Yangian Symmetry, S-Matrices and Bethe Ansatz for the AdS5 x S5 Superstring

We discuss the relation between the recently derived bound state S-matrices for the AdS5 x S5 superstring and Yangian symmetry. We will study the relation between this Yangian symmetry and the Bethe ansatz. In particular we can use it to derive the Bethe equations for bound states.Comment: Proceedings of the work presented at the 4-th EU RTN Workshop in Varna, Bulgari

Bound States, Yangian Symmetry and Classical r-matrix for the AdS5 x S5 Superstring

We show that the recently found S-matrices describing the scattering of two-particle bound states of the light-cone string sigma model on AdS5 x S5 are compatible with Yangian symmetry. In case the invariance with respect to the centrally extended su(2|2) algebra is not sufficient to fully specify the scattering matrix, the requirement of Yangian symmetry provides an alternative to the Yang-Baxter equation and leads to a complete, up to an overall phase, determination of the S-matrix. We then compare the semi-classical limit of the bound state S-matrices with the universal classical r-matrix by Beisert and Spill evaluated in the corresponding bound state representations and find perfect agreement.Comment: V3: Published version, reference adde

Bound States of the q-Deformed AdS5 x S5 Superstring S-matrix

The investigation of the q deformation of the S-matrix for excitations on the string world sheet in AdS5 x S5 is continued. We argue that due to the lack of Lorentz invariance the situation is more subtle than in a relativistic theory in that the nature of bound states depends on their momentum. At low enough momentum |p|<E the bound states transform in the anti-symmetric representation of the super-algebra symmetry and become the solitons of the Pohlmeyer reduced theory in the relativistic limit. At a critical momentum |p|=E they become marginally unstable, and at higher momenta the stable bound states are in the symmetric representation and become the familiar magnons in the string limit as q->1. This subtlety fixes a problem involving the consistency of crossing symmetry with the relativistic limit found in earlier work. With mirror kinematics, obtained after a double Wick rotation, the bound state structure is simpler and there are no marginally unstable bound states.Comment: 25 page

Evaluation of ERA-Interim reanalysis precipitation products using England and Wales observations

Precipitation forecast data from the ERA-Interim reanalysis (33 years) are evaluated using the daily England and Wales Precipitation (EWP) observations obtained from a rain gauge network. Observed and reanalysis daily precipitation data are both described well by Weibull distributions with indistinguishable shapes but different scale parameters, such that the reanalysis underestimates the observations by an average factor of 22%. The correlation between the observed and ERA-Interim time series of regional, daily precipitation is 0.91. ERA-Interim also captures the statistics of extreme precipitation including a slightly lower likelihood of the heaviest precipitation events (>15 mm day− 1 for the regional average) than indicated by the Weibull fit. ERA-Interim is also closer to EWP for the high precipitation events. Since these carry weight in longer accumulations, a smaller underestimation of 19% is found for monthly mean precipitation. The partition between convective and stratiform precipitation in the ERA-Interim forecast is also examined. In summer both components contribute equally to the total precipitation amount, while in winter the stratiform precipitation is approximately double convective. These results are expected to be relevant to other regions with low orography on the coast of a continent at the downstream end of mid-latitude stormtracks

Mechanisms of CO2 Capture in Ionic Liquids: A Computational Perspective

We present computational studies of CO2 sorption in two different classes of ionic liquid. The addition of carbon dioxide to four superbase ionic liquids, [P3333][Benzim], [P3333][124Triz], [P3333][123Triz] and [P3333][Bentriz] was studied using DFT approach and considering anions alone and individual ion pairs. Addition of CO2 to the anion alone clearly resulted in the formation of a covalently-bound carbamate function with the strength of binding correlated to experimental capacity. In the ion pair however the cation significantly alters the nature of the bonding such that the overall cohesive energy is reduced. Formation of a strong carbamate function occurs at the expense of weakening the interaction between anion and cation. In [N111][L-ALA], a representative amino acid ionic liquid, evidence was found for a low-enegy monomolecular mechanism for carbamate formation, explaining the 1:1 molar uptake ratio observed in some amino acid ionic liquids. The mechanism involves proton transfer to to the carboxylate group of the aminate anion

Grid computing and molecular simulations: the vision of the eMinerals Project

This paper discusses a number of aspects of using grid computing methods in support of molecular simulations, with examples drawn from the eMinerals project. A number of components for a useful grid infrastructure are discussed, including the integration of compute and data grids, automatic metadata capture from simulation studies, interoperability of data between simulation codes, management of data and data accessibility, management of jobs and workflow, and tools to support collaboration. Use of a grid infrastructure also brings certain challenges, which are discussed. These include making use of boundless computing resources, the necessary changes, and the need to be able to manage experimentation

Nationwide population-based cohort study of uterine rupture in Belgium : results from the Belgian Obstetric Surveillance System

Objectives: We aimed to assess the prevalence of uterine rupture in Belgium and to evaluate risk factors, management and outcomes for mother and child. Design: Nationwide population-based prospective cohort study. Setting: Emergency obstetric care. Participation of 97% of maternity units covering 98.6% of the deliveries in Belgium. Participants: All women with uterine rupture in Belgium between January 2012 and December 2013. 8 women were excluded because data collection forms were not returned. Results: Data on 90 cases of confirmed uterine rupture were obtained, of which 73 had a previous Caesarean section (CS), representing an estimated prevalence of 3.6 (95% CI 2.9 to 4.4) per 10000 deliveries overall and of 27 (95% CI 21 to 33) and 0.7 (95% CI 0.4 to 1.2) per 10000 deliveries in women with and without previous CS, respectively. Rupture occurred during trial of labour after caesarean section (TOLAC) in 57 women (81.4%, 95% CI 68% to 88%), with a high rate of augmented (38.5%) and induced (29.8%) labour. All patients who underwent induction of labour had an unfavourable cervix at start of induction (Bishop Score 7 in 100%). Other uterine surgery was reported in the history of 22 cases (24%, 95% CI 17% to 34%), including 1 case of myomectomy, 3 cases of salpingectomy and 2 cases of hysteroscopic resection of a uterine septum. 14 cases ruptured in the absence of labour (15.6%, 95% CI 9.5% to 24.7%). No mothers died; 8 required hysterectomy (8.9%, 95% CI 4.6% to 16.6%). There were 10 perinatal deaths (perinatal mortality rate 117/1000 births, 95% CI 60 to 203) and perinatal asphyxia was observed in 29 infants (34.5%, 95% CI 25.2% to 45.1%). Conclusions: The prevalence of uterine rupture in Belgium is similar to that in other Western countries. There is scope for improvement through the implementation of nationally adopted guidelines on TOLAC, to prevent use of unsafe procedures, and thereby reduce avoidable morbidity and mortality