The role of institutions in cross-section income and panel data growth models: a deeper investigation on the weakness and proliferation of instruments

This paper investigates the role of institutions in determining per capita income levels and growth. It contributes to the empirical literature by using different variables as proxies for institutions and by developing a deeper analysis of the issues arising from the use of weak and too many instruments in per capita income and growth regressions. The cross-section estimation suggests that institutions seem to matter, regardless if they are the only explanatory variable or are combined with geographical and integration variables, although most models suffer from the issue of weak instruments. The results from the growth models provides some interesting results: there is mixed evidence on the role of institutions and such evidence is more likely to be associated with law and order and investment profile; government spending is an important policy variable; collapsing the number of instruments results in fewer significant coefficients for institutions.Institutions; Income Levels and Growth: Cross-Section and Panel Data Analysis: Weak Instruments and Instrument Proliferation

Acquired unilateral rubella retinopathy in adult

The authors report an uncommon case of unilateral rubella retinopathy in an adult patient, described for the first time in medical literature. A 28-year-old healthy white man acquired a case of vasculitis and retinitis on his right eye with sudden vision loss, preceded by an acute viral disease (best correct visual acuity was 20/200). Serology examinations on several viral diseases reveled positive signs to rubella. The treatment was based on corticoids therapy due to macular commitment with final visual acuity of 20/60. Serology concluded rubella etiology, with positive levels in the acute initial stage of viral infection, even during viral retinopathy

The billiard inside an ellipse deformed by the curvature flow

The billiard dynamics inside an ellipse is integrable. It has zero topological entropy, four separatrices in the phase space, and a continuous family of convex caustics: the confocal ellipses. We prove that the curvature flow destroys the integrability, increases the topological entropy, splits the separatrices in a transverse way, and breaks all resonant convex caustics.Comment: 13 pages, 1 figur

Combined hamartoma of the retina and retinal pigment epithelium associated with optic coloboma

The authors relate an uncommon case of combined hamartoma of the retina and retinal pigment epithelium associated with optic coloboma

A formação de relacionamentos em videochats de sistema randômico : usuários e conexões

Este artigo aborda a constituição de relacionamentos nos ambientes de videochat dos sites Chatroulette e Omegle, ambos caraterizados por um sistema randômico de formação de pares de interação. A partir dos pensamentos de Schutz e Simmel, definimos os relacionamentos como um fenômeno da sociabilidade que reproduz a estrutura da situação face a face. Baseados nos dados coletados em nossa observação participante, analisamos dois aspectos do fenômeno: primeiramente, interpretamos o alto índice de desconexão imediata que marcou a experiência; em segundo lugar, operamos uma tipificação dos usuários, na percepção de regularidades em relação às suas identidades.Este artículo aborda la constitución de relaciones en los ambientes de videochat de los websites Chatroulette y Omegle, que se caracterizan por tener un sistema aleatorio de formación de parejas de interacción. A partir de los pensamientos de Schutz y Simmel, definimos las relaciones como un fenómeno de la sociabilidad que reproduce la estructura de la situación cara a cara. Basados en los datos recogidos en nuestra observación participante, analizamos dos aspectos del fenómeno: primeramente, interpretamos la elevada tasa de desconexión inmediata que marcó la experiencia; en segundo lugar, operamos una tipificación de los usuarios, con la percepción de regularidades en relación a sus identidades