Bulk and boundary g2g_2 factorized S-matrices

We investigate the $g_2$-invariant bulk (1+1D, factorized) $S$-matrix constructed by Ogievetsky, using the bootstrap on the three-point coupling of the vector multiplet to constrain its CDD ambiguity. We then construct the corresponding boundary $S$-matrix, demonstrating it to be consistent with $Y(g_2,a_1\times a_1)$ symmetry.Comment: 7 page

The full set of cnc_n-invariant factorized SS-matrices

We use the method of the tensor product graph to construct rational (Yangian invariant) solutions of the Yang-Baxter equation in fundamental representations of $c_n$ and thence the full set of $c_n$-invariant factorized $S$-matrices. Brief comments are made on their bootstrap structure and on Belavin's scalar Yangian conserved charges.Comment: 10p

Numerical simulations of a flux rope ejection

Coronal mass ejections (CMEs) are the most violent phenomena observed on the Sun. One of the most successful models to explain CMEs is the flux rope ejection model, where a magnetic flux rope is expelled from the solar corona after a long phase along which the flux rope stays in equilibrium while magnetic energy is being accumulated. However, still many questions are outstanding on the detailed mechanism of the ejection and observations continuously provide new data to interpret and put in the context. Currently, extreme ultraviolet (EUV) images from the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamic Observatory (SDO) are providing new insights into the early phase of CME evolution. In particular, observations show the ejection of magnetic flux ropes from the solar corona and how they evolve into CMEs. However, these observations are difficult to interpret in terms of basic physical mechanisms and quantities, thus, we need to compare equivalent quantities to test and improve our models. In our work, we intend to bridge the gap between models and observations with our model of flux rope ejection where we consistently describe the full life span of a flux rope from its formation to ejection. This is done by coupling the global non-linear force-free model (GNLFFF) built to describe the slow low- β formation phase, with a full MHD simulation run with the software MPI-AMRVAC, suitable to describe the fast MHD evolution of the flux rope ejection that happens in a heterogeneous β regime. We also explore the parameter space to identify the conditions upon which the ejection is favoured (gravity stratification and magnetic field intensity) and we produce synthesised AIA observations (171 Å and 211 Å). To carry this out, we run 3D MHD simulation in spherical coordinates where we include the role of thermal conduction and radiative losses, both of which are important for determining the temperature distribution of the solar corona during a CME. Our model of flux rope ejection is successful in realistically describing the entire life span of a flux rope and we also set some conditions for the backgroud solar corona to favour the escape of the flux rope, so that it turns into a CME. Furthermore, our MHD simulation reproduces many of the features found in the AIA observations.Publisher PDFPeer reviewe

Tuberculosis in Scottish military veterans: evidence from a retrospective cohort study of 57 000 veterans and 173 000 matched non-veterans

Objective: Tuberculosis was a major cause of morbidity and manpower loss in the Armed Forces during World War II. Military control programmes commenced in the 1950s but were initially limited in scope by the many recruits who were already tuberculin positive on enlistment. The aim of our study was to examine whether veterans have an increased risk of tuberculosis compared with non-veterans. Methods: Retrospective cohort study of 57 000 veterans born 1945–1985, and 173 000 people with no record of military service, resident in Scotland, matched for age, sex and area of residence, using Cox proportional hazard analysis to compare the risk of tuberculosis overall, by birth cohort, length of service and year of diagnosis and to examine comorbidities. Results: Over mean 29 years follow-up, 69 (0.12%) veterans were recorded as having tuberculosis, compared with 267 (0.15%) non-veterans (unadjusted HR 0.90, 95% CIs 0.69 to 1.19, p=0.463). Only the 1945–1949 veterans' birth cohort was at higher risk, unadjusted HR 1.54, 95% CIs 0.98 to 2.45, p=0.061, although the difference in risk did not achieve significance. Veterans born from 1950 were at significantly reduced risk of tuberculosis compared with non-veterans after adjusting for deprivation, HR 0.67, 95% CI 0.47 to 0.95, p=0.026. The most common comorbidities were smoking-related and alcohol-related disease. The risk of comorbid hepatitis B or C was very low, in both veterans and non-veterans. No length of service was associated with an increased risk of tuberculosis in comparison with non-veterans. Conclusions: Scottish veterans born before 1950 are at moderately increased risk of tuberculosis compared with age, sex and geographically matched civilians with no record of service, although the difference is not statistically significant. Scottish veterans born from 1950 show a reduction in risk compared with civilians. Tuberculosis should be considered in the differential diagnosis of respiratory disease in the older veteran

Lymphohaematopoietic malignancies in Scottish military veterans: Retrospective cohort study of 57,000 veterans and 173,000 non-veterans

Background: Lymphohaematopoietic malignancies are common in the general population. There have been concerns that military service may be associated with increased risk as a result of occupational exposures. To date, few studies have demonstrated an increased risk, although a disability pension is payable to veterans who were present at nuclear tests and who develop leukaemia (other than chronic lymphocytic leukaemia). The aim of the study was to utilise data from the Scottish Veterans Health Study to examine the risk of lymphohaematopoietic malignancy following military service in a large national cohort of veterans. Methods: Retrospective cohort study of 57,000 veterans and 173,000 non-veterans born between 1945 and 1985 matched for age, sex and area of residence, adjusted for areal deprivation and followed up for up to 30 years, using Cox proportional hazard models to compare the risk of lymphohaematopoietic malignancy overall, by diagnosis and by sex and birth cohort. Results: We found no statistically significant difference in risk between veterans and non-veterans either for all leukaemias (Cox proportional hazard ratio 1.03, 95% confidence intervals 0.84–1.27, p = 0.773), Hodgkin lymphoma (hazard ratio 1.19, 95% confidence intervals 0.87–1.61, p = 0.272) or for non-Hodgkin lymphoma (hazard ratio 0.86, 95% confidence intervals 0.71–1.04, p = 0.110). Conclusion: Our findings provide reassurance that service in the UK Armed Forces is not associated with increased risk of lymphohaematopoietic malignancy

Secondhand smoke exposure and risk of incident peripheral arterial disease and mortality: a Scotland-wide retrospective cohort study of 4045 non-smokers with cotinine measurement

Background: Active smoking is an important risk factor for all-cause mortality and peripheral arterial disease (PAD). In contrast, published studies on the associations with secondhand smoke (SHS) are limited. The aim of this study was to examine the associations between SHS exposure and incident PAD, as well as mortality, among middle-aged non-smokers. Methods: We undertook a retrospective, cohort study using record linkage of the Scottish Health Surveys between 1998 and 2010 to hospital admissions and death certificates. Inclusion was restricted to participants aged > 45 years. Cox proportional hazard models were used to examine the association between SHS exposure and incident PAD (hospital admission or death) and all-cause mortality, with adjustment for potential confounders. Results: Of the 4045 confirmed non-smokers (self-reported non-smokers with salivary cotinine concentrations < 15 ng/mL), 1163 (28.8%) had either moderate or high exposure to SHS at baseline. In men, high exposure to SHS (cotinine ≥2.7 ng/mL) was associated with increased risk of all-cause mortality (fully adjusted hazard ratio [HR] 1.54, 95% CI 1.07–2.22, p = 0.020) with evidence of a dose-relationship (p for trend = 0.004). In men, high exposure to SHS was associated with increased risk of incident PAD over the first five years of follow-up (fully adjusted HR 4.29, 95% CI 1.14–16.10, p = 0.031) but the association became non-significant over longer term follow-up. Conclusions: SHS exposure was independently associated with all-cause mortality and may be associated with PAD, but larger studies, or meta-analyses, are required to confirm the latter