Developing Decentralised Resilience to Malicious Influence in Collective Perception Problem

In collective decision-making, designing algorithms that use only local information to effect swarm-level behaviour is a non-trivial problem. We used machine learning techniques to teach swarm members to map their local perceptions of the environment to an optimal action. A curriculum inspired by Machine Education approaches was designed to facilitate this learning process and teach the members the skills required for optimal performance in the collective perception problem. We extended upon previous approaches by creating a curriculum that taught agents resilience to malicious influence. The experimental results show that well-designed rules-based algorithms can produce effective agents. When performing opinion fusion, we implemented decentralised resilience by having agents dynamically weight received opinion. We found a non-significant difference between constant and dynamic weights, suggesting that momentum-based opinion fusion is perhaps already a resilience mechanism.Comment: 14 Pages, 14 Figure

First study of B→πB \to \pi semileptonic decay form factors using NRQCD

We present a quenched calculation of the form factors of the semileptonic weak decay $B \to \pi l \bar{\nu}$ with $O(1/m_Q)$ NRQCD heavy quark and Wilson light quark on a $16^3 \times 32$ lattice at $\beta=5.8$. The form factors are evaluated at six heavy quark masses, in the range of $m_Q \sim 1.5-8$ GeV. $1/m_Q$ dependence of matrix elements are investigated and compared with HQET predictions. We observe clear signal for the form factors near $q^2_{max}$, even at the $b$-quark mass range. $f^0(q^2_{max})$ is compared with $f_B/f_{\pi}$ based on the soft pion theorem and significant difference is observed.Comment: 3 pages, 5 ps figures, uses espcrc2.sty and epsf.sty, Talk presented at Lattice'9

Semileptonic Form Factors

I report the current status of the heavy-light decay constants, the bag parameters and the semileptonic form factors. I compare the heavy-light decay constants with Wilson-Wilson and clover-clover fermions. Systematic errors such as scale setting and renormalization factors are also discussed. 1/M dependences for the heavy-light semileptonic form factors near $q^2 = q^2_max$ with clover-clover and NRQCD-Wilson fermions are found to be small.Comment: 12 pgs. 15 figures. Talk presented at LATTICE9

Flavourful hadronic physics

We review theoretical approaches to form factors that arise in heavy-meson decays and are hadronic expressions of non-perturbative QCD. After motivating their origin in QCD factorisation, we retrace their evolution from quark-model calculations to non-perturbative QCD techniques with an emphasis on formulations of truncated heavy-light amplitudes based upon Dyson-Schwinger equations. We compare model predictions exemplarily for the B\to\pi transition form factor and discuss new results for the g_{D*D\pi} coupling in the hadronic D* decay.Comment: Based on a talk given at Light Cone 2009: Relativistic Hadronic And Particle Physics, 8-13 July 2009, Sao Jose dos Campos, Sao Paulo, Brazi

Partial and Incremental PCMH Practice Transformation: Implications for Quality and Costs

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/102699/1/hesr12085.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/102699/2/hesr12085-sup-0002-AuthorMatrix.pd

Bs∗BKB_s^* B K vertex from QCD sum rules

The form factors and the coupling constant of the $B_s^* B K$ vertex are calculated using the QCD sum rules method. Three point correlation functions are computed considering both $K$ and $B$ mesons off-shell and, after an extrapolation of the QCDSR results, we obtain the coupling constant of the vertex. We study the uncertainties in our result by calculating a third form factor obtained when the $B^*_s$ is the off-shell meson, considering other acceptable structures and computing the variations of the sum rules' parameters. The form factors obtained have different behaviors but their simultaneous extrapolations reach to the same value of the coupling constant $g_{B_s^* B K}=10.6 \pm 1.7$. We compare our result with other theoretical estimates.Comment: 11 pages, 11 figure

Decay constants, semi-leptonic and non-leptonic decays in a Bethe-Salpeter Model

We evaluate the decay constants for the B and $D$ mesons and the form factors for the semileptonic decays of the B meson to $D$ and $D^*$ mesons in a Bethe-Salpeter model. From data we extract $V_{cb}=0.039 \pm 0.002$ from ${\bar B} \to D^* l {\bar{\nu}}$ and $V_{cb}=0.037 \pm 0.004$ from ${\bar B} \to D l {\bar{\nu}}$ decays. The form factors are then used to obtain non-leptonic decay partial widths for $B\to D \pi (K)$ and $B \to D D (D_s)$ in the factorization approximation.Comment: 15 Pages, 3 Postscript figures (available also from [email protected]

Spin 3/23/2 Interacting Fields and Heavy Baryon Chiral Perturbation Theory

We analyze the consistency of the Chiral Lagrangian approach to the description of the spin 3/2 interacting theory. We argue that to lowest order in the 1/m expansion, the formalism leads to the appropriated constraints and the theory is free of the so called ``off shell" ambiguities.Comment: 12 pages, Late

Oropouche virus cases identified in Ecuador using an optimised qRT-PCR informed by metagenomic sequencing

Oropouche virus (OROV) is responsible for outbreaks of Oropouche fever in parts of South America. We recently identified and isolated OROV from a febrile Ecuadorian patient, however, a previously published qRT-PCR assay did not detect OROV in the patient sample. A primer mismatch to the Ecuadorian OROV lineage was identified from metagenomic sequencing data. We report the optimisation of an qRT-PCR assay for the Ecuadorian OROV lineage, which subsequently identified a further five cases in a cohort of 196 febrile patients. We isolated OROV via cell culture and developed an algorithmically-designed primer set for whole-genome amplification of the virus. Metagenomic sequencing of the patient samples provided OROV genome coverage ranging from 68-99%. The additional cases formed a single phylogenetic cluster together with the initial case. OROV should be considered as a differential diagnosis for Ecuadorian patients with febrile illness to avoid mis-diagnosis with other circulating pathogens