QCD effective action with dressing functions - consistency checks in the perturbative regime

In a previous paper, we presented solution to the Slavnov--Taylor identity for the QCD effective action, and argued that the action terms containing (anti)ghost fields are unique. These terms have the same form as those in the classical action, but the gluon and (anti)ghost effective fields are convoluted with gluon and ghost dressing functions G_A and G_c, the latter containing perturbative and nonperturbative effects (but not including the soliton-like vacuum effects). In the present work we show how the perturbative QCD (pQCD) can be incorporated into the framework of this action, and we present explicit one-loop pQCD expressions for G_A and G_c. We then go on to check the consistency of the obtained results by considering an antighost Dyson--Schwinger equation (DSE). By solving the relations that result from the Legendre transformation leading to the effective action, we obtain the effective fields as power expansions of sources. We check explicitly that the aforementioned one-loop functions G_A and G_c fulfil the antighost DSE at the linear source level. We further explicitly check that these one-loop G_A and G_c have the regularization-scale and momentum dependence consistent with the antighost DSE at the quadratic source level. These checks suggest that the the effective action with dressing functions represents a consistent framework for treating QCD, at least at the one-loop level.Comment: 17 pages, revtex4; dimensional regularization used instead of Pauli-Villars, the check of identity in the linear-in-sources Dyson-Schwinger equation now includes the finite part; conclusions unchanged; to appear in Phys.Rev.

An approach to solve Slavnov-Taylor identities in nonsupersymmetric non-Abelian gauge theories

We present a way to solve Slavnov--Taylor identities in a general nonsupersymmetric theory. The solution can be parametrized by a limited number of functions of spacetime coordinates, so that all the effective fields are dressed by these functions via integral convolution. The solution restricts the ghost part of the effective action and gives predictions for the physical part of the effective action.Comment: revised version, section 3 is enlarged, 24 pages, Latex2e, no figures, version accepted by Phys. Rev.

Inward propagating chemical waves in Taylor vortices

Advection-reaction-diffusion (ARD) waves in the Belousov-Zhabotinsky reaction in steady Taylor-Couette vortices have been visualized using magnetic-resonance imaging and simulated using an adapted Oregonator model. We show how propagating wave behavior depends on the ratio of advective, chemical and diffusive time scales. In simulations, inward propagating spiral flamelets are observed at high Damköhler number (Da). At low Da, the reaction distributes itself over several vortices and then propagates inwards as contracting ring pulses—also observed experimentally

Reconsidering radicalization: fanaticism and the link between ideas and violence

A central issue with many interpretations of radicalization remains their tendency to overemphasize the role of extremist beliefs in motivating involvement in terrorism. A er elaborating on this critique, the authors propose that ‘fanaticism’, a concept developed by Taylor in the early 1990s, o ers a way of overcoming this de ciency in radicalization-based approaches through its conditional understanding of when radical beliefs can lead to violent behavior. Primary-sources driven empirical analysis supports both the critique of radicalization and the discussion of fanaticism’s bene ts. Results are relevant to both academics and counterterrorism practitioners working to understand the role of extremist beliefs in motivating involvement in terrorist violence.  Security and Global Affair

Repeated measures regression mixture models

Regression mixture models are one increasingly utilized approach for developing theories about and exploring the heterogeneity of effects. In this study we aimed to extend the current use of regression mixtures to a repeated regression mixture method when repeated measures, such as diary-type and experience-sampling method, data are available. We hypothesized that additional information borrowed from the repeated measures would improve the model performance, in terms of class enumeration and accuracy of the parameter estimates. We specifically compared three types of model specifications in regression mixtures: (a) traditional single-outcome model; (b) repeated measures models with three, five, and seven measures; and (c) a single-outcome model with the average of seven repeated measures. The results showed that the repeated measures regression mixture models substantially outperformed the traditional and average single-outcome models in class enumeration, with less bias in the parameter estimates. For sample size, whereas prior recommendations have suggested that regression mixtures require samples of well over 1,000 participants, even for classes at a large distance from each other (classes with regression weights of.20 vs.70), the present repeated measures regression mixture models allow for samples as low as 200 participants with an increased number (i.e., seven) of repeated measures. We also demonstrate an application of the proposed repeated measures approach using data from the Sleep Research Project. Implications and limitations of the study are discussed

Space-time translational gauge identities in Abelian Yang-Mills gravity

We derive and calculate the space-time translational gauge identities in quantum Yang-Mills gravity with a general class of gauge conditions involving two arbitrary parameters. These identities of the Abelian group of translation are a generalization of Ward-Takahasi-Fradkin identities and important for general discussions of possible renormalization of Yang-Mills gravity with translational gauge symmetry. The gauge identities in Yang-Mills gravity with a general class of gauge conditions are substantiated by explicit calculations.Comment: 15 pages. To be published in The European Physical Journal - Plus (2012

Kernel density classification and boosting: an L2 sub analysis

Kernel density estimation is a commonly used approach to classification. However, most of the theoretical results for kernel methods apply to estimation per se and not necessarily to classification. In this paper we show that when estimating the difference between two densities, the optimal smoothing parameters are increasing functions of the sample size of the complementary group, and we provide a small simluation study which examines the relative performance of kernel density methods when the final goal is classification. A relative newcomer to the classification portfolio is “boosting”, and this paper proposes an algorithm for boosting kernel density classifiers. We note that boosting is closely linked to a previously proposed method of bias reduction in kernel density estimation and indicate how it will enjoy similar properties for classification. We show that boosting kernel classifiers reduces the bias whilst only slightly increasing the variance, with an overall reduction in error. Numerical examples and simulations are used to illustrate the findings, and we also suggest further areas of research

Genotyping cognate Plasmodium falciparum in humans and mosquitoes to estimate onward transmission of asymptomatic infections

Malaria control may be enhanced by targeting reservoirs of Plasmodium falciparum transmission. One putative reservoir is asymptomatic malaria infections and the scale of their contribution to transmission in natural settings is not known. We assess the contribution of asymptomatic malaria to onward transmission using a 14-month longitudinal cohort of 239 participants in a high transmission site in Western Kenya. We identify P. falciparum in asymptomatically- and symptomatically-infected participants and naturally-fed mosquitoes from their households, genotype all parasites using deep sequencing of the parasite genes pfama1 and pfcsp, and use haplotypes to infer participant-to-mosquito transmission through a probabilistic model. In 1,242 infections (1,039 in people and 203 in mosquitoes), we observe 229 (pfcsp) and 348 (pfama1) unique parasite haplotypes. Using these to link human and mosquito infections, compared with symptomatic infections, asymptomatic infections more than double the odds of transmission to a mosquito among people with both infection types (Odds Ratio: 2.56; 95% Confidence Interval (CI): 1.36–4.81) and among all participants (OR 2.66; 95% CI: 2.05–3.47). Overall, 94.6% (95% CI: 93.1–95.8%) of mosquito infections likely resulted from asymptomatic infections. In high transmission areas, asymptomatic infections are the major contributor to mosquito infections and may be targeted as a component of transmission reduction

Parity-violating Electron Deuteron Scattering and the Proton's Neutral Weak Axial Vector Form Factor

We report on a new measurement of the parity-violating asymmetry in quasielastic electron scattering from the deuteron at backward angles at Q2= 0.038 (GeV/c)2. This quantity provides a determination of the neutral weak axial vector form factor of the nucleon, which can potentially receive large electroweak corrections. The measured asymmetry A=-3.51 +/- 0.57(stat) +/- 0.58(sys)ppm is consistent with theoretical predictions. We also report on updated results of the previous experiment at Q2=0.091 (GeV/c)2, which are also consistent with theoretical predictions.Comment: 4 pages, 2 figures, submitted to Phys. Rev. Let

Impact of asymptomatic plasmodium falciparum infection on the risk of subsequent matic malaria in a longitudinal cohort in Kenya

Background: Asymptomatic Plasmodium falciparum infections are common in sub-Saharan Africa, but their effect on subsequent symptomaticity is incompletely understood. Methods: In a 29-month cohort of 268 people in Western Kenya, we investigated the association between asymptomatic P. falciparum and subsequent symptomatic malaria with frailty Cox models. Results: Compared to being uninfected, asymptomatic infections were associated with an increased 1-month likelihood of symptomatic malaria [adjusted Hazard Ratio (aHR):2.61, 95%CI:2.05–3.33], and this association was modified by sex, with females [aHR:3.71, 95%CI:2.62–5.24] at higher risk for symptomaticity than males [aHR:1.76, 95%CI:1.24–2.50]. This increased symptomatic malaria risk was observed for asymptomatic infections of all densities and in people of all ages. Long-term risk was attenuated but still present in children under 5 [29-month aHR:1.38, 95%CI:1.05–1.81]. Conclusions: In this high-transmission setting, asymptomatic P. falciparum can be quickly followed by symptoms and may be targeted to reduce the incidence of symptomatic illness