1/Nc Expansion in QCD: Double-Line Counting Rules and the Undeservingly Discarded U(1) Ghost

The 1/Nc expansion is one of the very few methods we have for generating a systematic expansion of QCD at the energy scale relevant to hadron structure. The present formulation of this theory relies on the double-line notation for calculating the leading order of a diagram in the 1/Nc expansion, where the local SU(Nc) gauge symmetry is substituted by a U(Nc) symmetry and the associated U(1) ghost field is ignored. In the current work we demonstrate the insufficiency of this formulation for describing certain non-planar diagrams. We derive a more complete set of Feynman rules that include the U(1) ghost field and provide a useful tool for calculating both color factors and 1/Nc orders of all color-singlet diagrams

Simulating disease transmission dynamics at a multi-scale level

We present a model of the global spread of a generic human infectious disease using a Monte Carlo micro-simulation with large-scale parallel-processing. This prototype has been constructed and tested on a model of the entire population of the British Isles. Typical results are presented. A microsimulation of this order of magnitude of population simulation has not been previously attained. Further, an efficiency assessment of processor usage indicates that extension to the global scale is feasible. We conclude that the flexible approach outlined provides the framework for a virtual laboratory capable of supporting public health policy making at a variety of spatial scales.high-performance computing; global modelling; disease transmission

Thermolysis of imidates: A new method for the generation of carbonyl ylides

Thermolysis of dimethyl 2-[(3-oxo-3H-isoindol-1-yl)oxy]malonate (8) promotes a [1,4]-H shift in the imidic N¼C O CH fragment of the starting molecule, which leads to a reactive carbonyl ylide. This carbonyl ylide can be trapped by the C¼N bond of imidates and imines, as well as the C¼O bond of benzaldehyde. The corresponding cycloadducts 11, 14, and 16 are formed regioselectively in good yields (60 – 95%) and with high stereoselectivity. In the case of 11, the minor cycloadduct in solution undergoes an isomerization to give the more stable stereoisomer. The structures of two cycloadducts, i.e., 11a and 14a, have been established by X-ray crystallography

Study of contamination sensors. Volume I - Executive summary report

Design criteria for automatic remotely indicating fluid contamination sensors, monitors, counters, and recorders and for sampling equipment and technique

Phase space measure concentration for an ideal gas

We point out that a special case of an ideal gas exhibits concentration of the volume of its phase space, which is a sphere, around its equator in the thermodynamic limit. The rate of approach to the thermodynamic limit is determined. Our argument relies on the spherical isoperimetric inequality of L\'{e}vy and Gromov.Comment: 15 pages, No figures, Accepted by Modern Physics Letters

On local invariants of pure three-qubit states

We study invariants of three-qubit states under local unitary transformations, i.e. functions on the space of entanglement types, which is known to have dimension 6. We show that there is no set of six independent polynomial invariants of degree less than or equal to 6, and find such a set with maximum degree 8. We describe an intrinsic definition of a canonical state on each orbit, and discuss the (non-polynomial) invariants associated with it.Comment: LateX, 13 pages. Minor typoes corrected. Published versio

Integrating Community-Based Interventions to Reverse the Convergent TB/HIV Epidemics in Rural South Africa.

The WHO recommends integrating interventions to address the devastating TB/HIV co-epidemics in South Africa, yet integration has been poorly implemented and TB/HIV control efforts need strengthening. Identifying infected individuals is particularly difficult in rural settings. We used mathematical modeling to predict the impact of community-based, integrated TB/HIV case finding and additional control strategies on South Africa's TB/HIV epidemics. We developed a model incorporating TB and HIV transmission to evaluate the effectiveness of integrating TB and HIV interventions in rural South Africa over 10 years. We modeled the impact of a novel screening program that integrates case finding for TB and HIV in the community, comparing it to status quo and recommended TB/HIV control strategies, including GeneXpert, MDR-TB treatment decentralization, improved first-line TB treatment cure rate, isoniazid preventive therapy, and expanded ART. Combining recommended interventions averted 27% of expected TB cases (95% CI 18-40%) 18% HIV (95% CI 13-24%), 60% MDR-TB (95% CI 34-83%), 69% XDR-TB (95% CI 34-90%), and 16% TB/HIV deaths (95% CI 12-29). Supplementing these interventions with annual community-based TB/HIV case finding averted a further 17% of TB cases (44% total; 95% CI 31-56%), 5% HIV (23% total; 95% CI 17-29%), 8% MDR-TB (68% total; 95% CI 40-88%), 4% XDR-TB (73% total; 95% CI 38-91%), and 8% TB/HIV deaths (24% total; 95% CI 16-39%). In addition to increasing screening frequency, we found that improving TB symptom questionnaire sensitivity, second-line TB treatment delays, default before initiating TB treatment or ART, and second-line TB drug efficacy were significantly associated with even greater reductions in TB and HIV cases. TB/HIV epidemics in South Africa were most effectively curtailed by simultaneously implementing interventions that integrated community-based TB/HIV control strategies and targeted drug-resistant TB. Strengthening existing TB and HIV treatment programs is needed to further reduce disease incidence