RESUMO
A novel polarimetric method of generating a variety of Poincaré beams such as half Poincaré beams and full Poincaré beams using doubly inhomogeneous wave plates (d-plates) is proposed. In this method, every input state of polarization (SoP) through such a d-plate generates a unique Poincaré beam, thereby giving access to a potentially infinite number of them. Furthermore, the generation of full Poincaré beams is presented here as an instance of the geometrical problem of mapping the surface of a sphere onto a plane, and this insight allows one to design d-plates that convert the input SoP to every possible SoP, within a finite region of the beam. A gadget composed of three singly inhomogeneous wave plates for an equivalent realization of these d-plates is also presented.
RESUMO
With a few exceptions, there remains a paucity of good epidemiological studies from India and South-East Asia. The overall impression is that the prevalence of rheumatoid arthritis (RA) is slightly less compared with the West and follows a milder course. There may be differences in the articular expression of the disease with the wrist and forefoot less commonly affected than in Caucasian studies. Extra-articular manifestations and erosive change are less frequent and severe. HLA DR4 does not correlate with seropositivity and severity of RA. The prevalence of SLE may be less in the Indian subcontinent than in the West. However, recent indications are that in South-East Asia and the Pacific region the prevalence morbidity and mortality are higher than in developed countries. An improvement in socio-economic conditions may be accompanied by an improvement in the survival of patients with SLE.