Factorization Contributions and the Breaking of the ΔI=1/2\Delta I=1/2 Rule in Weak ΛNρ\Lambda N\rho and ΣNρ\Sigma N\rho Couplings

We compute the modified factorization contributions to the $\Lambda\rightarrow N\rho$ and $\Sigma\rightarrow N\rho$ couplings and demonstrate that these contributions naturally include $\Delta I=3/2$ terms which are comparable ($\simeq 0.4$ to $-0.8$ times) in magnitude to the corresponding $\Delta I=1/2$ terms. As a consequence, we conclude that models which treat vector meson exchange contributions to the weak conversion process $\Lambda N\rightarrow NN$ assuming such weak couplings to satisfy the $\Delta I=1/2$ rule are unlikely to be reliable.Comment: 13 pages, uses REVTEX Entire manuscript available as a ps file at http://www.physics.adelaide.edu.au/theory/home.html . Also available via anonymous ftp at ftp://adelphi.adelaide.edu.au/pub/theory/ADP-95-5.T172.ps To appear in Physical Review

Resonant behaviour in double charge exchange reaction of \pi^+ mesons on the nuclear photoemulsion

The invariant mass spectra of the $pp\pi^-$ and $pp$ systems produced in the double charge exchange (DCX) of positively charged pions on photoemulsion are analysed. A pronounced peak is observed in the $pp\pi^-$ invariant mass spectrum, while the $M_{pp}$ spectrum exhibits a strong Migdal-Watson effect of the proton-proton final state interaction. These findings are in favor of the $NN$-decoupled $NN\pi$ pseudoscalar resonance with T=0 called $d'$.Comment: 13 pages, 5 figures, revised versio

SU(3) Decomposition of Two-Body B Decay Amplitudes

We present the complete flavor SU(3) decomposition of decay amplitudes for decays of the triplet (B^+_u, B^0_d, B^0_s) of B mesons nonleptonically into two pseudoscalar mesons. This analysis holds for arbitrarily broken SU(3) and can be used to generate amplitude relations when physical arguments permit one to neglect or relate any of the reduced amplitudes.Comment: 31 pages, revtex, no figure

Mechanisms of Addition and Substitution Reactions of Furfural and Derivatives

In a complete series of substitution reactions (such as halogenation, nitration, mercuration, etc.,) of furfural and its derivatives, it appears that substitution is preceded by addition. For example, in bromination, two atoms of bromine first add to give a relatively unstable intermediate which then loses hydrogen bromide. These preliminary additions may be 1, 2- or 1, 4- or 1, 6- additions depending upon reactants and upon experimental conditions. Accompanying some of these transformations are ring fission and ring closure, and rearrangements involving unsaturated linkages. Typical illustrations of these changes were presented

Discriminating active from latent tuberculosis in patients presenting to community clinics.

BACKGROUND: Because of the high global prevalence of latent TB infection (LTBI), a key challenge in endemic settings is distinguishing patients with active TB from patients with overlapping clinical symptoms without active TB but with co-existing LTBI. Current methods are insufficiently accurate. Plasma proteomic fingerprinting can resolve this difficulty by providing a molecular snapshot defining disease state that can be used to develop point-of-care diagnostics. METHODS: Plasma and clinical data were obtained prospectively from patients attending community TB clinics in Peru and from household contacts. Plasma was subjected to high-throughput proteomic profiling by mass spectrometry. Statistical pattern recognition methods were used to define mass spectral patterns that distinguished patients with active TB from symptomatic controls with or without LTBI. RESULTS: 156 patients with active TB and 110 symptomatic controls (patients with respiratory symptoms without active TB) were investigated. Active TB patients were distinguishable from undifferentiated symptomatic controls with accuracy of 87% (sensitivity 84%, specificity 90%), from symptomatic controls with LTBI (accuracy of 87%, sensitivity 89%, specificity 82%) and from symptomatic controls without LTBI (accuracy 90%, sensitivity 90%, specificity 92%). CONCLUSIONS: We show that active TB can be distinguished accurately from LTBI in symptomatic clinic attenders using a plasma proteomic fingerprint. Translation of biomarkers derived from this study into a robust and affordable point-of-care format will have significant implications for recognition and control of active TB in high prevalence settings

One Spin Trace Formalism for BK B_K

It has been known for some time that there are two methods to calculate $B_K$ with staggered fermions: one is the two spin trace formalism and the other is the one spin trace formalism. Until now, the two spin trace formalism has been exclusively used for weak matrix element calculations with staggered fermions. Here, the one spin trace formalism to calculate $B_K$ with staggered fermions is explained. It is shown that the one spin trace operators require additional chiral partner operators in order to keep the continuum chiral behavior. The renormalization of the one spin trace operators is described and compared with the two spin trace formalism.Comment: 47 pages, latex, 4 figures are available on reques

Determination of CKM phases through rigid polygons of flavor SU(3) amplitudes

Some new methods for the extraction of CKM phases $\alpha$ and $\gamma$ using flavor SU(3) symmetry have been suggested through the construction of rigid polygons in the complex plane with sides equal to the decay amplitudes of B mesons into two mesons belonging to the light (charmless) pseudoscalar octet. These rigid polygons incorporate all the possible amplitude triangles and, being overdetermined, also serve as consistency checks and in estimating the rates of some decay modes. The same techniques also lead to numerous useful amplitude triangles when octet-singlet mixing has been taken into account and nearly physical $\eta,\eta'$ are used.Comment: A few detailed explanations added, some rearrangement of sections and a few minor changes in notation. 19 pages, 1 PostScript figure, uses psfig.st

A Simulation Model Articulation of the REA Ontology

This paper demonstrates how the REA enterprise ontology can be used to construct simulation models for business processes, value chains and collaboration spaces in supply chains. These models support various high-level and operational management simulation applications, e.g. the analysis of enterprise sustainability and day-to-day planning. First, the basic constructs of the REA ontology and the ExSpect modelling language for simulation are introduced. Second, collaboration space, value chain and business process models and their conceptual dependencies are shown, using the ExSpect language. Third, an exhibit demonstrates the use of value chain models in predicting the financial performance of an enterprise

Determining the Weak Phase γ\gamma From Charged BB Decays

A quadrangle relation is shown to be satisfied by the amplitudes for $B^+ \to \pi^0 K^+,~\pi^+ K^0,~\eta K^+$, and $\eta' K^+$. By comparison with the corresponding relation satisfied by $B^-$ decay amplitudes, it is shown that the relative phases of all the amplitudes can be determined up to discrete ambiguities. Making use of an SU(3) relation between amplitudes contributing to the above decays and those contributing to $B^{\pm} \to \pi^{\pm} \pi^0$, it is then shown that one can determine the weak phase $\gamma \equiv {\rm Arg} (V_{ub}^* V_{cb}/V_{us}^* V_{cs})$, where $V$ is the Cabibbo-Kobayashi-Maskawa matrix describing the charge-changing weak interactions between the quarks $(u,c,t)$ and $(d,s,b)$.Comment: 16 pages, latex, 7 uuencoded figure

Isospin Structure of Penguins And Their Consequences in BB Physics

Isospin structure of gluon mediated or strong penguin is significantly altered when the full electroweak corrections are included. This has the consequence that some previous analyses which relied on a simple isospin structure in charmless $B$ decays become inapplicable. We present the general Hamiltonian in next-to-leading order QCD, and illustrate our conclusion quantitatively for $B\rightarrow \pi\pi$ and $B\rightarrow K\pi$ decays in the factorization approximation. Some remarks on CP asymmetries in $B$ decays are also made.Comment: Revtex, 11 pages, typos in eq.(17) were correcte