155 research outputs found
Bulk perturbations of N=2 branes
The evolution of supersymmetric A-type D-branes under the bulk
renormalization group flow between two different N=2 minimal models is studied.
Using the Landau-Ginzburg description we show that a specific set of branes
decouples from the infrared theory, and we make detailed predictions for the
behavior of the remaining branes. The Landau-Ginzburg picture is then checked
against a direct conformal field theory analysis. In particular we construct a
natural index pairing which is preserved by the RG flow, and show that the
branes that decouple have vanishing index with the surviving branes.Comment: 35 pages (30 pages plus title and references), 8 figure
A quantum McKay correspondence for fractional 2p-branes on LG orbifolds
We study fractional 2p-branes and their intersection numbers in non-compact
orbifolds as well the continuation of these objects in Kahler moduli space to
coherent sheaves in the corresponding smooth non-compact Calabi-Yau manifolds.
We show that the restriction of these objects to compact Calabi-Yau
hypersurfaces gives the new fractional branes in LG orbifolds constructed by
Ashok et. al. in hep-th/0401135. We thus demonstrate the equivalence of the
B-type branes corresponding to linear boundary conditions in LG orbifolds,
originally constructed in hep-th/9907131, to a subset of those constructed in
LG orbifolds using boundary fermions and matrix factorization of the
world-sheet superpotential. The relationship between the coherent sheaves
corresponding to the fractional two-branes leads to a generalization of the
McKay correspondence that we call the quantum McKay correspondence due to a
close parallel with the construction of branes on non-supersymmetric orbifolds.
We also provide evidence that the boundary states associated to these branes in
a conformal field theory description corresponds to a sub-class of the boundary
states associated to the permutation branes in the Gepner model associated with
the LG orbifold.Comment: LaTeX2e, 1+39 pages, 3 figures (v2) refs added, typos and report no.
correcte
Fractional two-branes, toric orbifolds and the quantum McKay correspondence
We systematically study and obtain the large-volume analogues of fractional
two-branes on resolutions of orbifolds C^3/Z_n. We study a generalisation of
the McKay correspondence proposed in hep-th/0504164 called the quantum McKay
correspondence by constructing duals to the fractional two-branes. Details are
explicitly worked out for two examples -- the crepant resolutions of C^3/Z_3
and C^3/Z_5.Comment: 34 pages, 2 figures, LaTeX (JHEP3 style); (v2) typos corrected; (v3)
sec 3 reorganise
The effectiveness of anaerobic digestion in removing estrogens and nonylphenol ethoxylates
This is the post-print version of the final paper published in Journal of Hazardous Materials. The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright @ 2011 Elsevier B.V.The fate and behaviour of two groups of endocrine disrupting chemicals, steroid estrogens and nonylphenol ethoxylates, have been evaluated during the anaerobic digestion of primary and mixed sewage sludge under mesophilic and thermophilic conditions. Digestion occurred over six retention times, in laboratory scale reactors, treating sludges collected from a sewage treatment works in the United Kingdom. It has been established that sludge concentrations of both groups of compounds demonstrated temporal variations and that concentrations in mixed sludge were influenced by the presence of waste activated sludge as a result of transformations during aerobic treatment. The biodegradation of total steroid estrogens was >50% during primary sludge digestion with lower removals observed for mixed sludge, which reflected bulk organic solids removal efficiencies. The removal of nonylphenol ethoxylates was greater in mixed sludge digestion (>58%) compared with primary sludge digestion and did not reflect bulk organic removal efficiencies. It is apparent that anaerobic digestion reduces the concentrations of these compounds, and would therefore be expected to confer a degree of protection against exposure and transfer of both groups of compounds to the receiving/re-use environment.Thames Water, Yorkshire Water, and EPSRC
Application of non-HDL cholesterol for population-based cardiovascular risk stratification: results from the Multinational Cardiovascular Risk Consortium.
BACKGROUND: The relevance of blood lipid concentrations to long-term incidence of cardiovascular disease and the relevance of lipid-lowering therapy for cardiovascular disease outcomes is unclear. We investigated the cardiovascular disease risk associated with the full spectrum of bloodstream non-HDL cholesterol concentrations. We also created an easy-to-use tool to estimate the long-term probabilities for a cardiovascular disease event associated with non-HDL cholesterol and modelled its risk reduction by lipid-lowering treatment. METHODS: In this risk-evaluation and risk-modelling study, we used Multinational Cardiovascular Risk Consortium data from 19 countries across Europe, Australia, and North America. Individuals without prevalent cardiovascular disease at baseline and with robust available data on cardiovascular disease outcomes were included. The primary composite endpoint of atherosclerotic cardiovascular disease was defined as the occurrence of the coronary heart disease event or ischaemic stroke. Sex-specific multivariable analyses were computed using non-HDL cholesterol categories according to the European guideline thresholds, adjusted for age, sex, cohort, and classical modifiable cardiovascular risk factors. In a derivation and validation design, we created a tool to estimate the probabilities of a cardiovascular disease event by the age of 75 years, dependent on age, sex, and risk factors, and the associated modelled risk reduction, assuming a 50% reduction of non-HDL cholesterol. FINDINGS: Of the 524 444 individuals in the 44 cohorts in the Consortium database, we identified 398 846 individuals belonging to 38 cohorts (184 055 [48·7%] women; median age 51·0 years [IQR 40·7-59·7]). 199 415 individuals were included in the derivation cohort (91 786 [48·4%] women) and 199 431 (92 269 [49·1%] women) in the validation cohort. During a maximum follow-up of 43·6 years (median 13·5 years, IQR 7·0-20·1), 54 542 cardiovascular endpoints occurred. Incidence curve analyses showed progressively higher 30-year cardiovascular disease event-rates for increasing non-HDL cholesterol categories (from 7·7% for non-HDL cholesterol <2·6 mmol/L to 33·7% for ≥5·7 mmol/L in women and from 12·8% to 43·6% in men; p<0·0001). Multivariable adjusted Cox models with non-HDL cholesterol lower than 2·6 mmol/L as reference showed an increase in the association between non-HDL cholesterol concentration and cardiovascular disease for both sexes (from hazard ratio 1·1, 95% CI 1·0-1·3 for non-HDL cholesterol 2·6 to <3·7 mmol/L to 1·9, 1·6-2·2 for ≥5·7 mmol/L in women and from 1·1, 1·0-1·3 to 2·3, 2·0-2·5 in men). The derived tool allowed the estimation of cardiovascular disease event probabilities specific for non-HDL cholesterol with high comparability between the derivation and validation cohorts as reflected by smooth calibration curves analyses and a root mean square error lower than 1% for the estimated probabilities of cardiovascular disease. A 50% reduction of non-HDL cholesterol concentrations was associated with reduced risk of a cardiovascular disease event by the age of 75 years, and this risk reduction was greater the earlier cholesterol concentrations were reduced. INTERPRETATION: Non-HDL cholesterol concentrations in blood are strongly associated with long-term risk of atherosclerotic cardiovascular disease. We provide a simple tool for individual long-term risk assessment and the potential benefit of early lipid-lowering intervention. These data could be useful for physician-patient communication about primary prevention strategies. FUNDING: EU Framework Programme, UK Medical Research Council, and German Centre for Cardiovascular Research
Relations between the milnor and quillen K-theory of fields
De novo mutations in specific mTOR pathway genes cause brain overgrowth in the context of intellectual disability (ID). By analyzing 101 mMTOR-related genes in a large ID patient cohort and two independent population cohorts, we show that these genes modulate brain growth in health and disease. We report the mTOR activator gene RHEB as an ID gene that is associated with megalencephaly when mutated. Functional testing of mutant RHEB in vertebrate animal models indicates pathway hyperactivation with a concomitant increase in cell and head size, aberrant neuronal migration, and induction of seizures, concordant with the human phenotype. This study reveals that tight control of brain volume is exerted through a large community of mTOR-related genes. Human brain volume can be altered, by either rare disruptive events causing hyperactivation of the pathway, or through the collective effects of common alleles
История развития физической культуры и спорта на Урале в дореволюционный период
На сегодняшний день становится чрезвычайно актуальным рассмотрение феномена физической культуры и спорта сквозь призму принципа историзма. Существует еще много неизвестного в истории физической культуры, что требует переоценки событий, фактов с позиции современност
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