N=2 Coset Compactifications with Non-Diagonal Invariants

We consider 4-dimensional string models obtained by tensoring N=2 coset theories with non-diagonal modular invariants. We present results from a systematic analysis including moddings by discrete symmetries.Comment: 29 page

Cyclic Permutations in Kazama-Suzuki String Models

Moddings by cyclic permutation symmetries are performed in 4-dimensional strings, built up from N=2 coset models of the type $CP_m=SU(m+1)/SU(m)\times U(1)$. For some exemplifying cases, the massless chiral and antichiral states of $E_6$ are computed. The extent of the equivalence between different conformal invariant theories which possess equal chiral rings is analyzed.Comment: 26 pages, LaTex fil

Quality of mortality statistics in Chile, 1997-2003

Nunez, M.L. Departamento de Salud Pública, Facultad de Ciencias de la Salud, Universidad de Talca. Icaza, M.G.Instituto de Matemática y Física, Universidad de Talca.Death certification is the basis for the study of mortality patterns and the identification of leading causes of death. These data are used for planning health policies and prevention programs. Aim: To evaluate the quality of mortality statistics in Chile from 1997 and 2003. Material and methods: Mortality data from 1997 to 2003 available at the Chilean Ministry of Health was used. Quality of information was evaluated using the percentage of certifications done by physicians and ill-defined causes of death according to rural or urban residence, medical services, age and gender. Results: Death certification done by physicians increased from 97.6% to 99.0% in the studied period. The greatest increase was observed in rural areas, from 89.9% to 94,8%. There was a steady reduction in the percentage of ill-defined causes of deaths, from 4.7% in 1997 to 2.8% in 2003. The percentage of ill-defined causes had a great variation among the different medical services. The variation went from 1.5% in Magallanes to 13.7% in Araucania Sur. There was an inverse linear correlation between death certification by physicians and ill-defined conditions. Conclusions: Quality of Chilean mortality statistics has improved over time. Nevertheless, there is still space for enhancement for the appropriate use of this information

Swift observations of the 2015 outburst of AG Peg -- from slow nova to classical symbiotic outburst

Symbiotic stars often contain white dwarfs with quasi-steady shell burning on their surfaces. However, in most symbiotics, the origin of this burning is unclear. In symbiotic slow novae, however, it is linked to a past thermonuclear runaway. In June 2015, the symbiotic slow nova AG Peg was seen in only its second optical outburst since 1850. This recent outburst was of much shorter duration and lower amplitude than the earlier eruption, and it contained multiple peaks -- like outbursts in classical symbiotic stars such as Z And. We report Swift X-ray and UV observations of AG Peg made between June 2015 and January 2016. The X-ray flux was markedly variable on a time scale of days, particularly during four days near optical maximum, when the X-rays became bright and soft. This strong X-ray variability continued for another month, after which the X-rays hardened as the optical flux declined. The UV flux was high throughout the outburst, consistent with quasi-steady shell burning on the white dwarf. Given that accretion disks around white dwarfs with shell burning do not generally produce detectable X-rays (due to Compton-cooling of the boundary layer), the X-rays probably originated via shocks in the ejecta. As the X-ray photo-electric absorption did not vary significantly, the X-ray variability may directly link to the properties of the shocked material. AG Peg's transition from a slow symbiotic nova (which drove the 1850 outburst) to a classical symbiotic star suggests that shell burning in at least some symbiotic stars is residual burning from prior novae.Comment: Accepted by MNRAS 23 June 2016. Manuscript submitted in original form 5 April 201