Integrable models of galactic discs with double nuclei

We introduce a new class of 2-D mass models, whose potentials are of St\"ackel form in elliptic coordinates. Our model galaxies have two separate strong cusps that form double nuclei. The potential and surface density distributions are locally axisymmetric near the nuclei and become {\it highly} non-axisymmetric outside the nucleus. The surface density diverges toward the cuspy nuclei with the law $\Sigma \propto r^{-2}$. Our model is sustained by four general types of regular orbits: {\it butterfly}, {\it nucleuphilic banana}, {\it horseshoe} and {\it aligned loop} orbits. Horseshoes and nucleuphilic bananas support the existence of cuspy regions. Butterflies and aligned loops control the non-axisymmetric shape of outer regions. Without any need for central black holes, our distributed mass models resemble the nuclei of M31 and NGC4486B. It is also shown that the self-gravity of the stellar disc can prevent the double nucleus to collapse.Comment: 8 pages, accepted for publication in MNRA

Epidemiology of tuberculosis in northeast of Iran: A population-based study

Background: Tuberculosis (TB) is currently one of the greatest problems in public health. Mycobacterium tuberculosis infects about one third of the world's population, of whom more than 80% are living in developing countries. The incidence and prevalence of TB are very different in various parts of Iran and also throughout the world. Golestan province is one of the areas in the country where the risk of TB is the highest because of its ethnically varied population and special location. We aimed to describe the prevalence of TB and related demographic data in Golestan province (northeast of Iran). Methods: We collected all data of patients with TB who registered in 2005 and 2006 in each of the 11 districts of Golestan province. Data were entered into the computer database and age-specific incidence rates per 100 000 population were calculated. Results: There were 321 new smear-positive cases. The incidence and prevalence of TB were 20.88 and 38.15 per 100 000 population, respectively. The male to female ratio was 0.96. Relapse of TB was reported in 20 patients. We found 141 cases of extrapulmonary TB, with a significant predominance in women. The organ most frequently involved in extrapulmonary TB was the lymph nodes. Generally, smear-negative TB was more common in men and extrapulmonary TB was more common in women. Conclusion: The incidence and prevalence of TB were higher in Golestan province in comparison with other provinces in Iran. We suggest using improved screening strategies and better education about TB for high-risk groups and physicians

Embodied space-pitch associations are shaped by language

Height-pitch associations are claimed to be universal and independent of language, but this claim remains controversial. The present study sheds new light on this debate with a multimodal analysis of individual sound and melody descriptions obtained in an interactive communication paradigm with speakers of Dutch and Farsi. The findings reveal that, in contrast to Dutch speakers, Farsi speakers do not use a height-pitch metaphor consistently in speech. Both Dutch and Farsi speakers’ co-speech gestures did reveal a mapping of higher pitches to higher space and lower pitches to lower space, and this gesture space-pitch mapping tended to co-occur with corresponding spatial words (high-low). However, this mapping was much weaker in Farsi speakers than Dutch speakers. This suggests that cross-linguistic differences shape the conceptualization of pitch and further calls into question the universality of height-pitch associations