Manifestly Finite Perturbation Theory for the Short-Distance Expansion of Correlation Functions in the Two Dimensional Ising Model

In the spirit of classic works of Wilson on the renormalization group and operator product expansion, a new framework for the study of the theory space of euclidean quantum field theories has been introduced. This formalism is particularly useful for elucidating the structure of the short-distance expansions of the $n$-point functions of a renormalizable quantum field theory near a non-trivial fixed point. We review and apply this formalism in the study of the scaling limit of the two dimensional massive Ising model. Renormalization group analysis and operator product expansions determine all the non-analytic mass dependence of the short-distance expansion of the correlation functions. An extension of the first order variational formula to higher orders provides a manifestly finite scheme for the perturbative calculation of the operator product coefficients to any order in parameters. A perturbative expansion of the correlation functions follows. We implement this scheme for a systematic study of correlation functions involving two spin operators. We show how the necessary non-trivial integrals can be calculated. As two concrete examples we explicitly calculate the short-distance expansion of the spin-spin correlation function to third order and the spin-spin-energy density correlation function to first order in the mass. We also discuss the applicability of our results to perturbations near other non-trivial fixed points corresponding to other unitary minimal models.Comment: 38 pages with 1 figure, UCLA/93/TEP/4

Lung dendritic cells imprint T cell lung homing and promote lung immunity through the chemokine receptor CCR4

T cell trafficking into the lung is critical for lung immunity, but the mechanisms that mediate T cell lung homing are not well understood. Here, we show that lung dendritic cells (DCs) imprint T cell lung homing, as lung DC–activated T cells traffic more efficiently into the lung in response to inhaled antigen and at homeostasis compared with T cells activated by DCs from other tissues. Consequently, lung DC–imprinted T cells protect against influenza more effectively than do gut and skin DC–imprinted T cells. Lung DCs imprint the expression of CCR4 on T cells, and CCR4 contributes to T cell lung imprinting. Lung DC–activated, CCR4-deficient T cells fail to traffic into the lung as efficiently and to protect against influenza as effectively as lung DC–activated, CCR4-sufficient T cells. Thus, lung DCs imprint T cell lung homing and promote lung immunity in part through CCR4

Exploring children's designs for maker technologies

There is growing interest in maker technologies around how they can be included in school curriculums to engage children with science subjects and about their use to explore new creative possibilities. Given that maker technologies are currently unfamiliar to most children across the world this work sought to use these technologies to investigate whether technology experience has an influence on design within a making context. A study was carried out with 29 participants aged 8-9 that involved a design task and a scaffolded making task based around a physical game using Arduino. Half of the participants completed the making task first then the design task, the other half completed the design task first then the making task. The design ideas created were then coded on 5-point scales for complexity of construction and novelty of concept, the coders also looked for evidence of transference from the making task to the design ideas. Results indicated that completing the making task prior to the design task increased the mean complexity of construction score. No clear evidence was found of elements from the making task being transferred into the design ideas. In addition to the specific findings about technology influence on design, the paper offers more general insights for those working within this space

Short distance behaviour of correlators in the 2D Ising model in a magnetic field

We study the spin-spin, spin-energy and energy-energy correlators in the 2d Ising model perturbed by a magnetic field. We compare the results of a set of high precision Montecarlo simulations with the predictions of two different approximations: the Form Factor approach, based on the exact S-matrix description of the model, and a short distance perturbative expansion around the conformal point. Both methods give very good results, the first one performs better for distances larger than the correlation length, while the second one is more precise for distances smaller than the correlation length. In order to improve this agreement we extend the perturbative analysis to the second order in the derivatives of the OPE constants.Comment: 46 pages, 10 figures, final version to appear in Nucl. Phys.

Vacuum Expectation Values from a variational approach

In this letter we propose to use an extension of the variational approach known as Truncated Conformal Space to compute numerically the Vacuum Expectation Values of the operators of a conformal field theory perturbed by a relevant operator. As an example we estimate the VEV's of all (UV regular) primary operators of the Ising model and of some of the Tricritical Ising Model conformal field theories when perturbed by any choice of the relevant primary operators. We compare our results with some other independent predictions.Comment: LaTeX file, 11 pages. Revised Versio

All order I.R. finite expansion for short distance behavior of massless theories perturbed by a relevant operator

We consider here renormalizable theories without relevant couplings and present an I.R. consistent technique to study corrections to short distance behavior (Wilson O.P.E. coefficients) due to a relevant perturbation. Our method is the result of a complete reformulation of recent works on the field, and is characterized by a more orthodox treatment of U.V. divergences that allows for simpler formulae and consequently an explicit all order (regularization invariant) I.R. finitess proof. Underlying hypotheses are discussed in detail and found to be satisfied in conformal theories that constitute a natural field of application of this approach.Comment: 27 page

Circulating vitamin D, vitamin D-related genetic variation, and risk of fatal prostate cancer in the National Cancer Institute Breast and Prostate Cancer Cohort Consortium

BACKGROUND: Evidence from experimental animal and cell line studies supports a beneficial role for vitamin D in prostate cancer (PCa). Although the results from human studies have been mainly null for overall PCa risk, there may be a benefit for survival. This study assessed the associations of circulating 25-hydroxyvitamin D (25(OH)D) and common variations in key vitamin D-related genes with fatal PCa. METHODS: In a large cohort consortium, 518 fatal cases and 2986 controls with 25(OH)D data were identified. Genotyping information for 91 single-nucleotide polymorphisms (SNPs) in 7 vitamin D-related genes (vitamin D receptor, group-specific component, cytochrome P450 27A1 [CYP27A1], CYP27B1, CYP24A1, CYP2R1, and retinoid X receptor α) was available for 496 fatal cases and 3577 controls. Unconditional logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for the associations of 25(OH)D and SNPs with fatal PCa. The study also tested for 25(OH)D-SNP interactions among 264 fatal cases and 1169 controls. RESULTS: No statistically significant relationship was observed between 25(OH)D and fatal PCa (OR for extreme quartiles, 0.86; 95% CI, 0.65-1.14; P for trend = .22) or the main effects of the SNPs and fatal PCa. There was evidence suggesting that associations of several SNPs, including 5 related to circulating 25(OH)D, with fatal PCa were modified by 25(OH)D. Individually, these associations did not remain significant after multiple testing; however, the P value for the set-based test for CYP2R1 was .002. CONCLUSIONS: Statistically significant associations were not observed for either 25(OH)D or vitamin D-related SNPs with fatal PCa. The effect modification of 25(OH)D associations by biologically plausible genetic variation may deserve further exploration

Associations of vitamin D pathway genes with circulating 25-hydroxyvitamin-D, 1,25-dihydroxyvitamin-D, and prostate cancer:a nested case-control study

Vitamin D pathway single nucleotide polymorphisms (SNPs) are potentially useful proxies for investigating whether circulating vitamin D metabolites [total 25-hydroxyvitamin-D, 25(OH)D; 1,25-dihydroxyvitamin, 1,25(OH)2D] are causally related to prostate cancer. We investigated associations of sixteen SNPs across seven genes with prostate-specific antigen-detected prostate cancer

Expression of CCR8 is increased in asthma

BACKGROUND: Chemokines and their receptors could play key roles in the recruitment of T cells to the asthmatic lung. CCR8 is preferentially expressed on T-helper type 2 cells, and is thought to play a role in the pathogenesis of human asthma. OBJECTIVE: Determine the expression of CCR8 on T cells in blood, bronchoalveolar lavage (BAL) and bronchial mucosa from asthmatics and normal subjects. METHODS: CCR8 expression in blood and BAL from asthma and normal subjects was studied using flow cytometry. CCR8 expression on IFN-gamma+ and IL-4+/IL-13+ blood and BAL T cells was studied following stimulation with Phorbol-Myristate-Acetate and Calcium Ionophore. Paraffin-embedded bronchial biopsies were used to study CCR8 in bronchial epithelium. RESULTS: The percentage of CD3+ cells expressing CCR8 in the blood was higher in asthmatics (4.7+/-0.4%) compared with normal subjects (3.0+/-0.4%; P<0.01). There was an approximately sixfold enrichment of CCR8 on IL-4+/IL-13+ cells compared with IFN-gamma+ T cells (P<0.001) in both asthmatic and normal subjects in both blood and BAL. Significantly more BAL T cells expressed CCR8 in asthmatic (8.6+/-0.8%) compared with normal subjects (3.9+/-0.7%) (P<0.01). In paired blood-BAL samples from asthmatics, significantly more CCR8+CD3+ T cells were present in BAL (9.0+/-0.9%) than in blood (5.6+/-0.9%; P<0.05). There were more CCR8-positive cells in bronchial biopsies from asthmatic (93+/-11 cells/mm2) compared with normal subjects (30+/-16 cells/mm2) (P<0.05). The ligand CCL1 was increased in the BAL of asthmatics compared with normal subjects (35+/-6 vs. 12.9+/-7 pg/mL; P<0.05). CONCLUSION: There may be a role for CCR8 in the recruitment of T cells to the lung in asthmatics