Four Point Functions in the SL(2,R) WZW Model

We consider winding conserving four point functions in the SL(2,R) WZW model for states in arbitrary spectral flow sectors. We compute the leading order contribution to the expansion of the amplitudes in powers of the cross ratio of the four points on the worldsheet, both in the m- and x-basis, with at least one state in the spectral flow image of the highest weight discrete representation. We also perform certain consistency check on the winding conserving three point functions.Comment: 15 pages, Late

What Next? Toddler Netizens, Playstation Thumb

ABSTRACT This article considers how traditional mass media and new information technologies change our thinking about childhood, and the very experience of childhood. It asks questions such as: How does the merchandise of the marketplace, the media and new technologies construct and segment childhood? What should early childhood educators and parents consider in the selection of instructional or entertainment CDs or websites? Four major issues are raised in relation to the 'information revolution' and early childhood: concepts of development; media and information technology literacy; critical criteria for software selection; issues of equity and access

Optimal sampling of dynamical large deviations in two dimensions via tensor networks

We use projected entangled-pair states (PEPS) to calculate the large deviations (LD) statistics of the dynamical activity of the two dimensional East model, and the two dimensional symmetric simple exclusion process (SSEP) with open boundaries, in lattices of up to 40x40 sites. We show that at long-times both models have phase transitions between active and inactive dynamical phases. For the 2D East model we find that this trajectory transition is of the first-order, while for the SSEP we find indications of a second order transition. We then show how the PEPS can be used to implement a trajectory sampling scheme capable of directly accessing rare trajectories. We also discuss how the methods described here can be extended to study rare events at finite times.Comment: 6 pages, 4 figure

Potentials for offset approaches in selected sectors post 2020

This report develops an evaluation framework that policymakers can use to identify whether offsets can add value and uphold environmental integrity of a compliance scheme. It uses a scoring framework on factors to: (1) identify which sectors have hard-to-abate emissions that can justify demanding offsets as cost-containment measures for ambitious climate policies; and (2) identify mitigation activities that are otherwise inaccessible, fosters sustainable development, and the extent to which it enables transformative sectoral action to be eligible to supply offsets. This evaluation framework identifies the optimal conditions that make factors successful in either having sectors demand offsets, or specific mitigation activities supply offsets. Sectoral emissions that are hard-to-abate are those that are technically unavoidable due to a lack and maturity of technologies, and therefore should be allowed to have cost-containment measures - such as offsets - to avoid adverse economic ramifications such as carbon leakage. Mitigation activities that can supply offsets are those that are currently inaccessible to local actor’s due to lack of access to technology, finance or capabilities. Allowing these mitigation activities to be eligible to supply offsets allows to pilot such activities and realize mitigation outcomes outside the original scope of the compliance scheme. This report has chosen selected sectors and mitigation activities to illustrate how this framework can be applied at the global level. It recognizes that country-specific factors can change the assessment of whether the offset approach will add value and uphold environmental integrity to proposed compliance schemes of a country. The report further proposes practical steps policymakers can do to undertake an evaluation at the national level

Dynamics and large deviation transitions of the XOR-Fredrickson-Andersen kinetically constrained model

We study a one-dimensional classical stochastic kinetically constrained model (KCM) inspired by Rydberg atoms in their "facilitated" regime, where sites can flip only if a single of their nearest neighbours is excited. We call this model "XOR-FA" to distinguish it from the standard Fredrickson-Andersen (FA) model. We describe the dynamics of the XOR-FA model, including its relation to simple exclusion processes in its domain wall representation. The interesting relaxation dynamics of the XOR-FA is related to the prominence of large dynamical fluctuations that lead to phase transitions between active and inactive dynamical phases as in other KCMs. By means of numerical tensor network methods we study in detail such transitions in the dynamical large deviation regime.Comment: 13+2 pages, 7+1 figure

Prevalence of Illicit Tobacco use and Tobacco Tax Avoidance in Pregnancy

Background Smoking during pregnancy is associated with adverse maternal and fetal outcomes. Tobacco tax avoidance and tax evasion undermine the effectiveness of tobacco tax policies, resulting in cheaper prices for smokers and increased tobacco usage. Aims The purpose of this study was to explore the purchasing habits of pregnant smokers with regard to tobacco expenditure anduse of illicit tobacco. Methods Prospective cohort study. Face to face interviews were conducted with 90 attendees (age range 18–42 years; mean age28 years) of a smoking cessation antenatal clinic in a large Irish tertiary level maternity hospital. Information regarding smoking habits, quantity of tobacco smoked, and location of purchase of tobacco was collected in addition to socioeconomic details. Tobacco products were examined to establish whether these were purchased from legitimate sources. Results 76.6% of women smoked 10 or fewer cigarettes per day. The mean weekly spend on tobacco was €39. Seventeen women (18.8%) smoked roll-your-own tobacco. One woman (1.1%) currently possessed a pack of illicit tobacco, while another 5.5% ofparticipants had purchased illicit tobacco in the past. Four women (4.4%) practiced tobacco tax avoidance by purchasing tobacco abroad or in Duty Free.Conclusions Use of illicit tobacco is low and only a minority of women engaged in tobacco tax avoidance. As the average price of tobacco in Ireland increases, weekly expenditure on tobacco products is a significant financial impact on low-income women. Smoking cessation would deliver significant financial gains in addition to health benefit

Smoking Cessation Through Optimisation of Clinical Care in Pregnancy: the STOP randomised controlled trial

This is a pragmatic randomised controlled trial of a dedicated smoking cessation clinic versus routine antenatal care as an intervention to reduce cigarette smoking behaviour. Smoking mothers randomised to the Smoking cessation Through Optimisation of clinical care in Pregnancy (STOP) clinic will have all antenatal care provided by a team comprising an obstetrician, a midwife, and a smoking cessation practitioner. This intervention includes ultrasound screening for fetal growth restriction. The control arm comprises two groups: one receiving standard care with ultrasound screening for fetal growth restriction, and one receiving standard care with ultrasound screening for growth restriction only if clinically indicated by their healthcare provider. Four hundred and fifty women will be recruited and randomised to either intervention or control arms stratifying for age, parity, and history of fetal growth restriction

Analysis of concrete-filled steel tubular columns after fire exposure

[EN] Concrete filled steel tubular (CFST) columns have a high probability to resist high temperatures compared to steel structures, whose evaluation after a fire is limited by the resulting deformation. A better understanding of the behaviour of CFST columns after a fire, affected by the maximum temperature achieved by the concrete infill, is required to properly estimate their residual strength and stiffness in order to adopt a reasonable strategy with minimum post-fire repair. In this paper, a fiber beam model for the simulation of the post-fire response of slender concrete-filled steel tubular (CFST) columns is presented. First, the model is validated against experimental results and subsequently it is employed to analyse the post-fire response of circular CFST columns. The variation of the residual strength with the load level for realistic fire resistance times is numerically studied. Actually, in a building, the columns support load even while a fire is being extinguished, so it is important to take into account this loading condition when predicting the post-fire behaviour. Therefore, in this research, the complete analysis comprises three stages: heating, cooling and post-fire under sustained load conditions. The model considers realistic features typical from the fire response of CFST columns, such as the existence of a gap conductance at the steel-concrete interface or the sliding and separation between the steel tube and the concrete.The authors gratefully acknowledge the financial support given by Generalitat Valenciana (Spain) for providing the funding BEST/2017/141 for the first author's stay as a visiting fellow at the School of Engineering of the University of Edinburgh.Ibáñez, C.; Bisby, L.; Rush, D.; Romero, ML.; Hospitaler, A. (2018). Analysis of concrete-filled steel tubular columns after fire exposure. En Proceedings of the 12th International Conference on Advances in Steel-Concrete Composite Structures. ASCCS 2018. Editorial Universitat Politècnica de València. 795-802. https://doi.org/10.4995/ASCCS2018.2018.7193OCS79580