Open Wilson Lines and Group Theory of Noncommutative Yang-Mills Theory in Two Dimensions

The correlation functions of open Wilson line operators in two-dimensional Yang-Mills theory on the noncommutative torus are computed exactly. The correlators are expressed in two equivalent forms. An instanton expansion involves only topological numbers of Heisenberg modules and enables extraction of the weak-coupling limit of the gauge theory. A dual algebraic expansion involves only group theoretic quantities, winding numbers and translational zero modes, and enables analysis of the strong-coupling limit of the gauge theory and the high-momentum behaviour of open Wilson lines. The dual expressions can be interpreted physically as exact sums over contributions from virtual electric dipole quanta.Comment: 37 pages. References adde

Two-dimensional non-commutative Yang-Mills theory: coherent effects in open Wilson line correlators

A perturbative calculation of the correlator of three parallel open Wilson lines is performed for the U(N) theory in two non-commutative space-time dimensions. In the large-N planar limit, the perturbative series is fully resummed and asymptotically leads to an exponential increase of the correlator with the lengths of the lines, in spite of an interference effect between lines with the same orientation. This result generalizes a similar increase occurring in the two-line correlator and is likely to persist when more lines are considered provided they share the same direction.Comment: 22 pages, 1 figure, typeset in JHEP styl

Coarse-Grained Finite-Temperature Theory for the Condensate in Optical Lattices

In this work, we derive a coarse-grained finite-temperature theory for a Bose condensate in a one-dimensional optical lattice, in addition to a confining harmonic trap potential. We start from a two-particle irreducible (2PI) effective action on the Schwinger-Keldysh closed-time contour path. In principle, this action involves all information of equilibrium and non-equilibrium properties of the condensate and noncondensate atoms. By assuming an ansatz for the variational function, i.e., the condensate order parameter in an effective action, we derive a coarse-grained effective action, which describes the dynamics on the length scale much longer than a lattice constant. Using the variational principle, coarse-grained equations of motion for the condensate variables are obtained. These equations include a dissipative term due to collisions between condensate and noncondensate atoms, as well as noncondensate mean-field. To illustrate the usefulness of our formalism, we discuss a Landau instability of the condensate in optical lattices by using the coarse-grained generalized Gross-Pitaevskii hydrodynamics. We found that the collisional damping rate due to collisions between the condensate and noncondensate atoms changes sign when the condensate velocity exceeds a renormalized sound velocity, leading to a Landau instability consistent with the Landau criterion. Our results in this work give an insight into the microscopic origin of the Landau instability.Comment: 38 pages, 2 figures. Submitted to Journal of Low Temperature Physic

A non-perturbative study of 4d U(1) non-commutative gauge theory -- the fate of one-loop instability

Recent perturbative studies show that in 4d non-commutative spaces, the trivial (classically stable) vacuum of gauge theories becomes unstable at the quantum level, unless one introduces sufficiently many fermionic degrees of freedom. This is due to a negative IR-singular term in the one-loop effective potential, which appears as a result of the UV/IR mixing. We study such a system non-perturbatively in the case of pure U(1) gauge theory in four dimensions, where two directions are non-commutative. Monte Carlo simulations are performed after mapping the regularized theory onto a U(N) lattice gauge theory in d=2. At intermediate coupling strength, we find a phase in which open Wilson lines acquire non-zero vacuum expectation values, which implies the spontaneous breakdown of translational invariance. In this phase, various physical quantities obey clear scaling behaviors in the continuum limit with a fixed non-commutativity parameter $\theta$, which provides evidence for a possible continuum theory. The extent of the dynamically generated space in the non-commutative directions becomes finite in the above limit, and its dependence on $\theta$ is evaluated explicitly. We also study the dispersion relation. In the weak coupling symmetric phase, it involves a negative IR-singular term, which is responsible for the observed phase transition. In the broken phase, it reveals the existence of the Nambu-Goldstone mode associated with the spontaneous symmetry breaking.Comment: 29 pages, 23 figures, references adde

Use of SMS texts for facilitating access to online alcohol interventions: a feasibility study

A41 Use of SMS texts for facilitating access to online alcohol interventions: a feasibility study In: Addiction Science & Clinical Practice 2017, 12(Suppl 1): A4

Protocol for a partially nested randomised controlled trial to evaluate the effectiveness of the scleroderma patient-centered intervention network COVID-19 home-isolation activities together (SPIN-CHAT) program to reduce anxiety among at-risk scleroderma patients

Objective: Contagious disease outbreaks and related restrictions can lead to negative psychological outcomes, particularly in vulnerable populations at risk due to pre-existing medical conditions. No randomised controlled trials (RCTs) have tested interventions to reduce mental health consequences of contagious disease outbreaks. The primary objective of the Scleroderma Patient-centered Intervention Network COVID-19 Home-isolation Activities Together (SPIN-CHAT) Trial is to evaluate the effect of a videoconference-based program on symptoms of anxiety. Secondary objectives include evaluating effects on symptoms of depression, stress, loneliness, boredom, physical activity, and social interaction.Methods: The SPIN-CHAT Trial is a pragmatic RCT that will be conducted using the SPIN-COVID-19 Cohort, a sub-cohort of the SPIN Cohort. Eligible participants will be SPIN-COVID-19 Cohort participants without a positive COVID-19 test, with at least mild anxiety (PROMIS Anxiety 4a v1.0 T-score >= 55), not working from home, and not receiving current counselling or psychotherapy. We will randomly assign 162 participants to intervention groups of 7 to 10 participants each or waitlist control. We will use a partially nested RCT design to reflect dependence between individuals in training groups but not in the waitlist control. The SPIN-CHAT Program includes activity engagement, education on strategies to support mental health, and mutual participant support. Intervention participants will receive the 4-week (3 sessions per week) SPIN-CHAT Program via video-conference. The primary outcome is PROMIS Anxiety 4a score immediately post-intervention.Ethics and dissemination: The SPIN-CHAT Trial will test whether a brief videoconference-based intervention will improve mental health outcomes among at-risk individuals during contagious disease outbreak

Reconhecimento e recordação dos produtos exibidos em filmes e em programas emitidos por televisão

The purpose of this article is to investigate product placements in film and broadcast programmes regarding recognition and recall of product names. The sample consisted of undergraduate male and female students aged 18 to 24 attending a tertiary level institution in Pretoria, South Africa. The findings showed that even though there was no perfectly positive relationship between the prominence and recognition of products placed in films, someone watching a film was more likely to recognise a product if it were to be shown audio-visually. It can therefore be concluded that if a product is placed more prominently in a film, the recognition thereof will be higher. This study can be a benchmark as it is one of the first studies conducted in South Africa regarding the perception of product placements in film. SPANISH: El propósito de este artículo es investigar la exhibición de productos (product placements ) en películas y en programas emitidos por televisión, para determinar el grado de reconocimiento y recordación de los nombres de estos productos. La muestra estuvo comprendida por un grupo de estudiantes de pregrado de una institución universitaria de Pretoria, Sudáfrica. Las edades del grupo oscilaban entre 18 y 24 años, con individuos de ambos sexos. Los hallazgos mostraron que a pesar de no existir una relación perfectamente proporcional entre la prominencia y el reconocimiento de productos mostrados en una película, un espectador es más dado a reconocer un producto si se muestra en una combinación de estímulos auditivos y visuales. Por tanto, se puede concluir que si un producto se exhibe de manera prominente, su reconocimiento posterior será más alto. Este estudio puede tomarse como punto de referencia sobre la comprensión de los “product placements”, por constituirse en uno de los primeros estudios realizados en Sudáfrica en este campo. FRENCH: L´objectif de cet article est d´étudier le placement de produits (product placements ) dans les films et les émissions télévisées, afin de déterminer le degré de reconnaissance et d´évocation des noms de ces produits. L´échantillon, un groupe d´étudiants et d´étudiantes universitaires de Pretoria, Afrique du Sud, correspondait à une tranche d´âge de 18 à 24 ans. Selon les résultats obtenus, même s´il n´y a pas de rapport totalement proportionnel entre la proéminence et la reconnaissance de produits placés dans un film, le spectateur est plus enclin à reconnaître un produit lorsque celui-ci apparaît accompagné de stimulus auditifs et visuels. Ainsi, il est possible de conclure que lorsqu´un produit est placé de façon proéminente dans un film, plus tard il sera reconnu davantage. S´agissant de l´une des premières études réalisées en Afrique du Sud dans ce domaine, elle pourra servir comme point de référence pour comprendre les « product placements » dans les films. PORTUGUESE: O propósito deste artigo é investigar a exibição de produtos (product placements ) em filmes e em programas emitidos por televisão, para determinar o grau de reconhecimento e recordação dos nomes destes produtos. A amostra esteve conformada por um grupo de estudantes de graduação de uma instituição universitária de Pretoria, África do Sul. As idades do grupo oscilavam entre 18 e 24 anos, com indivíduos de ambos os sexos. As descobertas mostraram que, apesar de não existir uma relação perfeitamente proporcional entre a proeminência e o reconhecimento de produtos mostrados em um filme, um espectador de filmes é mais propenso a reconhecer um produto se este é mostrado em uma combinação de estímulos auditivos e visuais. Portanto, pode-se concluir que se um produto é exibido de maneira proeminente em um filme, seu reconhecimento posterior será mais alto. Este estudo pode ser tomado como um ponto de referência sobre a compreensão dos product placements nos filmes, por constituir-se em um dos primeiros estudos realizados na África do Sul neste campo

Gender differences on ethically charged product placements : the case of tobacco products, alcoholic beverages and weapons

This study attempts to investigate how males and females aged 18 to 24 accept ethically charged products, in films shown in a cinema-type environment. The research was in the form of an exploratory study, which attempted to provide answers regarding this topic in a South African context, as previous research in this context is limited. The research was executed through the use of a questionnaire with 223 respondents were initially required to view a number scenes that were extracted from films that were targeted to this age group. It was found that there is no statistically significant difference in the acceptability between male and female film attendees with regard to tobacco products, alcoholic beverage products in films. There is no difference in the acceptance of tobacco products and alcoholic beverages between males and females as the results show neutral opinions from both of these groups, therefore they may not be easily persuaded to buy the branded products advertised. However, the acceptance of weapons between males and females does show a significant difference as females have a more negative opinion than the neutral opinion of males. This study can be a benchmark as it is one of the first studies conducted in South Africa regarding the perception of ethically charged product placements in film

Western Blot technique in the serological evaluation of three LAV/HTLV III-infected Italian families.

In order to confirm suspected LAV/HTLV III infection, serological evaluation of patients is of utmost importance. ELISA is currently being employed on a large scale for screening, but like the immunofluorescence assay, it has a variable rate of possible non-specific positivity. On the other hand, the Western Blot (WB) technique can detect antibodies to different viral proteins. In this paper we are reporting the serological patterns of three LAV/HTLV III-infected families. In particular, their viral protein-specific antibody patterns are described. With the exception of one child, all the patients tested showed seropositivity in both ELISA and WB. In the one child mentioned above, ELISA and immunofluorescence positivity were due to non-specific binding. Two out of three children tested showed a close correlation between a severe clinical course and the absence of p25-specific IgM. In contrast, one child showing a switch from IgM to p25-specific IgG antibodies had a favorable clinical course. We observed a family in which vertical transmission of LAV/HTLV III from the mother to her neonate seems not to have happened; the child was seronegative and healthy at the age of one. At birth, this neonate had LAV/HTLV III-specific IgG corresponding to the mother's pattern, but it lacked viral-specific IgM. Its mother had transmitted the viral infection to her first child, who died of AIDS. Preliminary suggestions are made about the detection of different specific antibodies and clinical features; the utility of WB is emphasized