usual dietary advice that accompanies smoking cessation i.e. avoiding feeling hungry but eating healthy snacks. After this, the VLCD participants receive IDAP to provide support for changing eating habits in the longer term; the IDAP group continues receiving this support. The control group receive IDAP 8 weeks after quitting. This allows us to compare IDAP following a successful quit attempt with dieting concurrently during quitting. It also aims to prevent attrition in the unblinded, control group by meeting their need for weight management. Follow-up occurs at 6 and 12 months. \ud
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Outcome measures include participant acceptability, measured qualitatively by semi-structured interviewing and quantitatively by recruitment and attrition rates. Feasibility of running the trial within primary care is measured by interview and questionnaire of the treatment providers. Adherence to the VLCD is verified by the presence of urinary ketones measured weekly. Daily urges to smoke, hunger and withdrawal are measured using the Mood and Physical Symptoms Scale-Combined (MPSS-C) and a Hunger Craving Score (HCS). 24 hour, 7 day point prevalence and 4-week prolonged abstinence (Russell Standard) is confirmed by CO < 10 ppm. Weight, waist and hip circumference and percentage body fat are measured at each visit. \ud
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Trial Registration\ud
Current controlled trials ISRCTN83865809\ud
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Counting Orbifolds
We present several methods of counting the orbifolds C^D/Gamma. A
correspondence between counting orbifold actions on C^D, brane tilings, and
toric diagrams in D-1 dimensions is drawn. Barycentric coordinates and scaling
mechanisms are introduced to characterize lattice simplices as toric diagrams.
We count orbifolds of C^3, C^4, C^5, C^6 and C^7. Some remarks are made on
closed form formulas for the partition function that counts distinct orbifold
actions.Comment: 69 pages, 9 figures, 24 tables; minor correction
Translating clinicians' beliefs into implementation interventions (TRACII) : a protocol for an intervention modeling experiment to change clinicians' intentions to implement evidence-based practice
Background: Biomedical research constantly produces new findings, but these are not routinely incorporated into health care practice. Currently, a range of interventions to promote the uptake of emerging evidence are available. While their effectiveness has been tested in pragmatic trials, these do not form a basis from which to generalise to routine care settings. Implementation research is the scientific study of methods to promote the uptake of research findings, and hence to reduce inappropriate care. As clinical practice is a form of human behaviour, theories of human behaviour that have proved to be useful in other settings offer a basis for developing a scientific rationale for the choice of interventions. Aims: The aims of this protocol are 1) to develop interventions to change beliefs that have already been identified as antecedents to antibiotic prescribing for sore throats, and 2) to experimentally evaluate these interventions to identify those that have the largest impact on behavioural intention and behavioural simulation.
Design: The clinical focus for this work will be the management of uncomplicated sore throat in general practice. Symptoms of upper respiratory tract infections are common presenting features in primary care. They are frequently treated with antibiotics, and research evidence is clear that antibiotic treatment offers little or no benefit to otherwise healthy adult patients.
Reducing antibiotic prescribing in the community by the "prudent" use of antibiotics is seen as one way to slow the rise in antibiotic resistance, and appears safe, at least in children. However, our understanding of how to do this is limited. Participants will be general medical practitioners. Two theory-based interventions will be designed to address the discriminant beliefs in the prescribing of antibiotics for sore throat, using empirically derived resources. The interventions will be evaluated in a 2 × 2 factorial randomised controlled trial delivered in a postal questionnaire survey. Two outcome measures will be assessed: behavioural intention and behavioural simulation.This study is funded by the European Commission Research Directorate as part of a multi-partner program: Research Based Education and Quality Improvement (ReBEQI): A Framework and tools to develop effective quality improvement programs in European healthcare. (Proposal No: QLRT-2001-00657)
Cancer symptom awareness and barriers to symptomatic presentation in England – Are we clear on cancer?
Background: Low cancer awareness may contribute to delayed diagnosis and poor cancer survival. We aimed to quantify socio-demographic differences in cancer symptom awareness and barriers to symptomatic presentation in the English population.
Methods: Using a uniquely large data set (n=49?270), we examined the association of cancer symptom awareness and barriers to presentation with age, gender, marital status and socio-economic position (SEP), using logistic regression models to control for confounders.
Results: The youngest and oldest, the single and participants with the lowest SEP recognised the fewest cancer symptoms, and reported most barriers to presentation. Recognition of nine common cancer symptoms was significantly lower, and embarrassment, fear and difficulties in arranging transport to the doctor’s surgery were significantly more common in participants living in the most deprived areas than in the most affluent areas. Women were significantly more likely than men to both recognise common cancer symptoms and to report barriers. Women were much more likely compared with men to report that fear would put them off from going to the doctor.
Conclusions: Large and robust socio-demographic differences in recognition of some cancer symptoms, and perception of some barriers to presentation, highlight the need for targeted campaigns to encourage early presentation and improve cancer outcomes
N=1 Chern-Simons theories, orientifolds and Spin(7) cones
We construct three dimensional N=1 Chern-Simons theories living on M2 branes
probing Spin(7) cones. We consider Spin(7) manifolds obtained as quotients of
Calabi-Yau four-folds by an anti-holomorphic involution, following a
construction by Joyce. The corresponding Chern-Simons theories can be obtained
from N=2 theories by an orientifolding procedure. These theories are
holographically dual to M theory solutions AdS_4 \times H, where the weak G_2
manifold H is the base of the Spin(7) cone.Comment: 26 pages, 3 figures, reference added
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